Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Thu Aug 08 2019 Valid 082000Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST...MID-ATLANITC...AND OHIO VALLEY... ...SUMMARY... Strong to severe storms should continue to produce isolated damaging wind gusts across parts of the Northeast into the Mid-Atlantic and mid/upper Ohio Valley through this evening. ...20Z Update... A bowing line segment producing wind damage and isolated measured severe wind gusts will continue moving eastward across parts of central/eastern NY this afternoon. This convection is occurring on the nose of a mid-level jet, and there is potential for strong to severe storms to persist into parts of western New England late this afternoon and early evening where weak instability exists. Therefore, have expanded wind probabilities eastward across this region. Behind the line of ongoing storms, severe probabilities have been reduced across western NY/PA and northern OH. A few storms have formed across parts of southwestern/central NE along a weak front. Even though large-scale forcing for ascent will remain weak across this region owing to upper ridging remaining centered over the Rockies, modestly enhanced mid-level winds and a veering wind profile are resulting in enough shear to support organized updrafts. Isolated strong to severe storms may occur through the early evening along/south of the boundary, with both large hail and severe wind gusts possible. Accordingly, have expanded the Marginal Risk to include this area. Across the southern Plains into the lower MS Valley, severe probabilities have been confined to a narrow corridor along and south of a convectively reinforced surface boundary. A weak mid-level perturbation associated with prior convection is present over north-central OK this afternoon per water vapor satellite imagery. Some short-term guidance suggests that a couple storms may strengthen across parts of central/eastern OK and then spread into western/central AR through the early evening. Strong diurnal heating has occurred to the south of the front, and isolated strong/gusty winds and perhaps some hail could occur with any robust storms that can form and then move southeastward along this boundary. Persistent cloud cover has hampered diurnal heating across parts of northern UT into far southern ID. The Marginal Risk has been adjusted slightly in NV/UT based on radar trends and where low-level lapse rates have been able to steepen this afternoon. With modest instability and shear noted, isolated strong/gusty winds will continue to be the main threat. ..Gleason.. 08/08/2019 .PREV DISCUSSION... /ISSUED 1121 AM CDT Thu Aug 08 2019/ ...Synopsis... A large trough will continue moving across eastern Canada and the eastern U.S. today, with another large trough surrounding a very slow-moving upper low over the eastern Pacific. In between, ridging will continue to prevail over the Rockies and south-central U.S. through tonight. At the surface, a weak pressure field prevails. A subtle cool front will continue crossing the lower Great Lakes/Ohio Valley today, while remnants of a prior/weak front linger from the southeastern U.S. west-northwestward into the Oklahoma vicinity. These two boundaries, and weak disturbances aloft crossing the Great Basin area ahead of the Pacific low/trough, will support showers and thunderstorm activity, along with limited/local severe risk. ...NY/PA/OH/WV vicinity... Showers and thunderstorms are ongoing across western New York and adjacent northwest Pennsylvania, near a very weak cool front moving across the region. As heating continues into the afternoon, resulting in additional/modest destabilization, an increase in convective coverage is expected, along with some uptick in intensity -- aided by moderate westerly/west-northwesterly flow through a deep layer. With this flow promoting rather quick eastward storm motion, stronger convective elements will be capable of producing gusty/damaging winds, that may reach severe levels locally. Risk should continue through the afternoon, diminishing with the onset of diurnal cooling early this evening. For additional short-term information, please refer to SWOMCD #1674. ...Southern KS/OK east-southeast to northern MS... A large area of weak convection is ongoing from the southern Plains, east across the Ozarks to the northern Mississippi Vicinity. An outflow boundary is observed from Oklahoma southeast to northern Mississippi, on the southern fringe of a stronger west-northwest to east-southeast band of storms. Some intensification of storms within this band, and/or new convective development near the aforementioned outflow, may -- given the favorably moist/gradually destabilizing airmass away from active convection -- intensify to occasionally severe levels. Gusty/locally damaging winds may occur with the strongest storms, along with some risk for large hail. Storms -- and possibly some severe risk -- will continue into the overnight hours, as a south-southwesterly low-level jet develops across the southern Plains, aiding continued storm development/sustenance. ...Central and southern high Plains... Daytime heating of a seasonally moist boundary layer across the high Plains region will permit afternoon destabilization, supporting development of scattered to isolated thunderstorms. Mid-level flow is not particularly strong across the region (generally 20 to 30 kt from the west), a weak easterly component to the low-level flow will help to provide both ample shear for a few organized storms, as well as some tendency for storms to progress southeastward off the higher terrain. The strongest storms/storm clusters may be capable of producing gusty/damaging winds, along with some hail risk. Severe risk should gradually decrease through the evening, as convection weakens. ...Parts of the Great Basin and vicinity... A relatively moist low-level airmass resides across the Great Basin vicinity, with dewpoints in the low 50s. Showers and isolated thunderstorms are ongoing across parts of the region -- partly in response to several disturbances aloft moving across the area, embedded within cyclonic upper flow surrounding the eastern Pacific upper low. Clearing is noted in morning visible imagery across parts of Nevada away from ongoing convection, which will aid in afternoon destabilization, and an associated increase in convective coverage. Given moderate deep-layer southwesterly flow supporting semi-organized cells/clusters, potential for locally damaging winds will exist with a few of the strongest storms, before convection weakens this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Thu Aug 08 2019 Valid 082000Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST...MID-ATLANITC...AND OHIO VALLEY... ...SUMMARY... Strong to severe storms should continue to produce isolated damaging wind gusts across parts of the Northeast into the Mid-Atlantic and mid/upper Ohio Valley through this evening. ...20Z Update... A bowing line segment producing wind damage and isolated measured severe wind gusts will continue moving eastward across parts of central/eastern NY this afternoon. This convection is occurring on the nose of a mid-level jet, and there is potential for strong to severe storms to persist into parts of western New England late this afternoon and early evening where weak instability exists. Therefore, have expanded wind probabilities eastward across this region. Behind the line of ongoing storms, severe probabilities have been reduced across western NY/PA and northern OH. A few storms have formed across parts of southwestern/central NE along a weak front. Even though large-scale forcing for ascent will remain weak across this region owing to upper ridging remaining centered over the Rockies, modestly enhanced mid-level winds and a veering wind profile are resulting in enough shear to support organized updrafts. Isolated strong to severe storms may occur through the early evening along/south of the boundary, with both large hail and severe wind gusts possible. Accordingly, have expanded the Marginal Risk to include this area. Across the southern Plains into the lower MS Valley, severe probabilities have been confined to a narrow corridor along and south of a convectively reinforced surface boundary. A weak mid-level perturbation associated with prior convection is present over north-central OK this afternoon per water vapor satellite imagery. Some short-term guidance suggests that a couple storms may strengthen across parts of central/eastern OK and then spread into western/central AR through the early evening. Strong diurnal heating has occurred to the south of the front, and isolated strong/gusty winds and perhaps some hail could occur with any robust storms that can form and then move southeastward along this boundary. Persistent cloud cover has hampered diurnal heating across parts of northern UT into far southern ID. The Marginal Risk has been adjusted slightly in NV/UT based on radar trends and where low-level lapse rates have been able to steepen this afternoon. With modest instability and shear noted, isolated strong/gusty winds will continue to be the main threat. ..Gleason.. 08/08/2019 .PREV DISCUSSION... /ISSUED 1121 AM CDT Thu Aug 08 2019/ ...Synopsis... A large trough will continue moving across eastern Canada and the eastern U.S. today, with another large trough surrounding a very slow-moving upper low over the eastern Pacific. In between, ridging will continue to prevail over the Rockies and south-central U.S. through tonight. At the surface, a weak pressure field prevails. A subtle cool front will continue crossing the lower Great Lakes/Ohio Valley today, while remnants of a prior/weak front linger from the southeastern U.S. west-northwestward into the Oklahoma vicinity. These two boundaries, and weak disturbances aloft crossing the Great Basin area ahead of the Pacific low/trough, will support showers and thunderstorm activity, along with limited/local severe risk. ...NY/PA/OH/WV vicinity... Showers and thunderstorms are ongoing across western New York and adjacent northwest Pennsylvania, near a very weak cool front moving across the region. As heating continues into the afternoon, resulting in additional/modest destabilization, an increase in convective coverage is expected, along with some uptick in intensity -- aided by moderate westerly/west-northwesterly flow through a deep layer. With this flow promoting rather quick eastward storm motion, stronger convective elements will be capable of producing gusty/damaging winds, that may reach severe levels locally. Risk should continue through the afternoon, diminishing with the onset of diurnal cooling early this evening. For additional short-term information, please refer to SWOMCD #1674. ...Southern KS/OK east-southeast to northern MS... A large area of weak convection is ongoing from the southern Plains, east across the Ozarks to the northern Mississippi Vicinity. An outflow boundary is observed from Oklahoma southeast to northern Mississippi, on the southern fringe of a stronger west-northwest to east-southeast band of storms. Some intensification of storms within this band, and/or new convective development near the aforementioned outflow, may -- given the favorably moist/gradually destabilizing airmass away from active convection -- intensify to occasionally severe levels. Gusty/locally damaging winds may occur with the strongest storms, along with some risk for large hail. Storms -- and possibly some severe risk -- will continue into the overnight hours, as a south-southwesterly low-level jet develops across the southern Plains, aiding continued storm development/sustenance. ...Central and southern high Plains... Daytime heating of a seasonally moist boundary layer across the high Plains region will permit afternoon destabilization, supporting development of scattered to isolated thunderstorms. Mid-level flow is not particularly strong across the region (generally 20 to 30 kt from the west), a weak easterly component to the low-level flow will help to provide both ample shear for a few organized storms, as well as some tendency for storms to progress southeastward off the higher terrain. The strongest storms/storm clusters may be capable of producing gusty/damaging winds, along with some hail risk. Severe risk should gradually decrease through the evening, as convection weakens. ...Parts of the Great Basin and vicinity... A relatively moist low-level airmass resides across the Great Basin vicinity, with dewpoints in the low 50s. Showers and isolated thunderstorms are ongoing across parts of the region -- partly in response to several disturbances aloft moving across the area, embedded within cyclonic upper flow surrounding the eastern Pacific upper low. Clearing is noted in morning visible imagery across parts of Nevada away from ongoing convection, which will aid in afternoon destabilization, and an associated increase in convective coverage. Given moderate deep-layer southwesterly flow supporting semi-organized cells/clusters, potential for locally damaging winds will exist with a few of the strongest storms, before convection weakens this evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... The main change to the ongoing forecast is to include portions of Washington, east of the Cascade crest, within the ISODRYT area. While there is some uncertainty with regard to how dry storms will be farther north, this area has observed the least amount of rainfall over the past week in the region. At a minimum, lightning ignitions should be quite efficient in the early on in the convective cycle. In Nevada, the ISODRYT area has been adjusted on account of the latest trends in model guidance. The elevated area remains on track. Portions of southern Nevada are likely to see meteorologically critical fire weather conditions. With the amount of lighting this region has received today, holdover fire potential will exist as winds increase and RH decreases tomorrow. The sparse nature of fuels in these locations, however, reduces confidence in the need for critical highlights. ..Wendt.. 08/08/2019 .PREV DISCUSSION... /ISSUED 0142 AM CDT Thu Aug 08 2019/ ...Synopsis... The overall synoptic pattern should remain similar throughout the D2/Thu forecast period. A longwave trough will begin to make eastward progression toward Oregon and northern California, resulting in strengthening mid-level flow from Nevada northward through western Idaho as a mid-level ridge keeps hold over the central Rockies and vicinity. Lift from the approaching trough and maintenance of mid-level moisture should promote a few thunderstorms during the afternoon and evening, while strengthening wind fields will result in elevated to locally critical fire weather in the western Great Basin. ...Much of Nevada and far northeastern California for dry/windy conditions... Vertical mixing processes beneath strengthening flow aloft and a strengthening surface trough across the region will result in areas of 20+ mph surface winds from afternoon onward, especially from southern and central Nevada northwestward through the lee of the Sierras. While critical wind fields will be exceeded in a few areas, RH values will be borderline critical based on latest forecast guidance. Furthermore, areas of thunderstorm development should also temper boundary-layer RH values in a few areas, with any critical fire weather conditions being brief and localized. Fuels are dry, however, and fire spread may occur with any ongoing fires especially where critical thresholds can be met for any length of time. ...Much of Oregon, far northern California, northern/central Nevada, and western Idaho for thunderstorms... Isolated to scattered thunderstorms are expected to develop from afternoon onward and should move north fairly quickly (25-35 kts) given the enhanced mid-level wind fields across the region. Cores should be wetter than in the previous day, however, given higher tropospheric moisture content and greater lift/ascent associated with the approach of the mid-level trough. Still, scattered, northward-moving clusters of storms should be most concentrated across southern/central Oregon and northeast Nevada/southwest Idaho and will be capable of isolated dry lightning strikes that will cause a few fire starts given dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... The main change to the ongoing forecast is to include portions of Washington, east of the Cascade crest, within the ISODRYT area. While there is some uncertainty with regard to how dry storms will be farther north, this area has observed the least amount of rainfall over the past week in the region. At a minimum, lightning ignitions should be quite efficient in the early on in the convective cycle. In Nevada, the ISODRYT area has been adjusted on account of the latest trends in model guidance. The elevated area remains on track. Portions of southern Nevada are likely to see meteorologically critical fire weather conditions. With the amount of lighting this region has received today, holdover fire potential will exist as winds increase and RH decreases tomorrow. The sparse nature of fuels in these locations, however, reduces confidence in the need for critical highlights. ..Wendt.. 08/08/2019 .PREV DISCUSSION... /ISSUED 0142 AM CDT Thu Aug 08 2019/ ...Synopsis... The overall synoptic pattern should remain similar throughout the D2/Thu forecast period. A longwave trough will begin to make eastward progression toward Oregon and northern California, resulting in strengthening mid-level flow from Nevada northward through western Idaho as a mid-level ridge keeps hold over the central Rockies and vicinity. Lift from the approaching trough and maintenance of mid-level moisture should promote a few thunderstorms during the afternoon and evening, while strengthening wind fields will result in elevated to locally critical fire weather in the western Great Basin. ...Much of Nevada and far northeastern California for dry/windy conditions... Vertical mixing processes beneath strengthening flow aloft and a strengthening surface trough across the region will result in areas of 20+ mph surface winds from afternoon onward, especially from southern and central Nevada northwestward through the lee of the Sierras. While critical wind fields will be exceeded in a few areas, RH values will be borderline critical based on latest forecast guidance. Furthermore, areas of thunderstorm development should also temper boundary-layer RH values in a few areas, with any critical fire weather conditions being brief and localized. Fuels are dry, however, and fire spread may occur with any ongoing fires especially where critical thresholds can be met for any length of time. ...Much of Oregon, far northern California, northern/central Nevada, and western Idaho for thunderstorms... Isolated to scattered thunderstorms are expected to develop from afternoon onward and should move north fairly quickly (25-35 kts) given the enhanced mid-level wind fields across the region. Cores should be wetter than in the previous day, however, given higher tropospheric moisture content and greater lift/ascent associated with the approach of the mid-level trough. Still, scattered, northward-moving clusters of storms should be most concentrated across southern/central Oregon and northeast Nevada/southwest Idaho and will be capable of isolated dry lightning strikes that will cause a few fire starts given dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... The main change to the ongoing forecast is to include portions of Washington, east of the Cascade crest, within the ISODRYT area. While there is some uncertainty with regard to how dry storms will be farther north, this area has observed the least amount of rainfall over the past week in the region. At a minimum, lightning ignitions should be quite efficient in the early on in the convective cycle. In Nevada, the ISODRYT area has been adjusted on account of the latest trends in model guidance. The elevated area remains on track. Portions of southern Nevada are likely to see meteorologically critical fire weather conditions. With the amount of lighting this region has received today, holdover fire potential will exist as winds increase and RH decreases tomorrow. The sparse nature of fuels in these locations, however, reduces confidence in the need for critical highlights. ..Wendt.. 08/08/2019 .PREV DISCUSSION... /ISSUED 0142 AM CDT Thu Aug 08 2019/ ...Synopsis... The overall synoptic pattern should remain similar throughout the D2/Thu forecast period. A longwave trough will begin to make eastward progression toward Oregon and northern California, resulting in strengthening mid-level flow from Nevada northward through western Idaho as a mid-level ridge keeps hold over the central Rockies and vicinity. Lift from the approaching trough and maintenance of mid-level moisture should promote a few thunderstorms during the afternoon and evening, while strengthening wind fields will result in elevated to locally critical fire weather in the western Great Basin. ...Much of Nevada and far northeastern California for dry/windy conditions... Vertical mixing processes beneath strengthening flow aloft and a strengthening surface trough across the region will result in areas of 20+ mph surface winds from afternoon onward, especially from southern and central Nevada northwestward through the lee of the Sierras. While critical wind fields will be exceeded in a few areas, RH values will be borderline critical based on latest forecast guidance. Furthermore, areas of thunderstorm development should also temper boundary-layer RH values in a few areas, with any critical fire weather conditions being brief and localized. Fuels are dry, however, and fire spread may occur with any ongoing fires especially where critical thresholds can be met for any length of time. ...Much of Oregon, far northern California, northern/central Nevada, and western Idaho for thunderstorms... Isolated to scattered thunderstorms are expected to develop from afternoon onward and should move north fairly quickly (25-35 kts) given the enhanced mid-level wind fields across the region. Cores should be wetter than in the previous day, however, given higher tropospheric moisture content and greater lift/ascent associated with the approach of the mid-level trough. Still, scattered, northward-moving clusters of storms should be most concentrated across southern/central Oregon and northeast Nevada/southwest Idaho and will be capable of isolated dry lightning strikes that will cause a few fire starts given dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...NO CRITICAL AREAS... The main change to the ongoing forecast is to include portions of Washington, east of the Cascade crest, within the ISODRYT area. While there is some uncertainty with regard to how dry storms will be farther north, this area has observed the least amount of rainfall over the past week in the region. At a minimum, lightning ignitions should be quite efficient in the early on in the convective cycle. In Nevada, the ISODRYT area has been adjusted on account of the latest trends in model guidance. The elevated area remains on track. Portions of southern Nevada are likely to see meteorologically critical fire weather conditions. With the amount of lighting this region has received today, holdover fire potential will exist as winds increase and RH decreases tomorrow. The sparse nature of fuels in these locations, however, reduces confidence in the need for critical highlights. ..Wendt.. 08/08/2019 .PREV DISCUSSION... /ISSUED 0142 AM CDT Thu Aug 08 2019/ ...Synopsis... The overall synoptic pattern should remain similar throughout the D2/Thu forecast period. A longwave trough will begin to make eastward progression toward Oregon and northern California, resulting in strengthening mid-level flow from Nevada northward through western Idaho as a mid-level ridge keeps hold over the central Rockies and vicinity. Lift from the approaching trough and maintenance of mid-level moisture should promote a few thunderstorms during the afternoon and evening, while strengthening wind fields will result in elevated to locally critical fire weather in the western Great Basin. ...Much of Nevada and far northeastern California for dry/windy conditions... Vertical mixing processes beneath strengthening flow aloft and a strengthening surface trough across the region will result in areas of 20+ mph surface winds from afternoon onward, especially from southern and central Nevada northwestward through the lee of the Sierras. While critical wind fields will be exceeded in a few areas, RH values will be borderline critical based on latest forecast guidance. Furthermore, areas of thunderstorm development should also temper boundary-layer RH values in a few areas, with any critical fire weather conditions being brief and localized. Fuels are dry, however, and fire spread may occur with any ongoing fires especially where critical thresholds can be met for any length of time. ...Much of Oregon, far northern California, northern/central Nevada, and western Idaho for thunderstorms... Isolated to scattered thunderstorms are expected to develop from afternoon onward and should move north fairly quickly (25-35 kts) given the enhanced mid-level wind fields across the region. Cores should be wetter than in the previous day, however, given higher tropospheric moisture content and greater lift/ascent associated with the approach of the mid-level trough. Still, scattered, northward-moving clusters of storms should be most concentrated across southern/central Oregon and northeast Nevada/southwest Idaho and will be capable of isolated dry lightning strikes that will cause a few fire starts given dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0562 Status Updates
STATUS REPORT ON WW 562 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SW BFD TO 25 SSE ELM TO 35 SSW UCA TO 20 SSE ART. ..SMITH..08/08/19 ATTN...WFO...PBZ...BGM...BUF...BTV...ALY...CTP... STATUS REPORT FOR WS 562 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MDC023-082010- MD . MARYLAND COUNTIES INCLUDED ARE GARRETT NYC001-007-017-021-025-027-033-035-039-041-043-049-053-057-065- 077-083-089-091-093-095-107-111-113-115-082010- NY . NEW YORK COUNTIES INCLUDED ARE ALBANY BROOME CHENANGO COLUMBIA DELAWARE DUTCHESS FRANKLIN FULTON GREENE HAMILTON HERKIMER LEWIS MADISON MONTGOMERY ONEIDA OTSEGO RENSSELAER ST. LAWRENCE SARATOGA SCHENECTADY SCHOHARIE TIOGA ULSTER WARREN WASHINGTON Read more

MD 1675 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWEST NEBRASKA AND FAR NORTHEAST COLORADO
Mesoscale Discussion 1675 NWS Storm Prediction Center Norman OK 0141 PM CDT Thu Aug 08 2019 Areas affected...Southwest Nebraska and far northeast Colorado Concerning...Severe potential...Watch unlikely Valid 081841Z - 082015Z Probability of Watch Issuance...20 percent SUMMARY...Isolated strong to severe storms are possible this afternoon. A watch is unlikely. DISCUSSION...A few thunderstorms have started to form in southwest Nebraska and northeast Colorado early this afternoon in a region with temperatures in the 80s and dewpoints ranging from the mid 60s to low 70s. MLCAPE in this region is around 1500 to 2000 J/kg with effective shear around 40 knots per RAP mesoanalysis. While the parameter space is conducive for large hail and damaging winds, storm coverage and duration is expected to be limited due to rising heights and warming temperatures aloft. Therefore, a couple of strong to severe storms are possible in this region, but a severe thunderstorm watch is unlikely due to the expected limited coverage and duration. ..Bentley/Goss.. 08/08/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...GLD...BOU...CYS... LAT...LON 41840213 42120155 41970047 41439937 40439881 39939902 39920033 39980195 40490276 41040305 41640302 41840213 Read more

WW 0562 Status Updates
STATUS REPORT ON WW 562 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNE BFD TO 25 NNW ELM TO 35 NW SYR. ..SMITH..08/08/19 ATTN...WFO...PBZ...BGM...BUF...BTV...ALY...CTP... STATUS REPORT FOR WS 562 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MDC023-081900- MD . MARYLAND COUNTIES INCLUDED ARE GARRETT NYC007-011-015-017-023-025-033-041-043-045-049-053-065-067-075- 077-089-097-099-101-107-109-123-081900- NY . NEW YORK COUNTIES INCLUDED ARE BROOME CAYUGA CHEMUNG CHENANGO CORTLAND DELAWARE FRANKLIN HAMILTON HERKIMER JEFFERSON LEWIS MADISON ONEIDA ONONDAGA OSWEGO OTSEGO ST. LAWRENCE SCHUYLER SENECA STEUBEN TIOGA TOMPKINS YATES OHC013-019-029-031-059-067-081-111-119-121-157-081900- Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND OREGON... ...SUMMARY... Isolated severe thunderstorms will be possible across portions of the northern Plains as well as parts Oregon and vicinity, mainly Friday afternoon and evening. Large hail and damaging wind gusts should be the main threats, but a couple tornadoes may also occur across parts of western/central South Dakota. ...Northern/Central Plains... A shortwave trough will round an upper ridge centered over the Rockies and encourage thunderstorms to develop by Friday afternoon along a surface trough/front located across the northern High Plains. Some storms may be ongoing Friday morning, which could limit destabilization with northward extent into ND. Upper 60s to lower 70s surface dewpoints will combine with strong diurnal heating to result in around 1500-3000 J/kg of MLCAPE, with the greatest instability expected across western/central SD. A veering/strengthening wind profile will likely support 35-50 kt of effective bulk shear, with supercells expected initially. Isolated large hail will probably be the main threat with this initially discrete convection. Storms may potentially grow upscale into a MCS across central SD Friday evening as a southerly low-level jet strengthens. If this occurs, then severe winds would become the primary severe threat. Given the veering low-level wind profile, a couple tornadoes also cannot be ruled out late Friday afternoon/evening, mainly across parts of western/central SD. Farther south, shear is forecast to be weaker across the central High Plains, but isolated large hail and strong/gusty winds could occur with the strongest storms. ...Pacific Northwest... An upper low over the eastern Pacific will approach the OR/CA Coast by Friday evening, with mid-level southerly winds forecast to strengthen across much of OR in response. Low-level southerly flow should transport low to mid 50s surface dewpoints into western OR, with values generally decreasing into the mid/upper 40s along and east of the Cascade crest. Mid-level lapse rates should steepen across this region through the day, which combined with diurnal heating should support around 500-1250 J/kg of MLCAPE. As wind fields increase by mid afternoon, around 30-40 kt of effective bulk shear should also develop. A vorticity maximum embedded within the upper low will likely encourage convective initiation along and east the Cascades by early afternoon. Storms should subsequently spread north-northeastward into eastern OR and parts of southern WA. The forecast combination of instability and shear suggests updrafts will become organized, with both a isolated large hail and severe wind gust threat existing through Friday evening. ...Virginia/North Carolina... A belt of 30-40 kt westerly flow will likely remain over much of VA/NC through the period. At the surface, a stalled front should be located west/east from WV into northern/central VA and the Delmarva Peninsula Friday afternoon. Large-scale forcing for ascent may remain somewhat nebulous across this area, but some guidance does suggest isolated to scattered storm development may occur along the front in central VA and then spread southeastward Friday afternoon and evening. NAM/RAP forecast soundings across this region show around 1500-2000 J/kg of MLCAPE and 30-40 kt of effective bulk shear. Both multicells and marginal supercell structures will be possible. Isolated large hail may occur with semi-discrete convection initially, with a damaging wind threat potentially increasing if storms can form into a small southeastward-moving cluster. ...Ozarks into the Mid-South/Lower Mississippi Valley and Southeast... A couple of MCVs from prior convection will likely be located across these regions Friday morning. Diurnal heating of a very moist low-level airmass will result in moderate to strong instability developing along/south of a convectively reinforced surface boundary. Around 20-30 kt of mid-level west-northwesterly flow should overlie these areas. Some modest storm organization may be realized, with potential for clustering of storms as they move east-southeastward through early Friday evening. Strong/gusty downdraft winds producing isolated damage may occur. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Gleason.. 08/08/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND OREGON... ...SUMMARY... Isolated severe thunderstorms will be possible across portions of the northern Plains as well as parts Oregon and vicinity, mainly Friday afternoon and evening. Large hail and damaging wind gusts should be the main threats, but a couple tornadoes may also occur across parts of western/central South Dakota. ...Northern/Central Plains... A shortwave trough will round an upper ridge centered over the Rockies and encourage thunderstorms to develop by Friday afternoon along a surface trough/front located across the northern High Plains. Some storms may be ongoing Friday morning, which could limit destabilization with northward extent into ND. Upper 60s to lower 70s surface dewpoints will combine with strong diurnal heating to result in around 1500-3000 J/kg of MLCAPE, with the greatest instability expected across western/central SD. A veering/strengthening wind profile will likely support 35-50 kt of effective bulk shear, with supercells expected initially. Isolated large hail will probably be the main threat with this initially discrete convection. Storms may potentially grow upscale into a MCS across central SD Friday evening as a southerly low-level jet strengthens. If this occurs, then severe winds would become the primary severe threat. Given the veering low-level wind profile, a couple tornadoes also cannot be ruled out late Friday afternoon/evening, mainly across parts of western/central SD. Farther south, shear is forecast to be weaker across the central High Plains, but isolated large hail and strong/gusty winds could occur with the strongest storms. ...Pacific Northwest... An upper low over the eastern Pacific will approach the OR/CA Coast by Friday evening, with mid-level southerly winds forecast to strengthen across much of OR in response. Low-level southerly flow should transport low to mid 50s surface dewpoints into western OR, with values generally decreasing into the mid/upper 40s along and east of the Cascade crest. Mid-level lapse rates should steepen across this region through the day, which combined with diurnal heating should support around 500-1250 J/kg of MLCAPE. As wind fields increase by mid afternoon, around 30-40 kt of effective bulk shear should also develop. A vorticity maximum embedded within the upper low will likely encourage convective initiation along and east the Cascades by early afternoon. Storms should subsequently spread north-northeastward into eastern OR and parts of southern WA. The forecast combination of instability and shear suggests updrafts will become organized, with both a isolated large hail and severe wind gust threat existing through Friday evening. ...Virginia/North Carolina... A belt of 30-40 kt westerly flow will likely remain over much of VA/NC through the period. At the surface, a stalled front should be located west/east from WV into northern/central VA and the Delmarva Peninsula Friday afternoon. Large-scale forcing for ascent may remain somewhat nebulous across this area, but some guidance does suggest isolated to scattered storm development may occur along the front in central VA and then spread southeastward Friday afternoon and evening. NAM/RAP forecast soundings across this region show around 1500-2000 J/kg of MLCAPE and 30-40 kt of effective bulk shear. Both multicells and marginal supercell structures will be possible. Isolated large hail may occur with semi-discrete convection initially, with a damaging wind threat potentially increasing if storms can form into a small southeastward-moving cluster. ...Ozarks into the Mid-South/Lower Mississippi Valley and Southeast... A couple of MCVs from prior convection will likely be located across these regions Friday morning. Diurnal heating of a very moist low-level airmass will result in moderate to strong instability developing along/south of a convectively reinforced surface boundary. Around 20-30 kt of mid-level west-northwesterly flow should overlie these areas. Some modest storm organization may be realized, with potential for clustering of storms as they move east-southeastward through early Friday evening. Strong/gusty downdraft winds producing isolated damage may occur. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Gleason.. 08/08/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND OREGON... ...SUMMARY... Isolated severe thunderstorms will be possible across portions of the northern Plains as well as parts Oregon and vicinity, mainly Friday afternoon and evening. Large hail and damaging wind gusts should be the main threats, but a couple tornadoes may also occur across parts of western/central South Dakota. ...Northern/Central Plains... A shortwave trough will round an upper ridge centered over the Rockies and encourage thunderstorms to develop by Friday afternoon along a surface trough/front located across the northern High Plains. Some storms may be ongoing Friday morning, which could limit destabilization with northward extent into ND. Upper 60s to lower 70s surface dewpoints will combine with strong diurnal heating to result in around 1500-3000 J/kg of MLCAPE, with the greatest instability expected across western/central SD. A veering/strengthening wind profile will likely support 35-50 kt of effective bulk shear, with supercells expected initially. Isolated large hail will probably be the main threat with this initially discrete convection. Storms may potentially grow upscale into a MCS across central SD Friday evening as a southerly low-level jet strengthens. If this occurs, then severe winds would become the primary severe threat. Given the veering low-level wind profile, a couple tornadoes also cannot be ruled out late Friday afternoon/evening, mainly across parts of western/central SD. Farther south, shear is forecast to be weaker across the central High Plains, but isolated large hail and strong/gusty winds could occur with the strongest storms. ...Pacific Northwest... An upper low over the eastern Pacific will approach the OR/CA Coast by Friday evening, with mid-level southerly winds forecast to strengthen across much of OR in response. Low-level southerly flow should transport low to mid 50s surface dewpoints into western OR, with values generally decreasing into the mid/upper 40s along and east of the Cascade crest. Mid-level lapse rates should steepen across this region through the day, which combined with diurnal heating should support around 500-1250 J/kg of MLCAPE. As wind fields increase by mid afternoon, around 30-40 kt of effective bulk shear should also develop. A vorticity maximum embedded within the upper low will likely encourage convective initiation along and east the Cascades by early afternoon. Storms should subsequently spread north-northeastward into eastern OR and parts of southern WA. The forecast combination of instability and shear suggests updrafts will become organized, with both a isolated large hail and severe wind gust threat existing through Friday evening. ...Virginia/North Carolina... A belt of 30-40 kt westerly flow will likely remain over much of VA/NC through the period. At the surface, a stalled front should be located west/east from WV into northern/central VA and the Delmarva Peninsula Friday afternoon. Large-scale forcing for ascent may remain somewhat nebulous across this area, but some guidance does suggest isolated to scattered storm development may occur along the front in central VA and then spread southeastward Friday afternoon and evening. NAM/RAP forecast soundings across this region show around 1500-2000 J/kg of MLCAPE and 30-40 kt of effective bulk shear. Both multicells and marginal supercell structures will be possible. Isolated large hail may occur with semi-discrete convection initially, with a damaging wind threat potentially increasing if storms can form into a small southeastward-moving cluster. ...Ozarks into the Mid-South/Lower Mississippi Valley and Southeast... A couple of MCVs from prior convection will likely be located across these regions Friday morning. Diurnal heating of a very moist low-level airmass will result in moderate to strong instability developing along/south of a convectively reinforced surface boundary. Around 20-30 kt of mid-level west-northwesterly flow should overlie these areas. Some modest storm organization may be realized, with potential for clustering of storms as they move east-southeastward through early Friday evening. Strong/gusty downdraft winds producing isolated damage may occur. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Gleason.. 08/08/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Aug 08 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND OREGON... ...SUMMARY... Isolated severe thunderstorms will be possible across portions of the northern Plains as well as parts Oregon and vicinity, mainly Friday afternoon and evening. Large hail and damaging wind gusts should be the main threats, but a couple tornadoes may also occur across parts of western/central South Dakota. ...Northern/Central Plains... A shortwave trough will round an upper ridge centered over the Rockies and encourage thunderstorms to develop by Friday afternoon along a surface trough/front located across the northern High Plains. Some storms may be ongoing Friday morning, which could limit destabilization with northward extent into ND. Upper 60s to lower 70s surface dewpoints will combine with strong diurnal heating to result in around 1500-3000 J/kg of MLCAPE, with the greatest instability expected across western/central SD. A veering/strengthening wind profile will likely support 35-50 kt of effective bulk shear, with supercells expected initially. Isolated large hail will probably be the main threat with this initially discrete convection. Storms may potentially grow upscale into a MCS across central SD Friday evening as a southerly low-level jet strengthens. If this occurs, then severe winds would become the primary severe threat. Given the veering low-level wind profile, a couple tornadoes also cannot be ruled out late Friday afternoon/evening, mainly across parts of western/central SD. Farther south, shear is forecast to be weaker across the central High Plains, but isolated large hail and strong/gusty winds could occur with the strongest storms. ...Pacific Northwest... An upper low over the eastern Pacific will approach the OR/CA Coast by Friday evening, with mid-level southerly winds forecast to strengthen across much of OR in response. Low-level southerly flow should transport low to mid 50s surface dewpoints into western OR, with values generally decreasing into the mid/upper 40s along and east of the Cascade crest. Mid-level lapse rates should steepen across this region through the day, which combined with diurnal heating should support around 500-1250 J/kg of MLCAPE. As wind fields increase by mid afternoon, around 30-40 kt of effective bulk shear should also develop. A vorticity maximum embedded within the upper low will likely encourage convective initiation along and east the Cascades by early afternoon. Storms should subsequently spread north-northeastward into eastern OR and parts of southern WA. The forecast combination of instability and shear suggests updrafts will become organized, with both a isolated large hail and severe wind gust threat existing through Friday evening. ...Virginia/North Carolina... A belt of 30-40 kt westerly flow will likely remain over much of VA/NC through the period. At the surface, a stalled front should be located west/east from WV into northern/central VA and the Delmarva Peninsula Friday afternoon. Large-scale forcing for ascent may remain somewhat nebulous across this area, but some guidance does suggest isolated to scattered storm development may occur along the front in central VA and then spread southeastward Friday afternoon and evening. NAM/RAP forecast soundings across this region show around 1500-2000 J/kg of MLCAPE and 30-40 kt of effective bulk shear. Both multicells and marginal supercell structures will be possible. Isolated large hail may occur with semi-discrete convection initially, with a damaging wind threat potentially increasing if storms can form into a small southeastward-moving cluster. ...Ozarks into the Mid-South/Lower Mississippi Valley and Southeast... A couple of MCVs from prior convection will likely be located across these regions Friday morning. Diurnal heating of a very moist low-level airmass will result in moderate to strong instability developing along/south of a convectively reinforced surface boundary. Around 20-30 kt of mid-level west-northwesterly flow should overlie these areas. Some modest storm organization may be realized, with potential for clustering of storms as they move east-southeastward through early Friday evening. Strong/gusty downdraft winds producing isolated damage may occur. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Gleason.. 08/08/2019 Read more

WW 0562 Status Updates
STATUS FOR WATCH 0562 HAS NOT BEEN ISSUED YET Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Thu Aug 08 2019 Valid 081630Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF PA/NY/OH/WV... ...SUMMARY... The greatest concentration of potentially severe storms today is expected across the lower Great Lakes and northern/central Appalachians to the mid/upper Ohio Valley. ...Synopsis... A large trough will continue moving across eastern Canada and the eastern U.S. today, with another large trough surrounding a very slow-moving upper low over the eastern Pacific. In between, ridging will continue to prevail over the Rockies and south-central U.S. through tonight. At the surface, a weak pressure field prevails. A subtle cool front will continue crossing the lower Great Lakes/Ohio Valley today, while remnants of a prior/weak front linger from the southeastern U.S. west-northwestward into the Oklahoma vicinity. These two boundaries, and weak disturbances aloft crossing the Great Basin area ahead of the Pacific low/trough, will support showers and thunderstorm activity, along with limited/local severe risk. ...NY/PA/OH/WV vicinity... Showers and thunderstorms are ongoing across western New York and adjacent northwest Pennsylvania, near a very weak cool front moving across the region. As heating continues into the afternoon, resulting in additional/modest destabilization, an increase in convective coverage is expected, along with some uptick in intensity -- aided by moderate westerly/west-northwesterly flow through a deep layer. With this flow promoting rather quick eastward storm motion, stronger convective elements will be capable of producing gusty/damaging winds, that may reach severe levels locally. Risk should continue through the afternoon, diminishing with the onset of diurnal cooling early this evening. For additional short-term information, please refer to SWOMCD #1674. ...Southern KS/OK east-southeast to northern MS... A large area of weak convection is ongoing from the southern Plains, east across the Ozarks to the northern Mississippi Vicinity. An outflow boundary is observed from Oklahoma southeast to northern Mississippi, on the southern fringe of a stronger west-northwest to east-southeast band of storms. Some intensification of storms within this band, and/or new convective development near the aforementioned outflow, may -- given the favorably moist/gradually destabilizing airmass away from active convection -- intensify to occasionally severe levels. Gusty/locally damaging winds may occur with the strongest storms, along with some risk for large hail. Storms -- and possibly some severe risk -- will continue into the overnight hours, as a south-southwesterly low-level jet develops across the southern Plains, aiding continued storm development/sustenance. ...Central and southern high Plains... Daytime heating of a seasonally moist boundary layer across the high Plains region will permit afternoon destabilization, supporting development of scattered to isolated thunderstorms. Mid-level flow is not particularly strong across the region (generally 20 to 30 kt from the west), a weak easterly component to the low-level flow will help to provide both ample shear for a few organized storms, as well as some tendency for storms to progress southeastward off the higher terrain. The strongest storms/storm clusters may be capable of producing gusty/damaging winds, along with some hail risk. Severe risk should gradually decrease through the evening, as convection weakens. ...Parts of the Great Basin and vicinity... A relatively moist low-level airmass resides across the Great Basin vicinity, with dewpoints in the low 50s. Showers and isolated thunderstorms are ongoing across parts of the region -- partly in response to several disturbances aloft moving across the area, embedded within cyclonic upper flow surrounding the eastern Pacific upper low. Clearing is noted in morning visible imagery across parts of Nevada away from ongoing convection, which will aid in afternoon destabilization, and an associated increase in convective coverage. Given moderate deep-layer southwesterly flow supporting semi-organized cells/clusters, potential for locally damaging winds will exist with a few of the strongest storms, before convection weakens this evening. ..Goss.. 08/08/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Thu Aug 08 2019 Valid 081630Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF PA/NY/OH/WV... ...SUMMARY... The greatest concentration of potentially severe storms today is expected across the lower Great Lakes and northern/central Appalachians to the mid/upper Ohio Valley. ...Synopsis... A large trough will continue moving across eastern Canada and the eastern U.S. today, with another large trough surrounding a very slow-moving upper low over the eastern Pacific. In between, ridging will continue to prevail over the Rockies and south-central U.S. through tonight. At the surface, a weak pressure field prevails. A subtle cool front will continue crossing the lower Great Lakes/Ohio Valley today, while remnants of a prior/weak front linger from the southeastern U.S. west-northwestward into the Oklahoma vicinity. These two boundaries, and weak disturbances aloft crossing the Great Basin area ahead of the Pacific low/trough, will support showers and thunderstorm activity, along with limited/local severe risk. ...NY/PA/OH/WV vicinity... Showers and thunderstorms are ongoing across western New York and adjacent northwest Pennsylvania, near a very weak cool front moving across the region. As heating continues into the afternoon, resulting in additional/modest destabilization, an increase in convective coverage is expected, along with some uptick in intensity -- aided by moderate westerly/west-northwesterly flow through a deep layer. With this flow promoting rather quick eastward storm motion, stronger convective elements will be capable of producing gusty/damaging winds, that may reach severe levels locally. Risk should continue through the afternoon, diminishing with the onset of diurnal cooling early this evening. For additional short-term information, please refer to SWOMCD #1674. ...Southern KS/OK east-southeast to northern MS... A large area of weak convection is ongoing from the southern Plains, east across the Ozarks to the northern Mississippi Vicinity. An outflow boundary is observed from Oklahoma southeast to northern Mississippi, on the southern fringe of a stronger west-northwest to east-southeast band of storms. Some intensification of storms within this band, and/or new convective development near the aforementioned outflow, may -- given the favorably moist/gradually destabilizing airmass away from active convection -- intensify to occasionally severe levels. Gusty/locally damaging winds may occur with the strongest storms, along with some risk for large hail. Storms -- and possibly some severe risk -- will continue into the overnight hours, as a south-southwesterly low-level jet develops across the southern Plains, aiding continued storm development/sustenance. ...Central and southern high Plains... Daytime heating of a seasonally moist boundary layer across the high Plains region will permit afternoon destabilization, supporting development of scattered to isolated thunderstorms. Mid-level flow is not particularly strong across the region (generally 20 to 30 kt from the west), a weak easterly component to the low-level flow will help to provide both ample shear for a few organized storms, as well as some tendency for storms to progress southeastward off the higher terrain. The strongest storms/storm clusters may be capable of producing gusty/damaging winds, along with some hail risk. Severe risk should gradually decrease through the evening, as convection weakens. ...Parts of the Great Basin and vicinity... A relatively moist low-level airmass resides across the Great Basin vicinity, with dewpoints in the low 50s. Showers and isolated thunderstorms are ongoing across parts of the region -- partly in response to several disturbances aloft moving across the area, embedded within cyclonic upper flow surrounding the eastern Pacific upper low. Clearing is noted in morning visible imagery across parts of Nevada away from ongoing convection, which will aid in afternoon destabilization, and an associated increase in convective coverage. Given moderate deep-layer southwesterly flow supporting semi-organized cells/clusters, potential for locally damaging winds will exist with a few of the strongest storms, before convection weakens this evening. ..Goss.. 08/08/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Thu Aug 08 2019 Valid 081630Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF PA/NY/OH/WV... ...SUMMARY... The greatest concentration of potentially severe storms today is expected across the lower Great Lakes and northern/central Appalachians to the mid/upper Ohio Valley. ...Synopsis... A large trough will continue moving across eastern Canada and the eastern U.S. today, with another large trough surrounding a very slow-moving upper low over the eastern Pacific. In between, ridging will continue to prevail over the Rockies and south-central U.S. through tonight. At the surface, a weak pressure field prevails. A subtle cool front will continue crossing the lower Great Lakes/Ohio Valley today, while remnants of a prior/weak front linger from the southeastern U.S. west-northwestward into the Oklahoma vicinity. These two boundaries, and weak disturbances aloft crossing the Great Basin area ahead of the Pacific low/trough, will support showers and thunderstorm activity, along with limited/local severe risk. ...NY/PA/OH/WV vicinity... Showers and thunderstorms are ongoing across western New York and adjacent northwest Pennsylvania, near a very weak cool front moving across the region. As heating continues into the afternoon, resulting in additional/modest destabilization, an increase in convective coverage is expected, along with some uptick in intensity -- aided by moderate westerly/west-northwesterly flow through a deep layer. With this flow promoting rather quick eastward storm motion, stronger convective elements will be capable of producing gusty/damaging winds, that may reach severe levels locally. Risk should continue through the afternoon, diminishing with the onset of diurnal cooling early this evening. For additional short-term information, please refer to SWOMCD #1674. ...Southern KS/OK east-southeast to northern MS... A large area of weak convection is ongoing from the southern Plains, east across the Ozarks to the northern Mississippi Vicinity. An outflow boundary is observed from Oklahoma southeast to northern Mississippi, on the southern fringe of a stronger west-northwest to east-southeast band of storms. Some intensification of storms within this band, and/or new convective development near the aforementioned outflow, may -- given the favorably moist/gradually destabilizing airmass away from active convection -- intensify to occasionally severe levels. Gusty/locally damaging winds may occur with the strongest storms, along with some risk for large hail. Storms -- and possibly some severe risk -- will continue into the overnight hours, as a south-southwesterly low-level jet develops across the southern Plains, aiding continued storm development/sustenance. ...Central and southern high Plains... Daytime heating of a seasonally moist boundary layer across the high Plains region will permit afternoon destabilization, supporting development of scattered to isolated thunderstorms. Mid-level flow is not particularly strong across the region (generally 20 to 30 kt from the west), a weak easterly component to the low-level flow will help to provide both ample shear for a few organized storms, as well as some tendency for storms to progress southeastward off the higher terrain. The strongest storms/storm clusters may be capable of producing gusty/damaging winds, along with some hail risk. Severe risk should gradually decrease through the evening, as convection weakens. ...Parts of the Great Basin and vicinity... A relatively moist low-level airmass resides across the Great Basin vicinity, with dewpoints in the low 50s. Showers and isolated thunderstorms are ongoing across parts of the region -- partly in response to several disturbances aloft moving across the area, embedded within cyclonic upper flow surrounding the eastern Pacific upper low. Clearing is noted in morning visible imagery across parts of Nevada away from ongoing convection, which will aid in afternoon destabilization, and an associated increase in convective coverage. Given moderate deep-layer southwesterly flow supporting semi-organized cells/clusters, potential for locally damaging winds will exist with a few of the strongest storms, before convection weakens this evening. ..Goss.. 08/08/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Thu Aug 08 2019 Valid 081630Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF PA/NY/OH/WV... ...SUMMARY... The greatest concentration of potentially severe storms today is expected across the lower Great Lakes and northern/central Appalachians to the mid/upper Ohio Valley. ...Synopsis... A large trough will continue moving across eastern Canada and the eastern U.S. today, with another large trough surrounding a very slow-moving upper low over the eastern Pacific. In between, ridging will continue to prevail over the Rockies and south-central U.S. through tonight. At the surface, a weak pressure field prevails. A subtle cool front will continue crossing the lower Great Lakes/Ohio Valley today, while remnants of a prior/weak front linger from the southeastern U.S. west-northwestward into the Oklahoma vicinity. These two boundaries, and weak disturbances aloft crossing the Great Basin area ahead of the Pacific low/trough, will support showers and thunderstorm activity, along with limited/local severe risk. ...NY/PA/OH/WV vicinity... Showers and thunderstorms are ongoing across western New York and adjacent northwest Pennsylvania, near a very weak cool front moving across the region. As heating continues into the afternoon, resulting in additional/modest destabilization, an increase in convective coverage is expected, along with some uptick in intensity -- aided by moderate westerly/west-northwesterly flow through a deep layer. With this flow promoting rather quick eastward storm motion, stronger convective elements will be capable of producing gusty/damaging winds, that may reach severe levels locally. Risk should continue through the afternoon, diminishing with the onset of diurnal cooling early this evening. For additional short-term information, please refer to SWOMCD #1674. ...Southern KS/OK east-southeast to northern MS... A large area of weak convection is ongoing from the southern Plains, east across the Ozarks to the northern Mississippi Vicinity. An outflow boundary is observed from Oklahoma southeast to northern Mississippi, on the southern fringe of a stronger west-northwest to east-southeast band of storms. Some intensification of storms within this band, and/or new convective development near the aforementioned outflow, may -- given the favorably moist/gradually destabilizing airmass away from active convection -- intensify to occasionally severe levels. Gusty/locally damaging winds may occur with the strongest storms, along with some risk for large hail. Storms -- and possibly some severe risk -- will continue into the overnight hours, as a south-southwesterly low-level jet develops across the southern Plains, aiding continued storm development/sustenance. ...Central and southern high Plains... Daytime heating of a seasonally moist boundary layer across the high Plains region will permit afternoon destabilization, supporting development of scattered to isolated thunderstorms. Mid-level flow is not particularly strong across the region (generally 20 to 30 kt from the west), a weak easterly component to the low-level flow will help to provide both ample shear for a few organized storms, as well as some tendency for storms to progress southeastward off the higher terrain. The strongest storms/storm clusters may be capable of producing gusty/damaging winds, along with some hail risk. Severe risk should gradually decrease through the evening, as convection weakens. ...Parts of the Great Basin and vicinity... A relatively moist low-level airmass resides across the Great Basin vicinity, with dewpoints in the low 50s. Showers and isolated thunderstorms are ongoing across parts of the region -- partly in response to several disturbances aloft moving across the area, embedded within cyclonic upper flow surrounding the eastern Pacific upper low. Clearing is noted in morning visible imagery across parts of Nevada away from ongoing convection, which will aid in afternoon destabilization, and an associated increase in convective coverage. Given moderate deep-layer southwesterly flow supporting semi-organized cells/clusters, potential for locally damaging winds will exist with a few of the strongest storms, before convection weakens this evening. ..Goss.. 08/08/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Thu Aug 08 2019 Valid 081700Z - 091200Z The forecast remains on track. Minor modifications have been made to the ISODRYT area based on latest observations and model guidance. Two shortwave troughs are evident in satellite water vapor imagery in northern Nevada and near the southern California coast. These features are already promoting thunderstorm activity and are expected to continue doing so into the afternoon/evening. Thunderstorm coverage may approach 40% within portions of Oregon, but GPS satellite and forecast soundings show increasing PWAT values which will help to mitigate some of the threat for ignitions. ..Wendt.. 08/08/2019 .PREV DISCUSSION... /ISSUED 0110 AM CDT Thu Aug 08 2019/ ...Synopsis... Deep southerly flow between a longwave trough over the northeastern Pacific and a longwave ridge centered over the Great Basin will maintain mid-level moisture in a corridor from Nevada northward to northern Washington State today. Heating beneath this moist plume will promote areas of isolated to scattered thunderstorms, which will serve as the main focus for fire weather threats across the West. ...Nevada, Idaho, southwestern Montana, central and eastern Oregon, and central and eastern Washington State... The aforementioned synoptic pattern and surface heating will foster development and gradual expansion of convective coverage - likely beginning around mid-morning across Nevada and expanding northward through the afternoon and evening. These storms will occur atop widespread areas of dry fuels, favoring lightning-related fire ignition and spread. Additionally, gusty/erratic downburst winds will complicate fire suppression efforts near ongoing fires in the region. The greatest coverage of storms is expected to occur across portions of Nevada during the afternoon, where 40%+ coverage of lightning strikes are expected. The primary limiting factor for a greater fire-weather threat in this area will be wetting thunderstorm cores and the likelihood of upscale growth of convection into bands/linear segments. The wetting rainfall should keep dry lightning relatively isolated in this area. Likewise, slow-moving convection across Idaho/southwestern Montana should also limit the extent of dry lightning and also result in heavy rainfall in localized areas. The extent of isolated dry lightning strikes will eventually reach Washington State later in the day (late afternoon through early evening). ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Thu Aug 08 2019 Valid 081700Z - 091200Z The forecast remains on track. Minor modifications have been made to the ISODRYT area based on latest observations and model guidance. Two shortwave troughs are evident in satellite water vapor imagery in northern Nevada and near the southern California coast. These features are already promoting thunderstorm activity and are expected to continue doing so into the afternoon/evening. Thunderstorm coverage may approach 40% within portions of Oregon, but GPS satellite and forecast soundings show increasing PWAT values which will help to mitigate some of the threat for ignitions. ..Wendt.. 08/08/2019 .PREV DISCUSSION... /ISSUED 0110 AM CDT Thu Aug 08 2019/ ...Synopsis... Deep southerly flow between a longwave trough over the northeastern Pacific and a longwave ridge centered over the Great Basin will maintain mid-level moisture in a corridor from Nevada northward to northern Washington State today. Heating beneath this moist plume will promote areas of isolated to scattered thunderstorms, which will serve as the main focus for fire weather threats across the West. ...Nevada, Idaho, southwestern Montana, central and eastern Oregon, and central and eastern Washington State... The aforementioned synoptic pattern and surface heating will foster development and gradual expansion of convective coverage - likely beginning around mid-morning across Nevada and expanding northward through the afternoon and evening. These storms will occur atop widespread areas of dry fuels, favoring lightning-related fire ignition and spread. Additionally, gusty/erratic downburst winds will complicate fire suppression efforts near ongoing fires in the region. The greatest coverage of storms is expected to occur across portions of Nevada during the afternoon, where 40%+ coverage of lightning strikes are expected. The primary limiting factor for a greater fire-weather threat in this area will be wetting thunderstorm cores and the likelihood of upscale growth of convection into bands/linear segments. The wetting rainfall should keep dry lightning relatively isolated in this area. Likewise, slow-moving convection across Idaho/southwestern Montana should also limit the extent of dry lightning and also result in heavy rainfall in localized areas. The extent of isolated dry lightning strikes will eventually reach Washington State later in the day (late afternoon through early evening). ...Please see www.spc.noaa.gov/fire for graphic product... Read more