Aggregator

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...Synopsis... A broad area of cyclonic flow -- attendant to a deepening mid/upper-level longwave trough -- is forecast to remain over the western CONUS through today. As this occurs, an area of enhanced mid-level flow near the base of the trough is forecast to strengthen while overspreading portions of southern California, the Southwest, and the southern Great Basin. ...Nevada/Utah/Arizona... Efficient vertical mixing of the aforementioned enhanced mid-level flow should allow for several hours of sustained surface winds of 15-20 mph (locally greater) this afternoon. Elevated to locally critical fire weather conditions are likely as these winds overlap near-critical RH values (e.g., around 15%) and receptive fuels. Currently, the expected brief/spotty nature of critical fire weather conditions precludes upgrading to a critical fire weather area. Locally elevated fire weather conditions are also possible in the lee of the Sierra Mountains over portions of western Inyo County in California, where several fires -- including the Taboose fire -- are ongoing. However, the limited coverage of elevated fire weather conditions precludes expanding the current area farther west. ...Southern California: Santa Barbara and Ventura Counties... Locally elevated fire weather conditions may be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara and western Ventura Counties this morning due to poor overnight RH recoveries and lingering gusty Sundowner winds. While surface winds are forecast to become less gusty during the late morning, elevated fire weather conditions are expected to redevelop by afternoon as surface winds increase. Elevated fire weather conditions may persist through tonight due to poor overnight RH recoveries and gusty winds. ..Elliott.. 09/09/2019 ...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 0132 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...Synopsis... A broad area of cyclonic flow -- attendant to a deepening mid/upper-level longwave trough -- is forecast to remain over the western CONUS through today. As this occurs, an area of enhanced mid-level flow near the base of the trough is forecast to strengthen while overspreading portions of southern California, the Southwest, and the southern Great Basin. ...Nevada/Utah/Arizona... Efficient vertical mixing of the aforementioned enhanced mid-level flow should allow for several hours of sustained surface winds of 15-20 mph (locally greater) this afternoon. Elevated to locally critical fire weather conditions are likely as these winds overlap near-critical RH values (e.g., around 15%) and receptive fuels. Currently, the expected brief/spotty nature of critical fire weather conditions precludes upgrading to a critical fire weather area. Locally elevated fire weather conditions are also possible in the lee of the Sierra Mountains over portions of western Inyo County in California, where several fires -- including the Taboose fire -- are ongoing. However, the limited coverage of elevated fire weather conditions precludes expanding the current area farther west. ...Southern California: Santa Barbara and Ventura Counties... Locally elevated fire weather conditions may be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara and western Ventura Counties this morning due to poor overnight RH recoveries and lingering gusty Sundowner winds. While surface winds are forecast to become less gusty during the late morning, elevated fire weather conditions are expected to redevelop by afternoon as surface winds increase. Elevated fire weather conditions may persist through tonight due to poor overnight RH recoveries and gusty winds. ..Elliott.. 09/09/2019 ...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 0132 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...Synopsis... A broad area of cyclonic flow -- attendant to a deepening mid/upper-level longwave trough -- is forecast to remain over the western CONUS through today. As this occurs, an area of enhanced mid-level flow near the base of the trough is forecast to strengthen while overspreading portions of southern California, the Southwest, and the southern Great Basin. ...Nevada/Utah/Arizona... Efficient vertical mixing of the aforementioned enhanced mid-level flow should allow for several hours of sustained surface winds of 15-20 mph (locally greater) this afternoon. Elevated to locally critical fire weather conditions are likely as these winds overlap near-critical RH values (e.g., around 15%) and receptive fuels. Currently, the expected brief/spotty nature of critical fire weather conditions precludes upgrading to a critical fire weather area. Locally elevated fire weather conditions are also possible in the lee of the Sierra Mountains over portions of western Inyo County in California, where several fires -- including the Taboose fire -- are ongoing. However, the limited coverage of elevated fire weather conditions precludes expanding the current area farther west. ...Southern California: Santa Barbara and Ventura Counties... Locally elevated fire weather conditions may be ongoing at higher elevations (e.g., > 1 kft) of eastern Santa Barbara and western Ventura Counties this morning due to poor overnight RH recoveries and lingering gusty Sundowner winds. While surface winds are forecast to become less gusty during the late morning, elevated fire weather conditions are expected to redevelop by afternoon as surface winds increase. Elevated fire weather conditions may persist through tonight due to poor overnight RH recoveries and gusty winds. ..Elliott.. 09/09/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Mon Sep 09 2019 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHWEST AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Thunderstorms associated with severe wind gusts, isolated large hail and perhaps a tornado threat will be possible across parts of the central Plains on Tuesday. ...Central and Northern Plains... A shortwave ridge will move northeastward across the northern Plains as southwest mid-level flow becomes established in its wake. At the surface, a lee trough will deepen as a corridor of maximized low-level moisture sets up from Iowa into northern Nebraska by afternoon. Thunderstorm development appears most likely to occur during the late afternoon along the western edge of the strongest instability from southeast Wyoming into northwest Nebraska. A cluster of storms is forecast to develop and move eastward across the central Plains during the late afternoon and early evening. NAM and GFS forecast soundings at 00Z/Wednesday across northwestern and north-central Nebraska show MLCAPE of 2000 to 3000 J/kg, 0-6 km shear of 45 to 50 kt and steep mid-level lapse rates. This should be favorable for supercell development. Supercells should be capable of isolated large hail, wind damage and perhaps a tornado threat. Confidence has increased that a cluster of severe storms will move eastward from northwest Nebraska into north-central Nebraska by early evening. For this reason, a slight risk area has been added for this outlook. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Broyles.. 09/09/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Mon Sep 09 2019 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHWEST AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Thunderstorms associated with severe wind gusts, isolated large hail and perhaps a tornado threat will be possible across parts of the central Plains on Tuesday. ...Central and Northern Plains... A shortwave ridge will move northeastward across the northern Plains as southwest mid-level flow becomes established in its wake. At the surface, a lee trough will deepen as a corridor of maximized low-level moisture sets up from Iowa into northern Nebraska by afternoon. Thunderstorm development appears most likely to occur during the late afternoon along the western edge of the strongest instability from southeast Wyoming into northwest Nebraska. A cluster of storms is forecast to develop and move eastward across the central Plains during the late afternoon and early evening. NAM and GFS forecast soundings at 00Z/Wednesday across northwestern and north-central Nebraska show MLCAPE of 2000 to 3000 J/kg, 0-6 km shear of 45 to 50 kt and steep mid-level lapse rates. This should be favorable for supercell development. Supercells should be capable of isolated large hail, wind damage and perhaps a tornado threat. Confidence has increased that a cluster of severe storms will move eastward from northwest Nebraska into north-central Nebraska by early evening. For this reason, a slight risk area has been added for this outlook. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Broyles.. 09/09/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Mon Sep 09 2019 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHWEST AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Thunderstorms associated with severe wind gusts, isolated large hail and perhaps a tornado threat will be possible across parts of the central Plains on Tuesday. ...Central and Northern Plains... A shortwave ridge will move northeastward across the northern Plains as southwest mid-level flow becomes established in its wake. At the surface, a lee trough will deepen as a corridor of maximized low-level moisture sets up from Iowa into northern Nebraska by afternoon. Thunderstorm development appears most likely to occur during the late afternoon along the western edge of the strongest instability from southeast Wyoming into northwest Nebraska. A cluster of storms is forecast to develop and move eastward across the central Plains during the late afternoon and early evening. NAM and GFS forecast soundings at 00Z/Wednesday across northwestern and north-central Nebraska show MLCAPE of 2000 to 3000 J/kg, 0-6 km shear of 45 to 50 kt and steep mid-level lapse rates. This should be favorable for supercell development. Supercells should be capable of isolated large hail, wind damage and perhaps a tornado threat. Confidence has increased that a cluster of severe storms will move eastward from northwest Nebraska into north-central Nebraska by early evening. For this reason, a slight risk area has been added for this outlook. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Broyles.. 09/09/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Mon Sep 09 2019 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHWEST AND NORTH-CENTRAL NEBRASKA... ...SUMMARY... Thunderstorms associated with severe wind gusts, isolated large hail and perhaps a tornado threat will be possible across parts of the central Plains on Tuesday. ...Central and Northern Plains... A shortwave ridge will move northeastward across the northern Plains as southwest mid-level flow becomes established in its wake. At the surface, a lee trough will deepen as a corridor of maximized low-level moisture sets up from Iowa into northern Nebraska by afternoon. Thunderstorm development appears most likely to occur during the late afternoon along the western edge of the strongest instability from southeast Wyoming into northwest Nebraska. A cluster of storms is forecast to develop and move eastward across the central Plains during the late afternoon and early evening. NAM and GFS forecast soundings at 00Z/Wednesday across northwestern and north-central Nebraska show MLCAPE of 2000 to 3000 J/kg, 0-6 km shear of 45 to 50 kt and steep mid-level lapse rates. This should be favorable for supercell development. Supercells should be capable of isolated large hail, wind damage and perhaps a tornado threat. Confidence has increased that a cluster of severe storms will move eastward from northwest Nebraska into north-central Nebraska by early evening. For this reason, a slight risk area has been added for this outlook. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% - Slight ..Broyles.. 09/09/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE IOWA/SOUTHERN MINNESOTA VICINITY... ...SUMMARY... Thunderstorms capable of producing large hail, and strong/gusty winds, and possibly a tornado will be possible across parts of the northern Plains and upper Mississippi Valley Monday afternoon and evening. A few strong/severe storms may also occur over the southern Virginia/northeast North Carolina area. ...Synopsis... A short-wave trough is forecast to shift northeastward across the central and northern Plains, toward the upper Mississippi Valley through the day, ahead of a much larger trough gradually evolving southeastward across the West. Meanwhile, a weak short-wave trough will move quickly east-southeastward from the upper Ohio Valley across the Mid Atlantic region through the first half of the period. Otherwise, short-wave troughing will prevail across the southeastern quarter of the country. At the surface, a baroclinic zone extending from Montana southeastward across the mid Missouri Valley is forecast to shift gradually northeastward across the northern Plains/upper Mississippi Valley/upper Great Lakes region through the period. Meanwhile, a weak/remnant front is forecast to linger from the northeast North Carolina area west-southwestward across the Southeast states, south of Northeast U.S. high pressure. ...Parts of the central and northern Plains into the Upper Midwest... Scattered to isolated thunderstorms are forecast to be ongoing across the risk area at the start of the period, in conjunction with the short-wave trough advancing northeastward across the central/northern Plains. The effects of this convection complicate the forecast -- particularly as it pertains to areas where storm reintensification and/or redevelopment may be most concentrated during the afternoon. Overall, a moist boundary layer will remain in place near and south of the warm front, such that where heating can occur, moderate instability will evolve. As such, storm development is expected, and at this time it appears will be most concentrated over the Iowa/southern Minnesota vicinity near where the warm front is expected to reside during the afternoon. Other, more isolated storms may develop southwestward across Nebraska and into western Kansas, though with this area in the wake of the short-wave troughing, subsidence should limit storm coverage across this region. Still, with ample instability and modest shear, a stronger storm or two may produce large hail or gusty winds during the afternoon. Still, greater risk will remain farther north, nearer the northeastward-advancing warm front and ahead of the mid-level feature. With stronger flow aloft across this region, organized storms are expected -- though mode remains uncertain. Any isolated cells which can develop -- particularly near the warm front -- would be capable of producing large hail and locally damaging winds, and possibly a tornado. However, a more clustered/loosely linear storm mode appears likely to evolve, with attendant risks for mainly damaging winds and hail. As a south-southwesterly low-level jet strengthens into the evening, elevated convection should increase in coverage into the Great Lakes area, where some risk for hail may linger well after dark. ...Southern Virginia/northeast North Carolina... As a short-wave trough moves quickly across the central Appalachians and into the Mid Atlantic region through the afternoon, a few thunderstorms are forecast to develop -- possibly over the higher terrain, as well as in the vicinity of the surface boundary progged to be lingering over the northeast North Carolina area. An amply moist/unstable environment will support the storms, and with moderate mid-level west-northwesterly flow shifting across the region, a few stronger storms may evolve. As such, local risk for damaging winds -- and possibly marginal hail -- remains apparent, prior to the onset of diurnal cooling. ..Goss/Elliott.. 09/09/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE IOWA/SOUTHERN MINNESOTA VICINITY... ...SUMMARY... Thunderstorms capable of producing large hail, and strong/gusty winds, and possibly a tornado will be possible across parts of the northern Plains and upper Mississippi Valley Monday afternoon and evening. A few strong/severe storms may also occur over the southern Virginia/northeast North Carolina area. ...Synopsis... A short-wave trough is forecast to shift northeastward across the central and northern Plains, toward the upper Mississippi Valley through the day, ahead of a much larger trough gradually evolving southeastward across the West. Meanwhile, a weak short-wave trough will move quickly east-southeastward from the upper Ohio Valley across the Mid Atlantic region through the first half of the period. Otherwise, short-wave troughing will prevail across the southeastern quarter of the country. At the surface, a baroclinic zone extending from Montana southeastward across the mid Missouri Valley is forecast to shift gradually northeastward across the northern Plains/upper Mississippi Valley/upper Great Lakes region through the period. Meanwhile, a weak/remnant front is forecast to linger from the northeast North Carolina area west-southwestward across the Southeast states, south of Northeast U.S. high pressure. ...Parts of the central and northern Plains into the Upper Midwest... Scattered to isolated thunderstorms are forecast to be ongoing across the risk area at the start of the period, in conjunction with the short-wave trough advancing northeastward across the central/northern Plains. The effects of this convection complicate the forecast -- particularly as it pertains to areas where storm reintensification and/or redevelopment may be most concentrated during the afternoon. Overall, a moist boundary layer will remain in place near and south of the warm front, such that where heating can occur, moderate instability will evolve. As such, storm development is expected, and at this time it appears will be most concentrated over the Iowa/southern Minnesota vicinity near where the warm front is expected to reside during the afternoon. Other, more isolated storms may develop southwestward across Nebraska and into western Kansas, though with this area in the wake of the short-wave troughing, subsidence should limit storm coverage across this region. Still, with ample instability and modest shear, a stronger storm or two may produce large hail or gusty winds during the afternoon. Still, greater risk will remain farther north, nearer the northeastward-advancing warm front and ahead of the mid-level feature. With stronger flow aloft across this region, organized storms are expected -- though mode remains uncertain. Any isolated cells which can develop -- particularly near the warm front -- would be capable of producing large hail and locally damaging winds, and possibly a tornado. However, a more clustered/loosely linear storm mode appears likely to evolve, with attendant risks for mainly damaging winds and hail. As a south-southwesterly low-level jet strengthens into the evening, elevated convection should increase in coverage into the Great Lakes area, where some risk for hail may linger well after dark. ...Southern Virginia/northeast North Carolina... As a short-wave trough moves quickly across the central Appalachians and into the Mid Atlantic region through the afternoon, a few thunderstorms are forecast to develop -- possibly over the higher terrain, as well as in the vicinity of the surface boundary progged to be lingering over the northeast North Carolina area. An amply moist/unstable environment will support the storms, and with moderate mid-level west-northwesterly flow shifting across the region, a few stronger storms may evolve. As such, local risk for damaging winds -- and possibly marginal hail -- remains apparent, prior to the onset of diurnal cooling. ..Goss/Elliott.. 09/09/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE IOWA/SOUTHERN MINNESOTA VICINITY... ...SUMMARY... Thunderstorms capable of producing large hail, and strong/gusty winds, and possibly a tornado will be possible across parts of the northern Plains and upper Mississippi Valley Monday afternoon and evening. A few strong/severe storms may also occur over the southern Virginia/northeast North Carolina area. ...Synopsis... A short-wave trough is forecast to shift northeastward across the central and northern Plains, toward the upper Mississippi Valley through the day, ahead of a much larger trough gradually evolving southeastward across the West. Meanwhile, a weak short-wave trough will move quickly east-southeastward from the upper Ohio Valley across the Mid Atlantic region through the first half of the period. Otherwise, short-wave troughing will prevail across the southeastern quarter of the country. At the surface, a baroclinic zone extending from Montana southeastward across the mid Missouri Valley is forecast to shift gradually northeastward across the northern Plains/upper Mississippi Valley/upper Great Lakes region through the period. Meanwhile, a weak/remnant front is forecast to linger from the northeast North Carolina area west-southwestward across the Southeast states, south of Northeast U.S. high pressure. ...Parts of the central and northern Plains into the Upper Midwest... Scattered to isolated thunderstorms are forecast to be ongoing across the risk area at the start of the period, in conjunction with the short-wave trough advancing northeastward across the central/northern Plains. The effects of this convection complicate the forecast -- particularly as it pertains to areas where storm reintensification and/or redevelopment may be most concentrated during the afternoon. Overall, a moist boundary layer will remain in place near and south of the warm front, such that where heating can occur, moderate instability will evolve. As such, storm development is expected, and at this time it appears will be most concentrated over the Iowa/southern Minnesota vicinity near where the warm front is expected to reside during the afternoon. Other, more isolated storms may develop southwestward across Nebraska and into western Kansas, though with this area in the wake of the short-wave troughing, subsidence should limit storm coverage across this region. Still, with ample instability and modest shear, a stronger storm or two may produce large hail or gusty winds during the afternoon. Still, greater risk will remain farther north, nearer the northeastward-advancing warm front and ahead of the mid-level feature. With stronger flow aloft across this region, organized storms are expected -- though mode remains uncertain. Any isolated cells which can develop -- particularly near the warm front -- would be capable of producing large hail and locally damaging winds, and possibly a tornado. However, a more clustered/loosely linear storm mode appears likely to evolve, with attendant risks for mainly damaging winds and hail. As a south-southwesterly low-level jet strengthens into the evening, elevated convection should increase in coverage into the Great Lakes area, where some risk for hail may linger well after dark. ...Southern Virginia/northeast North Carolina... As a short-wave trough moves quickly across the central Appalachians and into the Mid Atlantic region through the afternoon, a few thunderstorms are forecast to develop -- possibly over the higher terrain, as well as in the vicinity of the surface boundary progged to be lingering over the northeast North Carolina area. An amply moist/unstable environment will support the storms, and with moderate mid-level west-northwesterly flow shifting across the region, a few stronger storms may evolve. As such, local risk for damaging winds -- and possibly marginal hail -- remains apparent, prior to the onset of diurnal cooling. ..Goss/Elliott.. 09/09/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Sep 09 2019 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE IOWA/SOUTHERN MINNESOTA VICINITY... ...SUMMARY... Thunderstorms capable of producing large hail, and strong/gusty winds, and possibly a tornado will be possible across parts of the northern Plains and upper Mississippi Valley Monday afternoon and evening. A few strong/severe storms may also occur over the southern Virginia/northeast North Carolina area. ...Synopsis... A short-wave trough is forecast to shift northeastward across the central and northern Plains, toward the upper Mississippi Valley through the day, ahead of a much larger trough gradually evolving southeastward across the West. Meanwhile, a weak short-wave trough will move quickly east-southeastward from the upper Ohio Valley across the Mid Atlantic region through the first half of the period. Otherwise, short-wave troughing will prevail across the southeastern quarter of the country. At the surface, a baroclinic zone extending from Montana southeastward across the mid Missouri Valley is forecast to shift gradually northeastward across the northern Plains/upper Mississippi Valley/upper Great Lakes region through the period. Meanwhile, a weak/remnant front is forecast to linger from the northeast North Carolina area west-southwestward across the Southeast states, south of Northeast U.S. high pressure. ...Parts of the central and northern Plains into the Upper Midwest... Scattered to isolated thunderstorms are forecast to be ongoing across the risk area at the start of the period, in conjunction with the short-wave trough advancing northeastward across the central/northern Plains. The effects of this convection complicate the forecast -- particularly as it pertains to areas where storm reintensification and/or redevelopment may be most concentrated during the afternoon. Overall, a moist boundary layer will remain in place near and south of the warm front, such that where heating can occur, moderate instability will evolve. As such, storm development is expected, and at this time it appears will be most concentrated over the Iowa/southern Minnesota vicinity near where the warm front is expected to reside during the afternoon. Other, more isolated storms may develop southwestward across Nebraska and into western Kansas, though with this area in the wake of the short-wave troughing, subsidence should limit storm coverage across this region. Still, with ample instability and modest shear, a stronger storm or two may produce large hail or gusty winds during the afternoon. Still, greater risk will remain farther north, nearer the northeastward-advancing warm front and ahead of the mid-level feature. With stronger flow aloft across this region, organized storms are expected -- though mode remains uncertain. Any isolated cells which can develop -- particularly near the warm front -- would be capable of producing large hail and locally damaging winds, and possibly a tornado. However, a more clustered/loosely linear storm mode appears likely to evolve, with attendant risks for mainly damaging winds and hail. As a south-southwesterly low-level jet strengthens into the evening, elevated convection should increase in coverage into the Great Lakes area, where some risk for hail may linger well after dark. ...Southern Virginia/northeast North Carolina... As a short-wave trough moves quickly across the central Appalachians and into the Mid Atlantic region through the afternoon, a few thunderstorms are forecast to develop -- possibly over the higher terrain, as well as in the vicinity of the surface boundary progged to be lingering over the northeast North Carolina area. An amply moist/unstable environment will support the storms, and with moderate mid-level west-northwesterly flow shifting across the region, a few stronger storms may evolve. As such, local risk for damaging winds -- and possibly marginal hail -- remains apparent, prior to the onset of diurnal cooling. ..Goss/Elliott.. 09/09/2019 Read more

000
ABPZ20 KNHC 090524
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sun Sep 8 2019

For the eastern North Pacific...east of 140 degrees west longitude:

An area of disorganized showers and thunderstorms located a few
hundred miles south-southeast of Acapulco, Mexico, are associated
with a tropical wave. Environmental conditions are expected to
be conducive for gradual development over the next several days,
and a tropical depression is likely to form around the middle of
the week while the system moves west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...80 percent.

$$
Forecaster Brown

WW 0638 Status Updates
STATUS REPORT ON WW 638 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 NNW LAA TO 30 ENE PUB TO 20 ESE CYS. ..KERR..09/09/19 ATTN...WFO...BOU...PUB... STATUS REPORT FOR WS 638 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC039-073-087-121-123-090240- CO . COLORADO COUNTIES INCLUDED ARE ELBERT LINCOLN MORGAN WASHINGTON WELD THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 638 SEVERE TSTM CO 082055Z - 090300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 638 NWS Storm Prediction Center Norman OK 255 PM MDT Sun Sep 8 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and Northeastern Colorado * Effective this Sunday afternoon and evening from 255 PM until 900 PM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms over the high terrain of central Colorado will intensify as it moves eastward into the High Plains. Damaging wind gusts are the main concern with the strongest cells, along with some risk of hail. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 40 miles north northwest of Fort Collins CO to 15 miles southeast of Pueblo CO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 PM CDT Sun Sep 08 2019 Valid 090100Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT SOUTHEAST WYOMING AND THE NEBRASKA PANHANDLE... ...SUMMARY... Strong/locally severe thunderstorms -- capable of producing a few instances of strong/gusty winds and hail -- will continue this evening across parts of the central Rockies and adjacent High Plains this evening. ...Central high Plains area... While a strong gust or two may still occur across portions of northwestern Colorado/southern Wyoming, somewhat greater severe risk will persist across the high Plains of eastern Colorado, where locally more intense storms are ongoing. One small/bowing cluster of storms has moved northeastward through the Denver metro area, while another cluster of stronger storms is ongoing farther to the southeast. With ample instability (500 to 1500 J/kg mixed-layer CAPE), and a strengthening southerly low-level jet beneath mid-level westerly winds forecast to increase with time, severe threat should continue locally this evening, and may possibly linger into the overnight hours. Greatest risk however should be confined to the next couple of hours, owing to the onset of diurnal cooling/stabilization of the boundary layer. For additional short-term information, please refer to SWOMCD #1940. ..Goss.. 09/09/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0754 PM CDT Sun Sep 08 2019 Valid 090100Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN COLORADO AND ADJACENT SOUTHEAST WYOMING AND THE NEBRASKA PANHANDLE... ...SUMMARY... Strong/locally severe thunderstorms -- capable of producing a few instances of strong/gusty winds and hail -- will continue this evening across parts of the central Rockies and adjacent High Plains this evening. ...Central high Plains area... While a strong gust or two may still occur across portions of northwestern Colorado/southern Wyoming, somewhat greater severe risk will persist across the high Plains of eastern Colorado, where locally more intense storms are ongoing. One small/bowing cluster of storms has moved northeastward through the Denver metro area, while another cluster of stronger storms is ongoing farther to the southeast. With ample instability (500 to 1500 J/kg mixed-layer CAPE), and a strengthening southerly low-level jet beneath mid-level westerly winds forecast to increase with time, severe threat should continue locally this evening, and may possibly linger into the overnight hours. Greatest risk however should be confined to the next couple of hours, owing to the onset of diurnal cooling/stabilization of the boundary layer. For additional short-term information, please refer to SWOMCD #1940. ..Goss.. 09/09/2019 Read more

WW 0638 Status Updates
STATUS REPORT ON WW 638 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SE PUB TO 30 WSW CYS. ..KERR..09/09/19 ATTN...WFO...BOU...PUB... STATUS REPORT FOR WS 638 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-025-039-073-087-121-123-090140- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE CROWLEY ELBERT LINCOLN MORGAN WASHINGTON WELD THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

MD 1940 CONCERNING SEVERE THUNDERSTORM WATCH 638... FOR PARTS OF NORTHEASTERN COLORADO
Mesoscale Discussion 1940 NWS Storm Prediction Center Norman OK 0731 PM CDT Sun Sep 08 2019 Areas affected...Parts of northeastern Colorado Concerning...Severe Thunderstorm Watch 638... Valid 090031Z - 090200Z The severe weather threat for Severe Thunderstorm Watch 638 continues. SUMMARY...Strong to locally severe storms are ongoing the east of the Colorado Front Range, and may continue to pose a risk for strong surface gusts and marginally severe hail into the 7-8 PM MDT time frame. DISCUSSION...There has been some recent intensification of thunderstorm activity near/east of the Denver metro area, aided by lift along cold outflow generated by preceding storms across the higher terrain to the west. Some of this activity has produced strong surface gusts, including a 50 kt peak 3-second mean gust at the Denver International Airport at 2343Z. Convection is beginning to propagate away from the higher terrain into a cooler and more stable environment across northeastern Colorado, to the northwest of a stalled surface front, and it is unclear how much longer it will be able to maintain intensity. Even south of the front, roughly along the Interstate 70 corridor across eastern Colorado, the boundary layer has been impacted considerable by convective outflow. ..Kerr.. 09/09/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GLD...BOU... LAT...LON 40070429 40450453 40470331 39360295 39080362 39300422 39700404 40070429 Read more

000
ABPZ20 KNHC 082338
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sun Sep 8 2019

For the eastern North Pacific...east of 140 degrees west longitude:

A tropical wave located a couple of hundred miles south-southeast
of Acapulco, Mexico is accompanied by a large area of disturbed
weather. Environmental conditions are expected to become conducive
for gradual development, and a tropical depression is likely to
form by the middle of the week while the system moves
west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Pasch