Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0801 PM CDT Fri Aug 16 2019 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE LOWER MISSOURI VALLEY... ...SUMMARY... Scattered severe storms are expected to continue into tonight from the central Plains into the Lower Missouri Valley with very large hail and damaging winds as the primary threats. ...Central High Plains... Widely scattered storms that developed within the upslope flow regime over the higher terrain intensified as they moved into the moderately unstable environment across eastern CO through western NE and where effective shear from 40-50 kt is sufficient for supercells. It remains possible that a cluster of storms might organize and continue east through western KS and or southwest NE. However, there has been a trend for some storms to diminish over northeast CO as they move toward lower elevations where a very warm EML (16C at 700 mb) will result in strong surface based convective inhibition as the boundary layer begins to cool. This lowers confidence in future evolution of the storms moving off the higher terrain and into western KS but will maintain a SLGT risk for this possibility. ...Central Plains into the Lower Missouri Valley... A quasi-stationary front extends from northern MO through central and southwest KS and into southeast CO. The atmosphere is strongly unstable (3000-4000) J/kg MUCAPE) in vicinity of and south of this boundary where a plume of very steep (8-8.5 C/km) mid-level lapse rates have overspread the moist sector. However, the warm air at the base of an elevated mixed layer has also resulted in a substantial cap over much of this region, except in southwest KS and northwest OK where deep mixing has eroded the inversion, resulting in a few high-based severe storms. A substantial increase in storm coverage is expected later this evening into tonight from northern KS, southern NE into northern MO and possibly southern IA. This will be supported by increasing forcing for ascent along and north of the stationary front on nose of a strengthening southwesterly low-level jet. Most of these storms will probably be slightly elevated, but the thermodynamic environment and 30-40 kt effective bulk shear will support some supercell structures capable of large to very large hail and isolated damaging wind as the primary threats. Storms may eventually grow upscale with damaging wind becoming the main threat. ..Dial.. 08/17/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0801 PM CDT Fri Aug 16 2019 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE LOWER MISSOURI VALLEY... ...SUMMARY... Scattered severe storms are expected to continue into tonight from the central Plains into the Lower Missouri Valley with very large hail and damaging winds as the primary threats. ...Central High Plains... Widely scattered storms that developed within the upslope flow regime over the higher terrain intensified as they moved into the moderately unstable environment across eastern CO through western NE and where effective shear from 40-50 kt is sufficient for supercells. It remains possible that a cluster of storms might organize and continue east through western KS and or southwest NE. However, there has been a trend for some storms to diminish over northeast CO as they move toward lower elevations where a very warm EML (16C at 700 mb) will result in strong surface based convective inhibition as the boundary layer begins to cool. This lowers confidence in future evolution of the storms moving off the higher terrain and into western KS but will maintain a SLGT risk for this possibility. ...Central Plains into the Lower Missouri Valley... A quasi-stationary front extends from northern MO through central and southwest KS and into southeast CO. The atmosphere is strongly unstable (3000-4000) J/kg MUCAPE) in vicinity of and south of this boundary where a plume of very steep (8-8.5 C/km) mid-level lapse rates have overspread the moist sector. However, the warm air at the base of an elevated mixed layer has also resulted in a substantial cap over much of this region, except in southwest KS and northwest OK where deep mixing has eroded the inversion, resulting in a few high-based severe storms. A substantial increase in storm coverage is expected later this evening into tonight from northern KS, southern NE into northern MO and possibly southern IA. This will be supported by increasing forcing for ascent along and north of the stationary front on nose of a strengthening southwesterly low-level jet. Most of these storms will probably be slightly elevated, but the thermodynamic environment and 30-40 kt effective bulk shear will support some supercell structures capable of large to very large hail and isolated damaging wind as the primary threats. Storms may eventually grow upscale with damaging wind becoming the main threat. ..Dial.. 08/17/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0801 PM CDT Fri Aug 16 2019 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE LOWER MISSOURI VALLEY... ...SUMMARY... Scattered severe storms are expected to continue into tonight from the central Plains into the Lower Missouri Valley with very large hail and damaging winds as the primary threats. ...Central High Plains... Widely scattered storms that developed within the upslope flow regime over the higher terrain intensified as they moved into the moderately unstable environment across eastern CO through western NE and where effective shear from 40-50 kt is sufficient for supercells. It remains possible that a cluster of storms might organize and continue east through western KS and or southwest NE. However, there has been a trend for some storms to diminish over northeast CO as they move toward lower elevations where a very warm EML (16C at 700 mb) will result in strong surface based convective inhibition as the boundary layer begins to cool. This lowers confidence in future evolution of the storms moving off the higher terrain and into western KS but will maintain a SLGT risk for this possibility. ...Central Plains into the Lower Missouri Valley... A quasi-stationary front extends from northern MO through central and southwest KS and into southeast CO. The atmosphere is strongly unstable (3000-4000) J/kg MUCAPE) in vicinity of and south of this boundary where a plume of very steep (8-8.5 C/km) mid-level lapse rates have overspread the moist sector. However, the warm air at the base of an elevated mixed layer has also resulted in a substantial cap over much of this region, except in southwest KS and northwest OK where deep mixing has eroded the inversion, resulting in a few high-based severe storms. A substantial increase in storm coverage is expected later this evening into tonight from northern KS, southern NE into northern MO and possibly southern IA. This will be supported by increasing forcing for ascent along and north of the stationary front on nose of a strengthening southwesterly low-level jet. Most of these storms will probably be slightly elevated, but the thermodynamic environment and 30-40 kt effective bulk shear will support some supercell structures capable of large to very large hail and isolated damaging wind as the primary threats. Storms may eventually grow upscale with damaging wind becoming the main threat. ..Dial.. 08/17/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0801 PM CDT Fri Aug 16 2019 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE LOWER MISSOURI VALLEY... ...SUMMARY... Scattered severe storms are expected to continue into tonight from the central Plains into the Lower Missouri Valley with very large hail and damaging winds as the primary threats. ...Central High Plains... Widely scattered storms that developed within the upslope flow regime over the higher terrain intensified as they moved into the moderately unstable environment across eastern CO through western NE and where effective shear from 40-50 kt is sufficient for supercells. It remains possible that a cluster of storms might organize and continue east through western KS and or southwest NE. However, there has been a trend for some storms to diminish over northeast CO as they move toward lower elevations where a very warm EML (16C at 700 mb) will result in strong surface based convective inhibition as the boundary layer begins to cool. This lowers confidence in future evolution of the storms moving off the higher terrain and into western KS but will maintain a SLGT risk for this possibility. ...Central Plains into the Lower Missouri Valley... A quasi-stationary front extends from northern MO through central and southwest KS and into southeast CO. The atmosphere is strongly unstable (3000-4000) J/kg MUCAPE) in vicinity of and south of this boundary where a plume of very steep (8-8.5 C/km) mid-level lapse rates have overspread the moist sector. However, the warm air at the base of an elevated mixed layer has also resulted in a substantial cap over much of this region, except in southwest KS and northwest OK where deep mixing has eroded the inversion, resulting in a few high-based severe storms. A substantial increase in storm coverage is expected later this evening into tonight from northern KS, southern NE into northern MO and possibly southern IA. This will be supported by increasing forcing for ascent along and north of the stationary front on nose of a strengthening southwesterly low-level jet. Most of these storms will probably be slightly elevated, but the thermodynamic environment and 30-40 kt effective bulk shear will support some supercell structures capable of large to very large hail and isolated damaging wind as the primary threats. Storms may eventually grow upscale with damaging wind becoming the main threat. ..Dial.. 08/17/2019 Read more

WW 0588 Status Updates
STATUS REPORT ON WW 588 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1762 ..NAUSLAR..08/17/19 ATTN...WFO...BOU...GLD...PUB...CYS... STATUS REPORT FOR WS 588 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-017-039-061-063-073-075-087-095-115-121-123-125- 170140- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE CHEYENNE ELBERT KIOWA KIT CARSON LINCOLN LOGAN MORGAN PHILLIPS SEDGWICK WASHINGTON WELD YUMA KSC023-071-109-153-181-193-199-203-170140- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE GREELEY LOGAN RAWLINS SHERMAN THOMAS WALLACE WICHITA NEC007-013-033-057-105-123-157-165-170140- Read more

MD 1762 CONCERNING SEVERE THUNDERSTORM WATCH 588... FOR EASTERN COLORADO INTO SOUTHEAST WYOMING...THE NEBRASKA PANHANDLE...AND WESTERN KANSAS
Mesoscale Discussion 1762 NWS Storm Prediction Center Norman OK 0627 PM CDT Fri Aug 16 2019 Areas affected...eastern Colorado into southeast Wyoming...the Nebraska Panhandle...and western Kansas Concerning...Severe Thunderstorm Watch 588... Valid 162327Z - 170130Z The severe weather threat for Severe Thunderstorm Watch 588 continues. SUMMARY...Storms/severe risk continue to gradually increase across the WW area. DISCUSSION...The latest radar loop over the central High Plains vicinity shows a couple of strong/likely severe storms over Lincoln county, in southwestern portions of WW 588, moving southeastward. New/intense cells have developed quickly across northeast Colorado over the past half hour, while still farther north/northwest, a convective increase is noted over the southeast Wyoming vicinity. Severe risk continues across the watch area, where an axis of strong instability -- aided by a southeasterly influx of low-level moisture -- is indicated. Very large hail remains possible, along with locally damaging winds. With time, storms are expected to spread -- or redevelop -- eastward into more of Kansas and Nebraska, as a low-level jet intensifies this evening. We will continue to monitor convective evolution, with a new watch/watches anticipated east of the existing WW, during the evening. ..Goss.. 08/16/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...DDC...UNR...GLD...PUB...BOU...CYS... LAT...LON 38060339 38870406 40680508 42430538 43190436 42960294 41040065 38290072 38060339 Read more

MD 1763 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHWEST OKLAHOMA AND FAR SOUTHERN KANSAS
Mesoscale Discussion 1763 NWS Storm Prediction Center Norman OK 0629 PM CDT Fri Aug 16 2019 Areas affected...Northwest Oklahoma and far southern Kansas Concerning...Severe potential...Watch unlikely Valid 162329Z - 170100Z Probability of Watch Issuance...20 percent SUMMARY...An isolated severe threat will exist across northwest Oklahoma early this evening, although there is some potential for additional development into far southern Kansas and/or some eastward persistence across northwest Oklahoma. DISCUSSION...High-based thunderstorms have developed across northwest Oklahoma late this afternoon/early evening, particularly near Highway 64 near/west of Buffalo as of 615 PM CDT. This development is occurring near/east of a weak surface low and nearby surface trough/wind shift where the boundary layer is somewhat moist but otherwise hot (100+ F surface temperatures) and deeply mixed. Where this development is occurring, overall moisture and deep-layer/low-level shear are not particularly strong, but localized severe hail and/or severe-caliber downdrafts may occur over the next couple of hours. The most likely scenario is for any isolated severe risk to be relegated to the next couple of hours through around sunset, with storm intensity diminishing as the boundary layer begins to cool. However, somewhat richer low-level moisture and stronger deep-layer shear is available just to the east of this region and storms could persist/develop east-northeastward if storm/cold pool development becomes more extensive than currently anticipated, while a low-level jet begins to increase this evening. ..Guyer.. 08/16/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ICT...OUN...DDC...AMA... LAT...LON 36150017 37259951 37319786 36099812 36150017 Read more

WW 0588 Status Updates
STATUS REPORT ON WW 588 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..NAUSLAR..08/16/19 ATTN...WFO...BOU...GLD...PUB...CYS... STATUS REPORT FOR WS 588 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-017-039-061-063-073-075-087-095-115-121-123-125- 162340- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE CHEYENNE ELBERT KIOWA KIT CARSON LINCOLN LOGAN MORGAN PHILLIPS SEDGWICK WASHINGTON WELD YUMA KSC023-071-109-153-181-193-199-203-162340- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE GREELEY LOGAN RAWLINS SHERMAN THOMAS WALLACE WICHITA NEC007-013-033-057-105-123-157-165-162340- NE Read more

WW 588 SEVERE TSTM CO KS NE WY 162050Z - 170400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 588 NWS Storm Prediction Center Norman OK 250 PM MDT Fri Aug 16 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Northwest Kansas Western Nebraska Southeast Wyoming * Effective this Friday afternoon and evening from 250 PM until 1000 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...A few supercells should develop east off the Front Range with risks for very large hail and severe wind gusts. Uncertainty exists in how far east severe storms will be maintained later this evening into northwest Kansas. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 30 miles north of Torrington WY to 55 miles south of Burlington 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 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Grams Read more

WW 0588 Status Updates
STATUS REPORT ON WW 588 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..NAUSLAR..08/16/19 ATTN...WFO...BOU...GLD...PUB...CYS... STATUS REPORT FOR WS 588 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-017-039-061-063-073-075-087-095-115-121-123-125- 162240- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE CHEYENNE ELBERT KIOWA KIT CARSON LINCOLN LOGAN MORGAN PHILLIPS SEDGWICK WASHINGTON WELD YUMA KSC023-071-109-153-181-193-199-203-162240- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE GREELEY LOGAN RAWLINS SHERMAN THOMAS WALLACE WICHITA NEC007-013-033-057-105-123-157-165-162240- NE Read more

MD 1761 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR EASTERN WISCONSIN AND NORTHEAST ILLINOIS INTO WESTERN MICHIGAN
Mesoscale Discussion 1761 NWS Storm Prediction Center Norman OK 0432 PM CDT Fri Aug 16 2019 Areas affected...far eastern Wisconsin and northeast Illinois into western Michigan Concerning...Severe potential...Watch unlikely Valid 162132Z - 170000Z Probability of Watch Issuance...5 percent SUMMARY...Isolated to scattered thunderstorms are likely to develop across far eastern Wisconsin and northeast Illinois in the next hour or two and may continue into western Lower Michigan. A few of these storms may become capable of severe wind/hail. DISCUSSION...Multiple mid-level shortwave troughs are moving over the Great Lakes region today with one exiting Lower Michigan and another over Wisconsin/northern Illinois currently. A moist airmass with ample daytime heating has steepened low-level lapse rates and begun to breach convective temperatures across northeast Illinois and eastern Wisconsin. An agitated Cu field is present across this area and a few storms are now evident per KMKX/KGRB. Large-scale forcing for ascent is rather weak at the moment with the best 700-500 mb vertical motion present farther north over Lake Superior per mesoanalysis. As such, storms may struggle to intensify, but MLCAPE of 500-1000 J/Kg and effective bulk shear of 40-50 knots may support a few strong to severe storms this evening. Storms may struggle to maintain their intensity as they cross Lake Michigan, but some recent CAMs guidance suggest storms reintensify over western Lower Michigan. Continued low-level moisture advection and daytime heating over western Lower Michigan as well as some forcing for large-scale ascent moving eastward with time support these CAMS solutions. However, given the marginal severe threat and uncertainty regarding severe storm coverage, a watch issuance is unlikely. ..Nauslar/Guyer.. 08/16/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...APX...IWX...GRR...GRB...LOT...MKX... LAT...LON 42538866 43578843 44598836 45068776 45138682 44768607 43968572 42768568 41988576 41698617 41418706 41308752 41388829 41428882 42538866 Read more

No Mesoscale Discussions are in effect as of Fri Aug 16 20:52:08 UTC 2019.

WW 0588 Status Updates
STATUS FOR WATCH 0588 HAS NOT BEEN ISSUED YET Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2019 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS ACROSS KS AND INTO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe storms are expected from the central High Plains to the Lower Missouri Valley with very large hail and damaging winds as the primary threats. The central High Plains threat will increase by late afternoon and spread across Kansas through the night, with the Missouri portion beginning this evening and continuing through the night. ...20Z Update... ...Eastern CO/KS/MO... Persistent showers and thunderstorms across southeast KS/southwest MO have kept the steeper mid-level lapse rates west of the KS/MO border. The upper 60s/low 70s dewpoints have also concentrated across central KS, as opposed to eastern KS/western MO as suggested by most 12Z guidance. While some additional moisture recovery is possible across eastern KS/western MO and thunderstorms are still anticipated tonight, overall severe coverage is now expected to be lower and the 30% hail probability appears overdone. As a result, the 30% area was removed. Potential for significant hail still exists, so this delineation was trimmed but maintained. As discussed in MCD 1760, storms are still anticipated across eastern CO, with an initially supercellular storm mode. Thereafter, potential exists for upscale growth but confidence in overall convective evolution is low. A strengthening low-level jet and steep lapse rates will exist downstream across western/central KS but strong convective inhibition will be in place and a very deep cold pool would be needed to overcome this inhibition and maintain storm strength with eastern extent. ..Mosier.. 08/16/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 16 2019/ ...Central High Plains to the Lower MO Valley... While outflow from morning convection has spread across the Ozarks and northern OK, this should dissipate as convection further decays with a period of weakened low-level warm advection this afternoon. Primary surface front should become established by early evening from east-central CO arcing across southern KS through central MO as pronounced differential heating occurs across it. Warm 700-mb temperatures of 12-16 C within an intensifying and expanding stout elevated mixed layer, characterized by extremely steep 700-500 mb lapse rates of 9-9.5 C/km, will overspread much of the baroclinic zone and effectively cap surface-based storm development through early evening east of the high terrain. Initial storms should form near the Front Range within a weak low-level upslope flow regime north of the front, likely focused across northeast CO where more robust insolation is underway south of morning stratus. The western extent of upper 50s to low 60s surface dew points will coincide with the western periphery of MLCAPE exceeding 2000 J/kg. On the southern periphery of a strong mid-level jet centered on southeast WY to IA, a few supercells should develop with primary risks of very large hail and severe wind gusts. How this convection evolves through the evening and eastward into the northwest/north-central KS vicinity is uncertain given pronounced MLCIN. It is plausible that a sufficient cold pool might develop with colliding outflows and a subsequent MCS could expand/intensify eastward given broad strengthening of a southerly low-level jet across the frontal zone. With the presence of extreme mid-level lapse rates and strong to extreme buoyancy remaining centered across eastern KS, potential exists for a swath of significant severe wind and large hail continuing into early morning. Farther east across the Lower MO Valley, a separate zone of low-level warm-advection driven convection should develop near dusk and likely be regenerative through the night along the periphery of stronger MLCIN. Initial updrafts should have the greatest potential to produce significant severe hail. Convective mode should quickly evolve into potentially multiple clusters that would have a mixed risk of severe wind/hail given the ample buoyancy. The potential upstream MCS across northern KS might eventually merge with these clusters prior to dawn. ...Northeast to Great Lakes... A low-amplitude upper trough crossing the Lower Great Lakes to the Saint Lawrence Valley will foster scattered thunderstorm development along and ahead of its attendant surface trough. Modest mid-level lapse rates and weak lower-level flow will be limiting factors to a greater severe threat. Mid to upper-level speed shear will support small hail while a mixed boundary-layer yields potential for locally damaging winds. Overall threat should be more subdued compared to yesterday. A separate corridor of marginal severe potential is also apparent across eastern WI to western Lower MI along a cold front associated with a low-amplitude shortwave trough shifting east from northwest WI. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2019 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS ACROSS KS AND INTO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe storms are expected from the central High Plains to the Lower Missouri Valley with very large hail and damaging winds as the primary threats. The central High Plains threat will increase by late afternoon and spread across Kansas through the night, with the Missouri portion beginning this evening and continuing through the night. ...20Z Update... ...Eastern CO/KS/MO... Persistent showers and thunderstorms across southeast KS/southwest MO have kept the steeper mid-level lapse rates west of the KS/MO border. The upper 60s/low 70s dewpoints have also concentrated across central KS, as opposed to eastern KS/western MO as suggested by most 12Z guidance. While some additional moisture recovery is possible across eastern KS/western MO and thunderstorms are still anticipated tonight, overall severe coverage is now expected to be lower and the 30% hail probability appears overdone. As a result, the 30% area was removed. Potential for significant hail still exists, so this delineation was trimmed but maintained. As discussed in MCD 1760, storms are still anticipated across eastern CO, with an initially supercellular storm mode. Thereafter, potential exists for upscale growth but confidence in overall convective evolution is low. A strengthening low-level jet and steep lapse rates will exist downstream across western/central KS but strong convective inhibition will be in place and a very deep cold pool would be needed to overcome this inhibition and maintain storm strength with eastern extent. ..Mosier.. 08/16/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 16 2019/ ...Central High Plains to the Lower MO Valley... While outflow from morning convection has spread across the Ozarks and northern OK, this should dissipate as convection further decays with a period of weakened low-level warm advection this afternoon. Primary surface front should become established by early evening from east-central CO arcing across southern KS through central MO as pronounced differential heating occurs across it. Warm 700-mb temperatures of 12-16 C within an intensifying and expanding stout elevated mixed layer, characterized by extremely steep 700-500 mb lapse rates of 9-9.5 C/km, will overspread much of the baroclinic zone and effectively cap surface-based storm development through early evening east of the high terrain. Initial storms should form near the Front Range within a weak low-level upslope flow regime north of the front, likely focused across northeast CO where more robust insolation is underway south of morning stratus. The western extent of upper 50s to low 60s surface dew points will coincide with the western periphery of MLCAPE exceeding 2000 J/kg. On the southern periphery of a strong mid-level jet centered on southeast WY to IA, a few supercells should develop with primary risks of very large hail and severe wind gusts. How this convection evolves through the evening and eastward into the northwest/north-central KS vicinity is uncertain given pronounced MLCIN. It is plausible that a sufficient cold pool might develop with colliding outflows and a subsequent MCS could expand/intensify eastward given broad strengthening of a southerly low-level jet across the frontal zone. With the presence of extreme mid-level lapse rates and strong to extreme buoyancy remaining centered across eastern KS, potential exists for a swath of significant severe wind and large hail continuing into early morning. Farther east across the Lower MO Valley, a separate zone of low-level warm-advection driven convection should develop near dusk and likely be regenerative through the night along the periphery of stronger MLCIN. Initial updrafts should have the greatest potential to produce significant severe hail. Convective mode should quickly evolve into potentially multiple clusters that would have a mixed risk of severe wind/hail given the ample buoyancy. The potential upstream MCS across northern KS might eventually merge with these clusters prior to dawn. ...Northeast to Great Lakes... A low-amplitude upper trough crossing the Lower Great Lakes to the Saint Lawrence Valley will foster scattered thunderstorm development along and ahead of its attendant surface trough. Modest mid-level lapse rates and weak lower-level flow will be limiting factors to a greater severe threat. Mid to upper-level speed shear will support small hail while a mixed boundary-layer yields potential for locally damaging winds. Overall threat should be more subdued compared to yesterday. A separate corridor of marginal severe potential is also apparent across eastern WI to western Lower MI along a cold front associated with a low-amplitude shortwave trough shifting east from northwest WI. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2019 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS ACROSS KS AND INTO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe storms are expected from the central High Plains to the Lower Missouri Valley with very large hail and damaging winds as the primary threats. The central High Plains threat will increase by late afternoon and spread across Kansas through the night, with the Missouri portion beginning this evening and continuing through the night. ...20Z Update... ...Eastern CO/KS/MO... Persistent showers and thunderstorms across southeast KS/southwest MO have kept the steeper mid-level lapse rates west of the KS/MO border. The upper 60s/low 70s dewpoints have also concentrated across central KS, as opposed to eastern KS/western MO as suggested by most 12Z guidance. While some additional moisture recovery is possible across eastern KS/western MO and thunderstorms are still anticipated tonight, overall severe coverage is now expected to be lower and the 30% hail probability appears overdone. As a result, the 30% area was removed. Potential for significant hail still exists, so this delineation was trimmed but maintained. As discussed in MCD 1760, storms are still anticipated across eastern CO, with an initially supercellular storm mode. Thereafter, potential exists for upscale growth but confidence in overall convective evolution is low. A strengthening low-level jet and steep lapse rates will exist downstream across western/central KS but strong convective inhibition will be in place and a very deep cold pool would be needed to overcome this inhibition and maintain storm strength with eastern extent. ..Mosier.. 08/16/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 16 2019/ ...Central High Plains to the Lower MO Valley... While outflow from morning convection has spread across the Ozarks and northern OK, this should dissipate as convection further decays with a period of weakened low-level warm advection this afternoon. Primary surface front should become established by early evening from east-central CO arcing across southern KS through central MO as pronounced differential heating occurs across it. Warm 700-mb temperatures of 12-16 C within an intensifying and expanding stout elevated mixed layer, characterized by extremely steep 700-500 mb lapse rates of 9-9.5 C/km, will overspread much of the baroclinic zone and effectively cap surface-based storm development through early evening east of the high terrain. Initial storms should form near the Front Range within a weak low-level upslope flow regime north of the front, likely focused across northeast CO where more robust insolation is underway south of morning stratus. The western extent of upper 50s to low 60s surface dew points will coincide with the western periphery of MLCAPE exceeding 2000 J/kg. On the southern periphery of a strong mid-level jet centered on southeast WY to IA, a few supercells should develop with primary risks of very large hail and severe wind gusts. How this convection evolves through the evening and eastward into the northwest/north-central KS vicinity is uncertain given pronounced MLCIN. It is plausible that a sufficient cold pool might develop with colliding outflows and a subsequent MCS could expand/intensify eastward given broad strengthening of a southerly low-level jet across the frontal zone. With the presence of extreme mid-level lapse rates and strong to extreme buoyancy remaining centered across eastern KS, potential exists for a swath of significant severe wind and large hail continuing into early morning. Farther east across the Lower MO Valley, a separate zone of low-level warm-advection driven convection should develop near dusk and likely be regenerative through the night along the periphery of stronger MLCIN. Initial updrafts should have the greatest potential to produce significant severe hail. Convective mode should quickly evolve into potentially multiple clusters that would have a mixed risk of severe wind/hail given the ample buoyancy. The potential upstream MCS across northern KS might eventually merge with these clusters prior to dawn. ...Northeast to Great Lakes... A low-amplitude upper trough crossing the Lower Great Lakes to the Saint Lawrence Valley will foster scattered thunderstorm development along and ahead of its attendant surface trough. Modest mid-level lapse rates and weak lower-level flow will be limiting factors to a greater severe threat. Mid to upper-level speed shear will support small hail while a mixed boundary-layer yields potential for locally damaging winds. Overall threat should be more subdued compared to yesterday. A separate corridor of marginal severe potential is also apparent across eastern WI to western Lower MI along a cold front associated with a low-amplitude shortwave trough shifting east from northwest WI. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 16 2019 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS ACROSS KS AND INTO THE LOWER MS VALLEY... ...SUMMARY... Scattered severe storms are expected from the central High Plains to the Lower Missouri Valley with very large hail and damaging winds as the primary threats. The central High Plains threat will increase by late afternoon and spread across Kansas through the night, with the Missouri portion beginning this evening and continuing through the night. ...20Z Update... ...Eastern CO/KS/MO... Persistent showers and thunderstorms across southeast KS/southwest MO have kept the steeper mid-level lapse rates west of the KS/MO border. The upper 60s/low 70s dewpoints have also concentrated across central KS, as opposed to eastern KS/western MO as suggested by most 12Z guidance. While some additional moisture recovery is possible across eastern KS/western MO and thunderstorms are still anticipated tonight, overall severe coverage is now expected to be lower and the 30% hail probability appears overdone. As a result, the 30% area was removed. Potential for significant hail still exists, so this delineation was trimmed but maintained. As discussed in MCD 1760, storms are still anticipated across eastern CO, with an initially supercellular storm mode. Thereafter, potential exists for upscale growth but confidence in overall convective evolution is low. A strengthening low-level jet and steep lapse rates will exist downstream across western/central KS but strong convective inhibition will be in place and a very deep cold pool would be needed to overcome this inhibition and maintain storm strength with eastern extent. ..Mosier.. 08/16/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Aug 16 2019/ ...Central High Plains to the Lower MO Valley... While outflow from morning convection has spread across the Ozarks and northern OK, this should dissipate as convection further decays with a period of weakened low-level warm advection this afternoon. Primary surface front should become established by early evening from east-central CO arcing across southern KS through central MO as pronounced differential heating occurs across it. Warm 700-mb temperatures of 12-16 C within an intensifying and expanding stout elevated mixed layer, characterized by extremely steep 700-500 mb lapse rates of 9-9.5 C/km, will overspread much of the baroclinic zone and effectively cap surface-based storm development through early evening east of the high terrain. Initial storms should form near the Front Range within a weak low-level upslope flow regime north of the front, likely focused across northeast CO where more robust insolation is underway south of morning stratus. The western extent of upper 50s to low 60s surface dew points will coincide with the western periphery of MLCAPE exceeding 2000 J/kg. On the southern periphery of a strong mid-level jet centered on southeast WY to IA, a few supercells should develop with primary risks of very large hail and severe wind gusts. How this convection evolves through the evening and eastward into the northwest/north-central KS vicinity is uncertain given pronounced MLCIN. It is plausible that a sufficient cold pool might develop with colliding outflows and a subsequent MCS could expand/intensify eastward given broad strengthening of a southerly low-level jet across the frontal zone. With the presence of extreme mid-level lapse rates and strong to extreme buoyancy remaining centered across eastern KS, potential exists for a swath of significant severe wind and large hail continuing into early morning. Farther east across the Lower MO Valley, a separate zone of low-level warm-advection driven convection should develop near dusk and likely be regenerative through the night along the periphery of stronger MLCIN. Initial updrafts should have the greatest potential to produce significant severe hail. Convective mode should quickly evolve into potentially multiple clusters that would have a mixed risk of severe wind/hail given the ample buoyancy. The potential upstream MCS across northern KS might eventually merge with these clusters prior to dawn. ...Northeast to Great Lakes... A low-amplitude upper trough crossing the Lower Great Lakes to the Saint Lawrence Valley will foster scattered thunderstorm development along and ahead of its attendant surface trough. Modest mid-level lapse rates and weak lower-level flow will be limiting factors to a greater severe threat. Mid to upper-level speed shear will support small hail while a mixed boundary-layer yields potential for locally damaging winds. Overall threat should be more subdued compared to yesterday. A separate corridor of marginal severe potential is also apparent across eastern WI to western Lower MI along a cold front associated with a low-amplitude shortwave trough shifting east from northwest WI. Read more

No watches are valid as of Fri Aug 16 19:30:06 UTC 2019.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0134 PM CDT Fri Aug 16 2019 Valid 171200Z - 181200Z An isolated dry-thunderstorm area has been added for northeast UT and northwest CO, where it appears that moisture and low/midlevel lapse rates will be sufficient to support isolated mostly dry storms Saturday afternoon, within a similar regime to D1/Friday. Otherwise, elevated to locally critical conditions are still expected across portions of the Snake River Plain and also across portions of eastern UT, western CO, and southern WY. The elevated area has been expanded somewhat to include more higher-terrain valleys, but the forecast reasoning remains the same. See the previous discussion below for more details. ..Dean.. 08/16/2019 .PREV DISCUSSION... /ISSUED 0149 AM CDT Fri Aug 16 2019/ ...Synopsis... An upper-level shortwave trough will move over the northern Rockies and northern Plains tomorrow with zonal upper-level flow prevailing across much of the CONUS. The dry slot of this shortwave trough will move over portions of the Intermountain West with stronger 700-500 mb flow stretching from southern Idaho into northern Utah, southern Wyoming, and northern Colorado. With daytime heating, this stronger flow should mix to the surface and overlap a dry airmass resulting in elevated conditions (westerly sustained surface winds of 15-20 mph, RH values of 10-20%) across this area. Locally critical conditions are possible with portions of the Snake River Plain and Great Divide Basin/vicinity favored. However, there is enough uncertainty at this time to preclude introducing a critical area. ...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 0134 PM CDT Fri Aug 16 2019 Valid 171200Z - 181200Z An isolated dry-thunderstorm area has been added for northeast UT and northwest CO, where it appears that moisture and low/midlevel lapse rates will be sufficient to support isolated mostly dry storms Saturday afternoon, within a similar regime to D1/Friday. Otherwise, elevated to locally critical conditions are still expected across portions of the Snake River Plain and also across portions of eastern UT, western CO, and southern WY. The elevated area has been expanded somewhat to include more higher-terrain valleys, but the forecast reasoning remains the same. See the previous discussion below for more details. ..Dean.. 08/16/2019 .PREV DISCUSSION... /ISSUED 0149 AM CDT Fri Aug 16 2019/ ...Synopsis... An upper-level shortwave trough will move over the northern Rockies and northern Plains tomorrow with zonal upper-level flow prevailing across much of the CONUS. The dry slot of this shortwave trough will move over portions of the Intermountain West with stronger 700-500 mb flow stretching from southern Idaho into northern Utah, southern Wyoming, and northern Colorado. With daytime heating, this stronger flow should mix to the surface and overlap a dry airmass resulting in elevated conditions (westerly sustained surface winds of 15-20 mph, RH values of 10-20%) across this area. Locally critical conditions are possible with portions of the Snake River Plain and Great Divide Basin/vicinity favored. However, there is enough uncertainty at this time to preclude introducing a critical area. ...Please see www.spc.noaa.gov/fire for graphic product... Read more