SPC Day 2 Fire Weather Outlook

5 years 10 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Mon Aug 26 2019 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... The forecast remains on track, and please see the discussion for more details. ..Nauslar.. 08/26/2019 .PREV DISCUSSION... /ISSUED 0149 AM CDT Mon Aug 26 2019/ ...Synopsis... The upper-level ridge axis will situate itself across the Pacific Northwest coast on D2/Tuesday. A surface anticyclone will continue on a southward track into central Rockies/High Plains along with the continued presence of a thermally induced pressure trough across the Oregon coast and northern California. The surface pressure pattern will continue to favor offshore flow across Oregon coast, with more of an easterly component than Monday. ...Western Oregon... Hot/dry conditions will be prevalent on Tuesday as strong heating occurs underneath the upper-level ridge. Easterly downslope flow off the Cascades will help reduce afternoon RH values to potentially below 20% in some locations, but more broadly 25-35%. Wind speed still appears to be the limiting factor to a greater threat for fire spread. However, a probable location for locally elevated concerns will be northern portions of the Willamette Valley where terrain-enhanced flow out of the Columbia Gorge will bring potential for 15-20 mph winds. Elsewhere within western Oregon, 10-15 mph are more likely. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

5 years 10 months ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Mon Aug 26 2019 Valid 271200Z - 281200Z ...NO CRITICAL AREAS... The forecast remains on track, and please see the discussion for more details. ..Nauslar.. 08/26/2019 .PREV DISCUSSION... /ISSUED 0149 AM CDT Mon Aug 26 2019/ ...Synopsis... The upper-level ridge axis will situate itself across the Pacific Northwest coast on D2/Tuesday. A surface anticyclone will continue on a southward track into central Rockies/High Plains along with the continued presence of a thermally induced pressure trough across the Oregon coast and northern California. The surface pressure pattern will continue to favor offshore flow across Oregon coast, with more of an easterly component than Monday. ...Western Oregon... Hot/dry conditions will be prevalent on Tuesday as strong heating occurs underneath the upper-level ridge. Easterly downslope flow off the Cascades will help reduce afternoon RH values to potentially below 20% in some locations, but more broadly 25-35%. Wind speed still appears to be the limiting factor to a greater threat for fire spread. However, a probable location for locally elevated concerns will be northern portions of the Willamette Valley where terrain-enhanced flow out of the Columbia Gorge will bring potential for 15-20 mph winds. Elsewhere within western Oregon, 10-15 mph are more likely. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Severe Thunderstorm Watch 622 Status Reports

5 years 10 months ago
WW 0622 Status Updates
STATUS REPORT ON WW 622 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N JLN TO 30 NNW SGF TO 30 W TBN TO 10 NW TBN TO 10 WSW VIH TO 10 NNW VIH. ..DIAL..08/26/19 ATTN...WFO...SGF...EAX... STATUS REPORT FOR WS 622 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MOC009-011-043-057-059-065-067-077-091-105-109-125-149-153-161- 167-169-203-209-213-215-225-229-262040- MO . MISSOURI COUNTIES INCLUDED ARE BARRY BARTON CHRISTIAN DADE DALLAS DENT DOUGLAS GREENE HOWELL LACLEDE LAWRENCE MARIES OREGON OZARK PHELPS POLK PULASKI SHANNON STONE TANEY TEXAS WEBSTER WRIGHT 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

SPC Severe Thunderstorm Watch 622 Status Reports

5 years 10 months ago
WW 0622 Status Updates
STATUS REPORT ON WW 622 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N JLN TO 30 NNW SGF TO 30 W TBN TO 10 NW TBN TO 10 WSW VIH TO 10 NNW VIH. ..DIAL..08/26/19 ATTN...WFO...SGF...EAX... STATUS REPORT FOR WS 622 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MOC009-011-043-057-059-065-067-077-091-105-109-125-149-153-161- 167-169-203-209-213-215-225-229-262040- MO . MISSOURI COUNTIES INCLUDED ARE BARRY BARTON CHRISTIAN DADE DALLAS DENT DOUGLAS GREENE HOWELL LACLEDE LAWRENCE MARIES OREGON OZARK PHELPS POLK PULASKI SHANNON STONE TANEY TEXAS WEBSTER WRIGHT 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

SPC Severe Thunderstorm Watch 622 Status Reports

5 years 10 months ago
WW 0622 Status Updates
STATUS REPORT ON WW 622 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N JLN TO 30 NNW SGF TO 30 W TBN TO 10 NW TBN TO 10 WSW VIH TO 10 NNW VIH. ..DIAL..08/26/19 ATTN...WFO...SGF...EAX... STATUS REPORT FOR WS 622 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MOC009-011-043-057-059-065-067-077-091-105-109-125-149-153-161- 167-169-203-209-213-215-225-229-262040- MO . MISSOURI COUNTIES INCLUDED ARE BARRY BARTON CHRISTIAN DADE DALLAS DENT DOUGLAS GREENE HOWELL LACLEDE LAWRENCE MARIES OREGON OZARK PHELPS POLK PULASKI SHANNON STONE TANEY TEXAS WEBSTER WRIGHT 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

SPC Severe Thunderstorm Watch 622 Status Reports

5 years 10 months ago
WW 0622 Status Updates
STATUS REPORT ON WW 622 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N JLN TO 30 NNW SGF TO 30 W TBN TO 10 NW TBN TO 10 WSW VIH TO 10 NNW VIH. ..DIAL..08/26/19 ATTN...WFO...SGF...EAX... STATUS REPORT FOR WS 622 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MOC009-011-043-057-059-065-067-077-091-105-109-125-149-153-161- 167-169-203-209-213-215-225-229-262040- MO . MISSOURI COUNTIES INCLUDED ARE BARRY BARTON CHRISTIAN DADE DALLAS DENT DOUGLAS GREENE HOWELL LACLEDE LAWRENCE MARIES OREGON OZARK PHELPS POLK PULASKI SHANNON STONE TANEY TEXAS WEBSTER WRIGHT 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

SPC Severe Thunderstorm Watch 622

5 years 10 months ago
WW 622 SEVERE TSTM MO 261710Z - 262200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 622 NWS Storm Prediction Center Norman OK 1210 PM CDT Mon Aug 26 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Parts of central and southern Missouri * Effective this Monday afternoon from 1210 PM until 500 PM CDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2 inches in diameter possible SUMMARY...A well-developed storm cluster with bowing characteristics will likely persist into the afternoon while moving east-southeastward into an environment more supportive of surface-based storms. The storms have produced measured gusts up to 76 mph in the past hour or so, and the threat for damaging winds and isolated large hail should continue for several more hours. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 50 miles north of Joplin MO to 45 miles east southeast of Fort Leonard Wood MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30040. ...Thompson Read more

SPC MD 1867

5 years 10 months ago
MD 1867 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EAST CENTRAL THROUGH SOUTHEAST MO
Mesoscale Discussion 1867 NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 26 2019 Areas affected...east central through southeast MO Concerning...Severe potential...Watch possible Valid 261924Z - 262030Z Probability of Watch Issuance...40 percent SUMMARY...Storms may continue through east central and southeast MO posing a risk for damaging wind. Some uncertainty still exists regarding eastern extent of the threat, but trends are being monitored for a possible ww. DISCUSSION...Radar trends have indicated a recent increase in storm organization along the eastern flank of the MCS. An MCV is located along the northern end of the line, forcing a more eastward component to the movement. Moreover, the downstream atmosphere continues to destabilize with 2000 J/Kg MLCAPE and relatively weak convective inhibition. Storms are embedded with 30-40 kt effective shear. Given the downstream environment and sufficient mesoscale and storm scale forcing for ascent, there is a good chance storms may continue developing eastward next few hours, posing a risk for damaging wind. ..Dial/Thompson.. 08/26/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...SGF... LAT...LON 38609150 38709032 38058994 37669025 37579110 37999141 38609150 Read more

SPC Severe Thunderstorm Watch 622 Status Reports

5 years 10 months ago
WW 0622 Status Updates
STATUS REPORT ON WW 622 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 N JLN TO 45 SSW SZL TO 30 SSE SZL TO 35 SE SZL. ..DIAL..08/26/19 ATTN...WFO...SGF...EAX... STATUS REPORT FOR WS 622 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MOC011-015-029-039-057-059-065-077-085-105-125-131-141-161-167- 169-185-203-215-217-225-229-261940- MO . MISSOURI COUNTIES INCLUDED ARE BARTON BENTON CAMDEN CEDAR DADE DALLAS DENT GREENE HICKORY LACLEDE MARIES MILLER MORGAN PHELPS POLK PULASKI ST. CLAIR SHANNON TEXAS VERNON WEBSTER WRIGHT 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

SPC Aug 26, 2019 1730 UTC Day 2 Convective Outlook

5 years 10 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Mon Aug 26 2019 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH TEXAS AND LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across north Texas into western Louisiana Tuesday. ...TX/LA... Large-scale height falls will spread across the upper MS Valley into the Great Lakes region Tuesday ahead of a notable, progressive upper trough. Southern-most direct influence of this feature will extend into the mid MS Valley; however, surface pressures will build across the Plains in the wake of the short wave. This will drive a front to near the Red River by daybreak as mid/high-level flow becomes more northwesterly. Convection will likely be ongoing at the start of the period along the trailing front across AR/OK and this should aid southward push into north TX by early afternoon. Latest model guidance suggests strongest boundary-layer heating will be noted ahead of the wind shift from the Edwards Plateau into east-central TX where convective temperatures should be breached, perhaps as early as 20z. While early-day convection will not likely dissipate before this occurs, strongest updrafts should develop where surface temperatures warm into the mid 90s. Forecast soundings from ABI and SEP exhibit substantial SBCAPE at 20z with PW on the order of 2". While deep-layer flow will be weak, isolated damaging wind gusts are certainly possible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: <5% - None ..Darrow.. 08/26/2019 Read more

SPC Aug 26, 2019 1730 UTC Day 2 Convective Outlook

5 years 10 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Mon Aug 26 2019 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH TEXAS AND LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across north Texas into western Louisiana Tuesday. ...TX/LA... Large-scale height falls will spread across the upper MS Valley into the Great Lakes region Tuesday ahead of a notable, progressive upper trough. Southern-most direct influence of this feature will extend into the mid MS Valley; however, surface pressures will build across the Plains in the wake of the short wave. This will drive a front to near the Red River by daybreak as mid/high-level flow becomes more northwesterly. Convection will likely be ongoing at the start of the period along the trailing front across AR/OK and this should aid southward push into north TX by early afternoon. Latest model guidance suggests strongest boundary-layer heating will be noted ahead of the wind shift from the Edwards Plateau into east-central TX where convective temperatures should be breached, perhaps as early as 20z. While early-day convection will not likely dissipate before this occurs, strongest updrafts should develop where surface temperatures warm into the mid 90s. Forecast soundings from ABI and SEP exhibit substantial SBCAPE at 20z with PW on the order of 2". While deep-layer flow will be weak, isolated damaging wind gusts are certainly possible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: <5% - None ..Darrow.. 08/26/2019 Read more

SPC Aug 26, 2019 1730 UTC Day 2 Convective Outlook

5 years 10 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Mon Aug 26 2019 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH TEXAS AND LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across north Texas into western Louisiana Tuesday. ...TX/LA... Large-scale height falls will spread across the upper MS Valley into the Great Lakes region Tuesday ahead of a notable, progressive upper trough. Southern-most direct influence of this feature will extend into the mid MS Valley; however, surface pressures will build across the Plains in the wake of the short wave. This will drive a front to near the Red River by daybreak as mid/high-level flow becomes more northwesterly. Convection will likely be ongoing at the start of the period along the trailing front across AR/OK and this should aid southward push into north TX by early afternoon. Latest model guidance suggests strongest boundary-layer heating will be noted ahead of the wind shift from the Edwards Plateau into east-central TX where convective temperatures should be breached, perhaps as early as 20z. While early-day convection will not likely dissipate before this occurs, strongest updrafts should develop where surface temperatures warm into the mid 90s. Forecast soundings from ABI and SEP exhibit substantial SBCAPE at 20z with PW on the order of 2". While deep-layer flow will be weak, isolated damaging wind gusts are certainly possible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: <5% - None ..Darrow.. 08/26/2019 Read more

SPC Aug 26, 2019 1730 UTC Day 2 Convective Outlook

5 years 10 months ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Mon Aug 26 2019 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH TEXAS AND LOUISIANA... ...SUMMARY... Isolated severe thunderstorms are possible across north Texas into western Louisiana Tuesday. ...TX/LA... Large-scale height falls will spread across the upper MS Valley into the Great Lakes region Tuesday ahead of a notable, progressive upper trough. Southern-most direct influence of this feature will extend into the mid MS Valley; however, surface pressures will build across the Plains in the wake of the short wave. This will drive a front to near the Red River by daybreak as mid/high-level flow becomes more northwesterly. Convection will likely be ongoing at the start of the period along the trailing front across AR/OK and this should aid southward push into north TX by early afternoon. Latest model guidance suggests strongest boundary-layer heating will be noted ahead of the wind shift from the Edwards Plateau into east-central TX where convective temperatures should be breached, perhaps as early as 20z. While early-day convection will not likely dissipate before this occurs, strongest updrafts should develop where surface temperatures warm into the mid 90s. Forecast soundings from ABI and SEP exhibit substantial SBCAPE at 20z with PW on the order of 2". While deep-layer flow will be weak, isolated damaging wind gusts are certainly possible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: <5% - None ..Darrow.. 08/26/2019 Read more

SPC MD 1866

5 years 10 months ago
MD 1866 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEAST KANSAS INTO SOUTHWEST MISSOURI
Mesoscale Discussion 1866 NWS Storm Prediction Center Norman OK 1142 AM CDT Mon Aug 26 2019 Areas affected...southeast Kansas into southwest Missouri Concerning...Severe potential...Watch possible Valid 261642Z - 261745Z Probability of Watch Issuance...60 percent SUMMARY...Storms may continue to pose a risk for damaging wind and large hail as they develop into southwest MO. A ww might be required soon. DISCUSSION...MCS has evolved into a line segment just south of the Kansas City area and continues southeast at around 40 kt. Storms may still be slightly elevated, but the downstream atmosphere is destabilizing with temperatures rising through the 80s along with low 70s F dewpoints supporting moderate instability. The concern is that these storms may eventually become surface based as the boundary layer continues to warm and convective inhibition weakens, with convergence along the gust front supporting a forward propagating MCS. ..Dial/Thompson.. 08/26/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX... LAT...LON 38019493 38299447 38549414 38379349 38139246 37259258 37189453 38019493 Read more

SPC Aug 26, 2019 1630 UTC Day 1 Convective Outlook

5 years 10 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 26 2019 Valid 261630Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF MO...KS...AND OK... ...SUMMARY... The greatest severe-weather threats today will involve thunderstorm winds and hail, in a corridor from western/central Missouri to northeastern Oklahoma. ...MO/KS/OK through tonight... A midlevel trough over the Dakotas is in the process of evolving into a closed low near the international border. A series of embedded speed maxima will rotate through the southern periphery of the trough from NE/KS to the middle MS Valley. At the surface, a cold front will continue to move southeastward across KS toward OK. A weak low is expected to form near the intersection of this cold front and a separate baroclinic zone near the KS/MO border by late afternoon. This baroclinic zone will be reinforced and likely shifted south by outflow and differential heating associated with the ongoing storms near Kansas City, and the evolution of these ongoing storms pose the greatest uncertainty in the forecast for this afternoon/evening across MO. Large buoyancy (MLCAPE of 3000-4500 J/kg) is expected in the warm sector this afternoon as surface heating occurs within a moist boundary layer (mid 70s dewpoints) beneath steep midlevel lapse rates. The cap is weaker with eastward extent across MO, and the ongoing storms could become rooted at the surface by early afternoon, which would suggest the potential for large hail and damaging winds this afternoon into central MO. In the wake of the ongoing convection, renewed storm development is expected 21-23z near the triple point and along the cold front near the KS/MO border, though the northward extent of the threat is uncertain given the influence of the ongoing storms. Deep-layer vertical shear will be sufficient for supercells, while low-level hodograph curvature/SRH will be maximized near the outflow-reinforced baroclinic zone this afternoon/evening in MO. Cross-frontal shear vectors with storm motions to the east-southeast 25-30 kt should allow semi-discrete storms for a couple of hours late this afternoon/evening, with an attendant threat for a couple of tornadoes and isolated very large hail. Otherwise, cell mergers should lead to upscale growth into clusters/line segments. Damaging winds will become a primary threat with the clusters/line segments in an environment favoring strong downdrafts, and the threat for wind damage will persist into the early overnight hours. Weaker forcing for ascent and a warmer elevated mixed layer will tend to delay storm initiation until this evening farther southwest along the cold front into northern OK. Wind profiles will be sufficient for marginal supercells and/or organized clusters capable of producing isolated large hail. Damaging winds should be the primary threat given steep low-level lapse rates, large DCAPE, and precipitation loading with updrafts in a large CAPE environment. ...IL/IN this afternoon... A lead shortwave trough will eject northeastward from IL toward northern IN and Lower MI and weaken this afternoon, along with an accompanying surface cyclone in northern IL. Boundary-layer dewpoints near 70 F are present in the warm sector of the cyclone, though widespread clouds will tend to slow surface heating. There is some potential for renewed storm development this afternoon in a broken band across eastern IL into northwestern IN, where low-level shear will be marginally favorable for supercells and perhaps a brief tornado. ..Thompson/Cook.. 08/26/2019 Read more

SPC Aug 26, 2019 1630 UTC Day 1 Convective Outlook

5 years 10 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Aug 26 2019 Valid 261630Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF MO...KS...AND OK... ...SUMMARY... The greatest severe-weather threats today will involve thunderstorm winds and hail, in a corridor from western/central Missouri to northeastern Oklahoma. ...MO/KS/OK through tonight... A midlevel trough over the Dakotas is in the process of evolving into a closed low near the international border. A series of embedded speed maxima will rotate through the southern periphery of the trough from NE/KS to the middle MS Valley. At the surface, a cold front will continue to move southeastward across KS toward OK. A weak low is expected to form near the intersection of this cold front and a separate baroclinic zone near the KS/MO border by late afternoon. This baroclinic zone will be reinforced and likely shifted south by outflow and differential heating associated with the ongoing storms near Kansas City, and the evolution of these ongoing storms pose the greatest uncertainty in the forecast for this afternoon/evening across MO. Large buoyancy (MLCAPE of 3000-4500 J/kg) is expected in the warm sector this afternoon as surface heating occurs within a moist boundary layer (mid 70s dewpoints) beneath steep midlevel lapse rates. The cap is weaker with eastward extent across MO, and the ongoing storms could become rooted at the surface by early afternoon, which would suggest the potential for large hail and damaging winds this afternoon into central MO. In the wake of the ongoing convection, renewed storm development is expected 21-23z near the triple point and along the cold front near the KS/MO border, though the northward extent of the threat is uncertain given the influence of the ongoing storms. Deep-layer vertical shear will be sufficient for supercells, while low-level hodograph curvature/SRH will be maximized near the outflow-reinforced baroclinic zone this afternoon/evening in MO. Cross-frontal shear vectors with storm motions to the east-southeast 25-30 kt should allow semi-discrete storms for a couple of hours late this afternoon/evening, with an attendant threat for a couple of tornadoes and isolated very large hail. Otherwise, cell mergers should lead to upscale growth into clusters/line segments. Damaging winds will become a primary threat with the clusters/line segments in an environment favoring strong downdrafts, and the threat for wind damage will persist into the early overnight hours. Weaker forcing for ascent and a warmer elevated mixed layer will tend to delay storm initiation until this evening farther southwest along the cold front into northern OK. Wind profiles will be sufficient for marginal supercells and/or organized clusters capable of producing isolated large hail. Damaging winds should be the primary threat given steep low-level lapse rates, large DCAPE, and precipitation loading with updrafts in a large CAPE environment. ...IL/IN this afternoon... A lead shortwave trough will eject northeastward from IL toward northern IN and Lower MI and weaken this afternoon, along with an accompanying surface cyclone in northern IL. Boundary-layer dewpoints near 70 F are present in the warm sector of the cyclone, though widespread clouds will tend to slow surface heating. There is some potential for renewed storm development this afternoon in a broken band across eastern IL into northwestern IN, where low-level shear will be marginally favorable for supercells and perhaps a brief tornado. ..Thompson/Cook.. 08/26/2019 Read more