Severe Storms

WW 0626 Status Updates
STATUS REPORT ON WW 626 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N GLD TO 10 W MCK TO 35 SE LBF. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1891 ..SQUITIERI..08/30/19 ATTN...WFO...GLD...GID...LBF... STATUS REPORT FOR WS 626 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC039-063-065-071-109-137-141-147-153-163-179-181-183-193-199- 203-300140- KS . KANSAS COUNTIES INCLUDED ARE DECATUR GOVE GRAHAM GREELEY LOGAN NORTON OSBORNE PHILLIPS RAWLINS ROOKS SHERIDAN SHERMAN SMITH THOMAS WALLACE WICHITA NEC019-047-061-065-073-083-099-137-145-300140- NE . NEBRASKA COUNTIES INCLUDED ARE BUFFALO DAWSON FRANKLIN FURNAS GOSPER HARLAN KEARNEY PHELPS RED WILLOW Read more

MD 1891 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR FAR SOUTHERN NEBRASKA INTO MOST OF KANSAS
Mesoscale Discussion 1891 NWS Storm Prediction Center Norman OK 0715 PM CDT Thu Aug 29 2019 Areas affected...Far southern Nebraska into most of Kansas Concerning...Severe potential...Watch likely Valid 300015Z - 300215Z Probability of Watch Issuance...95 percent SUMMARY...Semi-discrete storms will continue to grow upscale into an MCS through the evening hours across a large portion of Kansas with mainly a large hail and damaging wind threat. The severe threat will likely continue overnight, both with ongoing storms, and with new convection that is expected to initiate along a near stationary front in southern Nebraska. A downstream issuance of a Severe Thunderstorm Watch will likely be issued to account for these scenarios. DISCUSSION...A mature supercell thunderstorm has recently begun to grow upscale into a small bowing complex across the northwest KS/southwest NE border, with weaker, shorter-lived cells progressing south-southeastward across western KS. The developing MCS is moving into a strongly unstable environment (3000-4000 J/kg MLCAPE), with 35+ knots of effective bulk shear in place, supportive of continued severe potential, including damaging wind gusts and large hail. The boundary layer will gradually decouple with the loss of daytime heating. Nonetheless, a nocturnal LLJ is expected to develop and intensify across the central Plains over the next few hours. Ample low-level convergence along the terminus of the LLJ (particularly in proximity to a near-stationary west-east orient baroclinic boundary located just north of the KS/NE border) is expected to foster additional convective development ahead of the ongoing, mature convection later this evening. Here, new storms will mature in a modestly sheared environment, with ample elevated buoyancy available to support a continued damaging wind and large hail threat. Given the likelihood of convective development/expansion of potential severe coverage later this evening, a Severe Thunderstorm Watch issuance downstream of WW 0626 will likely be needed soon. ..Squitieri/Goss.. 08/30/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX...OAX...TOP...ICT...GID...LBF...DDC... GLD... LAT...LON 39059498 37619503 37279556 37309695 37419807 37619893 37940030 38010154 38180179 38540188 39050193 39920161 40220143 40430078 40569923 40579756 40439625 40239558 39669529 39059498 Read more

WW 0627 Status Updates
STATUS REPORT ON WW 627 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NNE CDJ TO 30 SE CDJ TO 40 NW COU TO 25 NE COU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1890 ..DIAL..08/30/19 ATTN...WFO...EAX...LSX... STATUS REPORT FOR WS 627 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC043-300140- KS . KANSAS COUNTIES INCLUDED ARE DONIPHAN MOC003-005-019-021-025-027-033-041-049-051-053-061-063-075-079- 081-087-089-115-117-129-135-147-151-177-195-227-300140- MO . MISSOURI COUNTIES INCLUDED ARE ANDREW ATCHISON BOONE BUCHANAN CALDWELL CALLAWAY CARROLL CHARITON CLINTON COLE COOPER DAVIESS DEKALB GENTRY GRUNDY HARRISON HOLT HOWARD LINN LIVINGSTON MERCER MONITEAU NODAWAY OSAGE RAY SALINE WORTH Read more

MD 1889 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF SOUTHWEST OKLAHOMA INTO NORTHWEST TEXAS
Mesoscale Discussion 1889 NWS Storm Prediction Center Norman OK 0549 PM CDT Thu Aug 29 2019 Areas affected...Parts of southwest Oklahoma into northwest Texas Concerning...Severe potential...Watch unlikely Valid 292249Z - 300045Z Probability of Watch Issuance...5 percent SUMMARY...A couple of damaging wind gusts or instances of large hail may occur with the stronger storms over the next few hours. The brevity and localized nature of the severe threat precludes a WW issuance. DISCUSSION...A chaotic cluster of multicellular convection has become established across the southwest OK/northwest TX border area over the past couple of hours, with the aid of low-level lift supplied by both a confluence zone established across the area, and ample surface heating. These storms are continuing in an environment characterized by very strong buoyancy (up to 4000 J/kg MLCAPE), but relatively poor deep-layer shear (effective bulk shear values of 25-35 knots). Still, effective SRH values exceeding 100 m2/s2 combined with the aformentioned instability suggests that at least modest organization may occur with the stronger storms, perhaps allowing for the production of damaging wind gusts, given a relatively dry sfc-700 mb sub-cloud layer in place. In addition, a few large hail stones may also occur given the modest mid-level lapse rates in place. Given the likely diurnal dependencies of the ongoing convection and the limited areal coverage, the severe threat is expected to remain sparse and short-lived in nature. As such, a WW issuance is not expected. ..Squitieri/Goss.. 08/29/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...SJT...LUB... LAT...LON 35189784 34479746 34009776 33789834 33499905 33319997 33880049 34500010 35059944 35359806 35189784 Read more

MD 1890 CONCERNING SEVERE THUNDERSTORM WATCH 627... FOR NORTHERN THROUGH CENTRAL MISSOURI
Mesoscale Discussion 1890 NWS Storm Prediction Center Norman OK 0611 PM CDT Thu Aug 29 2019 Areas affected...northern through central Missouri Concerning...Severe Thunderstorm Watch 627... Valid 292311Z - 300045Z The severe weather threat for Severe Thunderstorm Watch 627 continues. SUMMARY...Storms are expected to continue developing from northwestern into east central Missouri, with gradual southward expansion with time. DISCUSSION...Storms continue developing from the intersection of a convective outflow boundary/cold front, southeastward along the outflow boundary into east central MO. The atmosphere remains strongly unstable with 4000 J/kg MLCAPE. This region remains south of stronger westerlies with weak winds through the lowest few km. Effective bulk shear from 25-35 kt will mostly support multicells, but some supercell structures will remain possible. Trend has been for storms to merge into line segments with eastern portion beginning to accelerate southward into central MO. Storms are expected to gradually develop southward along consolidated outflows with a continuing threat for isolated damaging wind and large hail next few hours. ..Dial.. 08/29/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...SGF...EAX... LAT...LON 40399427 40129344 39569234 38939160 38249181 39159386 39769519 40269538 40399427 Read more

WW 0626 Status Updates
STATUS REPORT ON WW 626 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S IML TO 25 NNW MCK TO 25 SE LBF. ..SQUITIERI..08/29/19 ATTN...WFO...GLD...GID...LBF... STATUS REPORT FOR WS 626 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC039-063-065-071-109-137-141-147-153-163-179-181-183-193-199- 203-300040- KS . KANSAS COUNTIES INCLUDED ARE DECATUR GOVE GRAHAM GREELEY LOGAN NORTON OSBORNE PHILLIPS RAWLINS ROOKS SHERIDAN SHERMAN SMITH THOMAS WALLACE WICHITA NEC019-047-061-063-065-073-083-085-087-099-137-145-300040- NE . NEBRASKA COUNTIES INCLUDED ARE BUFFALO DAWSON FRANKLIN FRONTIER FURNAS GOSPER HARLAN HAYES HITCHCOCK KEARNEY PHELPS RED WILLOW Read more

WW 0627 Status Updates
STATUS REPORT ON WW 627 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DIAL..08/29/19 ATTN...WFO...EAX...LSX... STATUS REPORT FOR WS 627 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC043-292340- KS . KANSAS COUNTIES INCLUDED ARE DONIPHAN MOC003-005-007-019-021-025-027-033-041-049-051-053-061-063-075- 079-081-087-089-115-117-129-135-147-151-175-177-195-211-227- 292340- MO . MISSOURI COUNTIES INCLUDED ARE ANDREW ATCHISON AUDRAIN BOONE BUCHANAN CALDWELL CALLAWAY CARROLL CHARITON CLINTON COLE COOPER DAVIESS DEKALB GENTRY GRUNDY HARRISON HOLT HOWARD LINN LIVINGSTON MERCER MONITEAU NODAWAY OSAGE RANDOLPH RAY SALINE SULLIVAN WORTH Read more

MD 1889 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF SOUTHWEST OKLAHOMA INTO NORTHWEST TEXAS
Mesoscale Discussion 1889 NWS Storm Prediction Center Norman OK 0549 PM CDT Thu Aug 29 2019 Areas affected...Parts of southwest Oklahoma into northwest Texas Concerning...Severe potential...Watch unlikely Valid 292249Z - 300045Z Probability of Watch Issuance...5 percent SUMMARY...A couple of damaging wind gusts or instances of large hail may occur with the stronger storms over the next few hours. The brevity and localized nature of the severe threat precludes a WW issuance. DISCUSSION...A chaotic cluster of multicellular convection has become established across the southwest OK/northwest TX border area over the past couple of hours, with the aid of low-level lift supplied by both a confluence zone established across the area, and ample surface heating. These storms are continuing in an environment characterized by very strong buoyancy (up to 4000 J/kg MLCAPE), but relatively poor deep-layer shear (effective bulk shear values of 25-35 knots). Still, effective SRH values exceeding 100 m2/s2 combined with the aformentioned instability suggests that at least modest organization may occur with the stronger storms, perhaps allowing for the production of damaging wind gusts, given a relatively dry sfc-700 mb sub-cloud layer in place. In addition, a few large hail stones may also occur given the modest mid-level lapse rates in place. Given the likely diurnal dependencies of the ongoing convection and the limited areal coverage, the severe threat is expected to remain sparse and short-lived in nature. As such, a WW issuance is not expected. ..Squitieri/Goss.. 08/29/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...SJT...LUB... LAT...LON 35189784 34479746 34009776 33789834 33499905 33319997 33880049 34500010 35059944 35359806 35189784 Read more

WW 0627 Status Updates
STATUS REPORT ON WW 627 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DIAL..08/29/19 ATTN...WFO...EAX...LSX... STATUS REPORT FOR WS 627 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC043-292340- KS . KANSAS COUNTIES INCLUDED ARE DONIPHAN MOC003-005-007-019-021-025-027-033-041-049-051-053-061-063-075- 079-081-087-089-115-117-129-135-147-151-175-177-195-211-227- 292340- MO . MISSOURI COUNTIES INCLUDED ARE ANDREW ATCHISON AUDRAIN BOONE BUCHANAN CALDWELL CALLAWAY CARROLL CHARITON CLINTON COLE COOPER DAVIESS DEKALB GENTRY GRUNDY HARRISON HOLT HOWARD LINN LIVINGSTON MERCER MONITEAU NODAWAY OSAGE RANDOLPH RAY SALINE SULLIVAN WORTH Read more

WW 627 SEVERE TSTM KS MO 292040Z - 300400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 627 NWS Storm Prediction Center Norman OK 340 PM CDT Thu Aug 29 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Extreme northeast Kansas Parts of northwest into central Missouri * Effective this Thursday afternoon and evening from 340 PM until 1100 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Ongoing isolated storms along an outflow boundary will likely persist into central Missouri, while additional storms form across north central Missouri and move southeastward along the same boundary. The storm environment is sufficient for supercells with large hail and damaging winds this afternoon. Later this evening, more widespread storm development is expected along a cold front into northwest Missouri, with upscale growth into a cluster or two with damaging winds possible. The severe thunderstorm watch area is approximately along and 35 statute miles north and south of a line from 35 miles northwest of Saint Joseph MO to 25 miles northeast of Columbia MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 626... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 600. Mean storm motion vector 32020. ...Thompson Read more

MD 1888 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WEST CENTRAL AND SOUTHWEST LOWER MICHIGAN
Mesoscale Discussion 1888 NWS Storm Prediction Center Norman OK 0533 PM CDT Thu Aug 29 2019 Areas affected...west central and southwest lower Michigan Concerning...Severe potential...Watch unlikely Valid 292233Z - 292330Z Probability of Watch Issuance...20 percent SUMMARY...Storms may produce a few instances of hail and locally strong wind gusts across west central and southwest lower Michigan into early evening. A ww will probably not be needed unless convective trends begin to suggest otherwise. DISCUSSION...Early this evening storms continue developing from central lake MI into western lower MI within what appears to be a zone of pre-frontal warm advection and isentropic ascent associated with a 40 kt southwesterly low-level jet. Based on point forecast sounding and observational data, storms appear to be elevated with updrafts probably based near 800 mb where a layer of richer moisture has advected into this region. Moreover, storms are moving around 40 kt which is close to the mean wind between 800 and 400 mb. Latest objective analysis data show MUCAPE from 1000-1500 J/kg along with 6.5 C/km mid-level lapse rates. Effective bulk shear from 30-40 kt may support some updraft rotation, especially if storms can root closer to the surface. Cumulus development is more limited with southwestern extent probably due to warmer temperatures between 800 and 700 mb. Moreover, relatively weak forcing with limited frontal convergence and onset of nocturnal cooling suggest surface based development is becoming increasingly unlikely. Nevertheless, the thermodynamic and kinematic environment will remain sufficient for a few instances of hail and locally strong wind gusts into early evening. ..Dial/Goss.. 08/29/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...APX...GRR... LAT...LON 43418712 43618611 43928441 42868431 42688640 43048723 43418712 Read more

WW 0626 Status Updates
STATUS REPORT ON WW 626 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SQUITIERI..08/29/19 ATTN...WFO...GLD...GID...LBF... STATUS REPORT FOR WS 626 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC039-063-065-071-109-137-141-147-153-163-179-181-183-193-199- 203-292340- KS . KANSAS COUNTIES INCLUDED ARE DECATUR GOVE GRAHAM GREELEY LOGAN NORTON OSBORNE PHILLIPS RAWLINS ROOKS SHERIDAN SHERMAN SMITH THOMAS WALLACE WICHITA NEC019-029-047-061-063-065-073-083-085-087-099-137-145-292340- NE . NEBRASKA COUNTIES INCLUDED ARE BUFFALO CHASE DAWSON FRANKLIN FRONTIER FURNAS GOSPER HARLAN HAYES HITCHCOCK KEARNEY PHELPS RED WILLOW Read more

WW 626 SEVERE TSTM KS NE 292020Z - 300300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 626 NWS Storm Prediction Center Norman OK 320 PM CDT Thu Aug 29 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest and north central Kansas Southwest and south central Nebraska * Effective this Thursday afternoon and evening from 320 PM until 1000 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter likely A tornado or two possible SUMMARY...Thunderstorm development is expected by 4-5pm CDT from northwest Kansas into southwest Nebraska, and storms will spread east-southeastward through late evening. The initial storms could be supercells with very large hail, and there will also be some potential for a tornado or two with storms developing on the surface boundary across northwest Kansas and southwest Nebraska. Thereafter, storm mergers and upscale growth will support an increasing threat for damaging winds. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 55 miles west southwest of Mccook NE to 55 miles south southeast of Kearney NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). 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 600. Mean storm motion vector 29020. ...Thompson Read more

WW 0627 Status Updates
STATUS FOR WATCH 0627 HAS NOT BEEN ISSUED YET Read more

WW 0626 Status Updates
STATUS FOR WATCH 0626 HAS NOT BEEN ISSUED YET Read more

No watches are valid as of Thu Aug 29 20:08:04 UTC 2019.

MD 1887 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF CENTRAL/EAST CENTRAL MISSOURI
Mesoscale Discussion 1887 NWS Storm Prediction Center Norman OK 0306 PM CDT Thu Aug 29 2019 Areas affected...Parts of central/east central Missouri Concerning...Severe potential...Watch possible Valid 292006Z - 292100Z Probability of Watch Issuance...40 percent SUMMARY...An isolated storm may continue to pose a risk for severe hail, before transitioning to more of a potentially damaging wind threat, through 5-6 PM. Unless activity shows signs of more substantive upscale growth, a severe weather watch might not be needed. DISCUSSION...Lingering warm advection along the southwestern flank of the convectively generated cold pool appeared to provide the support for redevelopment of ongoing isolated vigorous thunderstorm activity near Moberly. This is now likely rooted within a moist boundary layer air mass which appears characterized by CAPE in excess of 2000 J/kg, which has aided the evolution of supercell structure in the presence of favorable shear beneath 25-30+ kt northwesterly 500 mb flow. Models still suggest that west-southwesterly low-level flow will continue to generally weaken to the west the Mississippi River through late afternoon, and large-scale forcing for ascent to support maintenance of convection is unclear. However, given the boundary layer destabilization which has taken place, storm-scale processes could maintain the ongoing storm, which probably will tend to propagate south-southeastward, toward areas near/east of Columbia and Jefferson City through 21-23Z. If this occurs, activity may continue to pose a risk for severe hail, before perhaps transitioning to a severe wind threat. ..Kerr/Thompson.. 08/29/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...EAX... LAT...LON 39459194 38919146 38509185 38649219 39049244 39479248 39459194 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Thu Aug 29 2019 Valid 292000Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM FAR SOUTHERN NEBRASKA INTO MUCH OF NORTHERN KANSAS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF KANSAS...SOUTHERN NEBRASKA...AND NORTHERN MISSOURI...AS WELL EXTREME SOUTHEAST WISCONSIN INTO NORTHERN ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon into tonight from far southern Nebraska across much of northern Kansas with damaging winds and hail. A few severe storms are also possible over southeast Wisconsin and far northern Illinois. ...Southern NE into northeast KS... The air mass continues to destabilize across the region, with ample low-level moisture beneath steep lapse rates aloft. Visible imagery shows towering CU near the boundary from eastern CO into northwest KS where temperatures continued to rise into the lower 90s F. Rapid storm development is expected once the cap is completely breached, with additional development likely to follow along the primary east-west boundary over southern NE. Supercells are expected initially with very large hail, with an increasing damaging wind threat as storms bow toward the east/southeast. A more pronounced turn to the southeast is expected later tonight as activity develops into eastern KS, with a continued wind threat. For more information, see mesoscale discussion 1886. ...WI and IL... Outflow from earlier activity has created a relatively stable area from southeast IA into western IL and northeast MO. Given the progressing cold front just west of this area, it is unlikely that much severe activity will occur there. The best chance of a few severe storms, including a supercell or brief tornado, will be over southeast Wisconsin where the best combination of instability and shear exist. For more information see mesoscale discussion 1885. ..Jewell.. 08/29/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Aug 29 2019/ ...WI/Lower MI this afternoon/evening... Within a belt of broadly cyclonic flow aloft, an embedded shortwave trough/speed max will move over WI/Upper MI this afternoon, driving a surface cold front southeastward across WI/MI. A band of elevated thunderstorms immediately precedes the front across WI as of late morning, and some form of this convection is likely to persist into the afternoon into southeast WI and Lower MI. The degree of surface destabilization prior to frontal passage is the primary concern across WI/Lower MI this afternoon/evening, as the stronger forcing for ascent appears likely to overspread northeast WI/northern Lower MI, just northeast of the more substantial destabilization. Vertical shear profiles will favor supercells if sufficient destabilization can occur prior to frontal passage, though storm coverage is also in doubt northeast of the IA cluster and south of the stronger ascent. Farther southwest, a persistent cluster of thunderstorms will likely be maintained into early afternoon from southeast IA to northeast MO, in a zone of low-level warm advection. Additional storm development is expected west of this cluster late this afternoon/evening as the surface cold front reaches southern IA/northern MO. The background environment with large buoyancy and marginal deep-layer vertical shear appears to favor multicell clusters and some embedded supercells initially, though back-building as clusters/line segments is most probable along the front this evening into tonight. Damaging gusts and large hail will be the main threats. ...Southern NE/northern KS this afternoon through tonight... An embedded speed max over southern WY will translate east-southeastward to the NE/KS border region by early tonight. At the surface, a weak lee cyclone near the southwest NE/northwest KS border this morning will develop southward across western KS by this evening, as a cold front likewise moves southward in the wake of the upper Great Lakes shortwave trough. Strong surface heating is expected beneath steep midlevel lapse rates, and convective inhibition will be largely removed once surface temperatures reach the lower 90s F. Boundary-layer dewpoints of 65-72 F from the cold front/dryline triple point eastward along the front will contribute to strong buoyancy this afternoon (MLCAPE 3000-4000 J/kg), in an environment with effective bulk shear around 35 kt. Thus, a mix of supercells and multicell clusters appears probable, with an attendant threat for large hail and damaging winds. Steep lapse rates will favor a threat for both isolated very large hail with initial supercells, and isolated significant gusts with either supercells or cell mergers this evening into early tonight. Some upscale growth into one or more MCSs appears likely tonight from northwest MO into northern KS with merging clusters along the cold front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Thu Aug 29 2019 Valid 292000Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM FAR SOUTHERN NEBRASKA INTO MUCH OF NORTHERN KANSAS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF KANSAS...SOUTHERN NEBRASKA...AND NORTHERN MISSOURI...AS WELL EXTREME SOUTHEAST WISCONSIN INTO NORTHERN ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon into tonight from far southern Nebraska across much of northern Kansas with damaging winds and hail. A few severe storms are also possible over southeast Wisconsin and far northern Illinois. ...Southern NE into northeast KS... The air mass continues to destabilize across the region, with ample low-level moisture beneath steep lapse rates aloft. Visible imagery shows towering CU near the boundary from eastern CO into northwest KS where temperatures continued to rise into the lower 90s F. Rapid storm development is expected once the cap is completely breached, with additional development likely to follow along the primary east-west boundary over southern NE. Supercells are expected initially with very large hail, with an increasing damaging wind threat as storms bow toward the east/southeast. A more pronounced turn to the southeast is expected later tonight as activity develops into eastern KS, with a continued wind threat. For more information, see mesoscale discussion 1886. ...WI and IL... Outflow from earlier activity has created a relatively stable area from southeast IA into western IL and northeast MO. Given the progressing cold front just west of this area, it is unlikely that much severe activity will occur there. The best chance of a few severe storms, including a supercell or brief tornado, will be over southeast Wisconsin where the best combination of instability and shear exist. For more information see mesoscale discussion 1885. ..Jewell.. 08/29/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Aug 29 2019/ ...WI/Lower MI this afternoon/evening... Within a belt of broadly cyclonic flow aloft, an embedded shortwave trough/speed max will move over WI/Upper MI this afternoon, driving a surface cold front southeastward across WI/MI. A band of elevated thunderstorms immediately precedes the front across WI as of late morning, and some form of this convection is likely to persist into the afternoon into southeast WI and Lower MI. The degree of surface destabilization prior to frontal passage is the primary concern across WI/Lower MI this afternoon/evening, as the stronger forcing for ascent appears likely to overspread northeast WI/northern Lower MI, just northeast of the more substantial destabilization. Vertical shear profiles will favor supercells if sufficient destabilization can occur prior to frontal passage, though storm coverage is also in doubt northeast of the IA cluster and south of the stronger ascent. Farther southwest, a persistent cluster of thunderstorms will likely be maintained into early afternoon from southeast IA to northeast MO, in a zone of low-level warm advection. Additional storm development is expected west of this cluster late this afternoon/evening as the surface cold front reaches southern IA/northern MO. The background environment with large buoyancy and marginal deep-layer vertical shear appears to favor multicell clusters and some embedded supercells initially, though back-building as clusters/line segments is most probable along the front this evening into tonight. Damaging gusts and large hail will be the main threats. ...Southern NE/northern KS this afternoon through tonight... An embedded speed max over southern WY will translate east-southeastward to the NE/KS border region by early tonight. At the surface, a weak lee cyclone near the southwest NE/northwest KS border this morning will develop southward across western KS by this evening, as a cold front likewise moves southward in the wake of the upper Great Lakes shortwave trough. Strong surface heating is expected beneath steep midlevel lapse rates, and convective inhibition will be largely removed once surface temperatures reach the lower 90s F. Boundary-layer dewpoints of 65-72 F from the cold front/dryline triple point eastward along the front will contribute to strong buoyancy this afternoon (MLCAPE 3000-4000 J/kg), in an environment with effective bulk shear around 35 kt. Thus, a mix of supercells and multicell clusters appears probable, with an attendant threat for large hail and damaging winds. Steep lapse rates will favor a threat for both isolated very large hail with initial supercells, and isolated significant gusts with either supercells or cell mergers this evening into early tonight. Some upscale growth into one or more MCSs appears likely tonight from northwest MO into northern KS with merging clusters along the cold front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Thu Aug 29 2019 Valid 292000Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM FAR SOUTHERN NEBRASKA INTO MUCH OF NORTHERN KANSAS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF KANSAS...SOUTHERN NEBRASKA...AND NORTHERN MISSOURI...AS WELL EXTREME SOUTHEAST WISCONSIN INTO NORTHERN ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon into tonight from far southern Nebraska across much of northern Kansas with damaging winds and hail. A few severe storms are also possible over southeast Wisconsin and far northern Illinois. ...Southern NE into northeast KS... The air mass continues to destabilize across the region, with ample low-level moisture beneath steep lapse rates aloft. Visible imagery shows towering CU near the boundary from eastern CO into northwest KS where temperatures continued to rise into the lower 90s F. Rapid storm development is expected once the cap is completely breached, with additional development likely to follow along the primary east-west boundary over southern NE. Supercells are expected initially with very large hail, with an increasing damaging wind threat as storms bow toward the east/southeast. A more pronounced turn to the southeast is expected later tonight as activity develops into eastern KS, with a continued wind threat. For more information, see mesoscale discussion 1886. ...WI and IL... Outflow from earlier activity has created a relatively stable area from southeast IA into western IL and northeast MO. Given the progressing cold front just west of this area, it is unlikely that much severe activity will occur there. The best chance of a few severe storms, including a supercell or brief tornado, will be over southeast Wisconsin where the best combination of instability and shear exist. For more information see mesoscale discussion 1885. ..Jewell.. 08/29/2019 .PREV DISCUSSION... /ISSUED 1129 AM CDT Thu Aug 29 2019/ ...WI/Lower MI this afternoon/evening... Within a belt of broadly cyclonic flow aloft, an embedded shortwave trough/speed max will move over WI/Upper MI this afternoon, driving a surface cold front southeastward across WI/MI. A band of elevated thunderstorms immediately precedes the front across WI as of late morning, and some form of this convection is likely to persist into the afternoon into southeast WI and Lower MI. The degree of surface destabilization prior to frontal passage is the primary concern across WI/Lower MI this afternoon/evening, as the stronger forcing for ascent appears likely to overspread northeast WI/northern Lower MI, just northeast of the more substantial destabilization. Vertical shear profiles will favor supercells if sufficient destabilization can occur prior to frontal passage, though storm coverage is also in doubt northeast of the IA cluster and south of the stronger ascent. Farther southwest, a persistent cluster of thunderstorms will likely be maintained into early afternoon from southeast IA to northeast MO, in a zone of low-level warm advection. Additional storm development is expected west of this cluster late this afternoon/evening as the surface cold front reaches southern IA/northern MO. The background environment with large buoyancy and marginal deep-layer vertical shear appears to favor multicell clusters and some embedded supercells initially, though back-building as clusters/line segments is most probable along the front this evening into tonight. Damaging gusts and large hail will be the main threats. ...Southern NE/northern KS this afternoon through tonight... An embedded speed max over southern WY will translate east-southeastward to the NE/KS border region by early tonight. At the surface, a weak lee cyclone near the southwest NE/northwest KS border this morning will develop southward across western KS by this evening, as a cold front likewise moves southward in the wake of the upper Great Lakes shortwave trough. Strong surface heating is expected beneath steep midlevel lapse rates, and convective inhibition will be largely removed once surface temperatures reach the lower 90s F. Boundary-layer dewpoints of 65-72 F from the cold front/dryline triple point eastward along the front will contribute to strong buoyancy this afternoon (MLCAPE 3000-4000 J/kg), in an environment with effective bulk shear around 35 kt. Thus, a mix of supercells and multicell clusters appears probable, with an attendant threat for large hail and damaging winds. Steep lapse rates will favor a threat for both isolated very large hail with initial supercells, and isolated significant gusts with either supercells or cell mergers this evening into early tonight. Some upscale growth into one or more MCSs appears likely tonight from northwest MO into northern KS with merging clusters along the cold front. Read more