Severe Storms

WW 0657 Status Updates
STATUS FOR WATCH 0657 HAS NOT BEEN ISSUED YET Read more

WW 657 SEVERE TSTM KS NE 212210Z - 220500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 657 NWS Storm Prediction Center Norman OK 510 PM CDT Sat Sep 21 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest to northeast Kansas Southeast Nebraska * Effective this Saturday afternoon from 510 PM until Midnight CDT. * 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...Scattered thunderstorms will develop this evening from southwest Kansas into southeast Nebraska with primary threats of large hail and damaging wind. This activity should evolve into one or more clusters with the severe threat waning towards late evening as it transitions to predominantly a heavy rainfall hazard. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 35 miles northeast of Beatrice NE to 10 miles east southeast of Dodge City KS. 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. && 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 25035. ...Grams Read more

No watches are valid as of Sat Sep 21 20:30:08 UTC 2019.

MD 1997 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR SOUTHWEST AND NORTH-CENTRAL KS...SOUTHEAST NE
Mesoscale Discussion 1997 NWS Storm Prediction Center Norman OK 0329 PM CDT Sat Sep 21 2019 Areas affected...southwest and north-central KS...southeast NE Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 212029Z - 212230Z Probability of Watch Issuance...80 percent SUMMARY...Convective initiation may occur first over southwest KS. Storm coverage and intensity are forecast to increase this evening with storms eventually moving into north-central KS and parts of southern NE. DISCUSSION...Visible satellite imagery shows the early stages of cumulus development west of Garden City near a front. Surface analysis places a largely stationary segment of the front oriented southwest to northeast across southwest into north-central KS. Surface temperatures have warmed to 90 degrees F with dewpoints mixing into the upper 50s-lower 60s F. RAP forecast soundings indicate around 2000 J/kg MLCAPE with an elongated straight hodograph with 50kt shear in the 500-300mb layer. The weakness in the hodograph size in the lowest 3km suggests tornado potential will probably remain limited. However, the aforementioned speed shear in the -10 to -30 degrees C layer may support the risk for large to very large hail with the strongest storms later this evening. Surface analysis/visible satellite composite is suggesting storms will probably focus near the boundary where low-level convergence is maximized. With only weak large-scale forcing for ascent expected, storm development/coverage in the warm sector should remain low. Therefore, the risk for strong to severe storms will probably be confined from southwest KS into parts of southeast NE later this afternoon through the evening. ..Smith/Hart.. 09/21/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OAX...TOP...ICT...GID...DDC...GLD... LAT...LON 38240126 40949696 40159605 39829763 38339973 37760100 38240126 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sat Sep 21 2019 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MINNESOTA AND WISCONSIN...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail, damaging winds, and perhaps a couple of tornadoes remain possible this afternoon and evening from Kansas to Iowa, and across parts of central Minnesota into northwest Wisconsin. ...20Z Update... A small adjustment has been made to the Marginal Risk across the northern Plains into western MN to account for the eastward progression of a surface front. Convection across central MN along/ahead of the front has struggled to intensify so far this afternoon, even with moderate to strong shear and instability present across the warm sector. This may be related to the presence of a subtle inversion around 700 mb suggested in various RAP forecast soundings across this region. Even so, some increase in convective coverage and intensity still seems probable across central MN into northwestern WI through the remainder of the afternoon into the early evening as a shortwave trough moves over this region. All severe hazards remain possible. Large-scale lift and low-level convergence along the cold front are weaker with southward extent into southern MN and northern IA. Still, some chance exists for a isolated strong to severe storm across this area where modest surface heating has occurred. Farther south, no changes have been made to the Slight Risk extending from KS into southern/central IA. Convective development will probably occur across western into central KS along the front within the next few hours. Strong instability and enough effective bulk shear to support supercells suggests a large hail threat initially, with strong to damaging winds becoming a concern as storms grow upscale along the front. A couple of tornadoes also cannot be ruled out early in the convective event when storms are at least semi-discrete. ..Gleason.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1114 AM CDT Sat Sep 21 2019/ ...MN/WI... Morning surface analysis shows a weak low over northwest MN, with a trailing cold front extending southward across the eastern Dakotas. This front will move eastward today into central MN by mid-afternoon, where a combination of daytime heating and forcing associated with an upper trough tracking across the northern Plains will lead to the development of widely scattered thunderstorms. 12z model solutions are inconsistent on coverage of storms in this area, but forecast soundings suggest a conditional risk of rotating storms and the potential for hail and damaging wind in the strongest cells that form. An isolated tornado or two is also possible, given the presence of remnant outflow boundaries and ample low-level moisture. Storms will move into central WI and weaken this evening. ...Central Plains... The aforementioned surface cold front extends southward into central NE/KS. Strong heating is expected this afternoon ahead of the front from central/eastern KS into southeast NE, with MLCAPE values approaching 3000 J/kg. Convective initiation is expected during the late afternoon over central KS. Storms will build northeastward across the SLGT risk area during the evening, with the potential for large hail and damaging winds. Shear profiles will promote initial supercell structures with a risk of very large hail. Persistent clouds limit confidence in severe threat extending into central/eastern IA. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sat Sep 21 2019 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MINNESOTA AND WISCONSIN...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail, damaging winds, and perhaps a couple of tornadoes remain possible this afternoon and evening from Kansas to Iowa, and across parts of central Minnesota into northwest Wisconsin. ...20Z Update... A small adjustment has been made to the Marginal Risk across the northern Plains into western MN to account for the eastward progression of a surface front. Convection across central MN along/ahead of the front has struggled to intensify so far this afternoon, even with moderate to strong shear and instability present across the warm sector. This may be related to the presence of a subtle inversion around 700 mb suggested in various RAP forecast soundings across this region. Even so, some increase in convective coverage and intensity still seems probable across central MN into northwestern WI through the remainder of the afternoon into the early evening as a shortwave trough moves over this region. All severe hazards remain possible. Large-scale lift and low-level convergence along the cold front are weaker with southward extent into southern MN and northern IA. Still, some chance exists for a isolated strong to severe storm across this area where modest surface heating has occurred. Farther south, no changes have been made to the Slight Risk extending from KS into southern/central IA. Convective development will probably occur across western into central KS along the front within the next few hours. Strong instability and enough effective bulk shear to support supercells suggests a large hail threat initially, with strong to damaging winds becoming a concern as storms grow upscale along the front. A couple of tornadoes also cannot be ruled out early in the convective event when storms are at least semi-discrete. ..Gleason.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1114 AM CDT Sat Sep 21 2019/ ...MN/WI... Morning surface analysis shows a weak low over northwest MN, with a trailing cold front extending southward across the eastern Dakotas. This front will move eastward today into central MN by mid-afternoon, where a combination of daytime heating and forcing associated with an upper trough tracking across the northern Plains will lead to the development of widely scattered thunderstorms. 12z model solutions are inconsistent on coverage of storms in this area, but forecast soundings suggest a conditional risk of rotating storms and the potential for hail and damaging wind in the strongest cells that form. An isolated tornado or two is also possible, given the presence of remnant outflow boundaries and ample low-level moisture. Storms will move into central WI and weaken this evening. ...Central Plains... The aforementioned surface cold front extends southward into central NE/KS. Strong heating is expected this afternoon ahead of the front from central/eastern KS into southeast NE, with MLCAPE values approaching 3000 J/kg. Convective initiation is expected during the late afternoon over central KS. Storms will build northeastward across the SLGT risk area during the evening, with the potential for large hail and damaging winds. Shear profiles will promote initial supercell structures with a risk of very large hail. Persistent clouds limit confidence in severe threat extending into central/eastern IA. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sat Sep 21 2019 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MINNESOTA AND WISCONSIN...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail, damaging winds, and perhaps a couple of tornadoes remain possible this afternoon and evening from Kansas to Iowa, and across parts of central Minnesota into northwest Wisconsin. ...20Z Update... A small adjustment has been made to the Marginal Risk across the northern Plains into western MN to account for the eastward progression of a surface front. Convection across central MN along/ahead of the front has struggled to intensify so far this afternoon, even with moderate to strong shear and instability present across the warm sector. This may be related to the presence of a subtle inversion around 700 mb suggested in various RAP forecast soundings across this region. Even so, some increase in convective coverage and intensity still seems probable across central MN into northwestern WI through the remainder of the afternoon into the early evening as a shortwave trough moves over this region. All severe hazards remain possible. Large-scale lift and low-level convergence along the cold front are weaker with southward extent into southern MN and northern IA. Still, some chance exists for a isolated strong to severe storm across this area where modest surface heating has occurred. Farther south, no changes have been made to the Slight Risk extending from KS into southern/central IA. Convective development will probably occur across western into central KS along the front within the next few hours. Strong instability and enough effective bulk shear to support supercells suggests a large hail threat initially, with strong to damaging winds becoming a concern as storms grow upscale along the front. A couple of tornadoes also cannot be ruled out early in the convective event when storms are at least semi-discrete. ..Gleason.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1114 AM CDT Sat Sep 21 2019/ ...MN/WI... Morning surface analysis shows a weak low over northwest MN, with a trailing cold front extending southward across the eastern Dakotas. This front will move eastward today into central MN by mid-afternoon, where a combination of daytime heating and forcing associated with an upper trough tracking across the northern Plains will lead to the development of widely scattered thunderstorms. 12z model solutions are inconsistent on coverage of storms in this area, but forecast soundings suggest a conditional risk of rotating storms and the potential for hail and damaging wind in the strongest cells that form. An isolated tornado or two is also possible, given the presence of remnant outflow boundaries and ample low-level moisture. Storms will move into central WI and weaken this evening. ...Central Plains... The aforementioned surface cold front extends southward into central NE/KS. Strong heating is expected this afternoon ahead of the front from central/eastern KS into southeast NE, with MLCAPE values approaching 3000 J/kg. Convective initiation is expected during the late afternoon over central KS. Storms will build northeastward across the SLGT risk area during the evening, with the potential for large hail and damaging winds. Shear profiles will promote initial supercell structures with a risk of very large hail. Persistent clouds limit confidence in severe threat extending into central/eastern IA. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sat Sep 21 2019 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MINNESOTA AND WISCONSIN...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail, damaging winds, and perhaps a couple of tornadoes remain possible this afternoon and evening from Kansas to Iowa, and across parts of central Minnesota into northwest Wisconsin. ...20Z Update... A small adjustment has been made to the Marginal Risk across the northern Plains into western MN to account for the eastward progression of a surface front. Convection across central MN along/ahead of the front has struggled to intensify so far this afternoon, even with moderate to strong shear and instability present across the warm sector. This may be related to the presence of a subtle inversion around 700 mb suggested in various RAP forecast soundings across this region. Even so, some increase in convective coverage and intensity still seems probable across central MN into northwestern WI through the remainder of the afternoon into the early evening as a shortwave trough moves over this region. All severe hazards remain possible. Large-scale lift and low-level convergence along the cold front are weaker with southward extent into southern MN and northern IA. Still, some chance exists for a isolated strong to severe storm across this area where modest surface heating has occurred. Farther south, no changes have been made to the Slight Risk extending from KS into southern/central IA. Convective development will probably occur across western into central KS along the front within the next few hours. Strong instability and enough effective bulk shear to support supercells suggests a large hail threat initially, with strong to damaging winds becoming a concern as storms grow upscale along the front. A couple of tornadoes also cannot be ruled out early in the convective event when storms are at least semi-discrete. ..Gleason.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1114 AM CDT Sat Sep 21 2019/ ...MN/WI... Morning surface analysis shows a weak low over northwest MN, with a trailing cold front extending southward across the eastern Dakotas. This front will move eastward today into central MN by mid-afternoon, where a combination of daytime heating and forcing associated with an upper trough tracking across the northern Plains will lead to the development of widely scattered thunderstorms. 12z model solutions are inconsistent on coverage of storms in this area, but forecast soundings suggest a conditional risk of rotating storms and the potential for hail and damaging wind in the strongest cells that form. An isolated tornado or two is also possible, given the presence of remnant outflow boundaries and ample low-level moisture. Storms will move into central WI and weaken this evening. ...Central Plains... The aforementioned surface cold front extends southward into central NE/KS. Strong heating is expected this afternoon ahead of the front from central/eastern KS into southeast NE, with MLCAPE values approaching 3000 J/kg. Convective initiation is expected during the late afternoon over central KS. Storms will build northeastward across the SLGT risk area during the evening, with the potential for large hail and damaging winds. Shear profiles will promote initial supercell structures with a risk of very large hail. Persistent clouds limit confidence in severe threat extending into central/eastern IA. Read more

MD 1996 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHWESTERN IOWA...NORTHWEST WISCONSIN...AND A LARGE PORTION OF MINNESOTA
Mesoscale Discussion 1996 NWS Storm Prediction Center Norman OK 0133 PM CDT Sat Sep 21 2019 Areas affected...Northwestern Iowa...northwest Wisconsin...and a large portion of Minnesota Concerning...Severe potential...Watch possible Valid 211833Z - 212000Z Probability of Watch Issuance...40 percent SUMMARY...A gradual increase in storm coverage and intensity is expected through the afternoon. A watch is possible. DISCUSSION...Temperatures have warmed into the low 80s with dewpoints in the low 70s in the wake of morning convection across northwest Iowa and southwest Minnesota. 18Z surface analysis shows a cold front across western Minnesota which extends southward to just west of Sioux Falls. Surface observations show enhanced convergence along the front in west central Minnesota and northwest Iowa with less convergence in between. Further evidence for these areas of enhanced convergence can be seen on GOES 16 visible satellite imagery where there is line of agitated cumulus in northwest Iowa and southwest Minnesota with little development along the front north of there. While 12Z CAM guidance was not overall supportive for storm development in southern Minnesota and northwest Iowa, current observations and a few lightning strikes support the threat for at least a few severe thunderstorms this afternoon. Farther north, a combination of better upper-level forcing, and a pseudo warm front/differential heating boundary should support storm development by mid to late afternoon. Effective shear around 40 to 50 knots and MLCAPE around 2500 to 3000 J/kg will support supercells capable of mainly large hail and damaging winds. Mixing ahead of the front has veered most surface flow ahead of the front which should limit the overall tornado threat, but backed flow in the immediate vicinity of the warm front/differential heating boundary could support an isolated tornado threat. Overall, a watch is possible, with storm coverage as the primary limiting factor. The best potential for a watch would be in east Central Minnesota into northeast Minnesota and northwest Wisconsin where storm coverage should be greater with less likelihood of a watch for the activity in southern Minnesota and northwest Iowa. ..Bentley/Hart.. 09/21/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...DMX...FGF...FSD...OAX... LAT...LON 43409602 44139572 44919551 45329537 45899503 46719464 47289411 47639377 47719320 47559243 47349203 47019167 46459145 45549150 44669219 43229298 42429441 42139532 42119604 42329651 42409678 43409602 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes have been made to the outlook -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1243 AM CDT Sat Sep 21 2019/ ...Synopsis... A large upper-level trough located over the central/northern Plains will shift east into the Great Lakes region, while another deep/amplifying trough enters the West Coast. An upper-level ridge located between these features, to go along with a lack of appreciable mid-level flow should result in low fire-weather concerns. Breezy conditions could momentarily develop over central portions of Nevada during the afternoon, however disagreement among various sources of mid-range guidance in the placement/magnitude of the wind/RH combo precludes the introduction of any highlights at this time. ...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 0112 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes have been made to the outlook -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1243 AM CDT Sat Sep 21 2019/ ...Synopsis... A large upper-level trough located over the central/northern Plains will shift east into the Great Lakes region, while another deep/amplifying trough enters the West Coast. An upper-level ridge located between these features, to go along with a lack of appreciable mid-level flow should result in low fire-weather concerns. Breezy conditions could momentarily develop over central portions of Nevada during the afternoon, however disagreement among various sources of mid-range guidance in the placement/magnitude of the wind/RH combo precludes the introduction of any highlights at this time. ...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 0112 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes have been made to the outlook -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1243 AM CDT Sat Sep 21 2019/ ...Synopsis... A large upper-level trough located over the central/northern Plains will shift east into the Great Lakes region, while another deep/amplifying trough enters the West Coast. An upper-level ridge located between these features, to go along with a lack of appreciable mid-level flow should result in low fire-weather concerns. Breezy conditions could momentarily develop over central portions of Nevada during the afternoon, however disagreement among various sources of mid-range guidance in the placement/magnitude of the wind/RH combo precludes the introduction of any highlights at this time. ...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 0112 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes have been made to the outlook -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1243 AM CDT Sat Sep 21 2019/ ...Synopsis... A large upper-level trough located over the central/northern Plains will shift east into the Great Lakes region, while another deep/amplifying trough enters the West Coast. An upper-level ridge located between these features, to go along with a lack of appreciable mid-level flow should result in low fire-weather concerns. Breezy conditions could momentarily develop over central portions of Nevada during the afternoon, however disagreement among various sources of mid-range guidance in the placement/magnitude of the wind/RH combo precludes the introduction of any highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER GREAT LAKES/OHIO VALLEY... ...SUMMARY... Scattered storms capable of producing mainly isolated strong to damaging winds will be possible from Oklahoma to northwestern Ohio on Sunday. ...Oklahoma to Ohio... An amplified upper trough will be in place over much of the Plains Sunday morning. A surface cold front will extend from the Great Lakes region southwestward into the southern Plains. Both the upper trough and surface front are forecast to move eastward across parts of the Upper Midwest/mid MS Valley into the OH Valley and Great Lakes through the period as a weak surface low develops northeastward along the front. A broad area of precipitation with embedded storms will likely be ongoing at the beginning of the period along/near the front from southern WI/northern IL to KS/OK. Widespread cloudiness/precipitation may tend to limit downstream diurnal destabilization, with forecast MLCAPE generally less than 750 J/kg from MO northeastward. Poor mid-level lapse rates should also be present from the mid MS Valley into the OH Valley. Regardless, strong low to mid-level flow will be present along the length of the front. A 35-50 kt southwesterly low-level jet is forecast to develop northeastward from eastern KS/OK across MO to the Great Lakes vicinity by Sunday evening. Strong shear may support some organized storm structures early in the day, with potential for additional storms to develop Sunday afternoon along/ahead of the front or reinforcing outflow boundaries. With mid-level southwesterly flow largely parallel to the surface front, small clusters moving east-northeastward seem to the most likely storm mode. Isolated strong to damaging winds should be the main threat through Sunday evening, with some risk potentially extending into far southern lower MI, IN, and northwestern OH Sunday night given the strong low-level warm air advection expected. The lack of stronger forecast instability, meager mid-level lapse rates, and the tendency for convection to be undercut by the front lends too much uncertainty for any more than 5% total severe probabilities at this time. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/21/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER GREAT LAKES/OHIO VALLEY... ...SUMMARY... Scattered storms capable of producing mainly isolated strong to damaging winds will be possible from Oklahoma to northwestern Ohio on Sunday. ...Oklahoma to Ohio... An amplified upper trough will be in place over much of the Plains Sunday morning. A surface cold front will extend from the Great Lakes region southwestward into the southern Plains. Both the upper trough and surface front are forecast to move eastward across parts of the Upper Midwest/mid MS Valley into the OH Valley and Great Lakes through the period as a weak surface low develops northeastward along the front. A broad area of precipitation with embedded storms will likely be ongoing at the beginning of the period along/near the front from southern WI/northern IL to KS/OK. Widespread cloudiness/precipitation may tend to limit downstream diurnal destabilization, with forecast MLCAPE generally less than 750 J/kg from MO northeastward. Poor mid-level lapse rates should also be present from the mid MS Valley into the OH Valley. Regardless, strong low to mid-level flow will be present along the length of the front. A 35-50 kt southwesterly low-level jet is forecast to develop northeastward from eastern KS/OK across MO to the Great Lakes vicinity by Sunday evening. Strong shear may support some organized storm structures early in the day, with potential for additional storms to develop Sunday afternoon along/ahead of the front or reinforcing outflow boundaries. With mid-level southwesterly flow largely parallel to the surface front, small clusters moving east-northeastward seem to the most likely storm mode. Isolated strong to damaging winds should be the main threat through Sunday evening, with some risk potentially extending into far southern lower MI, IN, and northwestern OH Sunday night given the strong low-level warm air advection expected. The lack of stronger forecast instability, meager mid-level lapse rates, and the tendency for convection to be undercut by the front lends too much uncertainty for any more than 5% total severe probabilities at this time. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/21/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER GREAT LAKES/OHIO VALLEY... ...SUMMARY... Scattered storms capable of producing mainly isolated strong to damaging winds will be possible from Oklahoma to northwestern Ohio on Sunday. ...Oklahoma to Ohio... An amplified upper trough will be in place over much of the Plains Sunday morning. A surface cold front will extend from the Great Lakes region southwestward into the southern Plains. Both the upper trough and surface front are forecast to move eastward across parts of the Upper Midwest/mid MS Valley into the OH Valley and Great Lakes through the period as a weak surface low develops northeastward along the front. A broad area of precipitation with embedded storms will likely be ongoing at the beginning of the period along/near the front from southern WI/northern IL to KS/OK. Widespread cloudiness/precipitation may tend to limit downstream diurnal destabilization, with forecast MLCAPE generally less than 750 J/kg from MO northeastward. Poor mid-level lapse rates should also be present from the mid MS Valley into the OH Valley. Regardless, strong low to mid-level flow will be present along the length of the front. A 35-50 kt southwesterly low-level jet is forecast to develop northeastward from eastern KS/OK across MO to the Great Lakes vicinity by Sunday evening. Strong shear may support some organized storm structures early in the day, with potential for additional storms to develop Sunday afternoon along/ahead of the front or reinforcing outflow boundaries. With mid-level southwesterly flow largely parallel to the surface front, small clusters moving east-northeastward seem to the most likely storm mode. Isolated strong to damaging winds should be the main threat through Sunday evening, with some risk potentially extending into far southern lower MI, IN, and northwestern OH Sunday night given the strong low-level warm air advection expected. The lack of stronger forecast instability, meager mid-level lapse rates, and the tendency for convection to be undercut by the front lends too much uncertainty for any more than 5% total severe probabilities at this time. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/21/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Sep 21 2019 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF THE SOUTHERN PLAINS TO THE LOWER GREAT LAKES/OHIO VALLEY... ...SUMMARY... Scattered storms capable of producing mainly isolated strong to damaging winds will be possible from Oklahoma to northwestern Ohio on Sunday. ...Oklahoma to Ohio... An amplified upper trough will be in place over much of the Plains Sunday morning. A surface cold front will extend from the Great Lakes region southwestward into the southern Plains. Both the upper trough and surface front are forecast to move eastward across parts of the Upper Midwest/mid MS Valley into the OH Valley and Great Lakes through the period as a weak surface low develops northeastward along the front. A broad area of precipitation with embedded storms will likely be ongoing at the beginning of the period along/near the front from southern WI/northern IL to KS/OK. Widespread cloudiness/precipitation may tend to limit downstream diurnal destabilization, with forecast MLCAPE generally less than 750 J/kg from MO northeastward. Poor mid-level lapse rates should also be present from the mid MS Valley into the OH Valley. Regardless, strong low to mid-level flow will be present along the length of the front. A 35-50 kt southwesterly low-level jet is forecast to develop northeastward from eastern KS/OK across MO to the Great Lakes vicinity by Sunday evening. Strong shear may support some organized storm structures early in the day, with potential for additional storms to develop Sunday afternoon along/ahead of the front or reinforcing outflow boundaries. With mid-level southwesterly flow largely parallel to the surface front, small clusters moving east-northeastward seem to the most likely storm mode. Isolated strong to damaging winds should be the main threat through Sunday evening, with some risk potentially extending into far southern lower MI, IN, and northwestern OH Sunday night given the strong low-level warm air advection expected. The lack of stronger forecast instability, meager mid-level lapse rates, and the tendency for convection to be undercut by the front lends too much uncertainty for any more than 5% total severe probabilities at this time. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Gleason.. 09/21/2019 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Sat Sep 21 2019 Valid 211700Z - 221200Z ...Portions of the Southwest and Central/Southern High Plains... 16Z surface observations indicate that spotty elevated conditions have already developed across portions of northwest AZ and also across southern CO/northern NM. Elevated conditions will become more widespread this afternoon, with locally critical conditions possible. The previous Elevated delineations have been maintained in this update -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1242 AM CDT Sat Sep 21 2019/ ...Synopsis... A highly amplified upper-level trough located over much the Intermountain West will shift eastward into the central/northern Plains today while ridging develops in its wake across the northern Great Basin. Within the base of the trough, a mid-level short-wave trough, accompanied by enhanced mid-level flow, will quickly move across portions of the Southwest into the central/southern High Plains. ...Portions of the Southwest and Central/Southern High Plains... As the aforementioned enhanced mid-level flow overspreads the area in combination with diurnal heating, vertical mixing will allow winds near the surface to reach sustained speeds of 15-20 mph during the afternoon. A dry, post frontal airmass resides over much of the region, and thus RH values will fall into the teens amidst fuels that remain receptive to large-fire spread. Two areas have been highlighted for delineating elevated fire-weather potential, the first being a continuation of the previous forecast over portions of southern Colorado and northeastern New Mexico, with a minor expansion made to account for greater areal coverage of wind/RH threshold exceedance. A second area was added farther west across portions of northwest New Mexico into east-central Arizona, where better agreement exists in the wind/RH combo among the latest high-resolution deterministic- and ensemble-based guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Sat Sep 21 2019 Valid 211700Z - 221200Z ...Portions of the Southwest and Central/Southern High Plains... 16Z surface observations indicate that spotty elevated conditions have already developed across portions of northwest AZ and also across southern CO/northern NM. Elevated conditions will become more widespread this afternoon, with locally critical conditions possible. The previous Elevated delineations have been maintained in this update -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1242 AM CDT Sat Sep 21 2019/ ...Synopsis... A highly amplified upper-level trough located over much the Intermountain West will shift eastward into the central/northern Plains today while ridging develops in its wake across the northern Great Basin. Within the base of the trough, a mid-level short-wave trough, accompanied by enhanced mid-level flow, will quickly move across portions of the Southwest into the central/southern High Plains. ...Portions of the Southwest and Central/Southern High Plains... As the aforementioned enhanced mid-level flow overspreads the area in combination with diurnal heating, vertical mixing will allow winds near the surface to reach sustained speeds of 15-20 mph during the afternoon. A dry, post frontal airmass resides over much of the region, and thus RH values will fall into the teens amidst fuels that remain receptive to large-fire spread. Two areas have been highlighted for delineating elevated fire-weather potential, the first being a continuation of the previous forecast over portions of southern Colorado and northeastern New Mexico, with a minor expansion made to account for greater areal coverage of wind/RH threshold exceedance. A second area was added farther west across portions of northwest New Mexico into east-central Arizona, where better agreement exists in the wind/RH combo among the latest high-resolution deterministic- and ensemble-based guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Sat Sep 21 2019 Valid 211700Z - 221200Z ...Portions of the Southwest and Central/Southern High Plains... 16Z surface observations indicate that spotty elevated conditions have already developed across portions of northwest AZ and also across southern CO/northern NM. Elevated conditions will become more widespread this afternoon, with locally critical conditions possible. The previous Elevated delineations have been maintained in this update -- see the previous discussion below for more information. ..Dean.. 09/21/2019 .PREV DISCUSSION... /ISSUED 1242 AM CDT Sat Sep 21 2019/ ...Synopsis... A highly amplified upper-level trough located over much the Intermountain West will shift eastward into the central/northern Plains today while ridging develops in its wake across the northern Great Basin. Within the base of the trough, a mid-level short-wave trough, accompanied by enhanced mid-level flow, will quickly move across portions of the Southwest into the central/southern High Plains. ...Portions of the Southwest and Central/Southern High Plains... As the aforementioned enhanced mid-level flow overspreads the area in combination with diurnal heating, vertical mixing will allow winds near the surface to reach sustained speeds of 15-20 mph during the afternoon. A dry, post frontal airmass resides over much of the region, and thus RH values will fall into the teens amidst fuels that remain receptive to large-fire spread. Two areas have been highlighted for delineating elevated fire-weather potential, the first being a continuation of the previous forecast over portions of southern Colorado and northeastern New Mexico, with a minor expansion made to account for greater areal coverage of wind/RH threshold exceedance. A second area was added farther west across portions of northwest New Mexico into east-central Arizona, where better agreement exists in the wind/RH combo among the latest high-resolution deterministic- and ensemble-based guidance. ...Please see www.spc.noaa.gov/fire for graphic product... Read more