Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0347 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... AMENDED FOR LOWER MICHIGAN ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk, which includes upward-adjusted probabilities (Slight Risk) across parts of Lower Michigan. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0347 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... AMENDED FOR LOWER MICHIGAN ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk, which includes upward-adjusted probabilities (Slight Risk) across parts of Lower Michigan. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0347 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... AMENDED FOR LOWER MICHIGAN ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk, which includes upward-adjusted probabilities (Slight Risk) across parts of Lower Michigan. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0347 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... AMENDED FOR LOWER MICHIGAN ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk, which includes upward-adjusted probabilities (Slight Risk) across parts of Lower Michigan. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0347 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... AMENDED FOR LOWER MICHIGAN ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk, which includes upward-adjusted probabilities (Slight Risk) across parts of Lower Michigan. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

WW 0268 Status Updates
STATUS FOR WATCH 0268 HAS NOT BEEN ISSUED YET Read more

WW 0268 Status Updates
STATUS FOR WATCH 0268 HAS NOT BEEN ISSUED YET Read more

WW 0268 Status Updates
STATUS FOR WATCH 0268 HAS NOT BEEN ISSUED YET Read more

WW 0268 Status Updates
STATUS FOR WATCH 0268 HAS NOT BEEN ISSUED YET Read more

WW 268 SEVERE TSTM MI LM 202040Z - 210200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 268 NWS Storm Prediction Center Norman OK 440 PM EDT Mon May 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Central Lower Michigan Lake Michigan * Effective this Monday afternoon and evening from 440 PM until 1000 PM EDT. * Primary threats include... Isolated damaging wind gusts to 65 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms currently moving across Lake Michigan will spread into Lower Michigan soon. A few of the storms may pose a risk of locally damaging wind gusts and hail through early evening. The severe thunderstorm watch area is approximately along and 55 statute miles east and west of a line from 55 miles northeast of Muskegon MI to 15 miles southeast of Kalamazoo MI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 267... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25030. ...Hart Read more

WW 0267 Status Updates
STATUS REPORT ON WW 267 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MMO TO 25 SW RAC TO 20 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0853 ..DEAN..05/20/24 ATTN...WFO...LOT...MKX... STATUS REPORT FOR WS 267 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC097-202140- IL . ILLINOIS COUNTIES INCLUDED ARE LAKE WIC059-202140- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA LMZ644-645-646-740-202140- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI Read more

WW 0267 Status Updates
STATUS REPORT ON WW 267 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MMO TO 25 SW RAC TO 20 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0853 ..DEAN..05/20/24 ATTN...WFO...LOT...MKX... STATUS REPORT FOR WS 267 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC097-202140- IL . ILLINOIS COUNTIES INCLUDED ARE LAKE WIC059-202140- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA LMZ644-645-646-740-202140- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI Read more

WW 0267 Status Updates
STATUS REPORT ON WW 267 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MMO TO 25 SW RAC TO 20 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0853 ..DEAN..05/20/24 ATTN...WFO...LOT...MKX... STATUS REPORT FOR WS 267 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC097-202140- IL . ILLINOIS COUNTIES INCLUDED ARE LAKE WIC059-202140- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA LMZ644-645-646-740-202140- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI Read more

WW 0267 Status Updates
STATUS REPORT ON WW 267 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MMO TO 25 SW RAC TO 20 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0853 ..DEAN..05/20/24 ATTN...WFO...LOT...MKX... STATUS REPORT FOR WS 267 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC097-202140- IL . ILLINOIS COUNTIES INCLUDED ARE LAKE WIC059-202140- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA LMZ644-645-646-740-202140- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI Read more

WW 0267 Status Updates
STATUS REPORT ON WW 267 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MMO TO 25 SW RAC TO 20 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0853 ..DEAN..05/20/24 ATTN...WFO...LOT...MKX... STATUS REPORT FOR WS 267 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC097-202140- IL . ILLINOIS COUNTIES INCLUDED ARE LAKE WIC059-202140- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA LMZ644-645-646-740-202140- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI Read more

WW 0267 Status Updates
STATUS REPORT ON WW 267 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MMO TO 25 SW RAC TO 20 ENE MKE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0853 ..DEAN..05/20/24 ATTN...WFO...LOT...MKX... STATUS REPORT FOR WS 267 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC097-202140- IL . ILLINOIS COUNTIES INCLUDED ARE LAKE WIC059-202140- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA LMZ644-645-646-740-202140- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI Read more

WW 267 SEVERE TSTM IL WI LM 201740Z - 202200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 267 NWS Storm Prediction Center Norman OK 1240 PM CDT Mon May 20 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Illinois Southeast Wisconsin Lake Michigan * Effective this Monday afternoon from 1240 PM until 500 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 65 mph possible A tornado or two possible SUMMARY...Scattered thunderstorms are developing ahead of a low over southwest Wisconsin. These storms may pose a risk of hail and damaging wind gusts through the afternoon. There is also a small area of extreme southeast WI with a risk of a tornado or two. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 15 miles west northwest of Janesville WI to 5 miles south southeast of Racine WI. 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 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Mon May 20 2024 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN ILLINOIS AND SOUTHERN WISCONSIN... ...SUMMARY... The primary threat for severe thunderstorms today will be over parts of the central Plains, with large hail, damaging wind gusts, and a few tornadoes possible. ...20z Update... No changes to forecast reasoning and outlook thresholds for the Plains severe risk -- see previous discussion below. Some spatial adjustments made across southern Wisconsin and northern Illinois for an eastward-shifting severe risk. ..Guyer.. 05/20/2024 .PREV DISCUSSION... /ISSUED 1133 AM CDT Mon May 20 2024/ ...Central High Plains... A large upper trough will slowly deepen across the western United States today, with strengthening southwesterly mid/upper level flow spreading across the Plains states. A band of mid-level moisture and instability will result in scattered high-based thunderstorms across northern CO/southern WY by mid-afternoon, capable of locally damaging wind gusts. Other discrete supercell storms may form in vicinity of the DCVZ as southeasterly low-level winds and elevated terrain aid in initiation. These storms will track east-northeastward into a progressively more moist/unstable air mass, with the risk of very large hail and a few tornadoes through the evening. By mid-evening, coverage of storms will increase over southwest NE as a southerly low-level jet strengthens, with storms progressing across the central Plains overnight with a continued risk of large hail and damaging winds. ...IL/WI... A well-defined remnant MCV from overnight convection over KS is currently over northeast IA. A surface boundary extends eastward from the low across northern IL. Broken clouds and partial afternoon heating will aid in the development of thunderstorms near the MCV later today as it tracks across southern WI/northern IL. Any storm that can interact with the boundary would have the potential to become a supercell and pose a risk of a tornado or two. Otherwise, hail and gusty winds could occur with the strongest cells. ...Southeast FL... Widely scattered afternoon thunderstorms are possible across southeast FL. Ample low-level moisture, strong heating, cyclonic midlevel flow, and relatively steep lapse rates could result in a strong storm or two capable of gusty winds and hail. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0232 PM CDT Mon May 20 2024 Valid 211200Z - 221200Z The previous forecast (see below) remains on track, and only minor adjustments were made with this update. Confidence in the development of sustained critical conditions is highest over parts of northeastern NM, where the surface pressure gradient will be tightest on the western periphery of a lee cyclone. However, near-normal ERCs across this area (owing to rainfall during the last couple weeks) limits confidence in large-fire potential -- precluding Critical highlights at this time. ..Weinman.. 05/20/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon May 20 2024/ ...Synopsis... Moderate mid-level flow will remain across the Southwest on Tuesday with single-digit relative humidity across New Mexico. As deep mixing develops during the afternoon, some of this stronger flow will mix to the surface. In addition, a secondary lee cyclone is expected to develop in the TX/OK Panhandle vicinity. This will also aid in stronger surface winds. 15 to 25 mph sustained surface winds are expected across much of New Mexico. Locally critical conditions are probable and a Critical delineation may be needed at a later time, but for now, it is unclear where within the broader Elevated area, the greater threat may be. ...Please see www.spc.noaa.gov/fire for graphic product... Read more