Aggregator

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0449 PM CDT Mon May 20 2024 Valid 221200Z - 281200Z ...Southwest into the southern High Plains... ...Days 3-4/Wednesday-Thursday... A broad large-scale trough will persist across the West, with the strongest midlevel flow confined to the northwestern CONUS. Along the southern periphery of the trough, moderate west-southwesterly flow will overspread a dry/deeply mixed air mass from the Southwest into the southern High Plains. As a result, elevated to locally critical conditions are expected each afternoon, given increasingly dry/receptive fuels across the region. 40-percent Critical probabilities remain in place for these days, though confidence in any more than locally critical conditions is too low to introduce higher probabilities at this time. ...Days 5-6/Friday-Saturday... On Day 5/Friday, west-southwesterly midlevel flow will strengthen across the Southwest, where a warm/dry antecedent air mass will be in place. Given the strengthening midlevel flow and a modest surface pressure gradient, critical conditions are expected on Day 5/Friday over northeast AZ and northwest NM. Thereafter, a robust midlevel jet streak embedded in the west-southwesterlies will overspread the Southwest and southern High Plains on Day 6/Saturday. This will promote another day of dry/windy conditions across the region, with the best overlap of strong surface winds and low RH atop receptive fuels expected over southern NM, where critical conditions are expected. Elevated to locally critical conditions will likely continue on Day 7/Sunday, though midlevel flow will be slightly weaker than days prior -- precluding 70-percent probabilities at this time. ..Weinman.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0852 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTH FLORIDA
Mesoscale Discussion 0852 NWS Storm Prediction Center Norman OK 0204 PM CDT Mon May 20 2024 Areas affected...South Florida Concerning...Severe potential...Watch unlikely Valid 201904Z - 202100Z Probability of Watch Issuance...20 percent SUMMARY...Marginally severe hail and damaging winds are possible with isolated strong/severe storms this afternoon. DISCUSSION...Cumulus have become more vertically developed along a remnant surface boundary north of Lake Okeechobee. Other cumulus agitation is occurring in south-central Florida where outflow from convection in the Florida Keys/Straits has enhanced convergence. Storm initiation is most likely along the sea/lake breeze boundaries as well as the northward moving outflow and seems possible within the next 1-2 hours. Storm coverage should remain isolated given weak forcing aloft. Storm intensity should also be muted compared to yesterday given warmer mid-level temperatures (around -8 C per 12Z observed MFL sounding). Isolated marginally severe hail and damaging winds are the primary hazards with the strongest storms this afternoon. ..Wendt/Hart.. 05/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB...TBW... LAT...LON 27057975 26407974 25567991 25638030 25768077 26028108 26398132 27138122 27348114 27488113 27728103 27728075 27598036 27568008 27257979 27057975 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

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

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