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Issued at 2100 UTC SAT SEP 20 2025 000 WTNT22 KNHC 202032 TCMAT2 TROPICAL STORM GABRIELLE FORECAST/ADVISORY NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072025 2100 UTC SAT SEP 20 2025 TROPICAL STORM CENTER LOCATED NEAR 25.6N 59.0W AT 20/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 325 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 996 MB EYE DIAMETER 5 NM MAX SUSTAINED WINDS 55 KT WITH GUSTS TO 65 KT. 50 KT....... 10NE 0SE 0SW 10NW. 34 KT.......120NE 110SE 30SW 50NW. 4 M SEAS....180NE 135SE 90SW 150NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 25.6N 59.0W AT 20/2100Z AT 20/1800Z CENTER WAS LOCATED NEAR 25.2N 58.7W FORECAST VALID 21/0600Z 26.7N 60.0W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 0SE 0SW 0NW. 50 KT... 20NE 15SE 10SW 15NW. 34 KT...120NE 110SE 30SW 50NW. FORECAST VALID 21/1800Z 28.4N 61.1W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 20NE 15SE 10SW 15NW. 50 KT... 30NE 25SE 20SW 25NW. 34 KT...120NE 110SE 40SW 50NW. FORECAST VALID 22/0600Z 29.9N 61.5W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 25NE 20SE 15SW 20NW. 50 KT... 40NE 30SE 20SW 30NW. 34 KT...120NE 120SE 50SW 70NW. FORECAST VALID 22/1800Z 31.6N 60.8W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 25NE 25SE 20SW 20NW. 50 KT... 40NE 40SE 30SW 30NW. 34 KT...120NE 120SE 60SW 70NW. FORECAST VALID 23/0600Z 33.3N 58.9W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 25NE 25SE 20SW 20NW. 50 KT... 40NE 40SE 30SW 30NW. 34 KT...120NE 130SE 70SW 70NW. FORECAST VALID 23/1800Z 34.8N 55.8W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 25NE 30SE 25SW 20NW. 50 KT... 40NE 50SE 40SW 40NW. 34 KT...120NE 140SE 90SW 70NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 24/1800Z 36.6N 46.2W MAX WIND 70 KT...GUSTS 85 KT. 50 KT... 40NE 60SE 50SW 40NW. 34 KT...110NE 150SE 120SW 70NW. OUTLOOK VALID 25/1800Z 38.6N 33.8W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 40NE 60SE 50SW 40NW. 34 KT... 90NE 150SE 150SW 90NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 25.6N 59.0W NEXT ADVISORY AT 21/0300Z $$ FORECASTER BEVEN

Issued at 500 PM AST Sat Sep 20 2025 000 WTNT32 KNHC 202032 TCPAT2 BULLETIN Tropical Storm Gabrielle Advisory Number 15 NWS National Hurricane Center Miami FL AL072025 500 PM AST Sat Sep 20 2025 ...GABRIELLE EXPECTED TO BECOME A HURRICANE TONIGHT OR ON SUNDAY... ...EXPECTED TO PASS EAST OF BERMUDA SUNDAY NIGHT OR MONDAY... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...25.6N 59.0W ABOUT 575 MI...925 KM NNE OF THE NORTHERN LEEWARD ISLANDS ABOUT 580 MI...935 KM SE OF BERMUDA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. Interests in Bermuda should monitor the progress of Gabrielle. DISCUSSION AND OUTLOOK ---------------------- At 500 PM AST (2100 UTC), the center of Tropical Storm Gabrielle was located near latitude 25.6 North, longitude 59.0 West. Gabrielle is moving toward the northwest near 10 mph (17 km/h), and this general motion is expected to continue through tonight. A turn toward the north-northwest is forecast on Sunday, followed by a turn toward the north and northeast Monday and Monday night. On the forecast track, the center of Gabrielle is expected to pass east of Bermuda Sunday night or on Monday. Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds are near 65 mph (100 km/h) with higher gusts. Strengthening is forecast during the next couple of days, and Gabrielle is expected to become a hurricane tonight or on Sunday. Tropical-storm-force winds extend outward up to 140 miles (220 km) mainly to the east of the center. The minimum central pressure estimated from the Hurricane Hunter aircraft data is 996 mb (29.42 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Gabrielle can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and WMO header WTNT42 KNHC. SURF: Swells generated by Gabrielle are beginning to reach Bermuda and will build through the weekend. Swells generated by Gabrielle should reach the east coast of the United States from North Carolina northward, along with Atlantic Canada, later this weekend into early next week. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1100 PM AST. $$ Forecaster Beven

...GABRIELLE EXPECTED TO BECOME A HURRICANE TONIGHT OR ON SUNDAY... ...EXPECTED TO PASS EAST OF BERMUDA SUNDAY NIGHT OR MONDAY... As of 5:00 PM AST Sat Sep 20 the center of Gabrielle was located near 25.6, -59.0 with movement NW at 10 mph. The minimum central pressure was 996 mb with maximum sustained winds of about 65 mph.

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...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 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...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 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...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 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...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 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...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 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...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 0247 PM CDT Sat Sep 20 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Day 2/Sunday Update... No changes to previous forecast with no large scale fire weather concerns across CONUS. ...North Cascades into the Columbia Basin... A mid-level trough and cold front will move through the Pacific Northwest Sunday. Increasing cloud cover, higher relative humidity with increasing onshore flow, and potential for light rain showers during the day will suppress the fire weather threat across the Columbia Basin, despite locally higher Cascade gap winds from the west of up to 20 mph. ..Williams.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1254 AM CDT Sat Sep 20 2025/ ...Synopsis... On Sunday-- weak surface winds, higher relative humidity, and high precipitable water content with forecast convection will generally suppress any fire-weather concerns across the continental U.S. ...North Cascades into the Columbia Basin... While conditions are forecast to be windier than Saturday, gusting as high as 15-20 MPH, relative humidity is forecast to remain above 30% due to persistent cloud cover and light precipitation. Though fuels are modestly receptive to wildfire ignition and spread, these conditions will limit the overall potential for that to occur. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sat Sep 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms may impact parts of the south-central Plains this afternoon and evening, accompanied by an isolated threat for strong to severe wind gusts and marginally severe hail. ...20z... ...Oklahoma... The primary update for this forecast was a slight northward expansion of severe probabilities into far southern KS to encompass the placement of a weak surface front analyzed in recent surface observations. This boundary may act as a foci for thunderstorm development later this evening and likely delimits the northern extent of appreciable buoyancy/severe threat. Additionally, a targeted corridor of 2% tornado probabilities was introduced to parts of northeastern OK and far southeast KS. A residual outflow boundary is noted in surface observations with temperatures on the cool side of the boundary increasing into the low/mid 80s and dewpoints remaining in the upper 60s. RAP mesoanalysis estimates suggest MLCAPE has increased to around 2000 J/kg along this boundary with decreasing inhibition, and VWP observations from KINX (Tulsa, OK) sample 0-1 km SRH on the order of 125 m2/s2. This low-level SRH and low through the lowest 3 km is notably stronger than depicted by morning/early afternoon model guidance, and is sufficient for at least a brief tornado threat (though this threat is conditional on semi-discrete thunderstorm development on/near the boundary). Elsewhere, the forecast largely remains on track. Latest GOES imagery and lightning data show initial thunderstorm development from the OK/TX Panhandles into southwest OK. Thunderstorm coverage should steadily increase through the evening across western to central OK. Regional VWP observations continue to show meager deep-layer wind shear, which implies that convection will largely remain only loosely organized. While instances of large hail are possible, strong heating/boundary-layer mixing will promote sporadic strong to severe gusts this afternoon/evening (see MCD #2106 for additional details). ...Illinois... Consideration was given to introducing 5% hail probabilities across central to northeast IL. Thunderstorms across this region have periodically intensified to near severe limits based on MRMS hail and vertical ice metrics. However, weak shear has limited storm longevity with most convective cores persisting for only around 10-20 minutes. This trend should continue through early evening, but the overall duration and coverage is expected to remain sufficiently limited to warrant broader risk probabilities. ..Moore.. 09/20/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat Sep 20 2025/ ...South-Central Plains... Visible-satellite imagery late this morning shows a couple of small thunderstorm clusters over parts of the Ozarks into northeast OK and mostly clear skies farther west and southwest over OK into the TX Panhandle. Surface analysis places a zone of outflow extending from west-central AR northwestward into north-central OK. The primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast by mid-late afternoon across the Marginal Risk. A relatively non-descript upper pattern, north of a flattened upper ridge, features a couple of very minor perturbations slowly moving east across the central High Plains into the mid MS Valley, to the south of more amplified disturbances over the upper MS Valley and ND. Weak capping and the aforementioned seasonably moist airmass will favor isolated to scattered thunderstorms developing near the front and outflow late this afternoon into the evening. Diurnal steepening of low-level lapse rates may yield an isolated risk for localized severe gusts and perhaps marginally severe hail. This activity will likely diminish by mid evening owing to the loss of heating. ...Upper Midwest/Great Lakes... An upper trough centered near the IA/WI/MN/IL border will continue to slowly migrate east across WI/northern IL today. Similar to areas farther southwest over the south-central Plains, a seasonably moist will undergo some heating in areas void of thicker cloud cover and aid in 1000 J/kg MLCAPE developing over WI according to forecast soundings. Weak 0-6 km shear (i.e., < 20 kt) should temper updraft organization and limit storm intensity. Nonetheless, a couple of strong gusts or small hail may occur with the more vigorous storms this afternoon. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sat Sep 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHWEST/SOUTH-CENTRAL KANSAS...WESTERN/CENTRAL OKLAHOMA...AND THE EASTERN TEXAS/OKLAHOMA PANHANDLES... ...SUMMARY... Scattered severe thunderstorms will be possible on Monday across portions of the central and southern High Plains. ...Central and Southern Plains... A substantial midlevel wave will track southeastward across the central Rockies into the adjacent High Plains on Monday. In the low-levels, a surface front will extend from NE southward across western KS to an evolving triple point in the vicinity of southwest KS. In response to the approaching wave, strong low-level positive theta-e advection beneath a robust EML will yield a strongly unstable air mass across parts of the southern and central Plains. As midlevel height falls preceding the wave impinge on the surface boundary and triple point, inhibition at the base of the EML should gradually erode and support widely scattered thunderstorms by late afternoon. Around 40-50 kt of off-boundary deep-layer shear should initially support semi-discrete supercells with a risk of large hail and severe wind gusts across parts of western KS into the eastern OK/TX Panhandles. Additional strong to severe thunderstorms are expected farther north along the surface front into NE, though deep-layer shear will be weaker here in comparison. With time, thunderstorms will spread/develop east-southeastward across KS and western/central OK into a strengthening southerly low-level jet during the evening/overnight hours. This should promote a continuation of embedded supercells and upscale growth into one or more southeastward-moving MCSs. Severe hail and swath of wind damage will be possible with this convective evolution. ..Weinman.. 09/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sat Sep 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHWEST/SOUTH-CENTRAL KANSAS...WESTERN/CENTRAL OKLAHOMA...AND THE EASTERN TEXAS/OKLAHOMA PANHANDLES... ...SUMMARY... Scattered severe thunderstorms will be possible on Monday across portions of the central and southern High Plains. ...Central and Southern Plains... A substantial midlevel wave will track southeastward across the central Rockies into the adjacent High Plains on Monday. In the low-levels, a surface front will extend from NE southward across western KS to an evolving triple point in the vicinity of southwest KS. In response to the approaching wave, strong low-level positive theta-e advection beneath a robust EML will yield a strongly unstable air mass across parts of the southern and central Plains. As midlevel height falls preceding the wave impinge on the surface boundary and triple point, inhibition at the base of the EML should gradually erode and support widely scattered thunderstorms by late afternoon. Around 40-50 kt of off-boundary deep-layer shear should initially support semi-discrete supercells with a risk of large hail and severe wind gusts across parts of western KS into the eastern OK/TX Panhandles. Additional strong to severe thunderstorms are expected farther north along the surface front into NE, though deep-layer shear will be weaker here in comparison. With time, thunderstorms will spread/develop east-southeastward across KS and western/central OK into a strengthening southerly low-level jet during the evening/overnight hours. This should promote a continuation of embedded supercells and upscale growth into one or more southeastward-moving MCSs. Severe hail and swath of wind damage will be possible with this convective evolution. ..Weinman.. 09/20/2025 Read more