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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Sat Sep 20 2025 Valid 201630Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...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. ..Smith/Wendt.. 09/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Sat Sep 20 2025 Valid 201630Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...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. ..Smith/Wendt.. 09/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Sat Sep 20 2025 Valid 201630Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...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. ..Smith/Wendt.. 09/20/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Sat Sep 20 2025 Valid 201630Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...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. ..Smith/Wendt.. 09/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Sat Sep 20 2025 Valid 201300Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...South-Central Plains... A small cluster of thunderstorms across northeast OK, southwest MO, and northwest AR this morning has remained mostly sub-severe overnight owing to weak instability and deep-layer shear. Current expectations are for this activity to further weaken as it spreads eastward across AR and southern MO through mid/late morning. Outflow from these thunderstorms has surged southward across much of OK per radar imagery. Recent surface observations also show the primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast to exist this afternoon along/south of the front where daytime heating occurs. Large-scale ascent aloft will remain nebulous/weak, with multiple low-amplitude mid-level perturbations present on the eastern periphery of upper ridging centered over Mexico and the Southwest. Still, isolated to scattered thunderstorms should develop this afternoon and evening, potentially along and south of the residual outflow boundary from the ongoing convection this morning. As low-level lapse rates become steepened through the day, isolated strong to severe gusts may occur with the more robust thunderstorms that form. Even though deep-layer shear will remain meager, modestly steepened mid-level lapse rates and cool temperatures aloft may also support occasional hail. The Marginal Risk has been adjusted for the latest guidance and observational trends, with somewhat greater confidence in convection occurring across the OK/TX Panhandles into OK along/near the outflow boundary compared to locations farther north in KS along the front. ...Upper Midwest/Great Lakes... A weak upper trough over the Upper Midwest this morning will translate slowly eastward across parts of the OH Valley and Upper Great Lakes through the period. A seasonably moist low-level airmass will remain over these areas along/south of a front, but mid-level lapse rates are expected to remain quite poor. Ongoing precipitation and cloud cover should also temper destabilization to some degree through this afternoon, with only weak MLCAPE forecast to develop. While isolated strong/gusty winds and small hail may occur with any of the stronger cores that can form later this afternoon across parts of WI into northern IL/IN and southern Lower MI, the overall severe threat appears too limited to include low severe probabilities at this time. ..Gleason/Grams.. 09/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Sat Sep 20 2025 Valid 201300Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...South-Central Plains... A small cluster of thunderstorms across northeast OK, southwest MO, and northwest AR this morning has remained mostly sub-severe overnight owing to weak instability and deep-layer shear. Current expectations are for this activity to further weaken as it spreads eastward across AR and southern MO through mid/late morning. Outflow from these thunderstorms has surged southward across much of OK per radar imagery. Recent surface observations also show the primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast to exist this afternoon along/south of the front where daytime heating occurs. Large-scale ascent aloft will remain nebulous/weak, with multiple low-amplitude mid-level perturbations present on the eastern periphery of upper ridging centered over Mexico and the Southwest. Still, isolated to scattered thunderstorms should develop this afternoon and evening, potentially along and south of the residual outflow boundary from the ongoing convection this morning. As low-level lapse rates become steepened through the day, isolated strong to severe gusts may occur with the more robust thunderstorms that form. Even though deep-layer shear will remain meager, modestly steepened mid-level lapse rates and cool temperatures aloft may also support occasional hail. The Marginal Risk has been adjusted for the latest guidance and observational trends, with somewhat greater confidence in convection occurring across the OK/TX Panhandles into OK along/near the outflow boundary compared to locations farther north in KS along the front. ...Upper Midwest/Great Lakes... A weak upper trough over the Upper Midwest this morning will translate slowly eastward across parts of the OH Valley and Upper Great Lakes through the period. A seasonably moist low-level airmass will remain over these areas along/south of a front, but mid-level lapse rates are expected to remain quite poor. Ongoing precipitation and cloud cover should also temper destabilization to some degree through this afternoon, with only weak MLCAPE forecast to develop. While isolated strong/gusty winds and small hail may occur with any of the stronger cores that can form later this afternoon across parts of WI into northern IL/IN and southern Lower MI, the overall severe threat appears too limited to include low severe probabilities at this time. ..Gleason/Grams.. 09/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Sat Sep 20 2025 Valid 201300Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...South-Central Plains... A small cluster of thunderstorms across northeast OK, southwest MO, and northwest AR this morning has remained mostly sub-severe overnight owing to weak instability and deep-layer shear. Current expectations are for this activity to further weaken as it spreads eastward across AR and southern MO through mid/late morning. Outflow from these thunderstorms has surged southward across much of OK per radar imagery. Recent surface observations also show the primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast to exist this afternoon along/south of the front where daytime heating occurs. Large-scale ascent aloft will remain nebulous/weak, with multiple low-amplitude mid-level perturbations present on the eastern periphery of upper ridging centered over Mexico and the Southwest. Still, isolated to scattered thunderstorms should develop this afternoon and evening, potentially along and south of the residual outflow boundary from the ongoing convection this morning. As low-level lapse rates become steepened through the day, isolated strong to severe gusts may occur with the more robust thunderstorms that form. Even though deep-layer shear will remain meager, modestly steepened mid-level lapse rates and cool temperatures aloft may also support occasional hail. The Marginal Risk has been adjusted for the latest guidance and observational trends, with somewhat greater confidence in convection occurring across the OK/TX Panhandles into OK along/near the outflow boundary compared to locations farther north in KS along the front. ...Upper Midwest/Great Lakes... A weak upper trough over the Upper Midwest this morning will translate slowly eastward across parts of the OH Valley and Upper Great Lakes through the period. A seasonably moist low-level airmass will remain over these areas along/south of a front, but mid-level lapse rates are expected to remain quite poor. Ongoing precipitation and cloud cover should also temper destabilization to some degree through this afternoon, with only weak MLCAPE forecast to develop. While isolated strong/gusty winds and small hail may occur with any of the stronger cores that can form later this afternoon across parts of WI into northern IL/IN and southern Lower MI, the overall severe threat appears too limited to include low severe probabilities at this time. ..Gleason/Grams.. 09/20/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0738 AM CDT Sat Sep 20 2025 Valid 201300Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTH-CENTRAL 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. ...South-Central Plains... A small cluster of thunderstorms across northeast OK, southwest MO, and northwest AR this morning has remained mostly sub-severe overnight owing to weak instability and deep-layer shear. Current expectations are for this activity to further weaken as it spreads eastward across AR and southern MO through mid/late morning. Outflow from these thunderstorms has surged southward across much of OK per radar imagery. Recent surface observations also show the primary front arcs from the OK Panhandle vicinity northeastward into central/eastern KS. A moist and moderately unstable airmass is forecast to exist this afternoon along/south of the front where daytime heating occurs. Large-scale ascent aloft will remain nebulous/weak, with multiple low-amplitude mid-level perturbations present on the eastern periphery of upper ridging centered over Mexico and the Southwest. Still, isolated to scattered thunderstorms should develop this afternoon and evening, potentially along and south of the residual outflow boundary from the ongoing convection this morning. As low-level lapse rates become steepened through the day, isolated strong to severe gusts may occur with the more robust thunderstorms that form. Even though deep-layer shear will remain meager, modestly steepened mid-level lapse rates and cool temperatures aloft may also support occasional hail. The Marginal Risk has been adjusted for the latest guidance and observational trends, with somewhat greater confidence in convection occurring across the OK/TX Panhandles into OK along/near the outflow boundary compared to locations farther north in KS along the front. ...Upper Midwest/Great Lakes... A weak upper trough over the Upper Midwest this morning will translate slowly eastward across parts of the OH Valley and Upper Great Lakes through the period. A seasonably moist low-level airmass will remain over these areas along/south of a front, but mid-level lapse rates are expected to remain quite poor. Ongoing precipitation and cloud cover should also temper destabilization to some degree through this afternoon, with only weak MLCAPE forecast to develop. While isolated strong/gusty winds and small hail may occur with any of the stronger cores that can form later this afternoon across parts of WI into northern IL/IN and southern Lower MI, the overall severe threat appears too limited to include low severe probabilities at this time. ..Gleason/Grams.. 09/20/2025 Read more

000
ABPZ20 KNHC 201129
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 AM PDT Sat Sep 20 2025

For the eastern and central North Pacific east of 180 longitude:

South of the Baja California Peninsula (EP96):
Shower and thunderstorm activity remains limited in association with
an area of low pressure located a few hundred miles southwest of the
southern tip of the Baja California Peninsula. The system is
forecast to move west-northwestward into a more hostile environment
later today and tonight, where cooler waters and a drier airmass
will inhibit further development.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

Off the Coast of Southern Mexico (EP97):
A broad area of low pressure located a couple of hundred miles south
of the southern coast of Mexico is producing a large area of
disorganized showers and thunderstorms. No development is expected
today while wind shear remains strong. However, environmental
conditions are forecast to become more conducive along the path of
the system beginning late this weekend, and a tropical depression is
likely to form early next week while it moves west-northwestward at
5 to 10 mph, roughly parallel to the coast of southern and
southwestern Mexico.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...80 percent.

$$
Forecaster Hagen

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0346 AM CDT Sat Sep 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... A complex, low-predictability upper pattern will exist next week and should eventually evolve into a closed upper low somewhere across the eastern CONUS by the end of the week. The operational ECMWF and GFS have significantly different evolution of the upper pattern, almost switching places from the solution each showed 24 hours ago. The ECMWF is now more progressive with a large cutoff low from the GFS by Wed/D5 and Thu/D6. Even the EPS and GEFS (which showed similar 500mb solutions 24 hours ago) have diverged and have lead to increasing predictability concerns. Therefore, beyond Day 4, some severe weather chances are possible within the warm sector ahead of a surface front. However, significant differences in timing and evolution of the pattern cast uncertainty on the overall threat. ...Day 4/Tuesday... As the stronger mid-level trough emerges across the Plains Monday night, a low-level jet will strengthen across Oklahoma. Therefore, a MCS will likely be ongoing at 12Z Tuesday in the Oklahoma vicinity. Moderate destabilization is forecast to the south of the remnant MCS/outflow boundary on Tuesday. This region will likely be the focus for some severe weather threat. It is unclear how the Monday/D3 convection will evolve and how that may impact Tuesday, but there is some potential for severe storms Tuesday afternoon/evening. Once the evolution of the mid-level trough and location of Monday night convection becomes more clear, severe weather probabilities may be needed. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0346 AM CDT Sat Sep 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... A complex, low-predictability upper pattern will exist next week and should eventually evolve into a closed upper low somewhere across the eastern CONUS by the end of the week. The operational ECMWF and GFS have significantly different evolution of the upper pattern, almost switching places from the solution each showed 24 hours ago. The ECMWF is now more progressive with a large cutoff low from the GFS by Wed/D5 and Thu/D6. Even the EPS and GEFS (which showed similar 500mb solutions 24 hours ago) have diverged and have lead to increasing predictability concerns. Therefore, beyond Day 4, some severe weather chances are possible within the warm sector ahead of a surface front. However, significant differences in timing and evolution of the pattern cast uncertainty on the overall threat. ...Day 4/Tuesday... As the stronger mid-level trough emerges across the Plains Monday night, a low-level jet will strengthen across Oklahoma. Therefore, a MCS will likely be ongoing at 12Z Tuesday in the Oklahoma vicinity. Moderate destabilization is forecast to the south of the remnant MCS/outflow boundary on Tuesday. This region will likely be the focus for some severe weather threat. It is unclear how the Monday/D3 convection will evolve and how that may impact Tuesday, but there is some potential for severe storms Tuesday afternoon/evening. Once the evolution of the mid-level trough and location of Monday night convection becomes more clear, severe weather probabilities may be needed. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0346 AM CDT Sat Sep 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... A complex, low-predictability upper pattern will exist next week and should eventually evolve into a closed upper low somewhere across the eastern CONUS by the end of the week. The operational ECMWF and GFS have significantly different evolution of the upper pattern, almost switching places from the solution each showed 24 hours ago. The ECMWF is now more progressive with a large cutoff low from the GFS by Wed/D5 and Thu/D6. Even the EPS and GEFS (which showed similar 500mb solutions 24 hours ago) have diverged and have lead to increasing predictability concerns. Therefore, beyond Day 4, some severe weather chances are possible within the warm sector ahead of a surface front. However, significant differences in timing and evolution of the pattern cast uncertainty on the overall threat. ...Day 4/Tuesday... As the stronger mid-level trough emerges across the Plains Monday night, a low-level jet will strengthen across Oklahoma. Therefore, a MCS will likely be ongoing at 12Z Tuesday in the Oklahoma vicinity. Moderate destabilization is forecast to the south of the remnant MCS/outflow boundary on Tuesday. This region will likely be the focus for some severe weather threat. It is unclear how the Monday/D3 convection will evolve and how that may impact Tuesday, but there is some potential for severe storms Tuesday afternoon/evening. Once the evolution of the mid-level trough and location of Monday night convection becomes more clear, severe weather probabilities may be needed. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0346 AM CDT Sat Sep 20 2025 Valid 231200Z - 281200Z ...DISCUSSION... A complex, low-predictability upper pattern will exist next week and should eventually evolve into a closed upper low somewhere across the eastern CONUS by the end of the week. The operational ECMWF and GFS have significantly different evolution of the upper pattern, almost switching places from the solution each showed 24 hours ago. The ECMWF is now more progressive with a large cutoff low from the GFS by Wed/D5 and Thu/D6. Even the EPS and GEFS (which showed similar 500mb solutions 24 hours ago) have diverged and have lead to increasing predictability concerns. Therefore, beyond Day 4, some severe weather chances are possible within the warm sector ahead of a surface front. However, significant differences in timing and evolution of the pattern cast uncertainty on the overall threat. ...Day 4/Tuesday... As the stronger mid-level trough emerges across the Plains Monday night, a low-level jet will strengthen across Oklahoma. Therefore, a MCS will likely be ongoing at 12Z Tuesday in the Oklahoma vicinity. Moderate destabilization is forecast to the south of the remnant MCS/outflow boundary on Tuesday. This region will likely be the focus for some severe weather threat. It is unclear how the Monday/D3 convection will evolve and how that may impact Tuesday, but there is some potential for severe storms Tuesday afternoon/evening. Once the evolution of the mid-level trough and location of Monday night convection becomes more clear, severe weather probabilities may be needed. Read more

5-Day Uncertainty Track last updated Sat, 20 Sep 2025 08:40:03 GMT


Wind Speed Probabilities last updated Sat, 20 Sep 2025 08:40:03 GMT

Issued at 500 AM AST Sat Sep 20 2025 000 WTNT42 KNHC 200837 TCDAT2 Tropical Storm Gabrielle Discussion Number 13 NWS National Hurricane Center Miami FL AL072025 500 AM AST Sat Sep 20 2025 Although Gabrielle's low-level center is obscured by high cirrus clouds, an 0555 UTC AMSR2 microwave pass confirms that it is still located to the west of the deep convective mass due to continued moderate westerly shear. The convection itself has been quite intense, with a high density of lightning co-located with cloud-top temperatures as cold as -85 to -90 degrees Celsius. The latest satellite intensity estimates, as well as ASCAT data from yesterday evening, still support an intensity of 45 kt. The ASCAT data also showed that there are currently no tropical-storm-force winds on Gabrielle's western side. Mid-tropospheric high pressure over the central Atlantic is steering Gabrielle northwestward, or 315 degrees at 11 kt. The storm is expected to recurve between the western periphery of the high and a trough located over the southeastern United States over the next several days. Mostly because of an adjustment of Gabrielle's initial position, the new NHC track forecast has been adjusted a bit west of the previous prediction during the first 3 days of the forecast. That said, all of the reliable track models continue to keep the core of Gabrielle well east of Bermuda Sunday night and Monday during the recurvature. By Tuesday, global model fields indicate that Gabrielle will become embedded in fast zonal mid-latitude flow, and there has been a significant southward shift in the track models on days 4 and 5. The NHC track forecast has also been adjusted southward at those times, close to the HCCA and Google DeepMind ensemble but not as far south as the GFS and many of the multi-model consensus aids. Vertical shear is expected to decrease over the next day or two, which should allow Gabrielle's circulation to become more vertically aligned, leading to strengthening. The intensity models are generally split into two camps. The statistical-dynamical models (SHIPS and LGEM) and global models (GFS and ECMWF) are more subdued on the amount of strengthening that Gabrielle might experience. The regional hurricane models, as well as the HCCA and Florida State Superensemble, are more aggressive, with the HAFS models in particular bringing Gabrielle to major hurricane strength in about 2 days. While not going that high, the NHC intensity forecast is close to the other models in that camp and continues to show a possible peak of 90 kt in 60-72 hours. With the southward shift in the track forecast at days 4 and 5, Gabrielle's extratropical transition has likely been delayed, and the official forecast continues to depict a tropical cyclone through the next 5 days. KEY MESSAGES: 1. Gabrielle is forecast to become a hurricane by Sunday and pass east of Bermuda Sunday night and Monday. Interests on Bermuda should continue to monitor Gabrielle's forecasts since some wind and rainfall impacts are still possible. 2. Swells generated by Gabrielle are beginning to reach Bermuda and will build through the weekend. These swells are likely to cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 24.3N 58.1W 45 KT 50 MPH 12H 20/1800Z 25.4N 59.3W 50 KT 60 MPH 24H 21/0600Z 27.0N 60.5W 60 KT 70 MPH 36H 21/1800Z 28.6N 61.6W 70 KT 80 MPH 48H 22/0600Z 30.3N 62.1W 80 KT 90 MPH 60H 22/1800Z 32.1N 61.3W 90 KT 105 MPH 72H 23/0600Z 34.0N 59.1W 90 KT 105 MPH 96H 24/0600Z 37.0N 50.6W 80 KT 90 MPH 120H 25/0600Z 38.7N 38.5W 65 KT 75 MPH $$ Forecaster Berg

Issued at 0900 UTC SAT SEP 20 2025 292 FONT12 KNHC 200836 PWSAT2 TROPICAL STORM GABRIELLE WIND SPEED PROBABILITIES NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072025 0900 UTC SAT SEP 20 2025 AT 0900Z THE CENTER OF TROPICAL STORM GABRIELLE WAS LOCATED NEAR LATITUDE 24.3 NORTH...LONGITUDE 58.1 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 45 KTS...50 MPH...85 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 06Z SAT AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 06Z SAT 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED PERIODS TO TO TO TO TO TO TO 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED 06Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT SANTA CRUZ AZO 34 X X( X) X( X) X( X) X( X) X( X) 6( 6) BERMUDA 34 X X( X) 5( 5) 14(19) 16(35) X(35) X(35) BERMUDA 50 X X( X) X( X) 1( 1) 5( 6) X( 6) X( 6) BERMUDA 64 X X( X) X( X) X( X) 2( 2) X( 2) X( 2) $$ FORECASTER BERG

Issued at 500 AM AST Sat Sep 20 2025 275 WTNT32 KNHC 200836 TCPAT2 BULLETIN Tropical Storm Gabrielle Advisory Number 13 NWS National Hurricane Center Miami FL AL072025 500 AM AST Sat Sep 20 2025 ...GABRIELLE MOVING NORTHWESTWARD... ...EXPECTED TO BECOME A HURRICANE AND PASS EAST OF BERMUDA SUNDAY NIGHT AND MONDAY... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...24.3N 58.1W ABOUT 530 MI...855 KM NE OF THE NORTHERN LEEWARD ISLANDS ABOUT 685 MI...1105 KM SE OF BERMUDA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...NW OR 315 DEGREES AT 13 MPH...20 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 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 AM AST (0900 UTC), the center of Tropical Storm Gabrielle was located near latitude 24.3 North, longitude 58.1 West. Gabrielle is moving toward the northwest near 13 mph (20 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 and Monday. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Gradual strengthening is forecast, and Gabrielle is expected to become a hurricane by Sunday. Tropical-storm-force winds extend outward up to 140 miles (220 km) to the east of the center. The estimated minimum central pressure is 1004 mb (29.65 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. 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 AM AST. $$ Forecaster Berg

...GABRIELLE MOVING NORTHWESTWARD... ...EXPECTED TO BECOME A HURRICANE AND PASS EAST OF BERMUDA SUNDAY NIGHT AND MONDAY... As of 5:00 AM AST Sat Sep 20 the center of Gabrielle was located near 24.3, -58.1 with movement NW at 13 mph. The minimum central pressure was 1004 mb with maximum sustained winds of about 50 mph.

Issued at 0900 UTC SAT SEP 20 2025 000 WTNT22 KNHC 200836 TCMAT2 TROPICAL STORM GABRIELLE FORECAST/ADVISORY NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072025 0900 UTC SAT SEP 20 2025 TROPICAL STORM CENTER LOCATED NEAR 24.3N 58.1W AT 20/0900Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 315 DEGREES AT 11 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1004 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT.......120NE 110SE 0SW 0NW. 4 M SEAS....210NE 120SE 120SW 210NW. 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 24.3N 58.1W AT 20/0900Z AT 20/0600Z CENTER WAS LOCATED NEAR 23.9N 57.7W FORECAST VALID 20/1800Z 25.4N 59.3W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 20NE 0SE 0SW 0NW. 34 KT...120NE 110SE 0SW 0NW. FORECAST VALID 21/0600Z 27.0N 60.5W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 25NE 20SE 0SW 0NW. 34 KT...120NE 110SE 30SW 30NW. FORECAST VALID 21/1800Z 28.6N 61.6W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 20NE 15SE 0SW 0NW. 50 KT... 40NE 30SE 20SW 20NW. 34 KT...120NE 120SE 40SW 50NW. FORECAST VALID 22/0600Z 30.3N 62.1W MAX WIND 80 KT...GUSTS 100 KT. 64 KT... 20NE 15SE 10SW 10NW. 50 KT... 40NE 30SE 20SW 20NW. 34 KT...120NE 120SE 50SW 70NW. FORECAST VALID 22/1800Z 32.1N 61.3W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 25NE 20SE 10SW 15NW. 50 KT... 40NE 40SE 30SW 30NW. 34 KT...120NE 130SE 60SW 70NW. FORECAST VALID 23/0600Z 34.0N 59.1W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 30NE 30SE 20SW 20NW. 50 KT... 40NE 50SE 40SW 40NW. 34 KT...120NE 140SE 70SW 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 24/0600Z 37.0N 50.6W MAX WIND 80 KT...GUSTS 100 KT. 50 KT... 40NE 60SE 50SW 40NW. 34 KT...110NE 150SE 110SW 70NW. OUTLOOK VALID 25/0600Z 38.7N 38.5W MAX WIND 65 KT...GUSTS 80 KT. 50 KT... 40NE 50SE 50SW 40NW. 34 KT... 90NE 140SE 130SW 90NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 24.3N 58.1W NEXT ADVISORY AT 20/1500Z $$ FORECASTER BERG