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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 AM CDT Thu Sep 04 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN NORTH CAROLINA NORTHWARD INTO SOUTHERN PENNSYLVANIA... ...SUMMARY... Strong thunderstorms are expected from northern North Carolina into southern Pennsylvania on Saturday. The strongest storms may pose a threat for damaging winds. ... Discussion ... A surface cold front will slowly move east across the eastern US on Saturday. Along and ahead of this front, surface temperatures should warm into the upper-80Fs to low-90Fs from the Mid-Atlantic region southward into the Carolinas, with surface dewpoint temperatures in the upper-60Fs to low-70Fs. As a result a corridor of instability perhaps as great as 2000 J/kg will develop from North Carolina northward into the Mid-Atlantic area. Isolated to scattered thunderstorms should develop during the afternoon along the slow moving front across the Carolinas into the Mid Atlantic. Despite deep layer shear on the order of 40 knots and 2000 J/kg CAPE, poor mid-level lapse rates and precipitable water values around 1.75 inches should limit the overall severe threat to the potential for isolated damaging thunderstorm winds. ..Marsh.. 09/04/2025 Read more

5-Day Uncertainty Track last updated Thu, 04 Sep 2025 05:46:06 GMT


Wind Speed Probabilities last updated Thu, 04 Sep 2025 03:26:46 GMT

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS STRETCHING FROM NORTHERN TEXAS NORTHEAST INTO SOUTHERN OHIO... ...SUMMARY... Strong thunderstorms will be possible from the southern Plains into the Ohio and Tennessee Valleys during the afternoon into the overnight hours. Isolated large hail and damaging winds may be possible with the strongest storms. ... Synopsis ... A seasonably strong/cold midlevel low will persist across Ontario, with an attendant larger-scale trough persisting across much of the eastern United States. A potent midlevel shortwave trough will be across the Upper Great Lakes at the start of the period and will quickly rotate around the upper low into Quebec through the period. In its wake a midlevel ribbon of higher vorticity will be left behind from Iowa northeast across Michigan. Upstream from this, the midlevel height field will begin to respond to another shortwave trough rotating around the Ontario low. At the surface, a surface low will quickly lift northeast from northern Michigan through Ontario and into Quebec through the forecast period. A cold from will extend southwest from this low and will push south and east as the surface low lifts northeast. Although somewhat diffuse initially, the temperature gradient across the cold front will rapidly strengthen through the day. ... Ohio and Tennessee Valleys ... Diurnal heating should allow afternoon temperatures to warm into the 80Fs and 90Fs across the region. Given surface dewpoint temperatures in the mid 60Fs perhaps as far north as southern Ohio, this heating will result in most-unstable CAPE values in excess of 2000 J/kg across the area. The region will also be on the periphery of the stronger midlevel flow, yield effective shear of around 40 knots. Thunderstorms should develop by late afternoon in response to increasing large-scale ascent associated with both differential vorticity advection and frontal circulations. Given the degree of instability and effective layer shear, initial thunderstorms may exhibit supercellular structures. However, given the temperature-dewpoint spreads on the order of 20F+ the expectation is that thunderstorms should tend to favor upscale growth toward linear segments. As such, thunderstorms may initially pose a hail threat, especially across western Kentucky and Tennessee, but should transition to more of a wind threat with eastward extent. Across portions of Kentucky and southern Ohio, a short-window, conditional tornado threat may evolve as thunderstorms develop in the vicinity of the surface boundary. As thunderstorms interact with or cross over the boundary, strong northeasterly surface winds will enlarge low-level hodographs supporting at least some tornado threat. ... Greater Arklatex Region ... The surface cold front across the region is expected to strengthen during the day as it slowly moves south. During the evening into the overnight hours, strong warm-air advection on the nose of a strengthening low-level jet may support thunderstorm development on the cool side of the cold front. Despite surface temperatures in the 60Fs and low 70Fs, steep mid-level lapse rates atop the colder surface layer may support isolated large hail. ..Marsh.. 09/04/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS STRETCHING FROM NORTHERN TEXAS NORTHEAST INTO SOUTHERN OHIO... ...SUMMARY... Strong thunderstorms will be possible from the southern Plains into the Ohio and Tennessee Valleys during the afternoon into the overnight hours. Isolated large hail and damaging winds may be possible with the strongest storms. ... Synopsis ... A seasonably strong/cold midlevel low will persist across Ontario, with an attendant larger-scale trough persisting across much of the eastern United States. A potent midlevel shortwave trough will be across the Upper Great Lakes at the start of the period and will quickly rotate around the upper low into Quebec through the period. In its wake a midlevel ribbon of higher vorticity will be left behind from Iowa northeast across Michigan. Upstream from this, the midlevel height field will begin to respond to another shortwave trough rotating around the Ontario low. At the surface, a surface low will quickly lift northeast from northern Michigan through Ontario and into Quebec through the forecast period. A cold from will extend southwest from this low and will push south and east as the surface low lifts northeast. Although somewhat diffuse initially, the temperature gradient across the cold front will rapidly strengthen through the day. ... Ohio and Tennessee Valleys ... Diurnal heating should allow afternoon temperatures to warm into the 80Fs and 90Fs across the region. Given surface dewpoint temperatures in the mid 60Fs perhaps as far north as southern Ohio, this heating will result in most-unstable CAPE values in excess of 2000 J/kg across the area. The region will also be on the periphery of the stronger midlevel flow, yield effective shear of around 40 knots. Thunderstorms should develop by late afternoon in response to increasing large-scale ascent associated with both differential vorticity advection and frontal circulations. Given the degree of instability and effective layer shear, initial thunderstorms may exhibit supercellular structures. However, given the temperature-dewpoint spreads on the order of 20F+ the expectation is that thunderstorms should tend to favor upscale growth toward linear segments. As such, thunderstorms may initially pose a hail threat, especially across western Kentucky and Tennessee, but should transition to more of a wind threat with eastward extent. Across portions of Kentucky and southern Ohio, a short-window, conditional tornado threat may evolve as thunderstorms develop in the vicinity of the surface boundary. As thunderstorms interact with or cross over the boundary, strong northeasterly surface winds will enlarge low-level hodographs supporting at least some tornado threat. ... Greater Arklatex Region ... The surface cold front across the region is expected to strengthen during the day as it slowly moves south. During the evening into the overnight hours, strong warm-air advection on the nose of a strengthening low-level jet may support thunderstorm development on the cool side of the cold front. Despite surface temperatures in the 60Fs and low 70Fs, steep mid-level lapse rates atop the colder surface layer may support isolated large hail. ..Marsh.. 09/04/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS STRETCHING FROM NORTHERN TEXAS NORTHEAST INTO SOUTHERN OHIO... ...SUMMARY... Strong thunderstorms will be possible from the southern Plains into the Ohio and Tennessee Valleys during the afternoon into the overnight hours. Isolated large hail and damaging winds may be possible with the strongest storms. ... Synopsis ... A seasonably strong/cold midlevel low will persist across Ontario, with an attendant larger-scale trough persisting across much of the eastern United States. A potent midlevel shortwave trough will be across the Upper Great Lakes at the start of the period and will quickly rotate around the upper low into Quebec through the period. In its wake a midlevel ribbon of higher vorticity will be left behind from Iowa northeast across Michigan. Upstream from this, the midlevel height field will begin to respond to another shortwave trough rotating around the Ontario low. At the surface, a surface low will quickly lift northeast from northern Michigan through Ontario and into Quebec through the forecast period. A cold from will extend southwest from this low and will push south and east as the surface low lifts northeast. Although somewhat diffuse initially, the temperature gradient across the cold front will rapidly strengthen through the day. ... Ohio and Tennessee Valleys ... Diurnal heating should allow afternoon temperatures to warm into the 80Fs and 90Fs across the region. Given surface dewpoint temperatures in the mid 60Fs perhaps as far north as southern Ohio, this heating will result in most-unstable CAPE values in excess of 2000 J/kg across the area. The region will also be on the periphery of the stronger midlevel flow, yield effective shear of around 40 knots. Thunderstorms should develop by late afternoon in response to increasing large-scale ascent associated with both differential vorticity advection and frontal circulations. Given the degree of instability and effective layer shear, initial thunderstorms may exhibit supercellular structures. However, given the temperature-dewpoint spreads on the order of 20F+ the expectation is that thunderstorms should tend to favor upscale growth toward linear segments. As such, thunderstorms may initially pose a hail threat, especially across western Kentucky and Tennessee, but should transition to more of a wind threat with eastward extent. Across portions of Kentucky and southern Ohio, a short-window, conditional tornado threat may evolve as thunderstorms develop in the vicinity of the surface boundary. As thunderstorms interact with or cross over the boundary, strong northeasterly surface winds will enlarge low-level hodographs supporting at least some tornado threat. ... Greater Arklatex Region ... The surface cold front across the region is expected to strengthen during the day as it slowly moves south. During the evening into the overnight hours, strong warm-air advection on the nose of a strengthening low-level jet may support thunderstorm development on the cool side of the cold front. Despite surface temperatures in the 60Fs and low 70Fs, steep mid-level lapse rates atop the colder surface layer may support isolated large hail. ..Marsh.. 09/04/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS STRETCHING FROM NORTHERN TEXAS NORTHEAST INTO SOUTHERN OHIO... ...SUMMARY... Strong thunderstorms will be possible from the southern Plains into the Ohio and Tennessee Valleys during the afternoon into the overnight hours. Isolated large hail and damaging winds may be possible with the strongest storms. ... Synopsis ... A seasonably strong/cold midlevel low will persist across Ontario, with an attendant larger-scale trough persisting across much of the eastern United States. A potent midlevel shortwave trough will be across the Upper Great Lakes at the start of the period and will quickly rotate around the upper low into Quebec through the period. In its wake a midlevel ribbon of higher vorticity will be left behind from Iowa northeast across Michigan. Upstream from this, the midlevel height field will begin to respond to another shortwave trough rotating around the Ontario low. At the surface, a surface low will quickly lift northeast from northern Michigan through Ontario and into Quebec through the forecast period. A cold from will extend southwest from this low and will push south and east as the surface low lifts northeast. Although somewhat diffuse initially, the temperature gradient across the cold front will rapidly strengthen through the day. ... Ohio and Tennessee Valleys ... Diurnal heating should allow afternoon temperatures to warm into the 80Fs and 90Fs across the region. Given surface dewpoint temperatures in the mid 60Fs perhaps as far north as southern Ohio, this heating will result in most-unstable CAPE values in excess of 2000 J/kg across the area. The region will also be on the periphery of the stronger midlevel flow, yield effective shear of around 40 knots. Thunderstorms should develop by late afternoon in response to increasing large-scale ascent associated with both differential vorticity advection and frontal circulations. Given the degree of instability and effective layer shear, initial thunderstorms may exhibit supercellular structures. However, given the temperature-dewpoint spreads on the order of 20F+ the expectation is that thunderstorms should tend to favor upscale growth toward linear segments. As such, thunderstorms may initially pose a hail threat, especially across western Kentucky and Tennessee, but should transition to more of a wind threat with eastward extent. Across portions of Kentucky and southern Ohio, a short-window, conditional tornado threat may evolve as thunderstorms develop in the vicinity of the surface boundary. As thunderstorms interact with or cross over the boundary, strong northeasterly surface winds will enlarge low-level hodographs supporting at least some tornado threat. ... Greater Arklatex Region ... The surface cold front across the region is expected to strengthen during the day as it slowly moves south. During the evening into the overnight hours, strong warm-air advection on the nose of a strengthening low-level jet may support thunderstorm development on the cool side of the cold front. Despite surface temperatures in the 60Fs and low 70Fs, steep mid-level lapse rates atop the colder surface layer may support isolated large hail. ..Marsh.. 09/04/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE EAST... ...SUMMARY... Isolated damaging winds are possible across parts of the Northeast to the southern Appalachians and Tennessee Valley from late morning through the afternoon. ...Synopsis... A vertically stacked cyclone will drift north in northern ON, as an intense mid-level jetlet and shortwave trough amplifies from the southern Canadian Prairies across the Upper Midwest/Great Lakes. A leading cold front will progress east into the Northeast to TN Valley by this afternoon, with a separate lee trough diurnally sharpening from VA into NY. ...Southern Appalachians/TN Valley to the Northeast... Convection will likely be ongoing at 12Z along parts of the aforementioned cold front from the Lake Erie to northern KY vicinity. Despite weak mid-level lapse rates, diabatic surface heating ahead of this activity should yield diurnal increases in convective coverage/intensity by late morning across parts of the Cumberland Plateau. This will overlap the northern extent of moderate buoyancy across the TN Valley where low-level moisture is richer. Combined with a more westerly component to mid-level flow near the basal portion of the broad trough, a few semi-discrete and loosely organized cells should develop southward during the afternoon. Locally damaging winds and marginally severe hail are possible, centered on the eastern TN vicinity. Isolated to scattered multicell clusters and short-line segments may also evolve in the afternoon from convection along/ahead of the cold front and lee trough. Weak MLCAPE and poor mid-level lapse rates will temper convective vigor, with damaging wind potential locally augmented where pockets of deeper boundary-layer heating occur. ...Mid-MO Valley... The aforementioned shortwave trough and intense mid-level jetlet amplifying into the Upper Midwest could support a couple brief strong storms in the early evening. A narrow corridor of meager surface-based buoyancy may develop ahead of a sharpening cold front by late afternoon. Modified moisture return in the wake of a prior frontal passage will be limited and convection should remain low-topped given the flimsy buoyancy. Still, the background wind fields and strengthening forcing for ascent render concern for a few locally strong gusts and small hail. ...KS... An accelerating and sharpening cold front will sweep south across the central High/Great Plains tonight. Undercut/elevated convection should form to the cold side of this boundary early Friday morning. Locally strong surface gusts may accompany this activity amid robust low-level northerlies. ..Grams/Thornton.. 09/04/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE EAST... ...SUMMARY... Isolated damaging winds are possible across parts of the Northeast to the southern Appalachians and Tennessee Valley from late morning through the afternoon. ...Synopsis... A vertically stacked cyclone will drift north in northern ON, as an intense mid-level jetlet and shortwave trough amplifies from the southern Canadian Prairies across the Upper Midwest/Great Lakes. A leading cold front will progress east into the Northeast to TN Valley by this afternoon, with a separate lee trough diurnally sharpening from VA into NY. ...Southern Appalachians/TN Valley to the Northeast... Convection will likely be ongoing at 12Z along parts of the aforementioned cold front from the Lake Erie to northern KY vicinity. Despite weak mid-level lapse rates, diabatic surface heating ahead of this activity should yield diurnal increases in convective coverage/intensity by late morning across parts of the Cumberland Plateau. This will overlap the northern extent of moderate buoyancy across the TN Valley where low-level moisture is richer. Combined with a more westerly component to mid-level flow near the basal portion of the broad trough, a few semi-discrete and loosely organized cells should develop southward during the afternoon. Locally damaging winds and marginally severe hail are possible, centered on the eastern TN vicinity. Isolated to scattered multicell clusters and short-line segments may also evolve in the afternoon from convection along/ahead of the cold front and lee trough. Weak MLCAPE and poor mid-level lapse rates will temper convective vigor, with damaging wind potential locally augmented where pockets of deeper boundary-layer heating occur. ...Mid-MO Valley... The aforementioned shortwave trough and intense mid-level jetlet amplifying into the Upper Midwest could support a couple brief strong storms in the early evening. A narrow corridor of meager surface-based buoyancy may develop ahead of a sharpening cold front by late afternoon. Modified moisture return in the wake of a prior frontal passage will be limited and convection should remain low-topped given the flimsy buoyancy. Still, the background wind fields and strengthening forcing for ascent render concern for a few locally strong gusts and small hail. ...KS... An accelerating and sharpening cold front will sweep south across the central High/Great Plains tonight. Undercut/elevated convection should form to the cold side of this boundary early Friday morning. Locally strong surface gusts may accompany this activity amid robust low-level northerlies. ..Grams/Thornton.. 09/04/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE EAST... ...SUMMARY... Isolated damaging winds are possible across parts of the Northeast to the southern Appalachians and Tennessee Valley from late morning through the afternoon. ...Synopsis... A vertically stacked cyclone will drift north in northern ON, as an intense mid-level jetlet and shortwave trough amplifies from the southern Canadian Prairies across the Upper Midwest/Great Lakes. A leading cold front will progress east into the Northeast to TN Valley by this afternoon, with a separate lee trough diurnally sharpening from VA into NY. ...Southern Appalachians/TN Valley to the Northeast... Convection will likely be ongoing at 12Z along parts of the aforementioned cold front from the Lake Erie to northern KY vicinity. Despite weak mid-level lapse rates, diabatic surface heating ahead of this activity should yield diurnal increases in convective coverage/intensity by late morning across parts of the Cumberland Plateau. This will overlap the northern extent of moderate buoyancy across the TN Valley where low-level moisture is richer. Combined with a more westerly component to mid-level flow near the basal portion of the broad trough, a few semi-discrete and loosely organized cells should develop southward during the afternoon. Locally damaging winds and marginally severe hail are possible, centered on the eastern TN vicinity. Isolated to scattered multicell clusters and short-line segments may also evolve in the afternoon from convection along/ahead of the cold front and lee trough. Weak MLCAPE and poor mid-level lapse rates will temper convective vigor, with damaging wind potential locally augmented where pockets of deeper boundary-layer heating occur. ...Mid-MO Valley... The aforementioned shortwave trough and intense mid-level jetlet amplifying into the Upper Midwest could support a couple brief strong storms in the early evening. A narrow corridor of meager surface-based buoyancy may develop ahead of a sharpening cold front by late afternoon. Modified moisture return in the wake of a prior frontal passage will be limited and convection should remain low-topped given the flimsy buoyancy. Still, the background wind fields and strengthening forcing for ascent render concern for a few locally strong gusts and small hail. ...KS... An accelerating and sharpening cold front will sweep south across the central High/Great Plains tonight. Undercut/elevated convection should form to the cold side of this boundary early Friday morning. Locally strong surface gusts may accompany this activity amid robust low-level northerlies. ..Grams/Thornton.. 09/04/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE EAST... ...SUMMARY... Isolated damaging winds are possible across parts of the Northeast to the southern Appalachians and Tennessee Valley from late morning through the afternoon. ...Synopsis... A vertically stacked cyclone will drift north in northern ON, as an intense mid-level jetlet and shortwave trough amplifies from the southern Canadian Prairies across the Upper Midwest/Great Lakes. A leading cold front will progress east into the Northeast to TN Valley by this afternoon, with a separate lee trough diurnally sharpening from VA into NY. ...Southern Appalachians/TN Valley to the Northeast... Convection will likely be ongoing at 12Z along parts of the aforementioned cold front from the Lake Erie to northern KY vicinity. Despite weak mid-level lapse rates, diabatic surface heating ahead of this activity should yield diurnal increases in convective coverage/intensity by late morning across parts of the Cumberland Plateau. This will overlap the northern extent of moderate buoyancy across the TN Valley where low-level moisture is richer. Combined with a more westerly component to mid-level flow near the basal portion of the broad trough, a few semi-discrete and loosely organized cells should develop southward during the afternoon. Locally damaging winds and marginally severe hail are possible, centered on the eastern TN vicinity. Isolated to scattered multicell clusters and short-line segments may also evolve in the afternoon from convection along/ahead of the cold front and lee trough. Weak MLCAPE and poor mid-level lapse rates will temper convective vigor, with damaging wind potential locally augmented where pockets of deeper boundary-layer heating occur. ...Mid-MO Valley... The aforementioned shortwave trough and intense mid-level jetlet amplifying into the Upper Midwest could support a couple brief strong storms in the early evening. A narrow corridor of meager surface-based buoyancy may develop ahead of a sharpening cold front by late afternoon. Modified moisture return in the wake of a prior frontal passage will be limited and convection should remain low-topped given the flimsy buoyancy. Still, the background wind fields and strengthening forcing for ascent render concern for a few locally strong gusts and small hail. ...KS... An accelerating and sharpening cold front will sweep south across the central High/Great Plains tonight. Undercut/elevated convection should form to the cold side of this boundary early Friday morning. Locally strong surface gusts may accompany this activity amid robust low-level northerlies. ..Grams/Thornton.. 09/04/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1249 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... A secondary mid-level wave will traverse the Pacific Northwest on D2/Friday. This wave will bring much cooler temperatures, higher relative humidity, and potential for more widespread thunderstorm activity. While lightning efficiency may increase, increase coverage of thunderstorms and better organization with increasing shear should promote heavier cores and wetting rainfall potential. As such, no isolated thunderstorm areas were included at this time. ..Thornton.. 09/04/2025 ...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 1249 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... A secondary mid-level wave will traverse the Pacific Northwest on D2/Friday. This wave will bring much cooler temperatures, higher relative humidity, and potential for more widespread thunderstorm activity. While lightning efficiency may increase, increase coverage of thunderstorms and better organization with increasing shear should promote heavier cores and wetting rainfall potential. As such, no isolated thunderstorm areas were included at this time. ..Thornton.. 09/04/2025 ...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 1249 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... A secondary mid-level wave will traverse the Pacific Northwest on D2/Friday. This wave will bring much cooler temperatures, higher relative humidity, and potential for more widespread thunderstorm activity. While lightning efficiency may increase, increase coverage of thunderstorms and better organization with increasing shear should promote heavier cores and wetting rainfall potential. As such, no isolated thunderstorm areas were included at this time. ..Thornton.. 09/04/2025 ...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 1249 AM CDT Thu Sep 04 2025 Valid 051200Z - 061200Z ...NO CRITICAL AREAS... ...Synopsis... A secondary mid-level wave will traverse the Pacific Northwest on D2/Friday. This wave will bring much cooler temperatures, higher relative humidity, and potential for more widespread thunderstorm activity. While lightning efficiency may increase, increase coverage of thunderstorms and better organization with increasing shear should promote heavier cores and wetting rainfall potential. As such, no isolated thunderstorm areas were included at this time. ..Thornton.. 09/04/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...Synopsis... A departing mid-level wave will aid in thunderstorm development across portions of northern California into Washington this afternoon. Storm motions today will be slower than in recent days. A mix of wet/dry thunderstorms is expected. However, mainly mid-level moisture and dry sub-cloud layer should reduce rainfall amounts and increase potential for dry lightning strikes to occur. Activity over the last 24-48 hours has generally produced 0.25" of rain with several new fires detected. An area of isolated dry thunderstorm risk was maintained across portions of northern California into central Oregon with this outlook. A strike or two may extend as far north as the Washington Cascades. ..Thornton.. 09/04/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...Synopsis... A departing mid-level wave will aid in thunderstorm development across portions of northern California into Washington this afternoon. Storm motions today will be slower than in recent days. A mix of wet/dry thunderstorms is expected. However, mainly mid-level moisture and dry sub-cloud layer should reduce rainfall amounts and increase potential for dry lightning strikes to occur. Activity over the last 24-48 hours has generally produced 0.25" of rain with several new fires detected. An area of isolated dry thunderstorm risk was maintained across portions of northern California into central Oregon with this outlook. A strike or two may extend as far north as the Washington Cascades. ..Thornton.. 09/04/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...Synopsis... A departing mid-level wave will aid in thunderstorm development across portions of northern California into Washington this afternoon. Storm motions today will be slower than in recent days. A mix of wet/dry thunderstorms is expected. However, mainly mid-level moisture and dry sub-cloud layer should reduce rainfall amounts and increase potential for dry lightning strikes to occur. Activity over the last 24-48 hours has generally produced 0.25" of rain with several new fires detected. An area of isolated dry thunderstorm risk was maintained across portions of northern California into central Oregon with this outlook. A strike or two may extend as far north as the Washington Cascades. ..Thornton.. 09/04/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Thu Sep 04 2025 Valid 041200Z - 051200Z ...Synopsis... A departing mid-level wave will aid in thunderstorm development across portions of northern California into Washington this afternoon. Storm motions today will be slower than in recent days. A mix of wet/dry thunderstorms is expected. However, mainly mid-level moisture and dry sub-cloud layer should reduce rainfall amounts and increase potential for dry lightning strikes to occur. Activity over the last 24-48 hours has generally produced 0.25" of rain with several new fires detected. An area of isolated dry thunderstorm risk was maintained across portions of northern California into central Oregon with this outlook. A strike or two may extend as far north as the Washington Cascades. ..Thornton.. 09/04/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

5-Day Uncertainty Track last updated Thu, 04 Sep 2025 05:46:06 GMT


Wind Speed Probabilities last updated Thu, 04 Sep 2025 03:26:46 GMT

Issued at 1100 PM MST Wed Sep 03 2025 274 WTPZ32 KNHC 040544 TCPEP2 BULLETIN Hurricane Lorena Intermediate Advisory Number 9A NWS National Hurricane Center Miami FL EP122025 1100 PM MST Wed Sep 03 2025 ...LORENA EXPECTED TO WEAKEN QUICKLY ON THURSDAY AND FRIDAY... ...RISK OF LIFE-THREATENING FLASH FLOODING CONTINUES FOR BAJA CALIFORNIA SUR AND SOUTHWESTERN SONORA... SUMMARY OF 1100 PM MST...0600 UTC...INFORMATION ----------------------------------------------- LOCATION...23.7N 113.6W ABOUT 110 MI...180 KM SW OF CABO SAN LAZARO MEXICO ABOUT 240 MI...390 KM WNW OF CABO SAN LUCAS MEXICO MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...981 MB...28.97 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Government of Mexico has discontinued the Tropical Storm Watch for the west coast of Baja California Sur from Todos Santos northward to Santa Fe. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * West Coast of Baja California Sur from Santa Fe to Punta Eugenia A Tropical Storm Watch is in effect for... * East Coast of the Baja California peninsula from Santa Rosalia to Bahia de los Angeles A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area within 48 hours. Interests elsewhere on the Baja California peninsula and in northwestern Mexico should monitor the progress of Lorena. Additional watches or warnings may be required tonight or on Thursday. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM MST (0600 UTC), the center of Hurricane Lorena was located near latitude 23.7 North, longitude 113.6 West. Lorena is moving toward the northwest near 10 mph (17 km/h), and this motion with a decrease in forward speed is expected through early Thursday. A slow northward or north-northeastward motion is expected to begin on Thursday and continue into the weekend. On the forecast track, the center of Lorena is expected to move parallel to the west coast of the Baja California peninsula through Thursday, approach the coast of Baja California Sur Thursday night, and move inland over the Baja California peninsula on Friday. Maximum sustained winds are near 85 mph (140 km/h) with higher gusts. Lorena is expected to begin weakening quickly and become a tropical storm on Thursday. Lorena is likely to degenerate into a remnant low near or over the Baja California peninsula by early Saturday. Hurricane-force winds extend outward up to 15 miles (30 km) from the center and tropical-storm-force winds extend outward up to 80 miles (130 km). The estimated minimum central pressure is 981 mb (28.97 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Lorena can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP2 and WMO header WTPZ42 KNHC. RAINFALL: Bands of heavy rainfall will continue to impact Baja California Sur and move into southwestern Sonora by Thursday, with this rainfall potentially persisting through Friday. Additional rainfall totals of 4 to 8 inches, with maximum storm total amounts of 15 inches, are possible across portions of Baja California Sur, far southeast Baja California and southwestern Sonora into Friday. This will bring the risk of life-threatening flash floods and mudslides, especially in areas of higher terrain. Farther northeast, 1 to 3 inches of rain, with localized totals up to 5 inches, are expected from portions of the Mexican state of Sinaloa north and northeast into portions of southeast Arizona and southwest New Mexico through Saturday, bringing the potential for isolated to scattered flash flooding. For a complete depiction of forecast rainfall and flash flooding associated with Hurricane Lorena, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_ep2.shtml?rainqpf WIND: Tropical storm conditions are expected in the warning area beginning tonight and will spread northward within the warning area in Baja California Sur through Thursday and into Friday. Tropical storm conditions are possible within the watch area on the east coast of the Baja California peninsula late Friday into Friday night. STORM SURGE: Coastal flooding from storm surge is likely along the coast of Baja California Sur near and to the right of where Lorena makes landfall. SURF: Swells generated by Lorena will continue affecting portions of the south and west coasts of Baja California Sur through Friday. 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 200 AM MST. $$ Forecaster Beven