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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1215 PM CDT Sat Sep 06 2025 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain low on Sunday. ...Central/Southern High Plains... An upper level ridge will build over the Rockies/Western U.S. during the day on Sunday, with some warming in mid/upper levels noted. Near/after 00z, a weak shortwave impulse is forecast to eject east from the central Rockies into the central Plains, resulting in modest height falls and some forcing for ascent into CO/NE/KS. At the surface, weak lee troughing will support southerly return flow, and a narrow corridor of 50s to near 60 F dewpoints is forecast from southwest NE into eastern CO and western KS, southward over far eastern NM, and western TX/OK. Midlevel lapse rates are expected to remain modest with RAP/NAM forecast soundings indicating 700-500 mb lapse rates around 6.5-7 C/km atop the modest boundary layer moisture. This will support generally weak MLCAPE to around 1000 J/kg. Vertically veering wind profiles (southerly low-levels becoming northwesterly with height) will foster modest effective shear magnitudes around 25 kt. Isolated thunderstorms may develop by late afternoon into early evening within the modestly unstable/moist boundary layer near the surface trough. A low-level jet is forecast to increase during the evening, and may aid in sustaining thunderstorms despite a cooling boundary layer. A strong storm or two could produce small hail or gusty winds, but overall severe potential appears limited given a lack of stronger forcing/thermodynamic environment and concerns over limited storm coverage. ...Coastal Carolinas into southeast GA... Moderate southwesterly deep-layer flow will weaken with time and southward extent as the stronger upper shortwave trough over the Great Lakes/Northeast lifts northeast through the period. At the surface, a very moist airmass will be in place ahead of an eastward-advancing cold front. This will support MLCAPE of 1000-2000 J/kg during the afternoon. Vertical shear also will remain limited, with weak flow through at least 700 mb evident in forecast soundings. Cloud cover and poor lapse rates will likely limit severe potential, but where stronger heating can occur, locally gusty winds will be possible. ..Leitman.. 09/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1215 PM CDT Sat Sep 06 2025 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain low on Sunday. ...Central/Southern High Plains... An upper level ridge will build over the Rockies/Western U.S. during the day on Sunday, with some warming in mid/upper levels noted. Near/after 00z, a weak shortwave impulse is forecast to eject east from the central Rockies into the central Plains, resulting in modest height falls and some forcing for ascent into CO/NE/KS. At the surface, weak lee troughing will support southerly return flow, and a narrow corridor of 50s to near 60 F dewpoints is forecast from southwest NE into eastern CO and western KS, southward over far eastern NM, and western TX/OK. Midlevel lapse rates are expected to remain modest with RAP/NAM forecast soundings indicating 700-500 mb lapse rates around 6.5-7 C/km atop the modest boundary layer moisture. This will support generally weak MLCAPE to around 1000 J/kg. Vertically veering wind profiles (southerly low-levels becoming northwesterly with height) will foster modest effective shear magnitudes around 25 kt. Isolated thunderstorms may develop by late afternoon into early evening within the modestly unstable/moist boundary layer near the surface trough. A low-level jet is forecast to increase during the evening, and may aid in sustaining thunderstorms despite a cooling boundary layer. A strong storm or two could produce small hail or gusty winds, but overall severe potential appears limited given a lack of stronger forcing/thermodynamic environment and concerns over limited storm coverage. ...Coastal Carolinas into southeast GA... Moderate southwesterly deep-layer flow will weaken with time and southward extent as the stronger upper shortwave trough over the Great Lakes/Northeast lifts northeast through the period. At the surface, a very moist airmass will be in place ahead of an eastward-advancing cold front. This will support MLCAPE of 1000-2000 J/kg during the afternoon. Vertical shear also will remain limited, with weak flow through at least 700 mb evident in forecast soundings. Cloud cover and poor lapse rates will likely limit severe potential, but where stronger heating can occur, locally gusty winds will be possible. ..Leitman.. 09/06/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1215 PM CDT Sat Sep 06 2025 Valid 071200Z - 081200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is expected to remain low on Sunday. ...Central/Southern High Plains... An upper level ridge will build over the Rockies/Western U.S. during the day on Sunday, with some warming in mid/upper levels noted. Near/after 00z, a weak shortwave impulse is forecast to eject east from the central Rockies into the central Plains, resulting in modest height falls and some forcing for ascent into CO/NE/KS. At the surface, weak lee troughing will support southerly return flow, and a narrow corridor of 50s to near 60 F dewpoints is forecast from southwest NE into eastern CO and western KS, southward over far eastern NM, and western TX/OK. Midlevel lapse rates are expected to remain modest with RAP/NAM forecast soundings indicating 700-500 mb lapse rates around 6.5-7 C/km atop the modest boundary layer moisture. This will support generally weak MLCAPE to around 1000 J/kg. Vertically veering wind profiles (southerly low-levels becoming northwesterly with height) will foster modest effective shear magnitudes around 25 kt. Isolated thunderstorms may develop by late afternoon into early evening within the modestly unstable/moist boundary layer near the surface trough. A low-level jet is forecast to increase during the evening, and may aid in sustaining thunderstorms despite a cooling boundary layer. A strong storm or two could produce small hail or gusty winds, but overall severe potential appears limited given a lack of stronger forcing/thermodynamic environment and concerns over limited storm coverage. ...Coastal Carolinas into southeast GA... Moderate southwesterly deep-layer flow will weaken with time and southward extent as the stronger upper shortwave trough over the Great Lakes/Northeast lifts northeast through the period. At the surface, a very moist airmass will be in place ahead of an eastward-advancing cold front. This will support MLCAPE of 1000-2000 J/kg during the afternoon. Vertical shear also will remain limited, with weak flow through at least 700 mb evident in forecast soundings. Cloud cover and poor lapse rates will likely limit severe potential, but where stronger heating can occur, locally gusty winds will be possible. ..Leitman.. 09/06/2025 Read more

915
ABPZ20 KNHC 061714
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Sep 6 2025

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

Active Systems:
The National Hurricane Center is issuing advisories on Hurricane
Kiko, located in the central Pacific basin well east-southeast of
Hilo, Hawaii.

Central East Pacific:
An area of low pressure located a few hundred miles south-southwest
of the southwestern coast of Mexico is producing a few showers and
thunderstorms. Development, if any, of this system should be slow
to occur while it moves generally westward around 10 to 15 mph over
the open waters of the eastern Pacific.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Pasch

WW 0607 Status Updates
STATUS FOR WATCH 0607 HAS NOT BEEN ISSUED YET Read more

WW 0607 Status Updates
STATUS FOR WATCH 0607 HAS NOT BEEN ISSUED YET Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...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 1129 AM CDT Sat Sep 06 2025 Valid 061700Z - 071200Z The only change to the ongoing forecast was to expand the isolated dry thunderstorm area into northern California. Here, precipitable water values are running between 0.5"-0.75". Low-to-mid-level flow is sufficiently strong (on the order of 20-25 knots) that, when coupled with the low precipitable water values, any thunderstorm that can develop would pose at least some potential for being on the dry side. ..Marsh.. 09/06/2025 .PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/ ...Synopsis... A mid-level trough will progress across the Northeast while upper ridging persists over the Rockies, and another upper trough impinges on the West Coast today. The West Coast upper trough will provide enough upper support atop a dry boundary layer to encourage locally dry and windy conditions to the lee of the northern Sierra this afternoon. While occasional bouts of 15 mph sustained southwesterly surface winds may overlap with 15-20 percent RH, the brief and localized nature of these conditions preclude Elevated highlights. Farther to the northeast, upper support from the aforementioned upper trough will encounter greater buoyancy, which will support scattered thunderstorm development during the afternoon into the evening hours. Storms will be most likely over portions of the Pacific Northwest into the northern Rockies. Here, forecast soundings show a dry boundary layer extending to at least 700 mb, suggesting that a mix of wet and dry thunderstorms may occur. Regardless of precipitation production, some of these storms may overspread patches of very dry fuels that may be easily ignited by lightning, warranting the continuance of dry thunderstorm highlights over the Pacific Northwest to northern Rockies. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Sat Sep 06 2025 Valid 061630Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN MID-ATLANTIC REGION INTO NEW ENGLAND... ...SUMMARY... Scattered severe thunderstorms are possible from eastern Pennsylvania and New Jersey into New England this afternoon. The primary hazards will be strong to severe gusts capable of wind damage, isolated hail, and a tornado or two. ...The Mid Atlantic Region into New England... A large upper trough is present today over the Great Lakes region. At the surface, the effective low-level baroclinic zone extends from MD into eastern PA/NY and New England. To the east of the boundary, at least broken sunshine will help to steepen low-level lapse rates and destabilize the air mass. Thunderstorms have already begun to form along this zone, with intensification to scattered strong/severe storms by mid-afternoon. Mid-level lapse rates are not particularly steep, but southwesterly winds aloft are strong and deep layer shear will support rotating/bowing structures capable of damaging wind gusts and some hail. A tornado or two will also be possible. Model guidance is in agreement that the corridor of concern is rather narrow, with the main risk between about 19-23z. Refer to MD #2042 for further details. ..Hart/Weinman.. 09/06/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Sat Sep 06 2025 Valid 061630Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN MID-ATLANTIC REGION INTO NEW ENGLAND... ...SUMMARY... Scattered severe thunderstorms are possible from eastern Pennsylvania and New Jersey into New England this afternoon. The primary hazards will be strong to severe gusts capable of wind damage, isolated hail, and a tornado or two. ...The Mid Atlantic Region into New England... A large upper trough is present today over the Great Lakes region. At the surface, the effective low-level baroclinic zone extends from MD into eastern PA/NY and New England. To the east of the boundary, at least broken sunshine will help to steepen low-level lapse rates and destabilize the air mass. Thunderstorms have already begun to form along this zone, with intensification to scattered strong/severe storms by mid-afternoon. Mid-level lapse rates are not particularly steep, but southwesterly winds aloft are strong and deep layer shear will support rotating/bowing structures capable of damaging wind gusts and some hail. A tornado or two will also be possible. Model guidance is in agreement that the corridor of concern is rather narrow, with the main risk between about 19-23z. Refer to MD #2042 for further details. ..Hart/Weinman.. 09/06/2025 Read more