Aggregator

000
ABPZ20 KNHC 260521
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Mon Aug 25 2025

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

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Juliette, located in the east Pacific basin several hundred
miles southwest of the southern tip of the Baja California
peninsula.

Well Southeast of the Hawaiian Islands:
A trough of low pressure located several hundred miles southeast of
the Hawaiian Islands continues to produce disorganized showers and
thunderstorms. Environmental conditions appear conducive for some
gradual development of this system, and a tropical depression could
form late this week, while it moves westward at 10 to 15 mph across
the central Pacific basin.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...medium...40 percent.

Well Southwest of the Baja California Peninsula:
A tropical wave off the coast of southern Mexico is producing
limited shower activity. Some slow development is possible late
this week and into the weekend as the system moves westward to
west-northwestward at 10 to 15 mph across the central part of the
eastern Pacific basin.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Kelly

5-Day Uncertainty Track last updated Tue, 26 Aug 2025 02:33:08 GMT


Wind Speed Probabilities last updated Tue, 26 Aug 2025 03:27:24 GMT

5-Day Uncertainty Track last updated Tue, 26 Aug 2025 02:33:08 GMT


Wind Speed Probabilities last updated Tue, 26 Aug 2025 02:33:08 GMT

Issued at 800 PM PDT Mon Aug 25 2025 000 WTPZ45 KNHC 260232 TCDEP5 Tropical Storm Juliette Discussion Number 6 NWS National Hurricane Center Miami FL EP102025 800 PM PDT Mon Aug 25 2025 Juliette continues to strengthen. A microwave pass from a few hours ago suggested that the storm was developing an inner core, and recent infrared satellite images indicate that banding features are increasing south of the center. The Dvorak estimates from TAFB, SAB, and CIMSS have all increased to 3.5/55 kt, and therefore, the initial wind speed is increased to that value. Juliette is expected to remain in favorable conditions to strengthen for about another day, and it seems likely that it will become a hurricane on Tuesday. However, the strengthening trend should end by Tuesday night when the storm is forecast to cross the 26 C SST isotherm and then move into an environment of drier air and stronger shear. Juliette is expected to become a remnant low in about 3 days when it is forecast to be over cool 22 C waters, and dissipate entirely this weekend. The NHC intensity forecast is a blend of the HCCA and IVCN models. The storm is moving west-northwestward at 12 kt on the southwest side of a mid-level ridge. A gradual turn to the northwest and then the north-northwest with a notable reduction in forward speed is expected over the next few days as Juliette moves toward a weakness in the ridge. The NHC track forecast is largely an update of the previous one and lies on the western side of the guidance envelope, in best agreement with EMXI and the Google DeepMind models. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 17.8N 115.5W 55 KT 65 MPH 12H 26/1200Z 18.5N 116.8W 65 KT 75 MPH 24H 27/0000Z 19.8N 118.3W 65 KT 75 MPH 36H 27/1200Z 21.3N 119.7W 60 KT 70 MPH 48H 28/0000Z 22.8N 120.9W 50 KT 60 MPH 60H 28/1200Z 24.0N 121.6W 40 KT 45 MPH 72H 29/0000Z 24.9N 122.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 30/0000Z 25.6N 122.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 31/0000Z...DISSIPATED $$ Forecaster Cangialosi

Issued at 0300 UTC TUE AUG 26 2025 000 FOPZ15 KNHC 260231 PWSEP5 TROPICAL STORM JULIETTE WIND SPEED PROBABILITIES NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102025 0300 UTC TUE AUG 26 2025 AT 0300Z THE CENTER OF TROPICAL STORM JULIETTE WAS LOCATED NEAR LATITUDE 17.8 NORTH...LONGITUDE 115.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 55 KTS...65 MPH...100 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) PACIFIC DAYLIGHT TIME (PDT)...SUBTRACT 7 HOURS FROM Z TIME HAWAIIAN STANDARD TIME (HST)...SUBTRACT 10 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 00Z TUE 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 00Z TUE 12Z TUE 00Z WED 12Z WED 00Z THU 00Z FRI 00Z SAT PERIODS TO TO TO TO TO TO TO 12Z TUE 00Z WED 12Z WED 00Z THU 00Z FRI 00Z SAT 00Z SUN FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ISLA CLARION 34 5 3( 8) 1( 9) X( 9) X( 9) X( 9) X( 9) 15N 115W 34 2 1( 3) X( 3) X( 3) X( 3) X( 3) X( 3) 20N 115W 34 3 4( 7) 1( 8) X( 8) X( 8) X( 8) X( 8) 15N 120W 34 2 1( 3) X( 3) X( 3) X( 3) X( 3) X( 3) 20N 120W 34 3 21(24) 28(52) 1(53) X(53) X(53) X(53) 20N 120W 50 X 1( 1) 5( 6) X( 6) X( 6) X( 6) X( 6) 20N 120W 64 X X( X) 1( 1) X( 1) X( 1) X( 1) X( 1) 25N 120W 34 X X( X) 4( 4) 5( 9) 7(16) 1(17) X(17) 25N 125W 34 X X( X) X( X) 1( 1) 2( 3) 1( 4) X( 4) $$ FORECASTER CANGIALOSI

Issued at 800 PM PDT Mon Aug 25 2025 000 WTPZ35 KNHC 260231 TCPEP5 BULLETIN Tropical Storm Juliette Advisory Number 6 NWS National Hurricane Center Miami FL EP102025 800 PM PDT Mon Aug 25 2025 ...JULIETTE COULD BECOME A HURRICANE ON TUESDAY... SUMMARY OF 800 PM PDT...0300 UTC...INFORMATION ---------------------------------------------- LOCATION...17.8N 115.5W ABOUT 305 MI...490 KM WSW OF SOCORRO ISLAND ABOUT 505 MI...815 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 14 MPH...22 KM/H MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 800 PM PDT (0300 UTC), the center of Tropical Storm Juliette was located near latitude 17.8 North, longitude 115.5 West. Juliette is moving toward the west-northwest near 14 mph (22 km/h) and this general motion is expected to continue through Tuesday. A turn toward the northwest is forecast by Tuesday night, followed by a slower north-northwestward motion beginning late Wednesday. Maximum sustained winds have increased to near 65 mph (100 km/h) with higher gusts. Additional strengthening is expected, and Juliette could become a hurricane on Tuesday. Weakening is expected to begin on Wednesday. Tropical-storm-force winds extend outward up to 70 miles (110 km) from the center. An automated Mexican Navy station on Clarion Island recently reported a sustained wind of 36 mph (58 km/h) and a gust to 46 mph (74 km/h). The estimated minimum central pressure is 996 mb (29.42 inches). HAZARDS AFFECTING LAND ---------------------- None NEXT ADVISORY ------------- Next complete advisory at 200 AM PDT. $$ Forecaster Cangialosi

...JULIETTE COULD BECOME A HURRICANE ON TUESDAY... As of 8:00 PM PDT Mon Aug 25 the center of Juliette was located near 17.8, -115.5 with movement WNW at 14 mph. The minimum central pressure was 996 mb with maximum sustained winds of about 65 mph.

Issued at 0300 UTC TUE AUG 26 2025 000 WTPZ25 KNHC 260231 TCMEP5 TROPICAL STORM JULIETTE FORECAST/ADVISORY NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102025 0300 UTC TUE AUG 26 2025 TROPICAL STORM CENTER LOCATED NEAR 17.8N 115.5W AT 26/0300Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 12 KT ESTIMATED MINIMUM CENTRAL PRESSURE 996 MB MAX SUSTAINED WINDS 55 KT WITH GUSTS TO 65 KT. 50 KT....... 20NE 30SE 0SW 0NW. 34 KT....... 40NE 60SE 50SW 50NW. 4 M SEAS.... 60NE 60SE 45SW 45NW. 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 17.8N 115.5W AT 26/0300Z AT 26/0000Z CENTER WAS LOCATED NEAR 17.5N 115.1W FORECAST VALID 26/1200Z 18.5N 116.8W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 15SE 0SW 0NW. 50 KT... 20NE 30SE 0SW 20NW. 34 KT... 50NE 60SE 50SW 50NW. FORECAST VALID 27/0000Z 19.8N 118.3W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 15SE 0SW 0NW. 50 KT... 20NE 30SE 0SW 20NW. 34 KT... 50NE 60SE 60SW 50NW. FORECAST VALID 27/1200Z 21.3N 119.7W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 20NE 30SE 0SW 20NW. 34 KT... 50NE 60SE 60SW 50NW. FORECAST VALID 28/0000Z 22.8N 120.9W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 25SE 0SW 0NW. 34 KT... 50NE 60SE 50SW 40NW. FORECAST VALID 28/1200Z 24.0N 121.6W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 50NE 50SE 40SW 40NW. FORECAST VALID 29/0000Z 24.9N 122.0W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 100 NM ON DAY 4 AND 125 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 30/0000Z 25.6N 122.9W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. OUTLOOK VALID 31/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.8N 115.5W NEXT ADVISORY AT 26/0900Z $$ FORECASTER CANGIALOSI

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 PM CDT Mon Aug 25 2025 Valid 260100Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS A SMALL PORTION OF SOUTH-CENTRAL ARIZONA.... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona for a few more hours this evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...Discussion... A cluster of storms has produced some damaging winds across south-central Arizona. As the boundary layer cools this evening, expect these storms to weaken. However, the threat for isolated damaging winds will persist for a few more hours amid 1000+ J/kg DCAPE and steep low/mid level lapse rates. Elsewhere, diurnal thunderstorms across the western CONUS will wane this evening. Additional storms are expected to develop from the TX Panhandle to western Oklahoma tonight, but weak instability should limit any severe weather potential from this activity. ..Bentley.. 08/26/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 PM CDT Mon Aug 25 2025 Valid 260100Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS A SMALL PORTION OF SOUTH-CENTRAL ARIZONA.... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona for a few more hours this evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...Discussion... A cluster of storms has produced some damaging winds across south-central Arizona. As the boundary layer cools this evening, expect these storms to weaken. However, the threat for isolated damaging winds will persist for a few more hours amid 1000+ J/kg DCAPE and steep low/mid level lapse rates. Elsewhere, diurnal thunderstorms across the western CONUS will wane this evening. Additional storms are expected to develop from the TX Panhandle to western Oklahoma tonight, but weak instability should limit any severe weather potential from this activity. ..Bentley.. 08/26/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 PM CDT Mon Aug 25 2025 Valid 260100Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS A SMALL PORTION OF SOUTH-CENTRAL ARIZONA.... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona for a few more hours this evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...Discussion... A cluster of storms has produced some damaging winds across south-central Arizona. As the boundary layer cools this evening, expect these storms to weaken. However, the threat for isolated damaging winds will persist for a few more hours amid 1000+ J/kg DCAPE and steep low/mid level lapse rates. Elsewhere, diurnal thunderstorms across the western CONUS will wane this evening. Additional storms are expected to develop from the TX Panhandle to western Oklahoma tonight, but weak instability should limit any severe weather potential from this activity. ..Bentley.. 08/26/2025 Read more

No watches are valid as of Mon Aug 25 23:54:01 UTC 2025.

No Mesoscale Discussions are in effect as of Mon Aug 25 23:54:01 UTC 2025.

262
ABPZ20 KNHC 252314
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Mon Aug 25 2025

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

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Juliette, located in the east Pacific basin several hundred
miles southwest of the southern tip of the Baja California
peninsula.

Well Southeast of the Hawaiian Islands:
A trough of low pressure located several hundred miles southeast of
the Hawaiian Islands continues to produce disorganized showers and
thunderstorms. Gradual development of this system is possible
through the week and into the weekend while it moves westward at 10
to 15 mph across the central Pacific basin.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...30 percent.

Well Southwest of the Baja California Peninsula:
A tropical wave off the coast of southern Mexico is producing
limited shower activity. Some slow development is possible late
this week and into the weekend as the system moves westward to
west-northwestward at 10 to 15 mph across the central part of the
eastern Pacific basin.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Cangialosi

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0439 PM CDT Mon Aug 25 2025 Valid 271200Z - 021200Z Weak upper lows are likely to move north through the northwestern US on Day 3/Wednesday - Day 4/Thursday as the upper-level ridge continues to retreat southeastward. The location and strength of these upper lows will be somewhat dependent on the convection occurring today and tomorrow, but monsoonal moisture will continue to push northward across the Northwest and northern Rockies. The upper-level pattern remains rather quiescent and devoid of major features across the West until an upper-level trough approaches the Pacific Northwest on Day 5/Friday. Forecast guidance remains uncertain regarding the track, timing, and impacts of this upper-level trough. ...Day 3/Wednesday - Day 4/Thursday... As the weak upper lows drift northward with monsoonal moisture, isolated to scattered showers and thunderstorms are likely across the Northwest and northern Rockies. Forcing for ascent and easterly flow aloft indicate the potential for storms to move/develop west of the Cascades. There remains concern that the 10% areas may just have high-based showers with sporadic, occasional lightning at best, especially due to the potential cloud cover. PWAT values are likely to be 0.8-1.1" and some dewpoints will exceed 50F that may mitigate fire weather concerns. However, given the very receptive fuels and history of ignitions with thunderstorms on the leading edge of this monsoonal moisture, the 10% areas were introduced. These may be refined as more high-resolution forecast guidance and rainfall footprints from storms today/tomorrow become available. Monsoonal thunderstorms will continue across much of the Intermountain West on Day 3/Wednesday, but drier air will start to filter in from west to east late this week into the weekend. This will reduce chances and coverage of thunderstorms in California, Northwest, and portions of the Great Basin and lower RH. ..Nauslar.. 08/25/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0439 PM CDT Mon Aug 25 2025 Valid 271200Z - 021200Z Weak upper lows are likely to move north through the northwestern US on Day 3/Wednesday - Day 4/Thursday as the upper-level ridge continues to retreat southeastward. The location and strength of these upper lows will be somewhat dependent on the convection occurring today and tomorrow, but monsoonal moisture will continue to push northward across the Northwest and northern Rockies. The upper-level pattern remains rather quiescent and devoid of major features across the West until an upper-level trough approaches the Pacific Northwest on Day 5/Friday. Forecast guidance remains uncertain regarding the track, timing, and impacts of this upper-level trough. ...Day 3/Wednesday - Day 4/Thursday... As the weak upper lows drift northward with monsoonal moisture, isolated to scattered showers and thunderstorms are likely across the Northwest and northern Rockies. Forcing for ascent and easterly flow aloft indicate the potential for storms to move/develop west of the Cascades. There remains concern that the 10% areas may just have high-based showers with sporadic, occasional lightning at best, especially due to the potential cloud cover. PWAT values are likely to be 0.8-1.1" and some dewpoints will exceed 50F that may mitigate fire weather concerns. However, given the very receptive fuels and history of ignitions with thunderstorms on the leading edge of this monsoonal moisture, the 10% areas were introduced. These may be refined as more high-resolution forecast guidance and rainfall footprints from storms today/tomorrow become available. Monsoonal thunderstorms will continue across much of the Intermountain West on Day 3/Wednesday, but drier air will start to filter in from west to east late this week into the weekend. This will reduce chances and coverage of thunderstorms in California, Northwest, and portions of the Great Basin and lower RH. ..Nauslar.. 08/25/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0439 PM CDT Mon Aug 25 2025 Valid 271200Z - 021200Z Weak upper lows are likely to move north through the northwestern US on Day 3/Wednesday - Day 4/Thursday as the upper-level ridge continues to retreat southeastward. The location and strength of these upper lows will be somewhat dependent on the convection occurring today and tomorrow, but monsoonal moisture will continue to push northward across the Northwest and northern Rockies. The upper-level pattern remains rather quiescent and devoid of major features across the West until an upper-level trough approaches the Pacific Northwest on Day 5/Friday. Forecast guidance remains uncertain regarding the track, timing, and impacts of this upper-level trough. ...Day 3/Wednesday - Day 4/Thursday... As the weak upper lows drift northward with monsoonal moisture, isolated to scattered showers and thunderstorms are likely across the Northwest and northern Rockies. Forcing for ascent and easterly flow aloft indicate the potential for storms to move/develop west of the Cascades. There remains concern that the 10% areas may just have high-based showers with sporadic, occasional lightning at best, especially due to the potential cloud cover. PWAT values are likely to be 0.8-1.1" and some dewpoints will exceed 50F that may mitigate fire weather concerns. However, given the very receptive fuels and history of ignitions with thunderstorms on the leading edge of this monsoonal moisture, the 10% areas were introduced. These may be refined as more high-resolution forecast guidance and rainfall footprints from storms today/tomorrow become available. Monsoonal thunderstorms will continue across much of the Intermountain West on Day 3/Wednesday, but drier air will start to filter in from west to east late this week into the weekend. This will reduce chances and coverage of thunderstorms in California, Northwest, and portions of the Great Basin and lower RH. ..Nauslar.. 08/25/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0439 PM CDT Mon Aug 25 2025 Valid 271200Z - 021200Z Weak upper lows are likely to move north through the northwestern US on Day 3/Wednesday - Day 4/Thursday as the upper-level ridge continues to retreat southeastward. The location and strength of these upper lows will be somewhat dependent on the convection occurring today and tomorrow, but monsoonal moisture will continue to push northward across the Northwest and northern Rockies. The upper-level pattern remains rather quiescent and devoid of major features across the West until an upper-level trough approaches the Pacific Northwest on Day 5/Friday. Forecast guidance remains uncertain regarding the track, timing, and impacts of this upper-level trough. ...Day 3/Wednesday - Day 4/Thursday... As the weak upper lows drift northward with monsoonal moisture, isolated to scattered showers and thunderstorms are likely across the Northwest and northern Rockies. Forcing for ascent and easterly flow aloft indicate the potential for storms to move/develop west of the Cascades. There remains concern that the 10% areas may just have high-based showers with sporadic, occasional lightning at best, especially due to the potential cloud cover. PWAT values are likely to be 0.8-1.1" and some dewpoints will exceed 50F that may mitigate fire weather concerns. However, given the very receptive fuels and history of ignitions with thunderstorms on the leading edge of this monsoonal moisture, the 10% areas were introduced. These may be refined as more high-resolution forecast guidance and rainfall footprints from storms today/tomorrow become available. Monsoonal thunderstorms will continue across much of the Intermountain West on Day 3/Wednesday, but drier air will start to filter in from west to east late this week into the weekend. This will reduce chances and coverage of thunderstorms in California, Northwest, and portions of the Great Basin and lower RH. ..Nauslar.. 08/25/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0439 PM CDT Mon Aug 25 2025 Valid 271200Z - 021200Z Weak upper lows are likely to move north through the northwestern US on Day 3/Wednesday - Day 4/Thursday as the upper-level ridge continues to retreat southeastward. The location and strength of these upper lows will be somewhat dependent on the convection occurring today and tomorrow, but monsoonal moisture will continue to push northward across the Northwest and northern Rockies. The upper-level pattern remains rather quiescent and devoid of major features across the West until an upper-level trough approaches the Pacific Northwest on Day 5/Friday. Forecast guidance remains uncertain regarding the track, timing, and impacts of this upper-level trough. ...Day 3/Wednesday - Day 4/Thursday... As the weak upper lows drift northward with monsoonal moisture, isolated to scattered showers and thunderstorms are likely across the Northwest and northern Rockies. Forcing for ascent and easterly flow aloft indicate the potential for storms to move/develop west of the Cascades. There remains concern that the 10% areas may just have high-based showers with sporadic, occasional lightning at best, especially due to the potential cloud cover. PWAT values are likely to be 0.8-1.1" and some dewpoints will exceed 50F that may mitigate fire weather concerns. However, given the very receptive fuels and history of ignitions with thunderstorms on the leading edge of this monsoonal moisture, the 10% areas were introduced. These may be refined as more high-resolution forecast guidance and rainfall footprints from storms today/tomorrow become available. Monsoonal thunderstorms will continue across much of the Intermountain West on Day 3/Wednesday, but drier air will start to filter in from west to east late this week into the weekend. This will reduce chances and coverage of thunderstorms in California, Northwest, and portions of the Great Basin and lower RH. ..Nauslar.. 08/25/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0439 PM CDT Mon Aug 25 2025 Valid 271200Z - 021200Z Weak upper lows are likely to move north through the northwestern US on Day 3/Wednesday - Day 4/Thursday as the upper-level ridge continues to retreat southeastward. The location and strength of these upper lows will be somewhat dependent on the convection occurring today and tomorrow, but monsoonal moisture will continue to push northward across the Northwest and northern Rockies. The upper-level pattern remains rather quiescent and devoid of major features across the West until an upper-level trough approaches the Pacific Northwest on Day 5/Friday. Forecast guidance remains uncertain regarding the track, timing, and impacts of this upper-level trough. ...Day 3/Wednesday - Day 4/Thursday... As the weak upper lows drift northward with monsoonal moisture, isolated to scattered showers and thunderstorms are likely across the Northwest and northern Rockies. Forcing for ascent and easterly flow aloft indicate the potential for storms to move/develop west of the Cascades. There remains concern that the 10% areas may just have high-based showers with sporadic, occasional lightning at best, especially due to the potential cloud cover. PWAT values are likely to be 0.8-1.1" and some dewpoints will exceed 50F that may mitigate fire weather concerns. However, given the very receptive fuels and history of ignitions with thunderstorms on the leading edge of this monsoonal moisture, the 10% areas were introduced. These may be refined as more high-resolution forecast guidance and rainfall footprints from storms today/tomorrow become available. Monsoonal thunderstorms will continue across much of the Intermountain West on Day 3/Wednesday, but drier air will start to filter in from west to east late this week into the weekend. This will reduce chances and coverage of thunderstorms in California, Northwest, and portions of the Great Basin and lower RH. ..Nauslar.. 08/25/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more