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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

5-Day Uncertainty Track last updated Mon, 25 Aug 2025 20:33:36 GMT


Wind Speed Probabilities last updated Mon, 25 Aug 2025 21:27:30 GMT

Daily limits were increased at Nine Mile Reservoir in Sanpete County and Vernon Reservoir in Tooele County as reservoir levels declined due to drought and preparations for upcoming projects. Fishermen may keep as many as eight rainbow trout and eight tiger trout from Nine Mile Reservoir daily. At Vernon Reservoir, anglers may catch up to eight brown trout, eight rainbow trout and eight tiger trout daily. The limits will be in effect through the end of October. KSL.com (Salt Lake City, Utah), Aug 25, 2025

5-Day Uncertainty Track last updated Mon, 25 Aug 2025 20:33:36 GMT


Wind Speed Probabilities last updated Mon, 25 Aug 2025 20:33:36 GMT

Issued at 200 PM MST Mon Aug 25 2025 000 WTPZ45 KNHC 252032 TCDEP5 Tropical Storm Juliette Discussion Number 5 NWS National Hurricane Center Miami FL EP102025 200 PM MST Mon Aug 25 2025 A recent ASCAT-B scatterometer pass revealed that Juliette is now producing maximum winds around 50 kt within the southeastern quadrant. The center is well embedded beneath a persistent burst of deep convection, but interestingly, the cyclone has also been producing another semi-disconnected burst of convection to the southwest of the center. Juliette has another 24-36 hours before it reaches cooler waters and a drier, more stable atmosphere. Continued strengthening is expected in the short term, and Juliette does have the potential to become a hurricane. In fact, the latest SHIPS Rapid Intensification indices are showing a 40-45 percent change of a 25-kt increase over the next day. The NHC forecast therefore explicitly shows Juliette becoming a hurricane in 24 hours. Weakening is anticipated to begin in 36 hours, and Juliette could become post-tropical in about 3 days when it loses its deep convection. Dissipation into a trough is likely by day 5. The initial motion is west-northwestward (290 degrees) at 12 kt. Due to a break in the subtropical ridge which has developed near and to the west of the Baja California peninsula, Juliette is expected to gradually turn toward the northwest on Tuesday, and then the north-northwest by late Wednesday. The NHC largely follows a blend of the previous forecast and the Google Deep Mind model, but overall there isn't much spread in the track guidance. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 17.6N 114.5W 50 KT 60 MPH 12H 26/0600Z 18.3N 116.0W 60 KT 70 MPH 24H 26/1800Z 19.3N 117.7W 65 KT 75 MPH 36H 27/0600Z 20.6N 119.2W 60 KT 70 MPH 48H 27/1800Z 22.2N 120.6W 55 KT 65 MPH 60H 28/0600Z 23.5N 121.5W 45 KT 50 MPH 72H 28/1800Z 24.5N 122.0W 35 KT 40 MPH...POST-TROPICAL 96H 29/1800Z 25.7N 122.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 30/1800Z...DISSIPATED $$ Forecaster Berg

Issued at 2100 UTC MON AUG 25 2025 789 FOPZ15 KNHC 252032 PWSEP5 TROPICAL STORM JULIETTE WIND SPEED PROBABILITIES NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102025 2100 UTC MON AUG 25 2025 AT 2100Z THE CENTER OF TROPICAL STORM JULIETTE WAS LOCATED NEAR LATITUDE 17.6 NORTH...LONGITUDE 114.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 50 KTS...60 MPH...95 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 18Z MON 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 18Z MON 06Z TUE 18Z TUE 06Z WED 18Z WED 18Z THU 18Z FRI PERIODS TO TO TO TO TO TO TO 06Z TUE 18Z TUE 06Z WED 18Z WED 18Z THU 18Z FRI 18Z SAT FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT ISLA CLARION 34 59 1(60) X(60) X(60) X(60) X(60) X(60) 15N 115W 34 2 2( 4) X( 4) X( 4) X( 4) X( 4) X( 4) 20N 115W 34 5 5(10) 2(12) X(12) X(12) X(12) X(12) 15N 120W 34 X 3( 3) X( 3) X( 3) X( 3) X( 3) X( 3) 20N 120W 34 2 11(13) 39(52) 4(56) 1(57) X(57) X(57) 20N 120W 50 X 1( 1) 6( 7) 2( 9) X( 9) X( 9) X( 9) 20N 120W 64 X X( X) 1( 1) 1( 2) X( 2) X( 2) X( 2) 25N 120W 34 X X( X) 2( 2) 5( 7) 9(16) 1(17) X(17) 25N 125W 34 X X( X) X( X) 1( 1) 3( 4) 1( 5) X( 5) $$ FORECASTER BERG

Issued at 2100 UTC MON AUG 25 2025 000 WTPZ25 KNHC 252031 TCMEP5 TROPICAL STORM JULIETTE FORECAST/ADVISORY NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102025 2100 UTC MON AUG 25 2025 TROPICAL STORM CENTER LOCATED NEAR 17.6N 114.5W AT 25/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 12 KT ESTIMATED MINIMUM CENTRAL PRESSURE 999 MB MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT. 50 KT....... 0NE 25SE 0SW 0NW. 34 KT....... 30NE 60SE 50SW 50NW. 4 M SEAS.... 60NE 30SE 0SW 0NW. 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 17.6N 114.5W AT 25/2100Z AT 25/1800Z CENTER WAS LOCATED NEAR 17.3N 114.0W FORECAST VALID 26/0600Z 18.3N 116.0W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 20NE 25SE 0SW 0NW. 34 KT... 40NE 60SE 50SW 50NW. FORECAST VALID 26/1800Z 19.3N 117.7W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 10NE 15SE 0SW 0NW. 50 KT... 20NE 25SE 0SW 0NW. 34 KT... 50NE 60SE 60SW 50NW. FORECAST VALID 27/0600Z 20.6N 119.2W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 20NE 25SE 0SW 0NW. 34 KT... 50NE 60SE 60SW 50NW. FORECAST VALID 27/1800Z 22.2N 120.6W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 20NE 25SE 0SW 0NW. 34 KT... 50NE 60SE 50SW 40NW. FORECAST VALID 28/0600Z 23.5N 121.5W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 50NE 50SE 40SW 40NW. FORECAST VALID 28/1800Z 24.5N 122.0W...POST-TROPICAL MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 40NE 40SE 0SW 30NW. 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 29/1800Z 25.7N 122.5W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. OUTLOOK VALID 30/1800Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.6N 114.5W NEXT ADVISORY AT 26/0300Z $$ FORECASTER BERG

Issued at 200 PM MST Mon Aug 25 2025 000 WTPZ35 KNHC 252031 TCPEP5 BULLETIN Tropical Storm Juliette Advisory Number 5 NWS National Hurricane Center Miami FL EP102025 200 PM MST Mon Aug 25 2025 ...JULIETTE CONTINUES TO STRENGTHEN... SUMMARY OF 200 PM MST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...17.6N 114.5W ABOUT 245 MI...395 KM WSW OF SOCORRO ISLAND ABOUT 470 MI...760 KM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...WNW OR 290 DEGREES AT 14 MPH...22 KM/H MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 200 PM MST (2100 UTC), the center of Tropical Storm Juliette was located near latitude 17.6 North, longitude 114.5 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 late Tuesday, followed by a slower north-northwestward motion beginning late Wednesday. Maximum sustained winds have increased to near 60 mph (95 km/h) with higher gusts. Additional strengthening is expected, and Juliette has the potential to become a hurricane by Tuesday. 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 50 mph (81 km/h). The estimated minimum central pressure is 999 mb (29.50 inches). HAZARDS AFFECTING LAND ---------------------- None NEXT ADVISORY ------------- Next complete advisory at 800 PM MST. $$ Forecaster Berg

...JULIETTE CONTINUES TO STRENGTHEN... As of 2:00 PM MST Mon Aug 25 the center of Juliette was located near 17.6, -114.5 with movement WNW at 14 mph. The minimum central pressure was 999 mb with maximum sustained winds of about 60 mph.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 25 2025 Valid 252000Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...20z Update... Scattered storms are currently developing over parts of southern AZ and MX ahead of a weak MCV. Additional development is expected the remainder of the afternoon into this evening. Limited buoyancy (MLCAPE ~1000 J/kg) will support multicell updrafts atop fairly dry low-levels. A few of the semi-organized storm clusters could support stronger downdrafts with damaging gust potential. Minor changes were made to the edges of MRGL risk area, see MCD #2014 for short-term information. Elsewhere, scattered storms are expected over the central and western CONUS today/tonight. Limited buoyancy and vertical shear will keep the severe risk low. See the previous discussion. ..Lyons.. 08/25/2025 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Aug 25 2025/ ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 25 2025 Valid 252000Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...20z Update... Scattered storms are currently developing over parts of southern AZ and MX ahead of a weak MCV. Additional development is expected the remainder of the afternoon into this evening. Limited buoyancy (MLCAPE ~1000 J/kg) will support multicell updrafts atop fairly dry low-levels. A few of the semi-organized storm clusters could support stronger downdrafts with damaging gust potential. Minor changes were made to the edges of MRGL risk area, see MCD #2014 for short-term information. Elsewhere, scattered storms are expected over the central and western CONUS today/tonight. Limited buoyancy and vertical shear will keep the severe risk low. See the previous discussion. ..Lyons.. 08/25/2025 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Aug 25 2025/ ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 25 2025 Valid 252000Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...20z Update... Scattered storms are currently developing over parts of southern AZ and MX ahead of a weak MCV. Additional development is expected the remainder of the afternoon into this evening. Limited buoyancy (MLCAPE ~1000 J/kg) will support multicell updrafts atop fairly dry low-levels. A few of the semi-organized storm clusters could support stronger downdrafts with damaging gust potential. Minor changes were made to the edges of MRGL risk area, see MCD #2014 for short-term information. Elsewhere, scattered storms are expected over the central and western CONUS today/tonight. Limited buoyancy and vertical shear will keep the severe risk low. See the previous discussion. ..Lyons.. 08/25/2025 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Aug 25 2025/ ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 25 2025 Valid 252000Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...20z Update... Scattered storms are currently developing over parts of southern AZ and MX ahead of a weak MCV. Additional development is expected the remainder of the afternoon into this evening. Limited buoyancy (MLCAPE ~1000 J/kg) will support multicell updrafts atop fairly dry low-levels. A few of the semi-organized storm clusters could support stronger downdrafts with damaging gust potential. Minor changes were made to the edges of MRGL risk area, see MCD #2014 for short-term information. Elsewhere, scattered storms are expected over the central and western CONUS today/tonight. Limited buoyancy and vertical shear will keep the severe risk low. See the previous discussion. ..Lyons.. 08/25/2025 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Aug 25 2025/ ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 25 2025 Valid 252000Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...20z Update... Scattered storms are currently developing over parts of southern AZ and MX ahead of a weak MCV. Additional development is expected the remainder of the afternoon into this evening. Limited buoyancy (MLCAPE ~1000 J/kg) will support multicell updrafts atop fairly dry low-levels. A few of the semi-organized storm clusters could support stronger downdrafts with damaging gust potential. Minor changes were made to the edges of MRGL risk area, see MCD #2014 for short-term information. Elsewhere, scattered storms are expected over the central and western CONUS today/tonight. Limited buoyancy and vertical shear will keep the severe risk low. See the previous discussion. ..Lyons.. 08/25/2025 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Aug 25 2025/ ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 25 2025 Valid 252000Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...20z Update... Scattered storms are currently developing over parts of southern AZ and MX ahead of a weak MCV. Additional development is expected the remainder of the afternoon into this evening. Limited buoyancy (MLCAPE ~1000 J/kg) will support multicell updrafts atop fairly dry low-levels. A few of the semi-organized storm clusters could support stronger downdrafts with damaging gust potential. Minor changes were made to the edges of MRGL risk area, see MCD #2014 for short-term information. Elsewhere, scattered storms are expected over the central and western CONUS today/tonight. Limited buoyancy and vertical shear will keep the severe risk low. See the previous discussion. ..Lyons.. 08/25/2025 .PREV DISCUSSION... /ISSUED 1131 AM CDT Mon Aug 25 2025/ ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. Read more