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5-Day Uncertainty Track last updated Sun, 31 Aug 2025 20:35:18 GMT


Wind Speed Probabilities last updated Sun, 31 Aug 2025 21:21:28 GMT

5-Day Uncertainty Track last updated Sun, 31 Aug 2025 20:35:18 GMT


Wind Speed Probabilities last updated Sun, 31 Aug 2025 20:35:18 GMT

Issued at 2100 UTC SUN AUG 31 2025 000 FOPZ11 KNHC 312033 PWSEP1 TROPICAL STORM KIKO WIND SPEED PROBABILITIES NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112025 2100 UTC SUN AUG 31 2025 AT 2100Z THE CENTER OF TROPICAL STORM KIKO WAS LOCATED NEAR LATITUDE 14.4 NORTH...LONGITUDE 124.0 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 35 KTS...40 MPH...65 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 SUN 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 SUN 06Z MON 18Z MON 06Z TUE 18Z TUE 18Z WED 18Z THU PERIODS TO TO TO TO TO TO TO 06Z MON 18Z MON 06Z TUE 18Z TUE 18Z WED 18Z THU 18Z FRI FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 15N 125W 34 32 6(38) 1(39) 1(40) X(40) X(40) X(40) 10N 130W 34 X X( X) 2( 2) 2( 4) 3( 7) X( 7) X( 7) 15N 130W 34 X 2( 2) 26(28) 43(71) 7(78) X(78) X(78) 15N 130W 50 X X( X) 2( 2) 28(30) 7(37) X(37) X(37) 15N 130W 64 X X( X) X( X) 9( 9) 5(14) X(14) X(14) 10N 135W 34 X X( X) X( X) X( X) 4( 4) 4( 8) 1( 9) 10N 135W 50 X X( X) X( X) X( X) 1( 1) X( 1) X( 1) 10N 135W 64 X X( X) X( X) X( X) 1( 1) X( 1) X( 1) 15N 135W 34 X X( X) X( X) 2( 2) 49(51) 26(77) 1(78) 15N 135W 50 X X( X) X( X) X( X) 16(16) 24(40) 1(41) 15N 135W 64 X X( X) X( X) X( X) 5( 5) 14(19) 1(20) 10N 140W 34 X X( X) X( X) X( X) X( X) 3( 3) 5( 8) 15N 140W 34 X X( X) X( X) X( X) X( X) 29(29) 37(66) 15N 140W 50 X X( X) X( X) X( X) X( X) 8( 8) 24(32) 15N 140W 64 X X( X) X( X) X( X) X( X) 2( 2) 13(15) 20N 140W 34 X X( X) X( X) X( X) X( X) 1( 1) 2( 3) 10N 145W 34 X X( X) X( X) X( X) X( X) X( X) 3( 3) 15N 145W 34 X X( X) X( X) X( X) X( X) X( X) 16(16) 15N 145W 50 X X( X) X( X) X( X) X( X) X( X) 4( 4) 15N 145W 64 X X( X) X( X) X( X) X( X) X( X) 1( 1) $$ FORECASTER BEVEN

Issued at 1100 AM HST Sun Aug 31 2025 000 WTPZ41 KNHC 312033 TCDEP1 Tropical Storm Kiko Discussion Number 3 NWS National Hurricane Center Miami FL EP112025 1100 AM HST Sun Aug 31 2025 Kiko has changed little in organization during the past few hours, with a broad curved convective band wrapping around the western side of the cyclone. Recent ASCAT overpasses did not show tropical-storm force winds. However, there may be sampling issues at work since the central core of Kiko is small. Satellite intensity estimates are in the 35-45 kt range, and the initial intensity is held at 35 kt in deference to the scatterometer data. The scatterometer data and conventional imagery suggest the circulation center is elongated east-west with multiple cloud swirls present. The initial motion remains 270/8 kt. Kiko is on the south side of a deep-layer ridge that covers the tropical Pacific between 120W-155W, and this feature is expected to persist for the next several days. This should cause Kiko to move westward or just south of westward through the forecast period. While the track guidance generally agrees on the direction of motion, there is a considerable spread in forward speed with the faster UKMET/ECMWF being several hundred miles west of the slower GFS by 120 h. The new forecast track splits this speed difference, and it lies just north of the consensus models. The new forecast is a bit south of and slower than the previous forecast. Kiko is expected to encounter generally light vertical shear while it moves over sea surface temperatures that are around 27C. After 72 h, the cyclone is likely to move into a drier air mass that could inhibit strengthening despite the other favorable conditions. Based on this, the intensity forecast shows 72 h of strengthening followed by little change in strength at 96 and 120 h. There are two uncertainties in this forecast. First, the rapid intensification indices of the SHIPS model are notably above their climatological norms, and that combined with Kiko's small core suggests that a period of rapid intensification could occur during the next 72 h. Second, as mentioned earlier any deviation of the track slightly to the right of the forecast path could place the system over cooler waters that would slow or stop strengthening. The new intensity forecast is a little stronger than the previous forecast, and it lies near the intensity consensus. FORECAST POSITIONS AND MAX WINDS INIT 31/2100Z 14.4N 124.0W 35 KT 40 MPH 12H 01/0600Z 14.3N 125.2W 40 KT 45 MPH 24H 01/1800Z 14.2N 126.9W 50 KT 60 MPH 36H 02/0600Z 14.1N 128.5W 60 KT 70 MPH 48H 02/1800Z 14.1N 130.2W 70 KT 80 MPH 60H 03/0600Z 14.0N 131.9W 75 KT 85 MPH 72H 03/1800Z 14.0N 133.7W 80 KT 90 MPH 96H 04/1800Z 14.0N 137.6W 80 KT 90 MPH 120H 05/1800Z 14.1N 141.3W 80 KT 90 MPH $$ Forecaster Beven

Issued at 1100 AM HST Sun Aug 31 2025 262 WTPZ31 KNHC 312033 TCPEP1 BULLETIN Tropical Storm Kiko Advisory Number 3 NWS National Hurricane Center Miami FL EP112025 1100 AM HST Sun Aug 31 2025 ...KIKO MOVING WESTWARD WITH LITTLE CHANGE IN STRENGTH... SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION ----------------------------------------------- LOCATION...14.4N 124.0W ABOUT 1090 MI...1760 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 AM HST (2100 UTC), the center of Tropical Storm Kiko was located near latitude 14.4 North, longitude 124.0 West. Kiko is moving toward the west near 9 mph (15 km/h) and this motion is expected to continue over the next few days. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Strengthening is expected during the next couple of days, and the system is forecast to become a hurricane by Tuesday. Tropical-storm-force winds extend outward up to 35 miles (55 km) from the center. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 500 PM HST. $$ Forecaster Beven

...KIKO MOVING WESTWARD WITH LITTLE CHANGE IN STRENGTH... As of 11:00 AM HST Sun Aug 31 the center of Kiko was located near 14.4, -124.0 with movement W at 9 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 40 mph.

Issued at 2100 UTC SUN AUG 31 2025 000 WTPZ21 KNHC 312033 TCMEP1 TROPICAL STORM KIKO FORECAST/ADVISORY NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112025 2100 UTC SUN AUG 31 2025 TROPICAL STORM CENTER LOCATED NEAR 14.4N 124.0W AT 31/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT. 34 KT....... 30NE 0SE 0SW 30NW. 4 M SEAS.... 15NE 0SE 0SW 15NW. 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 14.4N 124.0W AT 31/2100Z AT 31/1800Z CENTER WAS LOCATED NEAR 14.4N 123.6W FORECAST VALID 01/0600Z 14.3N 125.2W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 30NE 0SE 0SW 30NW. FORECAST VALID 01/1800Z 14.2N 126.9W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 0SE 0SW 10NW. 34 KT... 30NE 10SE 10SW 30NW. FORECAST VALID 02/0600Z 14.1N 128.5W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 20NE 0SE 0SW 10NW. 34 KT... 40NE 20SE 20SW 40NW. FORECAST VALID 02/1800Z 14.1N 130.2W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 10NE 0SE 0SW 0NW. 50 KT... 20NE 10SE 10SW 20NW. 34 KT... 50NE 30SE 30SW 40NW. FORECAST VALID 03/0600Z 14.0N 131.9W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 15NE 10SE 10SW 15NW. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 50NE 30SE 30SW 40NW. FORECAST VALID 03/1800Z 14.0N 133.7W MAX WIND 80 KT...GUSTS 100 KT. 64 KT... 20NE 10SE 10SW 10NW. 50 KT... 30NE 20SE 15SW 20NW. 34 KT... 50NE 40SE 30SW 40NW. 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 04/1800Z 14.0N 137.6W MAX WIND 80 KT...GUSTS 100 KT. 50 KT... 30NE 20SE 20SW 20NW. 34 KT... 50NE 40SE 30SW 40NW. OUTLOOK VALID 05/1800Z 14.1N 141.3W MAX WIND 80 KT...GUSTS 100 KT. 50 KT... 30NE 20SE 20SW 20NW. 34 KT... 50NE 40SE 30SW 40NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.4N 124.0W NEXT ADVISORY AT 01/0300Z $$ FORECASTER BEVEN

Issued at 1100 AM HST Sun Aug 31 2025 ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM Tropical Storm Kiko Discussion Number 3 NWS National Hurricane Center Miami FL EP112025 1100 AM HST Sun Aug 31 2025 Kiko has changed little in organization during the past few hours, with a broad curved convective band wrapping around the western side of the cyclone. Recent ASCAT overpasses did not show tropical-storm force winds. However, there may be sampling issues at work since the central core of Kiko is small. Satellite intensity estimates are in the 35-45 kt range, and the initial intensity is held at 35 kt in deference to the scatterometer data. The scatterometer data and conventional imagery suggest the circulation center is elongated east-west with multiple cloud swirls present. The initial motion remains 270/8 kt. Kiko is on the south side of a deep-layer ridge that covers the tropical Pacific between 120W-155W, and this feature is expected to persist for the next several days. This should cause Kiko to move westward or just south of westward through the forecast period. While the track guidance generally agrees on the direction of motion, there is a considerable spread in forward speed with the faster UKMET/ECMWF being several hundred miles west of the slower GFS by 120 h. The new forecast track splits this speed difference, and it lies just north of the consensus models. The new forecast is a bit south of and slower than the previous forecast. Kiko is expected to encounter generally light vertical shear while it moves over sea surface temperatures that are around 27C. After 72 h, the cyclone is likely to move into a drier air mass that could inhibit strengthening despite the other favorable conditions. Based on this, the intensity forecast shows 72 h of strengthening followed by little change in strength at 96 and 120 h. There are two uncertainties in this forecast. First, the rapid intensification indices of the SHIPS model are notably above their climatological norms, and that combined with Kiko's small core suggests that a period of rapid intensification could occur during the next 72 h. Second, as mentioned earlier any deviation of the track slightly to the right of the forecast path could place the system over cooler waters that would slow or stop strengthening. The new intensity forecast is a little stronger than the previous forecast, and it lies near the intensity consensus. FORECAST POSITIONS AND MAX WINDS INIT 31/2100Z 14.4N 124.0W 35 KT 40 MPH 12H 01/0600Z 14.3N 125.2W 40 KT 45 MPH 24H 01/1800Z 14.2N 126.9W 50 KT 60 MPH 36H 02/0600Z 14.1N 128.5W 60 KT 70 MPH 48H 02/1800Z 14.1N 130.2W 70 KT 80 MPH 60H 03/0600Z 14.0N 131.9W 75 KT 85 MPH 72H 03/1800Z 14.0N 133.7W 80 KT 90 MPH 96H 04/1800Z 14.0N 137.6W 80 KT 90 MPH 120H 05/1800Z 14.1N 141.3W 80 KT 90 MPH $$ Forecaster Beven NNNN

Issued at 1100 AM HST Sun Aug 31 2025 ZCZC MIATCPEP1 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm Kiko Advisory Number 3 NWS National Hurricane Center Miami FL EP112025 1100 AM HST Sun Aug 31 2025 ...KIKO MOVING WESTWARD WITH LITTLE CHANGE IN STRENGTH... SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION ----------------------------------------------- LOCATION...14.4N 124.0W ABOUT 1090 MI...1760 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H PRESENT MOVEMENT...W OR 270 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 AM HST (2100 UTC), the center of Tropical Storm Kiko was located near latitude 14.4 North, longitude 124.0 West. Kiko is moving toward the west near 9 mph (15 km/h) and this motion is expected to continue over the next few days. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Strengthening is expected during the next couple of days, and the system is forecast to become a hurricane by Tuesday. Tropical-storm-force winds extend outward up to 35 miles (55 km) from the center. The estimated minimum central pressure is 1006 mb (29.71 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 500 PM HST. $$ Forecaster Beven NNNN

...KIKO MOVING WESTWARD WITH LITTLE CHANGE IN STRENGTH... As of 11:00 AM HST Sun Aug 31 the center of Kiko was located near 14.4, -124.0 with movement W at 9 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 40 mph.

Issued at 2100 UTC SUN AUG 31 2025 ZCZC MIATCMEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM KIKO FORECAST/ADVISORY NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112025 2100 UTC SUN AUG 31 2025 TROPICAL STORM CENTER LOCATED NEAR 14.4N 124.0W AT 31/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT. 34 KT....... 30NE 0SE 0SW 30NW. 4 M SEAS.... 15NE 0SE 0SW 15NW. 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 14.4N 124.0W AT 31/2100Z AT 31/1800Z CENTER WAS LOCATED NEAR 14.4N 123.6W FORECAST VALID 01/0600Z 14.3N 125.2W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 30NE 0SE 0SW 30NW. FORECAST VALID 01/1800Z 14.2N 126.9W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 0SE 0SW 10NW. 34 KT... 30NE 10SE 10SW 30NW. FORECAST VALID 02/0600Z 14.1N 128.5W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 20NE 0SE 0SW 10NW. 34 KT... 40NE 20SE 20SW 40NW. FORECAST VALID 02/1800Z 14.1N 130.2W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 10NE 0SE 0SW 0NW. 50 KT... 20NE 10SE 10SW 20NW. 34 KT... 50NE 30SE 30SW 40NW. FORECAST VALID 03/0600Z 14.0N 131.9W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 15NE 10SE 10SW 15NW. 50 KT... 30NE 20SE 20SW 30NW. 34 KT... 50NE 30SE 30SW 40NW. FORECAST VALID 03/1800Z 14.0N 133.7W MAX WIND 80 KT...GUSTS 100 KT. 64 KT... 20NE 10SE 10SW 10NW. 50 KT... 30NE 20SE 15SW 20NW. 34 KT... 50NE 40SE 30SW 40NW. 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 04/1800Z 14.0N 137.6W MAX WIND 80 KT...GUSTS 100 KT. 50 KT... 30NE 20SE 20SW 20NW. 34 KT... 50NE 40SE 30SW 40NW. OUTLOOK VALID 05/1800Z 14.1N 141.3W MAX WIND 80 KT...GUSTS 100 KT. 50 KT... 30NE 20SE 20SW 20NW. 34 KT... 50NE 40SE 30SW 40NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.4N 124.0W NEXT ADVISORY AT 01/0300Z $$ FORECASTER BEVEN NNNN

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Sun Aug 31 2025 Valid 312000Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Overall severe weather potential is expected to be low today and tonight. ...20Z Update... The general thunderstorm forecast was adjusted based on observational trends and recent guidance. See the previous discussion for additional details. ..Wendt.. 08/31/2025 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Aug 31 2025/ ...Synopsis and Discussion... Modest northwesterly flow aloft will persist today across the central CONUS, which is situation between a developing Rex block over southeast Canada and the northeast CONUS, and extensive upper ridging from the Southwest through the northern Rockies. Recent surface analysis shows moderate low-level moisture remains in place over the Great Plains, MS Valley, and Southeast. This analysis also placed a weak low along the central KS/OK border vicinity, with weak troughing extending northward from this low into south-central NE before arcing back northwestward through the NE Panhandle and western Dakotas. Modest surface troughing also extends southwestward from the low across the TX South Plains and into far southeast NM. Thunderstorms are anticipated in the vicinity of this troughing from the central Plains into southern High Plains, with additional low-level moisture convergence contributing to continued thunderstorms across much of central TX and southwest TX as well. Limited buoyancy, owing to poor lapse rates and cool temperatures, should temper the overall severe potential today. Some evening and overnight thunderstorms are also possible across central/eastern WA, northern ID, and far northwest MT as ascent attendant to a well-defined cyclone spreads into the region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Sun Aug 31 2025 Valid 312000Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Overall severe weather potential is expected to be low today and tonight. ...20Z Update... The general thunderstorm forecast was adjusted based on observational trends and recent guidance. See the previous discussion for additional details. ..Wendt.. 08/31/2025 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Aug 31 2025/ ...Synopsis and Discussion... Modest northwesterly flow aloft will persist today across the central CONUS, which is situation between a developing Rex block over southeast Canada and the northeast CONUS, and extensive upper ridging from the Southwest through the northern Rockies. Recent surface analysis shows moderate low-level moisture remains in place over the Great Plains, MS Valley, and Southeast. This analysis also placed a weak low along the central KS/OK border vicinity, with weak troughing extending northward from this low into south-central NE before arcing back northwestward through the NE Panhandle and western Dakotas. Modest surface troughing also extends southwestward from the low across the TX South Plains and into far southeast NM. Thunderstorms are anticipated in the vicinity of this troughing from the central Plains into southern High Plains, with additional low-level moisture convergence contributing to continued thunderstorms across much of central TX and southwest TX as well. Limited buoyancy, owing to poor lapse rates and cool temperatures, should temper the overall severe potential today. Some evening and overnight thunderstorms are also possible across central/eastern WA, northern ID, and far northwest MT as ascent attendant to a well-defined cyclone spreads into the region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Sun Aug 31 2025 Valid 312000Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Overall severe weather potential is expected to be low today and tonight. ...20Z Update... The general thunderstorm forecast was adjusted based on observational trends and recent guidance. See the previous discussion for additional details. ..Wendt.. 08/31/2025 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Aug 31 2025/ ...Synopsis and Discussion... Modest northwesterly flow aloft will persist today across the central CONUS, which is situation between a developing Rex block over southeast Canada and the northeast CONUS, and extensive upper ridging from the Southwest through the northern Rockies. Recent surface analysis shows moderate low-level moisture remains in place over the Great Plains, MS Valley, and Southeast. This analysis also placed a weak low along the central KS/OK border vicinity, with weak troughing extending northward from this low into south-central NE before arcing back northwestward through the NE Panhandle and western Dakotas. Modest surface troughing also extends southwestward from the low across the TX South Plains and into far southeast NM. Thunderstorms are anticipated in the vicinity of this troughing from the central Plains into southern High Plains, with additional low-level moisture convergence contributing to continued thunderstorms across much of central TX and southwest TX as well. Limited buoyancy, owing to poor lapse rates and cool temperatures, should temper the overall severe potential today. Some evening and overnight thunderstorms are also possible across central/eastern WA, northern ID, and far northwest MT as ascent attendant to a well-defined cyclone spreads into the region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Sun Aug 31 2025 Valid 312000Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Overall severe weather potential is expected to be low today and tonight. ...20Z Update... The general thunderstorm forecast was adjusted based on observational trends and recent guidance. See the previous discussion for additional details. ..Wendt.. 08/31/2025 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Aug 31 2025/ ...Synopsis and Discussion... Modest northwesterly flow aloft will persist today across the central CONUS, which is situation between a developing Rex block over southeast Canada and the northeast CONUS, and extensive upper ridging from the Southwest through the northern Rockies. Recent surface analysis shows moderate low-level moisture remains in place over the Great Plains, MS Valley, and Southeast. This analysis also placed a weak low along the central KS/OK border vicinity, with weak troughing extending northward from this low into south-central NE before arcing back northwestward through the NE Panhandle and western Dakotas. Modest surface troughing also extends southwestward from the low across the TX South Plains and into far southeast NM. Thunderstorms are anticipated in the vicinity of this troughing from the central Plains into southern High Plains, with additional low-level moisture convergence contributing to continued thunderstorms across much of central TX and southwest TX as well. Limited buoyancy, owing to poor lapse rates and cool temperatures, should temper the overall severe potential today. Some evening and overnight thunderstorms are also possible across central/eastern WA, northern ID, and far northwest MT as ascent attendant to a well-defined cyclone spreads into the region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Sun Aug 31 2025 Valid 312000Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Overall severe weather potential is expected to be low today and tonight. ...20Z Update... The general thunderstorm forecast was adjusted based on observational trends and recent guidance. See the previous discussion for additional details. ..Wendt.. 08/31/2025 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Aug 31 2025/ ...Synopsis and Discussion... Modest northwesterly flow aloft will persist today across the central CONUS, which is situation between a developing Rex block over southeast Canada and the northeast CONUS, and extensive upper ridging from the Southwest through the northern Rockies. Recent surface analysis shows moderate low-level moisture remains in place over the Great Plains, MS Valley, and Southeast. This analysis also placed a weak low along the central KS/OK border vicinity, with weak troughing extending northward from this low into south-central NE before arcing back northwestward through the NE Panhandle and western Dakotas. Modest surface troughing also extends southwestward from the low across the TX South Plains and into far southeast NM. Thunderstorms are anticipated in the vicinity of this troughing from the central Plains into southern High Plains, with additional low-level moisture convergence contributing to continued thunderstorms across much of central TX and southwest TX as well. Limited buoyancy, owing to poor lapse rates and cool temperatures, should temper the overall severe potential today. Some evening and overnight thunderstorms are also possible across central/eastern WA, northern ID, and far northwest MT as ascent attendant to a well-defined cyclone spreads into the region. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Aug 31 2025 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Strong thunderstorms are possible across parts of the northern Plains, Upper Midwest, and lower Mississippi Valley on Tuesday, though severe potential is uncertain. ...Parts of the northern Plains/Upper Midwest... Within a broader northwesterly flow regime, a vigorous mid/upper-level shortwave trough is forecast to move southeastward from northern SK into MB on Tuesday, and approach northern ND/MN by the end of the period. This shortwave and attendant large-scale ascent will eventually impinge upon a zone of favorable boundary-layer moisture and moderate instability along/ahead of a cold front from parts of the Dakotas into MN. However, guidance continues to vary regarding the timing of the shortwave and related mid/upper-level jet, placement of the cold front by late afternoon, and extent to which stronger deep-layer shear overspreads the more favorable instability. There will be some potential for storm development along/ahead of the front during the afternoon and evening, and also for elevated convection behind the front. A few strong storms (both elevated and surface-based) will be possible, and severe probabilities may be needed once confidence increases regarding the evolution of the primary synoptic features. ...Lower MS Valley into parts of the TN Valley... Scattered thunderstorms are possible during the afternoon and evening across parts of the lower MS Valley into parts of the TN Valley, within a modest west-northwesterly flow regime. A low-amplitude shortwave approaching the base of a deep mid/upper-level trough covering the eastern CONUS may locally enhance ascent and deep-layer shear, and gusty winds could accompany the strongest storms. However, midlevel lapse rates are expected to remain quite weak, and updrafts may not become sufficiently strong to support an organized severe threat. ..Dean.. 08/31/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Aug 31 2025 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Strong thunderstorms are possible across parts of the northern Plains, Upper Midwest, and lower Mississippi Valley on Tuesday, though severe potential is uncertain. ...Parts of the northern Plains/Upper Midwest... Within a broader northwesterly flow regime, a vigorous mid/upper-level shortwave trough is forecast to move southeastward from northern SK into MB on Tuesday, and approach northern ND/MN by the end of the period. This shortwave and attendant large-scale ascent will eventually impinge upon a zone of favorable boundary-layer moisture and moderate instability along/ahead of a cold front from parts of the Dakotas into MN. However, guidance continues to vary regarding the timing of the shortwave and related mid/upper-level jet, placement of the cold front by late afternoon, and extent to which stronger deep-layer shear overspreads the more favorable instability. There will be some potential for storm development along/ahead of the front during the afternoon and evening, and also for elevated convection behind the front. A few strong storms (both elevated and surface-based) will be possible, and severe probabilities may be needed once confidence increases regarding the evolution of the primary synoptic features. ...Lower MS Valley into parts of the TN Valley... Scattered thunderstorms are possible during the afternoon and evening across parts of the lower MS Valley into parts of the TN Valley, within a modest west-northwesterly flow regime. A low-amplitude shortwave approaching the base of a deep mid/upper-level trough covering the eastern CONUS may locally enhance ascent and deep-layer shear, and gusty winds could accompany the strongest storms. However, midlevel lapse rates are expected to remain quite weak, and updrafts may not become sufficiently strong to support an organized severe threat. ..Dean.. 08/31/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Aug 31 2025 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Strong thunderstorms are possible across parts of the northern Plains, Upper Midwest, and lower Mississippi Valley on Tuesday, though severe potential is uncertain. ...Parts of the northern Plains/Upper Midwest... Within a broader northwesterly flow regime, a vigorous mid/upper-level shortwave trough is forecast to move southeastward from northern SK into MB on Tuesday, and approach northern ND/MN by the end of the period. This shortwave and attendant large-scale ascent will eventually impinge upon a zone of favorable boundary-layer moisture and moderate instability along/ahead of a cold front from parts of the Dakotas into MN. However, guidance continues to vary regarding the timing of the shortwave and related mid/upper-level jet, placement of the cold front by late afternoon, and extent to which stronger deep-layer shear overspreads the more favorable instability. There will be some potential for storm development along/ahead of the front during the afternoon and evening, and also for elevated convection behind the front. A few strong storms (both elevated and surface-based) will be possible, and severe probabilities may be needed once confidence increases regarding the evolution of the primary synoptic features. ...Lower MS Valley into parts of the TN Valley... Scattered thunderstorms are possible during the afternoon and evening across parts of the lower MS Valley into parts of the TN Valley, within a modest west-northwesterly flow regime. A low-amplitude shortwave approaching the base of a deep mid/upper-level trough covering the eastern CONUS may locally enhance ascent and deep-layer shear, and gusty winds could accompany the strongest storms. However, midlevel lapse rates are expected to remain quite weak, and updrafts may not become sufficiently strong to support an organized severe threat. ..Dean.. 08/31/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Aug 31 2025 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Strong thunderstorms are possible across parts of the northern Plains, Upper Midwest, and lower Mississippi Valley on Tuesday, though severe potential is uncertain. ...Parts of the northern Plains/Upper Midwest... Within a broader northwesterly flow regime, a vigorous mid/upper-level shortwave trough is forecast to move southeastward from northern SK into MB on Tuesday, and approach northern ND/MN by the end of the period. This shortwave and attendant large-scale ascent will eventually impinge upon a zone of favorable boundary-layer moisture and moderate instability along/ahead of a cold front from parts of the Dakotas into MN. However, guidance continues to vary regarding the timing of the shortwave and related mid/upper-level jet, placement of the cold front by late afternoon, and extent to which stronger deep-layer shear overspreads the more favorable instability. There will be some potential for storm development along/ahead of the front during the afternoon and evening, and also for elevated convection behind the front. A few strong storms (both elevated and surface-based) will be possible, and severe probabilities may be needed once confidence increases regarding the evolution of the primary synoptic features. ...Lower MS Valley into parts of the TN Valley... Scattered thunderstorms are possible during the afternoon and evening across parts of the lower MS Valley into parts of the TN Valley, within a modest west-northwesterly flow regime. A low-amplitude shortwave approaching the base of a deep mid/upper-level trough covering the eastern CONUS may locally enhance ascent and deep-layer shear, and gusty winds could accompany the strongest storms. However, midlevel lapse rates are expected to remain quite weak, and updrafts may not become sufficiently strong to support an organized severe threat. ..Dean.. 08/31/2025 Read more