Aggregator

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Aug 06 2025 Valid 091200Z - 141200Z ...DISCUSSION... ...Saturday/Day 4 to Monday/Day 6... A mid-level trough will move across the northern Plains on Saturday, as a cold front advances southeastward into the upper Mississippi and mid Missouri Valleys. Moderate to strong instability should be in place ahead of the front by afternoon from eastern Nebraska northeastward into Wisconsin. Thunderstorm development is expected to take place along parts of the front from the afternoon into the evening, with the greatest convective coverage over the upper Mississippi Valley. A few storms could be severe, with large hail and isolated damaging wind gusts expected to be the primary threats. On Sunday, another mid-level trough is forecast to move into the central and northern Plains, as a moist and unstable airmass remains in place ahead of the front from the mid Missouri Valley northeastward upper Mississippi Valley. Thunderstorms will again be possible ahead of the trough near an axis of moderate instability during the afternoon and evening. Some model forecasts suggest the strongest instability will not be co-located with the greatest convective potential. Although a severe threat may develop across parts of the region, this would negatively affect severe threat magnitude. The mid-level trough is forecast to shift eastward across the north-central U.S. on Monday, as a cold front advances southeastward across the central Plains and Upper Midwest. Isolated severe thunderstorms will again be possible ahead of the front near an axis of moderate instability. However, large-scale ascent will be somewhat limited across much of the region, suggesting the convective potential and resulting severe threat should remain isolated. ...Tuesday/Day 7 and Wednesday/Day 8... From Tuesday into Wednesday, the mid-level trough and an associated cold front is forecast to advance eastward from the north-central U.S. into the Northeast. Along and ahead of the front each afternoon and evening, strong thunderstorms will be possible. However, the models are forecasting less instability and a more disorganized pattern compared to previous days, suggesting that any severe threat will remain localized. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Aug 06 2025 Valid 091200Z - 141200Z ...DISCUSSION... ...Saturday/Day 4 to Monday/Day 6... A mid-level trough will move across the northern Plains on Saturday, as a cold front advances southeastward into the upper Mississippi and mid Missouri Valleys. Moderate to strong instability should be in place ahead of the front by afternoon from eastern Nebraska northeastward into Wisconsin. Thunderstorm development is expected to take place along parts of the front from the afternoon into the evening, with the greatest convective coverage over the upper Mississippi Valley. A few storms could be severe, with large hail and isolated damaging wind gusts expected to be the primary threats. On Sunday, another mid-level trough is forecast to move into the central and northern Plains, as a moist and unstable airmass remains in place ahead of the front from the mid Missouri Valley northeastward upper Mississippi Valley. Thunderstorms will again be possible ahead of the trough near an axis of moderate instability during the afternoon and evening. Some model forecasts suggest the strongest instability will not be co-located with the greatest convective potential. Although a severe threat may develop across parts of the region, this would negatively affect severe threat magnitude. The mid-level trough is forecast to shift eastward across the north-central U.S. on Monday, as a cold front advances southeastward across the central Plains and Upper Midwest. Isolated severe thunderstorms will again be possible ahead of the front near an axis of moderate instability. However, large-scale ascent will be somewhat limited across much of the region, suggesting the convective potential and resulting severe threat should remain isolated. ...Tuesday/Day 7 and Wednesday/Day 8... From Tuesday into Wednesday, the mid-level trough and an associated cold front is forecast to advance eastward from the north-central U.S. into the Northeast. Along and ahead of the front each afternoon and evening, strong thunderstorms will be possible. However, the models are forecasting less instability and a more disorganized pattern compared to previous days, suggesting that any severe threat will remain localized. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Aug 06 2025 Valid 091200Z - 141200Z ...DISCUSSION... ...Saturday/Day 4 to Monday/Day 6... A mid-level trough will move across the northern Plains on Saturday, as a cold front advances southeastward into the upper Mississippi and mid Missouri Valleys. Moderate to strong instability should be in place ahead of the front by afternoon from eastern Nebraska northeastward into Wisconsin. Thunderstorm development is expected to take place along parts of the front from the afternoon into the evening, with the greatest convective coverage over the upper Mississippi Valley. A few storms could be severe, with large hail and isolated damaging wind gusts expected to be the primary threats. On Sunday, another mid-level trough is forecast to move into the central and northern Plains, as a moist and unstable airmass remains in place ahead of the front from the mid Missouri Valley northeastward upper Mississippi Valley. Thunderstorms will again be possible ahead of the trough near an axis of moderate instability during the afternoon and evening. Some model forecasts suggest the strongest instability will not be co-located with the greatest convective potential. Although a severe threat may develop across parts of the region, this would negatively affect severe threat magnitude. The mid-level trough is forecast to shift eastward across the north-central U.S. on Monday, as a cold front advances southeastward across the central Plains and Upper Midwest. Isolated severe thunderstorms will again be possible ahead of the front near an axis of moderate instability. However, large-scale ascent will be somewhat limited across much of the region, suggesting the convective potential and resulting severe threat should remain isolated. ...Tuesday/Day 7 and Wednesday/Day 8... From Tuesday into Wednesday, the mid-level trough and an associated cold front is forecast to advance eastward from the north-central U.S. into the Northeast. Along and ahead of the front each afternoon and evening, strong thunderstorms will be possible. However, the models are forecasting less instability and a more disorganized pattern compared to previous days, suggesting that any severe threat will remain localized. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Wed Aug 06 2025 Valid 091200Z - 141200Z ...DISCUSSION... ...Saturday/Day 4 to Monday/Day 6... A mid-level trough will move across the northern Plains on Saturday, as a cold front advances southeastward into the upper Mississippi and mid Missouri Valleys. Moderate to strong instability should be in place ahead of the front by afternoon from eastern Nebraska northeastward into Wisconsin. Thunderstorm development is expected to take place along parts of the front from the afternoon into the evening, with the greatest convective coverage over the upper Mississippi Valley. A few storms could be severe, with large hail and isolated damaging wind gusts expected to be the primary threats. On Sunday, another mid-level trough is forecast to move into the central and northern Plains, as a moist and unstable airmass remains in place ahead of the front from the mid Missouri Valley northeastward upper Mississippi Valley. Thunderstorms will again be possible ahead of the trough near an axis of moderate instability during the afternoon and evening. Some model forecasts suggest the strongest instability will not be co-located with the greatest convective potential. Although a severe threat may develop across parts of the region, this would negatively affect severe threat magnitude. The mid-level trough is forecast to shift eastward across the north-central U.S. on Monday, as a cold front advances southeastward across the central Plains and Upper Midwest. Isolated severe thunderstorms will again be possible ahead of the front near an axis of moderate instability. However, large-scale ascent will be somewhat limited across much of the region, suggesting the convective potential and resulting severe threat should remain isolated. ...Tuesday/Day 7 and Wednesday/Day 8... From Tuesday into Wednesday, the mid-level trough and an associated cold front is forecast to advance eastward from the north-central U.S. into the Northeast. Along and ahead of the front each afternoon and evening, strong thunderstorms will be possible. However, the models are forecasting less instability and a more disorganized pattern compared to previous days, suggesting that any severe threat will remain localized. Read more

5-Day Uncertainty Track last updated Wed, 06 Aug 2025 08:55:01 GMT


Wind Speed Probabilities last updated Wed, 06 Aug 2025 08:55:01 GMT

Issued at 1100 PM HST Tue Aug 05 2025 000 WTPZ43 KNHC 060853 TCDEP3 Tropical Storm Henriette Discussion Number 9 NWS National Hurricane Center Miami FL EP082025 1100 PM HST Tue Aug 05 2025 The satellite presentation of Henriette has changed little since the previous advisory, with intermittent bursts of deep convection continuing, primarily located over and west of the cyclone’s low-level center. Recent subjective Dvorak intensity estimates from TAFB and SAB were 3.0/45 kt and 2.5/35 kt, respectively, while objective estimates from UW-CIMSS have ranged between 34 and 46 kt over the past several hours. A timely 06/0525Z Metop-C ASCAT pass revealed several 40–45 kt wind barbs north of the low-level center. Based on these data, the initial intensity for this advisory remains 45 kt. Henriette has recently turned toward the west, or 280 degrees, at 13 kt. This general motion is expected to persist over the next couple of days as the cyclone is steered by a strengthening subtropical ridge situated to the north. By around 72 hours, a gradual turn toward the west-northwest or northwest is anticipated as an amplifying longwave trough northwest of Hawaii begins to erode the western periphery of the ridge. The official track forecast is closely aligned with the latest multi-model consensus aids and remains very similar to the previous advisory. Henriette is forecast to remain in a low vertical wind shear environment for the next several days. During this period, sea surface temperatures are expected to gradually decrease to near or slightly below 24C, while mid-level moisture drops below 50 percent. Despite these marginal thermodynamic conditions, Henriette’s broad circulation and well-established inner core should allow the system to remain relatively resilient in the low shear environment. Only slight weakening is forecast during the next few days, followed by little change in strength. Toward the end of the forecast period, sea surface temperatures are expected to rise again. If the system manages to endure the cooler waters, as persistently suggested by both the GFS and ECMWF models, some re-intensification is possible. The official forecast reflects this potential and lies near the middle of the intensity guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 17.8N 128.2W 45 KT 50 MPH 12H 06/1800Z 18.1N 130.4W 45 KT 50 MPH 24H 07/0600Z 18.4N 133.4W 40 KT 45 MPH 36H 07/1800Z 18.7N 136.4W 40 KT 45 MPH 48H 08/0600Z 19.2N 139.4W 40 KT 45 MPH 60H 08/1800Z 19.9N 142.3W 40 KT 45 MPH 72H 09/0600Z 20.9N 145.2W 40 KT 45 MPH 96H 10/0600Z 23.3N 149.9W 40 KT 45 MPH 120H 11/0600Z 26.1N 154.1W 50 KT 60 MPH $$ Forecaster Jelsema (CPHC)

Issued at 0900 UTC WED AUG 06 2025 000 FOPZ13 KNHC 060853 PWSEP3 TROPICAL STORM HENRIETTE WIND SPEED PROBABILITIES NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP082025 0900 UTC WED AUG 06 2025 AT 0900Z THE CENTER OF TROPICAL STORM HENRIETTE WAS LOCATED NEAR LATITUDE 17.8 NORTH...LONGITUDE 128.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 45 KTS...50 MPH...85 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 06Z WED 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 06Z WED 18Z WED 06Z THU 18Z THU 06Z FRI 06Z SAT 06Z SUN PERIODS TO TO TO TO TO TO TO 18Z WED 06Z THU 18Z THU 06Z FRI 06Z SAT 06Z SUN 06Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 20N 130W 34 6 X( 6) X( 6) X( 6) X( 6) X( 6) X( 6) 20N 135W 34 X 4( 4) 10(14) X(14) X(14) X(14) X(14) 20N 140W 34 X X( X) 1( 1) 21(22) 11(33) X(33) X(33) 20N 140W 50 X X( X) X( X) 3( 3) 4( 7) X( 7) X( 7) 20N 140W 64 X X( X) X( X) X( X) 1( 1) X( 1) X( 1) 20N 145W 34 X X( X) X( X) X( X) 16(16) 1(17) 1(18) 20N 145W 50 X X( X) X( X) X( X) 3( 3) 1( 4) X( 4) 20N 150W 34 X X( X) X( X) X( X) X( X) 3( 3) X( 3) 25N 150W 34 X X( X) X( X) X( X) X( X) 10(10) 7(17) 25N 150W 50 X X( X) X( X) X( X) X( X) 1( 1) 2( 3) 25N 150W 64 X X( X) X( X) X( X) X( X) X( X) 1( 1) 20N 151W 34 X X( X) X( X) X( X) X( X) 2( 2) 1( 3) $$ FORECASTER JELSEMA (CPHC)

Issued at 1100 PM HST Tue Aug 05 2025 000 WTPZ33 KNHC 060853 TCPEP3 BULLETIN Tropical Storm Henriette Advisory Number 9 NWS National Hurricane Center Miami FL EP082025 1100 PM HST Tue Aug 05 2025 ...HENRIETTE MOVING WEST-NORTHWESTWARD FAR TO THE EAST OF HAWAII... SUMMARY OF 1100 PM HST...0900 UTC...INFORMATION ----------------------------------------------- LOCATION...17.8N 128.2W ABOUT 1760 MI...2835 KM E OF HILO HAWAII MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM HST (0900 UTC), the center of Tropical Storm Henriette was located near latitude 17.8 North, longitude 128.2 West. Henriette is moving toward the west near 15 mph (24 km/h). This general motion is expected to continue for the next few days. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Some slight weakening is forecast during the next 24 hours, followed by little change in strength during the next couple of days. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. The estimated minimum central pressure is 1003 mb (29.62 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 500 AM HST. $$ Forecaster Jelsema (CPHC)

...HENRIETTE MOVING WEST-NORTHWESTWARD FAR TO THE EAST OF HAWAII... As of 11:00 PM HST Tue Aug 05 the center of Henriette was located near 17.8, -128.2 with movement W at 15 mph. The minimum central pressure was 1003 mb with maximum sustained winds of about 50 mph.

Issued at 0900 UTC WED AUG 06 2025 647 WTPZ23 KNHC 060852 TCMEP3 TROPICAL STORM HENRIETTE FORECAST/ADVISORY NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP082025 0900 UTC WED AUG 06 2025 TROPICAL STORM CENTER LOCATED NEAR 17.8N 128.2W AT 06/0900Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 13 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1003 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT....... 70NE 40SE 40SW 70NW. 4 M SEAS....120NE 45SE 60SW 90NW. 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 128.2W AT 06/0900Z AT 06/0600Z CENTER WAS LOCATED NEAR 17.7N 127.4W FORECAST VALID 06/1800Z 18.1N 130.4W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 70NE 40SE 40SW 70NW. FORECAST VALID 07/0600Z 18.4N 133.4W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 30SE 30SW 60NW. FORECAST VALID 07/1800Z 18.7N 136.4W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 30SE 30SW 60NW. FORECAST VALID 08/0600Z 19.2N 139.4W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 30SE 30SW 60NW. FORECAST VALID 08/1800Z 19.9N 142.3W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 30SE 30SW 60NW. FORECAST VALID 09/0600Z 20.9N 145.2W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 30SE 30SW 60NW. 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 10/0600Z 23.3N 149.9W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 40SE 30SW 50NW. OUTLOOK VALID 11/0600Z 26.1N 154.1W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 25NE 0SE 0SW 20NW. 34 KT... 60NE 50SE 40SW 60NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.8N 128.2W NEXT ADVISORY AT 06/1500Z $$ FORECASTER JELSEMA (CPHC)

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Wed Aug 06 2025 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with large hail and severe wind gusts are likely on Friday across parts of the northern Plains and upper Mississippi Valley. Hailstones greater than 2 inches in diameter will be possible. ...Central and Northern Plains/Upper Mississippi Valley... A mid-level trough will progress eastward into the northern High Plains on Friday, as an associated speed max moves over the northern Plains. At the surface, a low will deepen across the central Plains, as a cold front advances eastward the north-central states. Ahead of the front, a moist and unstable airmass will be in place from the central Dakotas eastward to the upper Mississippi Valley. A pronounced axis of strong instability is forecast by afternoon from northeastern South Dakota into far eastern North Dakota. Surface-based thunderstorms are expected to develop along an instability gradient located just ahead of the front during the mid to late afternoon. A cluster of strong to severe thunderstorms will move eastward across the eastern Dakotas into Minnesota from late afternoon into the evening. At 21Z on Friday, forecast soundings near the axis of instability have an impressive thermodynamic environment. To the west of Fargo, North Dakota, MLCAPE is forecast to peak in the 4500 to 6000 J/kg range, with 700-500 mb lapse rates in the 8 to 9 C/km range. In addition, 0-6 km shear is forecast to be in the 35 to 40 knot range, suggesting supercells with large hail will be likely. Hailstones greater than 2 inches in diameter will be possible with the stronger cores. In addition, 0-3 km storm-relative helicity is forecast reach the 200 to 275 m2/s2 range by late afternoon, suggesting that a tornado threat could develop. The potential for severe gusts is expected to increase in the early evening, as a cluster or broken line of strong to severe storms moves eastward across the region. Further south into southeastern South Dakota and northeastern Nebraska, cell coverage is forecast to be more isolated due to a capping inversion that is evident on forecast soundings. In spite of the cap, low-level convergence is forecast to become strong just ahead of the front. This should be enough for convective initiation during the evening. The environment along this part of the front will likely support large hail and severe wind gusts, but the threat should be more isolated with southward extent. ..Broyles.. 08/06/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Wed Aug 06 2025 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with large hail and severe wind gusts are likely on Friday across parts of the northern Plains and upper Mississippi Valley. Hailstones greater than 2 inches in diameter will be possible. ...Central and Northern Plains/Upper Mississippi Valley... A mid-level trough will progress eastward into the northern High Plains on Friday, as an associated speed max moves over the northern Plains. At the surface, a low will deepen across the central Plains, as a cold front advances eastward the north-central states. Ahead of the front, a moist and unstable airmass will be in place from the central Dakotas eastward to the upper Mississippi Valley. A pronounced axis of strong instability is forecast by afternoon from northeastern South Dakota into far eastern North Dakota. Surface-based thunderstorms are expected to develop along an instability gradient located just ahead of the front during the mid to late afternoon. A cluster of strong to severe thunderstorms will move eastward across the eastern Dakotas into Minnesota from late afternoon into the evening. At 21Z on Friday, forecast soundings near the axis of instability have an impressive thermodynamic environment. To the west of Fargo, North Dakota, MLCAPE is forecast to peak in the 4500 to 6000 J/kg range, with 700-500 mb lapse rates in the 8 to 9 C/km range. In addition, 0-6 km shear is forecast to be in the 35 to 40 knot range, suggesting supercells with large hail will be likely. Hailstones greater than 2 inches in diameter will be possible with the stronger cores. In addition, 0-3 km storm-relative helicity is forecast reach the 200 to 275 m2/s2 range by late afternoon, suggesting that a tornado threat could develop. The potential for severe gusts is expected to increase in the early evening, as a cluster or broken line of strong to severe storms moves eastward across the region. Further south into southeastern South Dakota and northeastern Nebraska, cell coverage is forecast to be more isolated due to a capping inversion that is evident on forecast soundings. In spite of the cap, low-level convergence is forecast to become strong just ahead of the front. This should be enough for convective initiation during the evening. The environment along this part of the front will likely support large hail and severe wind gusts, but the threat should be more isolated with southward extent. ..Broyles.. 08/06/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Wed Aug 06 2025 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with large hail and severe wind gusts are likely on Friday across parts of the northern Plains and upper Mississippi Valley. Hailstones greater than 2 inches in diameter will be possible. ...Central and Northern Plains/Upper Mississippi Valley... A mid-level trough will progress eastward into the northern High Plains on Friday, as an associated speed max moves over the northern Plains. At the surface, a low will deepen across the central Plains, as a cold front advances eastward the north-central states. Ahead of the front, a moist and unstable airmass will be in place from the central Dakotas eastward to the upper Mississippi Valley. A pronounced axis of strong instability is forecast by afternoon from northeastern South Dakota into far eastern North Dakota. Surface-based thunderstorms are expected to develop along an instability gradient located just ahead of the front during the mid to late afternoon. A cluster of strong to severe thunderstorms will move eastward across the eastern Dakotas into Minnesota from late afternoon into the evening. At 21Z on Friday, forecast soundings near the axis of instability have an impressive thermodynamic environment. To the west of Fargo, North Dakota, MLCAPE is forecast to peak in the 4500 to 6000 J/kg range, with 700-500 mb lapse rates in the 8 to 9 C/km range. In addition, 0-6 km shear is forecast to be in the 35 to 40 knot range, suggesting supercells with large hail will be likely. Hailstones greater than 2 inches in diameter will be possible with the stronger cores. In addition, 0-3 km storm-relative helicity is forecast reach the 200 to 275 m2/s2 range by late afternoon, suggesting that a tornado threat could develop. The potential for severe gusts is expected to increase in the early evening, as a cluster or broken line of strong to severe storms moves eastward across the region. Further south into southeastern South Dakota and northeastern Nebraska, cell coverage is forecast to be more isolated due to a capping inversion that is evident on forecast soundings. In spite of the cap, low-level convergence is forecast to become strong just ahead of the front. This should be enough for convective initiation during the evening. The environment along this part of the front will likely support large hail and severe wind gusts, but the threat should be more isolated with southward extent. ..Broyles.. 08/06/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Wed Aug 06 2025 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with large hail and severe wind gusts are likely on Friday across parts of the northern Plains and upper Mississippi Valley. Hailstones greater than 2 inches in diameter will be possible. ...Central and Northern Plains/Upper Mississippi Valley... A mid-level trough will progress eastward into the northern High Plains on Friday, as an associated speed max moves over the northern Plains. At the surface, a low will deepen across the central Plains, as a cold front advances eastward the north-central states. Ahead of the front, a moist and unstable airmass will be in place from the central Dakotas eastward to the upper Mississippi Valley. A pronounced axis of strong instability is forecast by afternoon from northeastern South Dakota into far eastern North Dakota. Surface-based thunderstorms are expected to develop along an instability gradient located just ahead of the front during the mid to late afternoon. A cluster of strong to severe thunderstorms will move eastward across the eastern Dakotas into Minnesota from late afternoon into the evening. At 21Z on Friday, forecast soundings near the axis of instability have an impressive thermodynamic environment. To the west of Fargo, North Dakota, MLCAPE is forecast to peak in the 4500 to 6000 J/kg range, with 700-500 mb lapse rates in the 8 to 9 C/km range. In addition, 0-6 km shear is forecast to be in the 35 to 40 knot range, suggesting supercells with large hail will be likely. Hailstones greater than 2 inches in diameter will be possible with the stronger cores. In addition, 0-3 km storm-relative helicity is forecast reach the 200 to 275 m2/s2 range by late afternoon, suggesting that a tornado threat could develop. The potential for severe gusts is expected to increase in the early evening, as a cluster or broken line of strong to severe storms moves eastward across the region. Further south into southeastern South Dakota and northeastern Nebraska, cell coverage is forecast to be more isolated due to a capping inversion that is evident on forecast soundings. In spite of the cap, low-level convergence is forecast to become strong just ahead of the front. This should be enough for convective initiation during the evening. The environment along this part of the front will likely support large hail and severe wind gusts, but the threat should be more isolated with southward extent. ..Broyles.. 08/06/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Wed Aug 06 2025 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PART OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Thunderstorms with large hail and severe wind gusts are likely on Friday across parts of the northern Plains and upper Mississippi Valley. Hailstones greater than 2 inches in diameter will be possible. ...Central and Northern Plains/Upper Mississippi Valley... A mid-level trough will progress eastward into the northern High Plains on Friday, as an associated speed max moves over the northern Plains. At the surface, a low will deepen across the central Plains, as a cold front advances eastward the north-central states. Ahead of the front, a moist and unstable airmass will be in place from the central Dakotas eastward to the upper Mississippi Valley. A pronounced axis of strong instability is forecast by afternoon from northeastern South Dakota into far eastern North Dakota. Surface-based thunderstorms are expected to develop along an instability gradient located just ahead of the front during the mid to late afternoon. A cluster of strong to severe thunderstorms will move eastward across the eastern Dakotas into Minnesota from late afternoon into the evening. At 21Z on Friday, forecast soundings near the axis of instability have an impressive thermodynamic environment. To the west of Fargo, North Dakota, MLCAPE is forecast to peak in the 4500 to 6000 J/kg range, with 700-500 mb lapse rates in the 8 to 9 C/km range. In addition, 0-6 km shear is forecast to be in the 35 to 40 knot range, suggesting supercells with large hail will be likely. Hailstones greater than 2 inches in diameter will be possible with the stronger cores. In addition, 0-3 km storm-relative helicity is forecast reach the 200 to 275 m2/s2 range by late afternoon, suggesting that a tornado threat could develop. The potential for severe gusts is expected to increase in the early evening, as a cluster or broken line of strong to severe storms moves eastward across the region. Further south into southeastern South Dakota and northeastern Nebraska, cell coverage is forecast to be more isolated due to a capping inversion that is evident on forecast soundings. In spite of the cap, low-level convergence is forecast to become strong just ahead of the front. This should be enough for convective initiation during the evening. The environment along this part of the front will likely support large hail and severe wind gusts, but the threat should be more isolated with southward extent. ..Broyles.. 08/06/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 AM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... ...Synopsis... A robust midlevel trough will advance eastward across the northwestern CONUS, while an expansive large-scale ridge remains in place across the southern Rockies and adjacent Plains. ...Great Basin into the Central Rockies... Compared to Day 1/Wednesday, slightly stronger deep-layer west-southwesterly flow will overspread the Great Basin into the central Rockies -- between the robust midlevel trough and expansive large-scale ridge. Diurnal heating amid a dry antecedent air mass will yield deep boundary-layer mixing into the strengthening flow aloft, resulting in 5-10 percent RH and 20-25 mph sustained west-southwesterly surface winds (with higher gusts). These hot, dry, and windy conditions atop receptive fuels will lead to another critical fire-weather day across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Midlevel moisture beneath the expansive large-scale ridge will once again contribute to inverted-V soundings and sufficient instability for diurnally driven high-based thunderstorms. Around 0.5 to 0.70 inch PW will favor dry thunderstorms, and given receptive fuels, lightning-induced ignitions will be a continued concern (along with strong/erratic outflow winds). ..Weinman.. 08/06/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 AM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... ...Synopsis... A robust midlevel trough will advance eastward across the northwestern CONUS, while an expansive large-scale ridge remains in place across the southern Rockies and adjacent Plains. ...Great Basin into the Central Rockies... Compared to Day 1/Wednesday, slightly stronger deep-layer west-southwesterly flow will overspread the Great Basin into the central Rockies -- between the robust midlevel trough and expansive large-scale ridge. Diurnal heating amid a dry antecedent air mass will yield deep boundary-layer mixing into the strengthening flow aloft, resulting in 5-10 percent RH and 20-25 mph sustained west-southwesterly surface winds (with higher gusts). These hot, dry, and windy conditions atop receptive fuels will lead to another critical fire-weather day across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Midlevel moisture beneath the expansive large-scale ridge will once again contribute to inverted-V soundings and sufficient instability for diurnally driven high-based thunderstorms. Around 0.5 to 0.70 inch PW will favor dry thunderstorms, and given receptive fuels, lightning-induced ignitions will be a continued concern (along with strong/erratic outflow winds). ..Weinman.. 08/06/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 AM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... ...Synopsis... A robust midlevel trough will advance eastward across the northwestern CONUS, while an expansive large-scale ridge remains in place across the southern Rockies and adjacent Plains. ...Great Basin into the Central Rockies... Compared to Day 1/Wednesday, slightly stronger deep-layer west-southwesterly flow will overspread the Great Basin into the central Rockies -- between the robust midlevel trough and expansive large-scale ridge. Diurnal heating amid a dry antecedent air mass will yield deep boundary-layer mixing into the strengthening flow aloft, resulting in 5-10 percent RH and 20-25 mph sustained west-southwesterly surface winds (with higher gusts). These hot, dry, and windy conditions atop receptive fuels will lead to another critical fire-weather day across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Midlevel moisture beneath the expansive large-scale ridge will once again contribute to inverted-V soundings and sufficient instability for diurnally driven high-based thunderstorms. Around 0.5 to 0.70 inch PW will favor dry thunderstorms, and given receptive fuels, lightning-induced ignitions will be a continued concern (along with strong/erratic outflow winds). ..Weinman.. 08/06/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 AM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... ...Synopsis... A robust midlevel trough will advance eastward across the northwestern CONUS, while an expansive large-scale ridge remains in place across the southern Rockies and adjacent Plains. ...Great Basin into the Central Rockies... Compared to Day 1/Wednesday, slightly stronger deep-layer west-southwesterly flow will overspread the Great Basin into the central Rockies -- between the robust midlevel trough and expansive large-scale ridge. Diurnal heating amid a dry antecedent air mass will yield deep boundary-layer mixing into the strengthening flow aloft, resulting in 5-10 percent RH and 20-25 mph sustained west-southwesterly surface winds (with higher gusts). These hot, dry, and windy conditions atop receptive fuels will lead to another critical fire-weather day across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Midlevel moisture beneath the expansive large-scale ridge will once again contribute to inverted-V soundings and sufficient instability for diurnally driven high-based thunderstorms. Around 0.5 to 0.70 inch PW will favor dry thunderstorms, and given receptive fuels, lightning-induced ignitions will be a continued concern (along with strong/erratic outflow winds). ..Weinman.. 08/06/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 AM CDT Wed Aug 06 2025 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE GREAT BASIN INTO THE CENTRAL ROCKIES... ...Synopsis... A robust midlevel trough will advance eastward across the northwestern CONUS, while an expansive large-scale ridge remains in place across the southern Rockies and adjacent Plains. ...Great Basin into the Central Rockies... Compared to Day 1/Wednesday, slightly stronger deep-layer west-southwesterly flow will overspread the Great Basin into the central Rockies -- between the robust midlevel trough and expansive large-scale ridge. Diurnal heating amid a dry antecedent air mass will yield deep boundary-layer mixing into the strengthening flow aloft, resulting in 5-10 percent RH and 20-25 mph sustained west-southwesterly surface winds (with higher gusts). These hot, dry, and windy conditions atop receptive fuels will lead to another critical fire-weather day across the region. ...Dry Thunderstorms - Southwest into the Central Rockies... Midlevel moisture beneath the expansive large-scale ridge will once again contribute to inverted-V soundings and sufficient instability for diurnally driven high-based thunderstorms. Around 0.5 to 0.70 inch PW will favor dry thunderstorms, and given receptive fuels, lightning-induced ignitions will be a continued concern (along with strong/erratic outflow winds). ..Weinman.. 08/06/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more