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Issued at 200 PM PDT Wed Aug 27 2025 000 WTPZ45 KNHC 272036 TCDEP5 Tropical Storm Juliette Discussion Number 13 NWS National Hurricane Center Miami FL EP102025 200 PM PDT Wed Aug 27 2025 GOES-18 imagery indicates that convection associated with Juliette continues to gradually decrease, and the cloud tops on IR imagery are gradually warming. However, there is an area of convection about 70 n mi wide in the NE quadrant, with the low-level center currently at the southwestern edge of the convective area. The latest subjective Dvorak CI numbers from TAFB and SAB are 3.0/45 kt, while objective intensity estimates from UW-CIMSS have a wider range (35-50 kt). A 1719 UTC ASCAT-C pass over the cyclone showed several 34-36 kt vectors in the northeast quadrant. The initial intensity is nudged downward to 40 kt for this advisory. Juliette is moving over cold sea surface temperatures of 23-24C, and the cyclone is forecast to reach water temperatures colder than 22C in 6-12 h. Juliette is also now reaching an area of increasing southwesterly wind shear, along with a drier, stable low- to mid-tropospheric environment. These negative factors will cause Juliette to continue weakening, and the cyclone should become a remnant low in about 24 h. Afterward, Juliette should open into a trough by late Friday. The NHC intensity forecast is near the middle of the guidance envelope, with slightly faster weakening shown compared to the previous advisory. The initial motion is estimated to be north-northwestward, or 330/12 kt. This motion should continue for the next 12-18 h while Juliette moves further into a growing weakness in the mid-level subtropical ridge. As Juliette degenerates into a vertically shallow cyclone on Thursday, a slower forward motion toward the north is expected while being steered by the weaker low-level flow. The official track forecast has been adjusted slightly to the left of the previous track, and lies close to the various consensus aids. Global models predict that residual mid- to upper-tropospheric moisture will be advected toward portions of northwestern Mexico and the southwestern U.S., potentially increasing humidity conditions and enhancing local monsoonal rainfall toward the end of the week. FORECAST POSITIONS AND MAX WINDS INIT 27/2100Z 23.9N 120.2W 40 KT 45 MPH 12H 28/0600Z 25.2N 120.7W 35 KT 40 MPH 24H 28/1800Z 26.6N 120.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 29/0600Z 27.3N 120.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 29/1800Z 27.8N 120.8W 15 KT 15 MPH...POST-TROP/REMNT LOW 60H 30/0600Z...DISSIPATED $$ Forecaster Hagen

Issued at 2100 UTC WED AUG 27 2025 000 FOPZ15 KNHC 272035 PWSEP5 TROPICAL STORM JULIETTE WIND SPEED PROBABILITIES NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102025 2100 UTC WED AUG 27 2025 AT 2100Z THE CENTER OF TROPICAL STORM JULIETTE WAS LOCATED NEAR LATITUDE 23.9 NORTH...LONGITUDE 120.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 40 KTS...45 MPH...75 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 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 18Z WED 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN PERIODS TO TO TO TO TO TO TO 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN 18Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT 25N 120W 34 37 1(38) X(38) X(38) X(38) X(38) X(38) $$ FORECASTER HAGEN

Issued at 200 PM PDT Wed Aug 27 2025 000 WTPZ35 KNHC 272035 TCPEP5 BULLETIN Tropical Storm Juliette Advisory Number 13 NWS National Hurricane Center Miami FL EP102025 200 PM PDT Wed Aug 27 2025 ...JULIETTE CONTINUES TO WEAKEN... SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...23.9N 120.2W ABOUT 655 MI...1055 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NNW OR 330 DEGREES AT 14 MPH...22 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 200 PM PDT (2100 UTC), the center of Tropical Storm Juliette was located near latitude 23.9 North, longitude 120.2 West. Juliette is moving toward the north-northwest near 14 mph (22 km/h). A turn to the north and a reduction in forward speed is expected on Thursday. Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Weakening is forecast, and Juliette is expected to degenerate into a remnant low by Thursday. Tropical-storm-force winds extend outward up to 45 miles (75 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 800 PM PDT. $$ Forecaster Hagen

...JULIETTE CONTINUES TO WEAKEN... As of 2:00 PM PDT Wed Aug 27 the center of Juliette was located near 23.9, -120.2 with movement NNW at 14 mph. The minimum central pressure was 1006 mb with maximum sustained winds of about 45 mph.

Issued at 2100 UTC WED AUG 27 2025 000 WTPZ25 KNHC 272035 TCMEP5 TROPICAL STORM JULIETTE FORECAST/ADVISORY NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102025 2100 UTC WED AUG 27 2025 TROPICAL STORM CENTER LOCATED NEAR 23.9N 120.2W AT 27/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 330 DEGREES AT 12 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT. 34 KT....... 40NE 30SE 0SW 30NW. 4 M SEAS.... 75NE 30SE 30SW 60NW. 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 23.9N 120.2W AT 27/2100Z AT 27/1800Z CENTER WAS LOCATED NEAR 23.5N 120.0W FORECAST VALID 28/0600Z 25.2N 120.7W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 30NE 20SE 0SW 20NW. FORECAST VALID 28/1800Z 26.6N 120.8W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 29/0600Z 27.3N 120.8W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 29/1800Z 27.8N 120.8W...POST-TROP/REMNT LOW MAX WIND 15 KT...GUSTS 20 KT. FORECAST VALID 30/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 23.9N 120.2W NEXT ADVISORY AT 28/0300Z $$ FORECASTER HAGEN

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL HIGH PLAINS AND THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the central High Plains and Upper Midwest this afternoon and early evening. ...20Z Update... The forecast remains on track with only minor adjustments to the general thunderstorm forecast. See the previous discussion for additional information. ..Wendt.. 08/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 27 2025/ ...Central High Plains... Upper ridging should remain suppressed over TX today, with modest mid-level westerly flow persisting across the central Plains. Late morning visible satellite imagery shows some clearing across eastern CO, which should aid in diurnal destabilization this afternoon. Gradual low-level moisture return is forecast to continue today across the central High Plains, generally along and east of a weak lee trough/low where low to mid 60s surface dewpoints are present. With scattered to numerous thunderstorms over much of the Southwest and southern/central Rockies yesterday, there is not a notable EML present over the central High Plains today (reference 12Z observed DDC sounding). This should temper the degree of instability that can develop through the afternoon to some extent. Even so, around 500-1500 J/kg of MLCAPE appears plausible with additional diurnal heating of the modestly moistened low-level airmass. Weak low-level southerly flow will veer to westerly and gradually strengthen with height through mid/upper levels, supporting around 25-40 kt of deep-layer shear. Thunderstorms are expected to develop initially along/near the Front Range this afternoon, before spreading slowly east-southeastward across eastern CO and parts of western KS through the evening. Isolated severe hail may occur with the strongest cores/marginal supercell structures, until gradual outflow/cold pool amalgamation encourages one or more clusters with a greater threat for occasional strong to severe gusts. Based on latest observational and short-term guidance trends, the Marginal Risk has been expanded to include more of eastern CO and western KS. Mainly elevated thunderstorms will likely continue overnight into central/eastern KS in a modest low-level warm advection regime. However, confidence in a continued hail/wind threat with this activity remains low at this time. ...Upper Midwest... On the western side of a large-scale upper trough over eastern Canada and the Atlantic Coast states, modestly enhanced northwesterly mid-level flow is forecast to persist through much of the period. A weak embedded shortwave trough moving across southern MN and vicinity late this morning suggests modest large-scale subsidence in its wake. This casts some uncertainty on the possible development of isolated to scattered thunderstorms later today along/south of a weak surface trough across eastern SD into central/southern MN. Even so, most guidance suggests at least isolated thunderstorms will form across this region by late afternoon/early evening. Cool mid-level temperatures and generally long/straight hodographs aloft suggest some threat for severe hail with any of the stronger cores that can be sustained. Have therefore added a focused Marginal Risk across parts of eastern SD into southern MN for this potential. Read more

Hooper Irrigation announced that it must end its secondary water season one month early on Sept. 15 as water allotments were also reduced by half due to low water supplies. Secondary water is used for lawn and garden watering. Deseret News (Salt Lake City, Utah), Aug 22, 2025

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Wed Aug 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...AND PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe storms are possible across southeast Texas into southwest Louisiana, and over parts of the central/southern High Plains on Friday. ...Portions of TX to the Lower MS Valley... An upper trough will persist over the eastern U.S. with modest northwesterly flow aloft overspreading much of the Plains to the MS Valley. At the surface, a cold front will be oriented from southwest TX to the ArkLaTex, then east/southeast toward the central Gulf Coast. Ahead of the front, a moist airmass will be in place across TX into the Lower MS Valley. Midlevel lapse rates are forecast to remain weak, but the rich boundary layer moisture and strong heating will allow MLCAPE reaching 1500-2500 J/kg, mainly across southeast TX into LA. Convection is likely to be ongoing during the morning in the form of a decaying/remnant MCS from the Day 2/Thursday period from parts of AR/LA into MS/AL. New development/re-intensification may occur during the afternoon as the surface front/outflow develops southward into the moderately unstable/very moist airmass. Locally strong/damaging wind gusts could occur with this activity. ...Central/Southern High Plains... Southeasterly surface winds in the post-frontal upslope flow regime will bring upper 50s to near 60 F dewpoints into western NE, southwest through eastern CO/NM along a surface trough. Strong daytime heating and midlevel lapse rates near 7-7.5 C/km will foster MLCAPE in the 1000-2000 J/kg range. Vertically veering wind profiles will support effective shear magnitudes around 25-35 kt. Isolated thunderstorms could occasionally become strong, producing gusty winds and marginally severe hail. ..Leitman.. 08/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Wed Aug 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...AND PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe storms are possible across southeast Texas into southwest Louisiana, and over parts of the central/southern High Plains on Friday. ...Portions of TX to the Lower MS Valley... An upper trough will persist over the eastern U.S. with modest northwesterly flow aloft overspreading much of the Plains to the MS Valley. At the surface, a cold front will be oriented from southwest TX to the ArkLaTex, then east/southeast toward the central Gulf Coast. Ahead of the front, a moist airmass will be in place across TX into the Lower MS Valley. Midlevel lapse rates are forecast to remain weak, but the rich boundary layer moisture and strong heating will allow MLCAPE reaching 1500-2500 J/kg, mainly across southeast TX into LA. Convection is likely to be ongoing during the morning in the form of a decaying/remnant MCS from the Day 2/Thursday period from parts of AR/LA into MS/AL. New development/re-intensification may occur during the afternoon as the surface front/outflow develops southward into the moderately unstable/very moist airmass. Locally strong/damaging wind gusts could occur with this activity. ...Central/Southern High Plains... Southeasterly surface winds in the post-frontal upslope flow regime will bring upper 50s to near 60 F dewpoints into western NE, southwest through eastern CO/NM along a surface trough. Strong daytime heating and midlevel lapse rates near 7-7.5 C/km will foster MLCAPE in the 1000-2000 J/kg range. Vertically veering wind profiles will support effective shear magnitudes around 25-35 kt. Isolated thunderstorms could occasionally become strong, producing gusty winds and marginally severe hail. ..Leitman.. 08/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Wed Aug 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...AND PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe storms are possible across southeast Texas into southwest Louisiana, and over parts of the central/southern High Plains on Friday. ...Portions of TX to the Lower MS Valley... An upper trough will persist over the eastern U.S. with modest northwesterly flow aloft overspreading much of the Plains to the MS Valley. At the surface, a cold front will be oriented from southwest TX to the ArkLaTex, then east/southeast toward the central Gulf Coast. Ahead of the front, a moist airmass will be in place across TX into the Lower MS Valley. Midlevel lapse rates are forecast to remain weak, but the rich boundary layer moisture and strong heating will allow MLCAPE reaching 1500-2500 J/kg, mainly across southeast TX into LA. Convection is likely to be ongoing during the morning in the form of a decaying/remnant MCS from the Day 2/Thursday period from parts of AR/LA into MS/AL. New development/re-intensification may occur during the afternoon as the surface front/outflow develops southward into the moderately unstable/very moist airmass. Locally strong/damaging wind gusts could occur with this activity. ...Central/Southern High Plains... Southeasterly surface winds in the post-frontal upslope flow regime will bring upper 50s to near 60 F dewpoints into western NE, southwest through eastern CO/NM along a surface trough. Strong daytime heating and midlevel lapse rates near 7-7.5 C/km will foster MLCAPE in the 1000-2000 J/kg range. Vertically veering wind profiles will support effective shear magnitudes around 25-35 kt. Isolated thunderstorms could occasionally become strong, producing gusty winds and marginally severe hail. ..Leitman.. 08/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Wed Aug 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...AND PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe storms are possible across southeast Texas into southwest Louisiana, and over parts of the central/southern High Plains on Friday. ...Portions of TX to the Lower MS Valley... An upper trough will persist over the eastern U.S. with modest northwesterly flow aloft overspreading much of the Plains to the MS Valley. At the surface, a cold front will be oriented from southwest TX to the ArkLaTex, then east/southeast toward the central Gulf Coast. Ahead of the front, a moist airmass will be in place across TX into the Lower MS Valley. Midlevel lapse rates are forecast to remain weak, but the rich boundary layer moisture and strong heating will allow MLCAPE reaching 1500-2500 J/kg, mainly across southeast TX into LA. Convection is likely to be ongoing during the morning in the form of a decaying/remnant MCS from the Day 2/Thursday period from parts of AR/LA into MS/AL. New development/re-intensification may occur during the afternoon as the surface front/outflow develops southward into the moderately unstable/very moist airmass. Locally strong/damaging wind gusts could occur with this activity. ...Central/Southern High Plains... Southeasterly surface winds in the post-frontal upslope flow regime will bring upper 50s to near 60 F dewpoints into western NE, southwest through eastern CO/NM along a surface trough. Strong daytime heating and midlevel lapse rates near 7-7.5 C/km will foster MLCAPE in the 1000-2000 J/kg range. Vertically veering wind profiles will support effective shear magnitudes around 25-35 kt. Isolated thunderstorms could occasionally become strong, producing gusty winds and marginally severe hail. ..Leitman.. 08/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Wed Aug 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...AND PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe storms are possible across southeast Texas into southwest Louisiana, and over parts of the central/southern High Plains on Friday. ...Portions of TX to the Lower MS Valley... An upper trough will persist over the eastern U.S. with modest northwesterly flow aloft overspreading much of the Plains to the MS Valley. At the surface, a cold front will be oriented from southwest TX to the ArkLaTex, then east/southeast toward the central Gulf Coast. Ahead of the front, a moist airmass will be in place across TX into the Lower MS Valley. Midlevel lapse rates are forecast to remain weak, but the rich boundary layer moisture and strong heating will allow MLCAPE reaching 1500-2500 J/kg, mainly across southeast TX into LA. Convection is likely to be ongoing during the morning in the form of a decaying/remnant MCS from the Day 2/Thursday period from parts of AR/LA into MS/AL. New development/re-intensification may occur during the afternoon as the surface front/outflow develops southward into the moderately unstable/very moist airmass. Locally strong/damaging wind gusts could occur with this activity. ...Central/Southern High Plains... Southeasterly surface winds in the post-frontal upslope flow regime will bring upper 50s to near 60 F dewpoints into western NE, southwest through eastern CO/NM along a surface trough. Strong daytime heating and midlevel lapse rates near 7-7.5 C/km will foster MLCAPE in the 1000-2000 J/kg range. Vertically veering wind profiles will support effective shear magnitudes around 25-35 kt. Isolated thunderstorms could occasionally become strong, producing gusty winds and marginally severe hail. ..Leitman.. 08/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0201 PM CDT Wed Aug 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA...AND PARTS OF THE CENTRAL/SOUTHERN HIGH PLAINS... ...SUMMARY... Isolated strong to severe storms are possible across southeast Texas into southwest Louisiana, and over parts of the central/southern High Plains on Friday. ...Portions of TX to the Lower MS Valley... An upper trough will persist over the eastern U.S. with modest northwesterly flow aloft overspreading much of the Plains to the MS Valley. At the surface, a cold front will be oriented from southwest TX to the ArkLaTex, then east/southeast toward the central Gulf Coast. Ahead of the front, a moist airmass will be in place across TX into the Lower MS Valley. Midlevel lapse rates are forecast to remain weak, but the rich boundary layer moisture and strong heating will allow MLCAPE reaching 1500-2500 J/kg, mainly across southeast TX into LA. Convection is likely to be ongoing during the morning in the form of a decaying/remnant MCS from the Day 2/Thursday period from parts of AR/LA into MS/AL. New development/re-intensification may occur during the afternoon as the surface front/outflow develops southward into the moderately unstable/very moist airmass. Locally strong/damaging wind gusts could occur with this activity. ...Central/Southern High Plains... Southeasterly surface winds in the post-frontal upslope flow regime will bring upper 50s to near 60 F dewpoints into western NE, southwest through eastern CO/NM along a surface trough. Strong daytime heating and midlevel lapse rates near 7-7.5 C/km will foster MLCAPE in the 1000-2000 J/kg range. Vertically veering wind profiles will support effective shear magnitudes around 25-35 kt. Isolated thunderstorms could occasionally become strong, producing gusty winds and marginally severe hail. ..Leitman.. 08/27/2025 Read more