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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Aug 15 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Sunday across parts of the northern Plains eastward into Upper Midwest and southern Great Lakes. ...Northern Plains/Upper Midwest into the southern Great Lakes... A flattened mid-level ridge will influence thunderstorm activity on Sunday across a large part of the CONUS. On the northern periphery of the ridge, a weak mid-level disturbance is forecast to crest the ridge over the north-central states and move from SD to the western Great Lakes. Warm 700-mb temperatures and an associated capping inversion will likely limit storm development across the lower MO Valley. A composite surface boundary, likely modulated by previous day's thunderstorm outflow, is forecast to be draped from the southern Great Lakes west-northwestward into parts of the Upper Midwest and into portions of the northern High Plains. Showers and storms may be ongoing early Sunday morning across the Upper Midwest in association with weak low-level warm advection in advance of the aforementioned impulse. Isolated to scattered diurnal storms are forecast to focus along the low-level boundary during the afternoon/evening given large-scale upper forcing for ascent will remain weak to negligible. Despite expected strong diurnal destabilization, deep-layer shear will likely remain modest and limit storm organization potential, with isolated severe gusts and large hail being the severe hazards. ..Smith.. 08/15/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Aug 15 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Sunday across parts of the northern Plains eastward into Upper Midwest and southern Great Lakes. ...Northern Plains/Upper Midwest into the southern Great Lakes... A flattened mid-level ridge will influence thunderstorm activity on Sunday across a large part of the CONUS. On the northern periphery of the ridge, a weak mid-level disturbance is forecast to crest the ridge over the north-central states and move from SD to the western Great Lakes. Warm 700-mb temperatures and an associated capping inversion will likely limit storm development across the lower MO Valley. A composite surface boundary, likely modulated by previous day's thunderstorm outflow, is forecast to be draped from the southern Great Lakes west-northwestward into parts of the Upper Midwest and into portions of the northern High Plains. Showers and storms may be ongoing early Sunday morning across the Upper Midwest in association with weak low-level warm advection in advance of the aforementioned impulse. Isolated to scattered diurnal storms are forecast to focus along the low-level boundary during the afternoon/evening given large-scale upper forcing for ascent will remain weak to negligible. Despite expected strong diurnal destabilization, deep-layer shear will likely remain modest and limit storm organization potential, with isolated severe gusts and large hail being the severe hazards. ..Smith.. 08/15/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Aug 15 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Sunday across parts of the northern Plains eastward into Upper Midwest and southern Great Lakes. ...Northern Plains/Upper Midwest into the southern Great Lakes... A flattened mid-level ridge will influence thunderstorm activity on Sunday across a large part of the CONUS. On the northern periphery of the ridge, a weak mid-level disturbance is forecast to crest the ridge over the north-central states and move from SD to the western Great Lakes. Warm 700-mb temperatures and an associated capping inversion will likely limit storm development across the lower MO Valley. A composite surface boundary, likely modulated by previous day's thunderstorm outflow, is forecast to be draped from the southern Great Lakes west-northwestward into parts of the Upper Midwest and into portions of the northern High Plains. Showers and storms may be ongoing early Sunday morning across the Upper Midwest in association with weak low-level warm advection in advance of the aforementioned impulse. Isolated to scattered diurnal storms are forecast to focus along the low-level boundary during the afternoon/evening given large-scale upper forcing for ascent will remain weak to negligible. Despite expected strong diurnal destabilization, deep-layer shear will likely remain modest and limit storm organization potential, with isolated severe gusts and large hail being the severe hazards. ..Smith.. 08/15/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Aug 15 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Sunday across parts of the northern Plains eastward into Upper Midwest and southern Great Lakes. ...Northern Plains/Upper Midwest into the southern Great Lakes... A flattened mid-level ridge will influence thunderstorm activity on Sunday across a large part of the CONUS. On the northern periphery of the ridge, a weak mid-level disturbance is forecast to crest the ridge over the north-central states and move from SD to the western Great Lakes. Warm 700-mb temperatures and an associated capping inversion will likely limit storm development across the lower MO Valley. A composite surface boundary, likely modulated by previous day's thunderstorm outflow, is forecast to be draped from the southern Great Lakes west-northwestward into parts of the Upper Midwest and into portions of the northern High Plains. Showers and storms may be ongoing early Sunday morning across the Upper Midwest in association with weak low-level warm advection in advance of the aforementioned impulse. Isolated to scattered diurnal storms are forecast to focus along the low-level boundary during the afternoon/evening given large-scale upper forcing for ascent will remain weak to negligible. Despite expected strong diurnal destabilization, deep-layer shear will likely remain modest and limit storm organization potential, with isolated severe gusts and large hail being the severe hazards. ..Smith.. 08/15/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Aug 15 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Sunday across parts of the northern Plains eastward into Upper Midwest and southern Great Lakes. ...Northern Plains/Upper Midwest into the southern Great Lakes... A flattened mid-level ridge will influence thunderstorm activity on Sunday across a large part of the CONUS. On the northern periphery of the ridge, a weak mid-level disturbance is forecast to crest the ridge over the north-central states and move from SD to the western Great Lakes. Warm 700-mb temperatures and an associated capping inversion will likely limit storm development across the lower MO Valley. A composite surface boundary, likely modulated by previous day's thunderstorm outflow, is forecast to be draped from the southern Great Lakes west-northwestward into parts of the Upper Midwest and into portions of the northern High Plains. Showers and storms may be ongoing early Sunday morning across the Upper Midwest in association with weak low-level warm advection in advance of the aforementioned impulse. Isolated to scattered diurnal storms are forecast to focus along the low-level boundary during the afternoon/evening given large-scale upper forcing for ascent will remain weak to negligible. Despite expected strong diurnal destabilization, deep-layer shear will likely remain modest and limit storm organization potential, with isolated severe gusts and large hail being the severe hazards. ..Smith.. 08/15/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Aug 15 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA THROUGH THE UPPER MIDWEST AND SOUTHERN GREAT LAKES... ...SUMMARY... Thunderstorms with potential for isolated severe wind gusts and hail will be possible on Sunday across parts of the northern Plains eastward into Upper Midwest and southern Great Lakes. ...Northern Plains/Upper Midwest into the southern Great Lakes... A flattened mid-level ridge will influence thunderstorm activity on Sunday across a large part of the CONUS. On the northern periphery of the ridge, a weak mid-level disturbance is forecast to crest the ridge over the north-central states and move from SD to the western Great Lakes. Warm 700-mb temperatures and an associated capping inversion will likely limit storm development across the lower MO Valley. A composite surface boundary, likely modulated by previous day's thunderstorm outflow, is forecast to be draped from the southern Great Lakes west-northwestward into parts of the Upper Midwest and into portions of the northern High Plains. Showers and storms may be ongoing early Sunday morning across the Upper Midwest in association with weak low-level warm advection in advance of the aforementioned impulse. Isolated to scattered diurnal storms are forecast to focus along the low-level boundary during the afternoon/evening given large-scale upper forcing for ascent will remain weak to negligible. Despite expected strong diurnal destabilization, deep-layer shear will likely remain modest and limit storm organization potential, with isolated severe gusts and large hail being the severe hazards. ..Smith.. 08/15/2025 Read more

WW 0589 Status Updates
STATUS REPORT ON WW 589 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SE SPW TO 20 SW MCW TO 15 NNW MCW. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1952. ..GRAMS..08/15/25 ATTN...WFO...DMX... STATUS REPORT FOR WS 589 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC013-015-017-023-025-027-033-069-073-075-079-083-091-127-151- 161-169-171-187-195-197-152040- IA . IOWA COUNTIES INCLUDED ARE BLACK HAWK BOONE BREMER BUTLER CALHOUN CARROLL CERRO GORDO FRANKLIN GREENE GRUNDY HAMILTON HARDIN HUMBOLDT MARSHALL POCAHONTAS SAC STORY TAMA WEBSTER WORTH WRIGHT THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0590 Status Updates
STATUS FOR WATCH 0590 HAS NOT BEEN ISSUED YET Read more

WW 0589 Status Updates
STATUS REPORT ON WW 589 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NE SLB TO 25 NNW FOD TO 15 SSE FRM. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1952. ..GRAMS..08/15/25 ATTN...WFO...DMX... STATUS REPORT FOR WS 589 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC015-025-027-033-069-073-079-081-083-091-109-127-151-161-169- 187-189-195-197-151940- IA . IOWA COUNTIES INCLUDED ARE BOONE CALHOUN CARROLL CERRO GORDO FRANKLIN GREENE HAMILTON HANCOCK HARDIN HUMBOLDT KOSSUTH MARSHALL POCAHONTAS SAC STORY WEBSTER WINNEBAGO WORTH WRIGHT THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

Water customers in Portsmouth were urged to adopt “water use efficiency measures” as little rain has fallen since May. The ongoing hot, dry conditions have driven up water use by about 5% above the July average. The public was asked to curb outdoor watering and voluntarily restrict outdoor water use between 8 p.m. and 7 a.m. Seacoast Online (Portsmouth, N.H.), Aug 15, 2025

MD 1951 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN/CENTRAL IA
Mesoscale Discussion 1951 NWS Storm Prediction Center Norman OK 1151 AM CDT Fri Aug 15 2025 Areas affected...northern/central IA Concerning...Severe potential...Watch possible Valid 151651Z - 151845Z Probability of Watch Issuance...60 percent SUMMARY...The severe hail and wind threat may increase this afternoon across northern and central Iowa with low forecast confidence on both coverage/intensity. A Severe Thunderstorm Watch issuance is possible. DISCUSSION...As alluded to in the 1630Z SWODY1, short-term forecast confidence is low with regard to a long-lived but small cluster over northwest IA. This had diminished for a time after earlier supercell evolution in northeast NE, but appears to be oscillating up/down again with some development flanking to its southwest. Gravity waves emanating from this cluster aided in elevated convective development downstream in west-central IA with cloud bases near 10k ft. These updrafts appear to have pulsed back down and may lack sustainability. In addition to the weak large-scale ascent, modest deep-layer shear may limit substantial organization unless a more pronounced cold pool develops. This could occur towards late afternoon if convective coverage indeed increases surrounding the confined cluster. Morning CAM guidance varies greatly from nil convection in the HRRR to an enlarging cluster and MCS development. For now, the most likely scenario is for an isolated severe hail/wind threat but with a wide range of potential scenarios into the late afternoon. ..Grams/Mosier.. 08/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX...FSD... LAT...LON 42889553 43239518 43439437 43369245 43179192 42789181 42419187 42009201 41639244 41589348 41789462 41999539 42319569 42889553 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 15 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF SOUTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible Saturday over South Dakota primarily during the late afternoon through the late evening period. Large hail and severe gusts appear to be the primary hazards with the stronger storms. ...Northern Great Plains... A mid-level ridge centered over the lower MS Valley/Mid South will feature a weak disturbance moving from the WY/CO vicinity into the Dakotas Saturday night. A residual composite front will remain draped east-west from the Upper Midwest into western SD, where it will intersect a lee trough from the central High Plains north-northwestward into eastern MT. Although large-scale ascent will remain fairly weak across the region, isolated thunderstorms will likely develop in the vicinity of the lee trough and Black Hills by the late afternoon as convective inhibition erodes. To the north of the front, a moist and unstable airmass featuring a moderate to very unstable boundary layer will develop by mid-late afternoon. Model guidance shows a gradual increase in storm coverage during the early evening over western/central SD. Ample directional shear will support effective shear magnitudes 30-40 kt and storm organization with the stronger storms. Large hail and severe gusts appear to be the primary threats. ...Midwest... A linear cluster of thunderstorms is expected to be ongoing Saturday morning across parts of the Upper MS Valley/western Great Lakes. Model guidance differs on the evolution of this potentia shower/thunderstorm activity, but west-northwesterly mid-level flow poleward of a mid-level anticyclone centered over the lower MS Valley, will potentially favor some continuation of storms downstream across the southwestern Great Lakes. Models continue to show a moist/unstable airmass across southern portions of the Great Lakes. Although large-scale ascent will remain weak across the region, regenerative storm development on remnant outflow may yield a subsequent evolution of a storm cluster but uncertainty remains high. Isolated damaging gusts/hail are the main threats with these storms. ..Smith.. 08/15/2025 Read more