Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Update... No changes are required for the forecast Friday. Wet thunderstorm chances will extend even further to the northwest tomorrow across portions of UT and WY. Although dry thunderstorms can't be completely ruled out over portions of far eastern ID and northeastern NV, chances appear too low over relatively average fuel states to warrant an Isolated Dry Thunderstorm area at this time. ..Barnes.. 06/20/2024 .PREV DISCUSSION... /ISSUED 0144 AM CDT Thu Jun 20 2024/ ...Synopsis... Fire weather concerns will largely remain low on Friday. High pressure will continue to build in across the desert southwest, keeping winds generally light outside of gusty thunderstorm outflow. Continued widely scattered thunderstorm activity is expected across much of New Mexico and Arizona as remnant tropical moisture continues to be in place, with precipitable water generally 0.75-1.00 in and slow storm motions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0438 Status Updates
STATUS REPORT ON WW 438 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SQUITIERI..06/20/24 ATTN...WFO...BOX...GYX...CAR...BTV...ALY... STATUS REPORT FOR WS 438 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC001-005-007-009-011-013-015-017-019-021-023-025-027-031- 201940- ME . MAINE COUNTIES INCLUDED ARE ANDROSCOGGIN CUMBERLAND FRANKLIN HANCOCK KENNEBEC KNOX LINCOLN OXFORD PENOBSCOT PISCATAQUIS SAGADAHOC SOMERSET WALDO YORK MAC009-011-017-027-201940- MA . MASSACHUSETTS COUNTIES INCLUDED ARE ESSEX FRANKLIN MIDDLESEX WORCESTER NHC001-003-005-007-009-011-013-015-017-019-201940- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE Read more

MD 1341 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST LOWER MI...NORTH OH...WEST NY...NORTHWEST PA
Mesoscale Discussion 1341 NWS Storm Prediction Center Norman OK 1117 AM CDT Thu Jun 20 2024 Areas affected...southeast Lower MI...north OH...west NY...northwest PA Concerning...Severe potential...Watch unlikely Valid 201617Z - 201815Z Probability of Watch Issuance...20 percent SUMMARY...Sporadic damaging winds and isolated marginally severe hail will be possible with isolated to scattered pulse-type thunderstorms surrounding the Lake Erie vicinity this afternoon. Severe thunderstorm watch issuance in this region is unlikely, but could be warranted if greater clustering becomes apparent. DISCUSSION...Pockets of enhanced Cu development are underway to the west/south of Lake Erie and along the NY/PA border. With remnant MCVs largely tracking north and northeast of these corridors, confidence is low in a more concentrated damaging wind threat area this afternoon. Deep-layer shear will remain weak south of the quasi-stationary front draped from southeast Lower MI into far northwest IN, with effective bulk shear from 10-20 kts. This suggests pulse-type cells should dominate. Isolated, marginally severe hail of 0.75-1.25 inches in diameter will be possible along with occasional downbursts from 45-60 mph wind gusts. ..Grams/Hart.. 06/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BGM...BUF...CTP...PBZ...CLE...ILN...DTX...IWX... GRR... LAT...LON 42817779 42307732 41867741 41437876 40958021 40818221 40798383 41168474 42078515 42708459 43148246 42817779 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS BLACK HILLS VICINITY EAST INTO THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Scattered strong to severe storms will be possible from the northern High Plains into the upper Mississippi Valley on Friday, with a few strong storms over parts of the Northeast. A few severe gusts are also possible over parts of the eastern Great Basin. ...North-Central High Plains to the upper MS Valley... An organized cluster of showers/thunderstorms will likely be ongoing early Friday morning in the vicinity of southern MN along a west-east oriented frontal zone. It is possible a rejuvenation of this activity or additional storms on the leading edge of the outflow will continue to develop east along the warm front during the late morning into the early afternoon east of the MS River. Some model data suggest appreciable destabilization will occur ahead of this thunderstorm cluster, supporting storm intensification and severe risk. Farther west, diurnal storms likely develop over the high terrain of eastern WY into north-central CO, and likely produce hail and wind as they move across western and into central NE. Ample instability will remain overnight ahead of High Plains activity to support a hail and wind risk as it persists all night across SD and into MN. ...MT... A weak mid-level trough over the southern Canadian Rockies will pivot east and glance the MT/Canadian border. Weak easterly low-level flow will advect increasing moisture with upper 40s to lower 50s dewpoints beneath steep 700-500 mb lapse rates (7.5 to 8 deg C/km). Model forecast soundings show 1500-2000 J/kg MLCAPE developing by mid afternoon as isolated storms begin to develop over terrain-favored locales. Ample mid to high-level westerly flow will favor storm organization, including the possibility for a couple of supercells. Large hail and severe gusts will be the primary hazards with the stronger storms. A thunderstorm cluster or two will probably evolve by evening and eventually move downstream into eastern MT by the late evening. ...Lower Great Lakes into the Northeast... Models agree in showing a moist air mass and heating contributing to destabilization and renewed thunderstorm activity developing from eastern OH into southern New England. Forecast soundings indicate perhaps poorer midlevel lapse rates overall compared to the previous day, with more of a subsidence inversion around 700 mb. However, heating will easily support at least isolated development by early afternoon along the weak front. Isolated to scattered strong to damaging gusts (50-65 mph) will be the primary concern. ...UT...northern AZ...western CO into WY... Early Thursday morning observed upper-air raobs and surface data showed a very moist airmass has advected westward into the Four Corners. A mid-level trough initially over CA/NV will weaken as it moves eastward into the central Rockies by early Saturday morning. However, ample moisture and diurnally steepening lapse rates coupled with weak ascent associated with the disturbance, will support scattered to numerous thunderstorms during the period. Severe gusts (60-75 mph) are possible with the stronger downdrafts. ...Southeast AZ... Isolated to widely scattered thunderstorms are forecast to develop during the afternoon as temperatures warm into the 90s to the lower 100s. An appreciably moist airmass (1.25 inch PW; observed on the 12 UTC El Paso, TX observed upper-air sounding) and the development of 9.5 deg C/km 0-3 km lapse rates will favor isolated microbursts capable of severe gusts (60-70 mph) with the stronger evaporatively cooled cores. ..Smith.. 06/20/2024 Read more

MD 1340 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PARTS OF NEW ENGLAND AND NY
Mesoscale Discussion 1340 NWS Storm Prediction Center Norman OK 1026 AM CDT Thu Jun 20 2024 Areas affected...parts of New England and NY Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 201526Z - 201730Z Probability of Watch Issuance...80 percent SUMMARY...Isolated to scattered damaging winds from gusts of 50-65 mph, along with isolated hail from 0.75-1.50 inches in diameter will be possible this afternoon. A severe thunderstorm watch is likely for parts of the region, centered from east NY into south ME. DISCUSSION...Low 70s surface dew points remain pervasive in lower elevations across central/east NY into ME. Robust diabatic heating of this moisture plume will result in moderately large buoyancy with MLCAPE of 2000-2500 J/kg becoming common in the next few hours. A pair of MCVs embedded within a zonal mid-level flow regime, the lead one over the Upper St. Lawrence Valley and an upstream one near the Georgian Bay of Lake Huron, should aid in scattered to widespread thunderstorm development through the afternoon. Deep-layer shear will be weak, especially with south extent, and initial mode will predominately be pulse. But some congealing and loosely organized multicell clustering may occur where effective bulk shear holds around 20 kts, ahead of the lead MCV. The most favored corridor appears to be centered on the Champlain Valley into south ME. Strong to isolated severe wind gusts of 50-65 mph producing potentially scattered tree damage appears to be the primary threat, but isolated marginally severe hail will be possible as well. ..Grams/Hart.. 06/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BOX...BTV...ALY...BGM...BUF... LAT...LON 42167637 44947430 45117192 45247061 45476931 44666848 43307011 42457107 41867462 42167637 Read more