Severe Storms

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Fri Jul 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC NORTH INTO WESTERN AND UPSTATE NEW YORK AS WELL AS ACROSS THE SOUTHERN GREAT PLAINS NORTHEAST INTO THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Marginally severe thunderstorms will be possible across the eastern US from the mid-Atlantic region northward into upstate New York. Additional strong-to-severe thunderstorms will be possible across the southern Great Plains northeast into the Mid-Mississippi Valley. ... Synopsis ... Broadly cyclonic mid-level flow will overspread the northeast United States on Sunday. At the same time, a surface cold front will slowly move east across the eastern US. Farther southwest, across the southern Great Plains, the aforementioned cold front will make little southward progress as southerly low-level flow increases in response to surface cyclogenesis across the northern High Plains late in the period. ... Mid-Atlantic northward into Upstate New York ... Numerous thunderstorms are expected to develop from late morning into the early afternoon associated with a modest increase in large-scale ascent and surface convergence along the cold front. Ahead of the front, surface dewpoints in the mid 60Fs to low 70Fs will combine with diurnal heating to result in most-unstable CAPE values in excess of 1500 J/kg. Despite the better effective-layer shear remaining north of the US, the degree of instability and the very moist airmass will support sporadic wind damage with the strongest thunderstorms. ... Southern Great Plains into the Mid-Mississippi Valley ... Multiple MCVs from the preceding days convection will likely be located across the region through the forecast period. A very moist airmass -- precipitable water values in excess of 2 inches in places -- and diurnal heating will result in a strongly unstable and weakly capped airmass. Although thunderstorms will be possible across the totality of the delineated area, it is likely that pockets of more concentrated thunderstorm activity will develop in the vicinity of the aforementioned MCVs. Some severe potential -- likely damaging wind gusts -- will be possible with the strongest storms. ..Marsh.. 07/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Fri Jul 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC NORTH INTO WESTERN AND UPSTATE NEW YORK AS WELL AS ACROSS THE SOUTHERN GREAT PLAINS NORTHEAST INTO THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Marginally severe thunderstorms will be possible across the eastern US from the mid-Atlantic region northward into upstate New York. Additional strong-to-severe thunderstorms will be possible across the southern Great Plains northeast into the Mid-Mississippi Valley. ... Synopsis ... Broadly cyclonic mid-level flow will overspread the northeast United States on Sunday. At the same time, a surface cold front will slowly move east across the eastern US. Farther southwest, across the southern Great Plains, the aforementioned cold front will make little southward progress as southerly low-level flow increases in response to surface cyclogenesis across the northern High Plains late in the period. ... Mid-Atlantic northward into Upstate New York ... Numerous thunderstorms are expected to develop from late morning into the early afternoon associated with a modest increase in large-scale ascent and surface convergence along the cold front. Ahead of the front, surface dewpoints in the mid 60Fs to low 70Fs will combine with diurnal heating to result in most-unstable CAPE values in excess of 1500 J/kg. Despite the better effective-layer shear remaining north of the US, the degree of instability and the very moist airmass will support sporadic wind damage with the strongest thunderstorms. ... Southern Great Plains into the Mid-Mississippi Valley ... Multiple MCVs from the preceding days convection will likely be located across the region through the forecast period. A very moist airmass -- precipitable water values in excess of 2 inches in places -- and diurnal heating will result in a strongly unstable and weakly capped airmass. Although thunderstorms will be possible across the totality of the delineated area, it is likely that pockets of more concentrated thunderstorm activity will develop in the vicinity of the aforementioned MCVs. Some severe potential -- likely damaging wind gusts -- will be possible with the strongest storms. ..Marsh.. 07/11/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Fri Jul 11 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC NORTH INTO WESTERN AND UPSTATE NEW YORK AS WELL AS ACROSS THE SOUTHERN GREAT PLAINS NORTHEAST INTO THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Marginally severe thunderstorms will be possible across the eastern US from the mid-Atlantic region northward into upstate New York. Additional strong-to-severe thunderstorms will be possible across the southern Great Plains northeast into the Mid-Mississippi Valley. ... Synopsis ... Broadly cyclonic mid-level flow will overspread the northeast United States on Sunday. At the same time, a surface cold front will slowly move east across the eastern US. Farther southwest, across the southern Great Plains, the aforementioned cold front will make little southward progress as southerly low-level flow increases in response to surface cyclogenesis across the northern High Plains late in the period. ... Mid-Atlantic northward into Upstate New York ... Numerous thunderstorms are expected to develop from late morning into the early afternoon associated with a modest increase in large-scale ascent and surface convergence along the cold front. Ahead of the front, surface dewpoints in the mid 60Fs to low 70Fs will combine with diurnal heating to result in most-unstable CAPE values in excess of 1500 J/kg. Despite the better effective-layer shear remaining north of the US, the degree of instability and the very moist airmass will support sporadic wind damage with the strongest thunderstorms. ... Southern Great Plains into the Mid-Mississippi Valley ... Multiple MCVs from the preceding days convection will likely be located across the region through the forecast period. A very moist airmass -- precipitable water values in excess of 2 inches in places -- and diurnal heating will result in a strongly unstable and weakly capped airmass. Although thunderstorms will be possible across the totality of the delineated area, it is likely that pockets of more concentrated thunderstorm activity will develop in the vicinity of the aforementioned MCVs. Some severe potential -- likely damaging wind gusts -- will be possible with the strongest storms. ..Marsh.. 07/11/2025 Read more

WW 0504 Status Updates
STATUS REPORT ON WW 504 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/11/25 ATTN...WFO...DVN... STATUS REPORT FOR WS 504 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC071-131-161-187-110840- IL . ILLINOIS COUNTIES INCLUDED ARE HENDERSON MERCER ROCK ISLAND WARREN IAC031-057-087-095-101-103-107-115-139-163-183-110840- IA . IOWA COUNTIES INCLUDED ARE CEDAR DES MOINES HENRY IOWA JEFFERSON JOHNSON KEOKUK LOUISA MUSCATINE SCOTT WASHINGTON 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 0504 Status Updates
STATUS REPORT ON WW 504 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/11/25 ATTN...WFO...DVN... STATUS REPORT FOR WS 504 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC071-131-161-187-110840- IL . ILLINOIS COUNTIES INCLUDED ARE HENDERSON MERCER ROCK ISLAND WARREN IAC031-057-087-095-101-103-107-115-139-163-183-110840- IA . IOWA COUNTIES INCLUDED ARE CEDAR DES MOINES HENRY IOWA JEFFERSON JOHNSON KEOKUK LOUISA MUSCATINE SCOTT WASHINGTON 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 0504 Status Updates
STATUS REPORT ON WW 504 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/11/25 ATTN...WFO...DVN... STATUS REPORT FOR WS 504 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC071-131-161-187-110840- IL . ILLINOIS COUNTIES INCLUDED ARE HENDERSON MERCER ROCK ISLAND WARREN IAC031-057-087-095-101-103-107-115-139-163-183-110840- IA . IOWA COUNTIES INCLUDED ARE CEDAR DES MOINES HENRY IOWA JEFFERSON JOHNSON KEOKUK LOUISA MUSCATINE SCOTT WASHINGTON 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 504 SEVERE TSTM IA IL 110615Z - 111100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 504 NWS Storm Prediction Center Norman OK 115 AM CDT Fri Jul 11 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Iowa Northwest Illinois * Effective this Friday morning from 115 AM until 600 AM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible A tornado or two possible SUMMARY...A well-organized cluster of storms with a history of wind damage and measured severe gusts, including a measured 74 mph wind gust at the Des Moines airport around 1250 am CDT, will continue eastward into eastern Iowa, and perhaps northwest Illinois, including the I-80 corridor. The severe thunderstorm watch area is approximately along and 30 statute miles north and south of a line from 90 miles west of Moline IL to 10 miles south of Moline IL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 503... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27040. ...Guyer Read more

MD 1639 CONCERNING SEVERE THUNDERSTORM WATCH 503... FOR EAST-CENTRAL AND EASTERN IOWA
Mesoscale Discussion 1639 NWS Storm Prediction Center Norman OK 1244 AM CDT Fri Jul 11 2025 Areas affected...east-central and eastern Iowa Concerning...Severe Thunderstorm Watch 503... Valid 110544Z - 110715Z The severe weather threat for Severe Thunderstorm Watch 503 continues. SUMMARY...A downstream severe thunderstorm watch may be needed soon across portions of eastern Iowa. DISCUSSION...A well-established bowing cluster with a history of severe wind gusts is currently moving across central Iowa. The KDMX VWP suggests this cluster has started to outrun the stronger low-level jet which could limit its intensity as it moves farther east. However, 2000 to 2500 J/kg MUCAPE is present across all of central and eastern Iowa which could maintain this cluster with some severe weather threat across eastern Iowa through the early morning hours. This threat would likely be maximized along the frontal zone (apparent by lead convection across eastern Iowa and far western Illinois). Confidence in this cluster of storms moving farther east into Illinois is low given the weaker instability, ongoing convection along the boundary, and a weaker low-level jet with eastward extent. However, there may be sufficient instability/forcing to necessitate a small downstream watch across eastern Iowa to address this threat. Convective trends will continue to be monitored. ..Bentley/Guyer.. 07/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...DMX... LAT...LON 41859412 41969294 41919166 41889065 41659027 41199055 40859096 40899157 40929208 40909244 40949361 41059404 41859412 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook CORR 3 NWS Storm Prediction Center Norman OK 0210 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST INDIANA...NORTHWEST OHIO...AND MUCH OF EASTERN MICHIGAN... CORRECTED FOR INCORRECT MARGINAL LINE GROUPING ...SUMMARY... Scattered damaging winds are possible across northeast Indiana, northwest Ohio, into eastern Michigan on Saturday. A broad swath of isolated severe thunderstorms is anticipated from the Great Lakes to the southern High Plains, mainly Saturday afternoon/evening. ... Synopsis ... The large-scale pattern across the US on Saturday will feature mid-level ridges on both coasts and a broad trough across the central US. Within this cyclonic flow, multiple vorticity ribbons will quickly move northeast across the Great Lakes and into Ontario. At the surface, a cold front will stretch from Wisconsin southwest into northwest Oklahoma and the Texas Panhandles at the start of the forecast period and should move east across Michigan while making little forward progress across the southern Great Plains. ... Great Lakes Region ... A lead shortwave trough/vorticity maximum will quickly move through eastern Wisconsin and lower Michigan during the late morning into afternoon. In response to the approaching trough, a modest low-level jet will support surface dewpoints rising to/being sustained in the upper 60Fs to lower 70Fs range. Given the degree of low-level moisture, modest diurnal heating will support most-unstable CAPE values in excess of 2000 J/kg. As large-scale ascent overspreads the surface cold front across lower Michigan, one or more bands of convection are expected to develop along and ahead of the front. Despite effective-layer shear being generally less than 35 knots, some severe potential will exist with this convection -- primarily strong downdraft winds -- owing to the degree of instability and precipitable water values around 1.75". Additionally, with a modest low-level jet and a preexisting boundary in the vicinity, a tornado or two cannot be ruled out. Farther west, in response to the large-scale ascent for the second, stronger shortwave trough, a second round of thunderstorms may develop across portions of Wisconsin and the Upper Peninsula of Michigan. Despite being post frontal, diurnal heating and residual low-level moisture will support most-unstable CAPE around 1000-1500 J/kg. Isolated large hail and strong thunderstorm outflows will be possible. ... Central and Southern Rockies into the Southern Plains ... One or more decaying MCSs and perhaps attendant MCVs may be ongoing at the start of the period across the Texas/Oklahoma Panhandles into Oklahoma. The combination of multiple potential outflow boundaries and localized ascent associated with any MCV will result in scattered to widespread thunderstorm development through the period. Diurnal heating of a very moist airmass will result in CAPE values perhaps as high as 3000 J/kg across portions of the area. This degree of instability coupled with precipitable water values approaching 2 inches will yield the potential for wet microbursts and associated damaging winds. Despite wind being the more likely severe threat, isolated large hail may also be possible given the degree of instability, especially early in the thunderstorm life cycle. During the afternoon, additional thunderstorms are anticipated across the higher terrain of the central and southern Rockies within a moist upslope low-level flow. Modest northwesterly mid-level flow and perhaps a subtle short-wave trough will help organize the convection into a slow moving south-southeast moving MCS. If confidence increases in a well-organized MCS, the area may need to be upgraded to categorical upgrade to Level 2/Slight Risk driven by wind potential. ..Marsh.. 07/11/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... High pressure across the western US will continue to keep winds mainly light and terrain driven where fuels are the driest Saturday. Moisture will increase across west-central Colorado, with PWs approaching 0.60-0.75". A mix of initially dry/wet thunderstorms will be possible again, though the dry thunderstorm risk should remain too localized to include areas with this outlook. ..Thornton.. 07/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Fri Jul 11 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... High pressure across the western US will continue to keep winds mainly light and terrain driven where fuels are the driest Saturday. Moisture will increase across west-central Colorado, with PWs approaching 0.60-0.75". A mix of initially dry/wet thunderstorms will be possible again, though the dry thunderstorm risk should remain too localized to include areas with this outlook. ..Thornton.. 07/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more