Severe Storms

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Tue Sep 03 2019 Valid 061200Z - 111200Z ...DISCUSSION... Depending on the speed/timing of Hurricane Dorian, some threat for an isolated tornado or two might exist across the NC coast on day 4. Otherwise, severe potential will remain relatively low over the rest of the U.S.. Day 5 a low-amplitude shortwave trough is forecast to emerge over the northern and central Plains, but the thermodynamic environment, with limited low-level moisture, will probably remain too marginal for an organized severe threat. Day 6, overall severe potential will probably remain relatively low due primarily to richer low-level moisture having been shunted south of the stronger westerlies. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Tue Sep 03 2019 Valid 061200Z - 111200Z ...DISCUSSION... Depending on the speed/timing of Hurricane Dorian, some threat for an isolated tornado or two might exist across the NC coast on day 4. Otherwise, severe potential will remain relatively low over the rest of the U.S.. Day 5 a low-amplitude shortwave trough is forecast to emerge over the northern and central Plains, but the thermodynamic environment, with limited low-level moisture, will probably remain too marginal for an organized severe threat. Day 6, overall severe potential will probably remain relatively low due primarily to richer low-level moisture having been shunted south of the stronger westerlies. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Tue Sep 03 2019 Valid 061200Z - 111200Z ...DISCUSSION... Depending on the speed/timing of Hurricane Dorian, some threat for an isolated tornado or two might exist across the NC coast on day 4. Otherwise, severe potential will remain relatively low over the rest of the U.S.. Day 5 a low-amplitude shortwave trough is forecast to emerge over the northern and central Plains, but the thermodynamic environment, with limited low-level moisture, will probably remain too marginal for an organized severe threat. Day 6, overall severe potential will probably remain relatively low due primarily to richer low-level moisture having been shunted south of the stronger westerlies. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Tue Sep 03 2019 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE COASTAL CAROLINAS... ...SUMMARY... A marginal risk for a tornado or two might evolve across the coastal Carolinas Thursday. ...Coastal Carolinas... Hurricane Dorian is forecast by the National Hurricane Center to be located just off the southeast North Carolina coast by Thursday evening. While the more favorable quadrant for isolated tornadoes will remain offshore, scattered thunderstorms developing within the outer rain bands will spread inland where 0-2 km hodographs will be sufficient for a threat of low-level mesocyclones and a couple of tornadoes. See latest discussion from the National Hurricane Center for updates on Dorian. ..Dial.. 09/03/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Tue Sep 03 2019 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE COASTAL CAROLINAS... ...SUMMARY... A marginal risk for a tornado or two might evolve across the coastal Carolinas Thursday. ...Coastal Carolinas... Hurricane Dorian is forecast by the National Hurricane Center to be located just off the southeast North Carolina coast by Thursday evening. While the more favorable quadrant for isolated tornadoes will remain offshore, scattered thunderstorms developing within the outer rain bands will spread inland where 0-2 km hodographs will be sufficient for a threat of low-level mesocyclones and a couple of tornadoes. See latest discussion from the National Hurricane Center for updates on Dorian. ..Dial.. 09/03/2019 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Tue Sep 03 2019 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE COASTAL CAROLINAS... ...SUMMARY... A marginal risk for a tornado or two might evolve across the coastal Carolinas Thursday. ...Coastal Carolinas... Hurricane Dorian is forecast by the National Hurricane Center to be located just off the southeast North Carolina coast by Thursday evening. While the more favorable quadrant for isolated tornadoes will remain offshore, scattered thunderstorms developing within the outer rain bands will spread inland where 0-2 km hodographs will be sufficient for a threat of low-level mesocyclones and a couple of tornadoes. See latest discussion from the National Hurricane Center for updates on Dorian. ..Dial.. 09/03/2019 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...Synopsis... An upper-level ridge will remain in place across the western CONUS for the Day 2/Wednesday period. The embedded mid-level shortwave trough moving across the Pacific Northwest on Day 1 will then traverse the northern Rockies while cresting the ridge on Day 2. With the passage of the trough, the low-level mass response will be a dry and breezy westerly wind that may foster some wildfire-spread potential. Elsewhere, from northern California into the Great Basin, adequate monsoonal moisture traversing the upper-level ridge will promote at least isolated thunderstorm potential, with a few dry strikes possible. ...Northern Rockies... With the passage of an upper-level trough and diurnal boundary layer mixing of stronger winds aloft to the surface, 15-25 mph sustained westerly surface winds are expected across parts of the northern Rockies (mainly north-central Montana) along with 15-25% RH. Finer fuels have recently begun to dry across the area, supporting the potential for grass-fire spread and as such, an elevated area has been delineated. ...Northern California into the northern Great Basin... As mid-level monsoonal moisture continues to drift northward across northern portions of the Great Basin, isolated high-based thunderstorms will become possible by afternoon peak heating. Despite slow storm motions, a dry sub-cloud layer will support at least some potential for dry strikes atop near-critical to critically dry fuels, where an isolated dry thunderstorm area was added. Isolated dry thunderstorms may also occur over northern parts of California into far southern Oregon, but low confidence in storm initiation over this area precludes a delineation at this time. ..Squitieri.. 09/03/2019 ...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 0201 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...Synopsis... An upper-level ridge will remain in place across the western CONUS for the Day 2/Wednesday period. The embedded mid-level shortwave trough moving across the Pacific Northwest on Day 1 will then traverse the northern Rockies while cresting the ridge on Day 2. With the passage of the trough, the low-level mass response will be a dry and breezy westerly wind that may foster some wildfire-spread potential. Elsewhere, from northern California into the Great Basin, adequate monsoonal moisture traversing the upper-level ridge will promote at least isolated thunderstorm potential, with a few dry strikes possible. ...Northern Rockies... With the passage of an upper-level trough and diurnal boundary layer mixing of stronger winds aloft to the surface, 15-25 mph sustained westerly surface winds are expected across parts of the northern Rockies (mainly north-central Montana) along with 15-25% RH. Finer fuels have recently begun to dry across the area, supporting the potential for grass-fire spread and as such, an elevated area has been delineated. ...Northern California into the northern Great Basin... As mid-level monsoonal moisture continues to drift northward across northern portions of the Great Basin, isolated high-based thunderstorms will become possible by afternoon peak heating. Despite slow storm motions, a dry sub-cloud layer will support at least some potential for dry strikes atop near-critical to critically dry fuels, where an isolated dry thunderstorm area was added. Isolated dry thunderstorms may also occur over northern parts of California into far southern Oregon, but low confidence in storm initiation over this area precludes a delineation at this time. ..Squitieri.. 09/03/2019 ...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 0201 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...Synopsis... An upper-level ridge will remain in place across the western CONUS for the Day 2/Wednesday period. The embedded mid-level shortwave trough moving across the Pacific Northwest on Day 1 will then traverse the northern Rockies while cresting the ridge on Day 2. With the passage of the trough, the low-level mass response will be a dry and breezy westerly wind that may foster some wildfire-spread potential. Elsewhere, from northern California into the Great Basin, adequate monsoonal moisture traversing the upper-level ridge will promote at least isolated thunderstorm potential, with a few dry strikes possible. ...Northern Rockies... With the passage of an upper-level trough and diurnal boundary layer mixing of stronger winds aloft to the surface, 15-25 mph sustained westerly surface winds are expected across parts of the northern Rockies (mainly north-central Montana) along with 15-25% RH. Finer fuels have recently begun to dry across the area, supporting the potential for grass-fire spread and as such, an elevated area has been delineated. ...Northern California into the northern Great Basin... As mid-level monsoonal moisture continues to drift northward across northern portions of the Great Basin, isolated high-based thunderstorms will become possible by afternoon peak heating. Despite slow storm motions, a dry sub-cloud layer will support at least some potential for dry strikes atop near-critical to critically dry fuels, where an isolated dry thunderstorm area was added. Isolated dry thunderstorms may also occur over northern parts of California into far southern Oregon, but low confidence in storm initiation over this area precludes a delineation at this time. ..Squitieri.. 09/03/2019 ...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 0201 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...Synopsis... An upper-level ridge will remain in place across the western CONUS for the Day 2/Wednesday period. The embedded mid-level shortwave trough moving across the Pacific Northwest on Day 1 will then traverse the northern Rockies while cresting the ridge on Day 2. With the passage of the trough, the low-level mass response will be a dry and breezy westerly wind that may foster some wildfire-spread potential. Elsewhere, from northern California into the Great Basin, adequate monsoonal moisture traversing the upper-level ridge will promote at least isolated thunderstorm potential, with a few dry strikes possible. ...Northern Rockies... With the passage of an upper-level trough and diurnal boundary layer mixing of stronger winds aloft to the surface, 15-25 mph sustained westerly surface winds are expected across parts of the northern Rockies (mainly north-central Montana) along with 15-25% RH. Finer fuels have recently begun to dry across the area, supporting the potential for grass-fire spread and as such, an elevated area has been delineated. ...Northern California into the northern Great Basin... As mid-level monsoonal moisture continues to drift northward across northern portions of the Great Basin, isolated high-based thunderstorms will become possible by afternoon peak heating. Despite slow storm motions, a dry sub-cloud layer will support at least some potential for dry strikes atop near-critical to critically dry fuels, where an isolated dry thunderstorm area was added. Isolated dry thunderstorms may also occur over northern parts of California into far southern Oregon, but low confidence in storm initiation over this area precludes a delineation at this time. ..Squitieri.. 09/03/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 AM CDT Tue Sep 03 2019 Valid 031200Z - 041200Z ...Synopsis... A mid-level ridge will remain in place across the western CONUS, with an embedded shortwave trough propagating around the ridge across the Pacific Northwest. Mildly dry and breezy conditions may occur east of the Cascades as the stronger flow aloft attempts to mix downward to the surface. Mid-level monsoonal moisture will also be present across parts of the Great Basin, fueling isolated thunderstorms, with a few dry strikes possible. ...Pacific Northwest... By afternoon peak heating, boundary layer mixing, in conjunction with downslope flow along the lee of the Cascades, will contribute to westerly winds reaching 15 mph at times, particularly in the Harney Basin area, with RH dropping into the 15-25% range. As winds exceeding 15 mph will be brief and confined to mainly terrain favoring locations, an elevated delineation has been withheld at this time. ...Portions of the Great Basin... Mid-level moisture will meander northwestward into central parts of the Great Basin (including parts of Nevada into western Utah), where afternoon heating will provide enough buoyancy and lift to induce isolated thunderstorms. Though these storms will be slow moving, cells are expected to be high based in nature (i.e. rooted atop a sfc-500 mb dry sub-cloud layer), and are expected to occur over fuels that are near-critical to critically receptive to fire spread, warranting the addition of an isolated dry thunderstorm delineation. ..Squitieri.. 09/03/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 AM CDT Tue Sep 03 2019 Valid 031200Z - 041200Z ...Synopsis... A mid-level ridge will remain in place across the western CONUS, with an embedded shortwave trough propagating around the ridge across the Pacific Northwest. Mildly dry and breezy conditions may occur east of the Cascades as the stronger flow aloft attempts to mix downward to the surface. Mid-level monsoonal moisture will also be present across parts of the Great Basin, fueling isolated thunderstorms, with a few dry strikes possible. ...Pacific Northwest... By afternoon peak heating, boundary layer mixing, in conjunction with downslope flow along the lee of the Cascades, will contribute to westerly winds reaching 15 mph at times, particularly in the Harney Basin area, with RH dropping into the 15-25% range. As winds exceeding 15 mph will be brief and confined to mainly terrain favoring locations, an elevated delineation has been withheld at this time. ...Portions of the Great Basin... Mid-level moisture will meander northwestward into central parts of the Great Basin (including parts of Nevada into western Utah), where afternoon heating will provide enough buoyancy and lift to induce isolated thunderstorms. Though these storms will be slow moving, cells are expected to be high based in nature (i.e. rooted atop a sfc-500 mb dry sub-cloud layer), and are expected to occur over fuels that are near-critical to critically receptive to fire spread, warranting the addition of an isolated dry thunderstorm delineation. ..Squitieri.. 09/03/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 AM CDT Tue Sep 03 2019 Valid 031200Z - 041200Z ...Synopsis... A mid-level ridge will remain in place across the western CONUS, with an embedded shortwave trough propagating around the ridge across the Pacific Northwest. Mildly dry and breezy conditions may occur east of the Cascades as the stronger flow aloft attempts to mix downward to the surface. Mid-level monsoonal moisture will also be present across parts of the Great Basin, fueling isolated thunderstorms, with a few dry strikes possible. ...Pacific Northwest... By afternoon peak heating, boundary layer mixing, in conjunction with downslope flow along the lee of the Cascades, will contribute to westerly winds reaching 15 mph at times, particularly in the Harney Basin area, with RH dropping into the 15-25% range. As winds exceeding 15 mph will be brief and confined to mainly terrain favoring locations, an elevated delineation has been withheld at this time. ...Portions of the Great Basin... Mid-level moisture will meander northwestward into central parts of the Great Basin (including parts of Nevada into western Utah), where afternoon heating will provide enough buoyancy and lift to induce isolated thunderstorms. Though these storms will be slow moving, cells are expected to be high based in nature (i.e. rooted atop a sfc-500 mb dry sub-cloud layer), and are expected to occur over fuels that are near-critical to critically receptive to fire spread, warranting the addition of an isolated dry thunderstorm delineation. ..Squitieri.. 09/03/2019 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND INTO THE MIDDLE ATLANTIC AND FROM COASTAL GEORGIA TO COASTAL SOUTH CAROLINA... ...SUMMARY... A couple of tornadoes are possible along the Georgia and south Carolina coastal areas Wednesday afternoon through Wednesday night in association with Hurricane Dorian. Otherwise, isolated damaging gusts are possible Wednesday afternoon from the Middle Atlantic through New England. ...Georgia and South Carolina coasts... Hurricane Dorian is forecast by the National Hurricane Center to begin a slow northwestward motion and should be located off the GA coast Wednesday afternoon based on the latest forecast. The most favorable quadrant for a more robust tornado threat will remain offshore. However, thunderstorms developing within the outer rain bands will spread inland, and low-level hodographs might become sufficient for at least a marginal isolated tornado threat along the GA and SC coast Wednesday afternoon and evening. See latest discussions from the National Hurricane center for updates on Dorian. ...Middle Atlantic through New England... A cold front will accompany a shortwave trough as it moves through the northeast states Wednesday afternoon. Low-level dewpoints in the 60s F will advect through pre-frontal warm sector, but areas of clouds and modest mid-level lapse rates should limit MLCAPE to near 500 J/kg over New England. A few showers and thunderstorms will probably be ongoing along warm conveyor belt just ahead of the cold front from NY into PA. Additional development/intensification will be possible downstream across New England as the atmosphere destabilizes. The strongest deep-layer shear (50+ kt) supportive of organized severe storms will reside across New England where instability should be weaker. Given this potential limiting factor, will maintain a MRGL risk this outlook, but a categorical upgrade might be needed in later updates if it begins to appear instability will be greater than currently anticipated. Other storms will likely develop along and ahead of the front as far south as the middle Atlantic region where instability will be greater (up to 1500 J/kg MLCAPE). These storms will reside in a weaker shear environment supportive of multicells with a risk for isolated damaging wind during the afternoon. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Dial.. 09/03/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND INTO THE MIDDLE ATLANTIC AND FROM COASTAL GEORGIA TO COASTAL SOUTH CAROLINA... ...SUMMARY... A couple of tornadoes are possible along the Georgia and south Carolina coastal areas Wednesday afternoon through Wednesday night in association with Hurricane Dorian. Otherwise, isolated damaging gusts are possible Wednesday afternoon from the Middle Atlantic through New England. ...Georgia and South Carolina coasts... Hurricane Dorian is forecast by the National Hurricane Center to begin a slow northwestward motion and should be located off the GA coast Wednesday afternoon based on the latest forecast. The most favorable quadrant for a more robust tornado threat will remain offshore. However, thunderstorms developing within the outer rain bands will spread inland, and low-level hodographs might become sufficient for at least a marginal isolated tornado threat along the GA and SC coast Wednesday afternoon and evening. See latest discussions from the National Hurricane center for updates on Dorian. ...Middle Atlantic through New England... A cold front will accompany a shortwave trough as it moves through the northeast states Wednesday afternoon. Low-level dewpoints in the 60s F will advect through pre-frontal warm sector, but areas of clouds and modest mid-level lapse rates should limit MLCAPE to near 500 J/kg over New England. A few showers and thunderstorms will probably be ongoing along warm conveyor belt just ahead of the cold front from NY into PA. Additional development/intensification will be possible downstream across New England as the atmosphere destabilizes. The strongest deep-layer shear (50+ kt) supportive of organized severe storms will reside across New England where instability should be weaker. Given this potential limiting factor, will maintain a MRGL risk this outlook, but a categorical upgrade might be needed in later updates if it begins to appear instability will be greater than currently anticipated. Other storms will likely develop along and ahead of the front as far south as the middle Atlantic region where instability will be greater (up to 1500 J/kg MLCAPE). These storms will reside in a weaker shear environment supportive of multicells with a risk for isolated damaging wind during the afternoon. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Dial.. 09/03/2019 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND INTO THE MIDDLE ATLANTIC AND FROM COASTAL GEORGIA TO COASTAL SOUTH CAROLINA... ...SUMMARY... A couple of tornadoes are possible along the Georgia and south Carolina coastal areas Wednesday afternoon through Wednesday night in association with Hurricane Dorian. Otherwise, isolated damaging gusts are possible Wednesday afternoon from the Middle Atlantic through New England. ...Georgia and South Carolina coasts... Hurricane Dorian is forecast by the National Hurricane Center to begin a slow northwestward motion and should be located off the GA coast Wednesday afternoon based on the latest forecast. The most favorable quadrant for a more robust tornado threat will remain offshore. However, thunderstorms developing within the outer rain bands will spread inland, and low-level hodographs might become sufficient for at least a marginal isolated tornado threat along the GA and SC coast Wednesday afternoon and evening. See latest discussions from the National Hurricane center for updates on Dorian. ...Middle Atlantic through New England... A cold front will accompany a shortwave trough as it moves through the northeast states Wednesday afternoon. Low-level dewpoints in the 60s F will advect through pre-frontal warm sector, but areas of clouds and modest mid-level lapse rates should limit MLCAPE to near 500 J/kg over New England. A few showers and thunderstorms will probably be ongoing along warm conveyor belt just ahead of the cold front from NY into PA. Additional development/intensification will be possible downstream across New England as the atmosphere destabilizes. The strongest deep-layer shear (50+ kt) supportive of organized severe storms will reside across New England where instability should be weaker. Given this potential limiting factor, will maintain a MRGL risk this outlook, but a categorical upgrade might be needed in later updates if it begins to appear instability will be greater than currently anticipated. Other storms will likely develop along and ahead of the front as far south as the middle Atlantic region where instability will be greater (up to 1500 J/kg MLCAPE). These storms will reside in a weaker shear environment supportive of multicells with a risk for isolated damaging wind during the afternoon. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Dial.. 09/03/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Tue Sep 03 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF LOWER MI INTO THE MIDWEST... ...SUMMARY... Severe storms may occur today from parts of Lower Michigan southwestward into Illinois, Indiana, and Ohio. Isolated damaging winds and large hail should be the main threats, but a couple tornadoes will also be possible. ...Midwest into the Great Lakes and Mid MS Valley... A long-lived MCS over far southeastern MN and western/central WI early this morning will likely continue southeastward across WI for at least the next several hours along an instability gradient. This line of storms should continue to gradually weaken with southeastward extent this morning as it encounters a less unstable airmass. However, strong low/mid-level flow associated with a shortwave trough over the northern Plains may allow these storms to persist for longer than most model guidance suggests. An isolated hail/wind threat may be ongoing at the start of the period across parts of northern IL and vicinity if these storms can maintain their intensity, especially on the southwestern flank of the line where instability is relatively greater. The convective scenario for today remains rather uncertain given the potential for this morning MCS to delay/disrupt diurnal destabilization, particularly with northward extent into Lower MI. A relatively greater chance for moderate to strong instability to develop may occur along a trailing outflow boundary from these morning storms across parts of northern IL/IN into far southern Lower MI. Strong large-scale forcing for ascent attendant to a southeastward-moving shortwave trough will overspread these areas by this afternoon. Additional convective development appears likely along or just ahead of a surface cold front by peak afternoon heating. The presence of a 50-70+ kt mid-level westerly jet will support strong effective bulk shear values over this region. Any storms that can form in this environment will likely become organized and pose an isolated large hail and damaging wind threat. Initially semi-discrete storms will probably grow upscale fairly quickly along the cold front or remnant outflow boundary, with a damaging wind threat potentially continuing into the evening across parts of central IL/IN and northwestern OH. The degree of the tornado threat will be dependent on storm mode, but a southwesterly low-level jet will overspread much of the warm sector through the afternoon. Isolated tornadoes will be possible given the strong low-level shear that will be present. Greater severe probabilities may be needed across some part of the Midwest into southern Lower MI, but too much uncertainty exists regarding morning storms to introduce them at them at this time. ...Florida... Latest forecast from the National Hurricane Center shows Hurricane Dorian should remain just offshore the east coast of the FL Peninsula today through tonight. However, low-level convergence and banded convection within the western half of the system will spread slowly northward. While tornadoes are generally not favored along the west side of the track, effective SRH around 200 m2/s2 during the day increasing to over 300 m2/s2 into early Wednesday morning may support a couple rotating storms with a brief/weak tornado risk. ..Gleason/Squitieri.. 09/03/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Tue Sep 03 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF LOWER MI INTO THE MIDWEST... ...SUMMARY... Severe storms may occur today from parts of Lower Michigan southwestward into Illinois, Indiana, and Ohio. Isolated damaging winds and large hail should be the main threats, but a couple tornadoes will also be possible. ...Midwest into the Great Lakes and Mid MS Valley... A long-lived MCS over far southeastern MN and western/central WI early this morning will likely continue southeastward across WI for at least the next several hours along an instability gradient. This line of storms should continue to gradually weaken with southeastward extent this morning as it encounters a less unstable airmass. However, strong low/mid-level flow associated with a shortwave trough over the northern Plains may allow these storms to persist for longer than most model guidance suggests. An isolated hail/wind threat may be ongoing at the start of the period across parts of northern IL and vicinity if these storms can maintain their intensity, especially on the southwestern flank of the line where instability is relatively greater. The convective scenario for today remains rather uncertain given the potential for this morning MCS to delay/disrupt diurnal destabilization, particularly with northward extent into Lower MI. A relatively greater chance for moderate to strong instability to develop may occur along a trailing outflow boundary from these morning storms across parts of northern IL/IN into far southern Lower MI. Strong large-scale forcing for ascent attendant to a southeastward-moving shortwave trough will overspread these areas by this afternoon. Additional convective development appears likely along or just ahead of a surface cold front by peak afternoon heating. The presence of a 50-70+ kt mid-level westerly jet will support strong effective bulk shear values over this region. Any storms that can form in this environment will likely become organized and pose an isolated large hail and damaging wind threat. Initially semi-discrete storms will probably grow upscale fairly quickly along the cold front or remnant outflow boundary, with a damaging wind threat potentially continuing into the evening across parts of central IL/IN and northwestern OH. The degree of the tornado threat will be dependent on storm mode, but a southwesterly low-level jet will overspread much of the warm sector through the afternoon. Isolated tornadoes will be possible given the strong low-level shear that will be present. Greater severe probabilities may be needed across some part of the Midwest into southern Lower MI, but too much uncertainty exists regarding morning storms to introduce them at them at this time. ...Florida... Latest forecast from the National Hurricane Center shows Hurricane Dorian should remain just offshore the east coast of the FL Peninsula today through tonight. However, low-level convergence and banded convection within the western half of the system will spread slowly northward. While tornadoes are generally not favored along the west side of the track, effective SRH around 200 m2/s2 during the day increasing to over 300 m2/s2 into early Wednesday morning may support a couple rotating storms with a brief/weak tornado risk. ..Gleason/Squitieri.. 09/03/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Tue Sep 03 2019 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF LOWER MI INTO THE MIDWEST... ...SUMMARY... Severe storms may occur today from parts of Lower Michigan southwestward into Illinois, Indiana, and Ohio. Isolated damaging winds and large hail should be the main threats, but a couple tornadoes will also be possible. ...Midwest into the Great Lakes and Mid MS Valley... A long-lived MCS over far southeastern MN and western/central WI early this morning will likely continue southeastward across WI for at least the next several hours along an instability gradient. This line of storms should continue to gradually weaken with southeastward extent this morning as it encounters a less unstable airmass. However, strong low/mid-level flow associated with a shortwave trough over the northern Plains may allow these storms to persist for longer than most model guidance suggests. An isolated hail/wind threat may be ongoing at the start of the period across parts of northern IL and vicinity if these storms can maintain their intensity, especially on the southwestern flank of the line where instability is relatively greater. The convective scenario for today remains rather uncertain given the potential for this morning MCS to delay/disrupt diurnal destabilization, particularly with northward extent into Lower MI. A relatively greater chance for moderate to strong instability to develop may occur along a trailing outflow boundary from these morning storms across parts of northern IL/IN into far southern Lower MI. Strong large-scale forcing for ascent attendant to a southeastward-moving shortwave trough will overspread these areas by this afternoon. Additional convective development appears likely along or just ahead of a surface cold front by peak afternoon heating. The presence of a 50-70+ kt mid-level westerly jet will support strong effective bulk shear values over this region. Any storms that can form in this environment will likely become organized and pose an isolated large hail and damaging wind threat. Initially semi-discrete storms will probably grow upscale fairly quickly along the cold front or remnant outflow boundary, with a damaging wind threat potentially continuing into the evening across parts of central IL/IN and northwestern OH. The degree of the tornado threat will be dependent on storm mode, but a southwesterly low-level jet will overspread much of the warm sector through the afternoon. Isolated tornadoes will be possible given the strong low-level shear that will be present. Greater severe probabilities may be needed across some part of the Midwest into southern Lower MI, but too much uncertainty exists regarding morning storms to introduce them at them at this time. ...Florida... Latest forecast from the National Hurricane Center shows Hurricane Dorian should remain just offshore the east coast of the FL Peninsula today through tonight. However, low-level convergence and banded convection within the western half of the system will spread slowly northward. While tornadoes are generally not favored along the west side of the track, effective SRH around 200 m2/s2 during the day increasing to over 300 m2/s2 into early Wednesday morning may support a couple rotating storms with a brief/weak tornado risk. ..Gleason/Squitieri.. 09/03/2019 Read more

WW 0633 Status Updates
STATUS REPORT ON WW 633 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SE MKT TO 25 ENE MKT TO 35 NW RST TO 45 N RST TO 25 WSW EAU TO 20 NW EAU TO 30 NNW EAU TO 40 N EAU TO 55 N EAU TO 60 W RHI TO 55 NE EAU TO 45 WSW RHI. FOR ADDITIONAL INFORMATION SEE SPC MESOSCALE DISCUSSION 1919. ..EDWARDS..09/03/19 ATTN...WFO...DLH...MPX...ARX... STATUS REPORT FOR WS 633 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MNC037-039-045-049-053-055-109-131-147-157-169-030540- MN . MINNESOTA COUNTIES INCLUDED ARE DAKOTA DODGE FILLMORE GOODHUE HENNEPIN HOUSTON OLMSTED RICE STEELE WABASHA WINONA WIC005-011-017-019-033-035-053-063-091-093-107-119-121-030540- WI . WISCONSIN COUNTIES INCLUDED ARE BARRON BUFFALO CHIPPEWA CLARK DUNN EAU CLAIRE JACKSON LA CROSSE PEPIN PIERCE RUSK TAYLOR TREMPEALEAU Read more