Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Sep 04 2019 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEW ENGLAND AND THE MID-ATLANTIC...AND COASTAL SC... ...SUMMARY... Strong to severe thunderstorms capable of producing mainly damaging winds will be possible this afternoon across parts of the Mid-Atlantic and New England. Isolated tornadoes may occur primarily along the coast of South Carolina late tonight through early Thursday morning in association with Hurricane Dorian. ...Northeast/Mid-Atlantic... An upper trough will move eastward across the Northeast and Mid-Atlantic today. At the surface, a low will develop northeastward across Quebec through the period, with a trailing cold front shifting quickly eastward over these areas. Strong forcing for ascent associated with the upper trough along with low-level convergence along the front will likely foster robust convective development by early afternoon across NY into southern New England. 50-60 kt of mid-level southwesterly flow associated with the upper trough will overspread the warm sector, and strong shear will support organized updrafts. Generally mid 60s to lower 70s surface dewpoints should advect northeastward ahead of the front in a low-level warm air advection regime. Even though mid-level lapse rates will likely remain modest, the increasing low-level moisture and at least modest diurnal heating should promote about 1000-2000 J/kg of MLCAPE. The greatest instability should reside across the Mid-Atlantic, with gradual lessening with northeastward extent into the Northeast. By contrast, relatively stronger shear should be present farther north in New England. Regardless, there appears to be a sufficient overlap of instability and shear to support organized storms, especially from northeastern PA/northern NJ into southern New England. Given the strength of the mid-level flow and some orthogonal component to the surface front, some supercells could occur initially, with clustering potential increasing later in the afternoon. Damaging winds will probably be the main threat given the strength of the low/mid-level flow, but isolated marginally severe hail could also occur. A tornado or two cannot be ruled out, although low-level flow will have a tendency to veer to southwesterly through the afternoon, generally limiting low-level hodograph length. Farther south into southern PA/NJ and MD/DE, low-level convergence should be weaker along the front and mid-level height falls will be more subdued. Resultant overall storm coverage will probably be more isolated. Still, some threat for damaging winds should exist with any storms that can form across this area as low-level lapse rates steepen and moderate instability develops. ...Southeast Coast... Hurricane Dorian is forecast by the National Hurricane Center to continue moving north-northeastward near the coast of FL/GA/SC through the period. The overall tornado threat is expected to remain quite limited today along the east coast of FL and coastal GA as this region will remain within the western semicircle of Dorian's circulation, limiting low-level curvature and effective SRH. A somewhat greater potential for isolated tornadoes may develop late tonight into early Thursday morning across parts of coastal SC, where strengthening northeasterly low-level winds will substantially increase low-level hodographs. Low-topped supercells within one or more outer rainbands could approach the immediate coast of SC late in the period, with this isolated tornado threat likely continuing into parts of coastal NC into Day 2/Thursday. ...Deep South Texas... Tropical Storm Fernand, now over the far western Gulf of Mexico, is forecast by the National Hurricane Center to move west-northwestward across parts of northeastern Mexico through the period. Low-level shear on the northern periphery of Fernand's circulation may be sufficient to support a low risk for a brief tornado or two as low-topped cells move onshore across deep south TX. ...North Dakota/Minnesota... A low-amplitude shortwave trough now over WA/southern BC will move eastward along the international border through the period. A south-southwesterly low-level jet should strengthen across the northern/central Plains in response this evening/overnight. Elevated storms may evolve southeastward from southern MB/SK into northeastern ND and northern MN late in the period. Forecast MUCAPE appears too marginal at this time to include any probabilities for large hail, although shear is forecast to be strong across this area. ..Gleason/Squitieri.. 09/04/2019 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Wed Sep 04 2019 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEW ENGLAND AND THE MID-ATLANTIC...AND COASTAL SC... ...SUMMARY... Strong to severe thunderstorms capable of producing mainly damaging winds will be possible this afternoon across parts of the Mid-Atlantic and New England. Isolated tornadoes may occur primarily along the coast of South Carolina late tonight through early Thursday morning in association with Hurricane Dorian. ...Northeast/Mid-Atlantic... An upper trough will move eastward across the Northeast and Mid-Atlantic today. At the surface, a low will develop northeastward across Quebec through the period, with a trailing cold front shifting quickly eastward over these areas. Strong forcing for ascent associated with the upper trough along with low-level convergence along the front will likely foster robust convective development by early afternoon across NY into southern New England. 50-60 kt of mid-level southwesterly flow associated with the upper trough will overspread the warm sector, and strong shear will support organized updrafts. Generally mid 60s to lower 70s surface dewpoints should advect northeastward ahead of the front in a low-level warm air advection regime. Even though mid-level lapse rates will likely remain modest, the increasing low-level moisture and at least modest diurnal heating should promote about 1000-2000 J/kg of MLCAPE. The greatest instability should reside across the Mid-Atlantic, with gradual lessening with northeastward extent into the Northeast. By contrast, relatively stronger shear should be present farther north in New England. Regardless, there appears to be a sufficient overlap of instability and shear to support organized storms, especially from northeastern PA/northern NJ into southern New England. Given the strength of the mid-level flow and some orthogonal component to the surface front, some supercells could occur initially, with clustering potential increasing later in the afternoon. Damaging winds will probably be the main threat given the strength of the low/mid-level flow, but isolated marginally severe hail could also occur. A tornado or two cannot be ruled out, although low-level flow will have a tendency to veer to southwesterly through the afternoon, generally limiting low-level hodograph length. Farther south into southern PA/NJ and MD/DE, low-level convergence should be weaker along the front and mid-level height falls will be more subdued. Resultant overall storm coverage will probably be more isolated. Still, some threat for damaging winds should exist with any storms that can form across this area as low-level lapse rates steepen and moderate instability develops. ...Southeast Coast... Hurricane Dorian is forecast by the National Hurricane Center to continue moving north-northeastward near the coast of FL/GA/SC through the period. The overall tornado threat is expected to remain quite limited today along the east coast of FL and coastal GA as this region will remain within the western semicircle of Dorian's circulation, limiting low-level curvature and effective SRH. A somewhat greater potential for isolated tornadoes may develop late tonight into early Thursday morning across parts of coastal SC, where strengthening northeasterly low-level winds will substantially increase low-level hodographs. Low-topped supercells within one or more outer rainbands could approach the immediate coast of SC late in the period, with this isolated tornado threat likely continuing into parts of coastal NC into Day 2/Thursday. ...Deep South Texas... Tropical Storm Fernand, now over the far western Gulf of Mexico, is forecast by the National Hurricane Center to move west-northwestward across parts of northeastern Mexico through the period. Low-level shear on the northern periphery of Fernand's circulation may be sufficient to support a low risk for a brief tornado or two as low-topped cells move onshore across deep south TX. ...North Dakota/Minnesota... A low-amplitude shortwave trough now over WA/southern BC will move eastward along the international border through the period. A south-southwesterly low-level jet should strengthen across the northern/central Plains in response this evening/overnight. Elevated storms may evolve southeastward from southern MB/SK into northeastern ND and northern MN late in the period. Forecast MUCAPE appears too marginal at this time to include any probabilities for large hail, although shear is forecast to be strong across this area. ..Gleason/Squitieri.. 09/04/2019 Read more

MD 1923 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN INDIANA...NORTHWEST OHIO...SOUTHERN LOWER MICHIGAN
Mesoscale Discussion 1923 NWS Storm Prediction Center Norman OK 0903 PM CDT Tue Sep 03 2019 Areas affected...Northern Indiana...Northwest Ohio...Southern Lower Michigan Concerning...Severe potential...Watch possible Valid 040203Z - 040430Z Probability of Watch Issuance...40 percent SUMMARY...An isolated severe threat will likely develop across parts of southern Lower Michigan into northern Indiana and possibly northwest Ohio this evening. Hail and strong gusty winds will be the primary threats. Weather watch issuance still remains possible and convective trends will continue to be monitored. DISCUSSION...The latest surface analysis shows a 1000 mb low across Ontario with a cold front extending south-southwestward across northern and western Lower Michigan into northern Illinois. Ahead of the front, surface dewpoints range from the mid 60s F in west-central Lower Michigan to the mid 70s F in northeastern Illinois, along which a corridor of moderate to strong instability is analyzed by the RAP. Scattered thunderstorms are developing along the instability axis from southwest Lower Michigan into northeast Illinois. This convection will continue to expand in coverage, moving eastward across southern Lower Michigan and northern Indiana this evening. Although low-level winds are veered to the south-southwest, the Grand Rapids WSR-88D VWP shows about 40 kt of 0-6 km shear. This would be enough for cell organization and a few severe multicells will be possible. The primary threats will be isolated wind damage and hail. ..Broyles/Hart.. 09/04/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...DTX...IWX...GRR...LOT... LAT...LON 41498335 40828669 41138759 42888561 43248452 42888252 41498335 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Tue Sep 03 2019 Valid 040100Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES AND MIDWEST... ...SUMMARY... Isolated severe thunderstorms may still occur this evening across parts of the Great Lakes and Midwest. Large hail and damaging winds remain possible. ...Midwest/Great Lakes... Isolated convection along/ahead of a surface cold front has struggled to intensify early this evening in the wake of earlier storms that moved over the Midwest and Great Lakes. A strongly sheared environment remains present across region owing to a pronounced shortwave trough moving eastward. But, only a narrow corridor of weak to moderate instability has developed ahead of the surface front. There still appears to be some potential for storms to increase in coverage and intensity this evening across parts of southern Lower MI, northeastern IL, northern IN, and northwestern OH. The Slight Risk has been generally confined to this area, where a relatively better chance for isolated large hail and strong to locally damaging winds exists. The tornado threat should continue to decrease this evening as low-level flow continues to veer, reducing hodograph size and effective SRH. The overall severe threat will likely wane with eastward extent tonight as the boundary layer continues to slowly stabilize. ...Florida... Hurricane Dorian is expected to continue moving northwest tonight into early Wednesday based on the most recent National Hurricane Center forecast. This will keep the east coast of the FL Peninsula in the typically unfavorable western periphery of Dorian's circulation. Still, some enlargement to the low-level hodograph combined with weak instability might support a couple of shallow rotating cells capable of a brief tornado through tonight. ...Deep South Texas... Tropical Storm Fernand will continue to slowly approach the coast of northeastern Mexico overnight per the latest forecast from the National Hurricane Center. A gradual strengthening of low-level easterly flow on its northern periphery could support isolated low-topped supercell potential and possibly a brief tornado across parts of deep south TX through the overnight hours. ..Gleason.. 09/04/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Tue Sep 03 2019 Valid 040100Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES AND MIDWEST... ...SUMMARY... Isolated severe thunderstorms may still occur this evening across parts of the Great Lakes and Midwest. Large hail and damaging winds remain possible. ...Midwest/Great Lakes... Isolated convection along/ahead of a surface cold front has struggled to intensify early this evening in the wake of earlier storms that moved over the Midwest and Great Lakes. A strongly sheared environment remains present across region owing to a pronounced shortwave trough moving eastward. But, only a narrow corridor of weak to moderate instability has developed ahead of the surface front. There still appears to be some potential for storms to increase in coverage and intensity this evening across parts of southern Lower MI, northeastern IL, northern IN, and northwestern OH. The Slight Risk has been generally confined to this area, where a relatively better chance for isolated large hail and strong to locally damaging winds exists. The tornado threat should continue to decrease this evening as low-level flow continues to veer, reducing hodograph size and effective SRH. The overall severe threat will likely wane with eastward extent tonight as the boundary layer continues to slowly stabilize. ...Florida... Hurricane Dorian is expected to continue moving northwest tonight into early Wednesday based on the most recent National Hurricane Center forecast. This will keep the east coast of the FL Peninsula in the typically unfavorable western periphery of Dorian's circulation. Still, some enlargement to the low-level hodograph combined with weak instability might support a couple of shallow rotating cells capable of a brief tornado through tonight. ...Deep South Texas... Tropical Storm Fernand will continue to slowly approach the coast of northeastern Mexico overnight per the latest forecast from the National Hurricane Center. A gradual strengthening of low-level easterly flow on its northern periphery could support isolated low-topped supercell potential and possibly a brief tornado across parts of deep south TX through the overnight hours. ..Gleason.. 09/04/2019 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Tue Sep 03 2019 Valid 040100Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES AND MIDWEST... ...SUMMARY... Isolated severe thunderstorms may still occur this evening across parts of the Great Lakes and Midwest. Large hail and damaging winds remain possible. ...Midwest/Great Lakes... Isolated convection along/ahead of a surface cold front has struggled to intensify early this evening in the wake of earlier storms that moved over the Midwest and Great Lakes. A strongly sheared environment remains present across region owing to a pronounced shortwave trough moving eastward. But, only a narrow corridor of weak to moderate instability has developed ahead of the surface front. There still appears to be some potential for storms to increase in coverage and intensity this evening across parts of southern Lower MI, northeastern IL, northern IN, and northwestern OH. The Slight Risk has been generally confined to this area, where a relatively better chance for isolated large hail and strong to locally damaging winds exists. The tornado threat should continue to decrease this evening as low-level flow continues to veer, reducing hodograph size and effective SRH. The overall severe threat will likely wane with eastward extent tonight as the boundary layer continues to slowly stabilize. ...Florida... Hurricane Dorian is expected to continue moving northwest tonight into early Wednesday based on the most recent National Hurricane Center forecast. This will keep the east coast of the FL Peninsula in the typically unfavorable western periphery of Dorian's circulation. Still, some enlargement to the low-level hodograph combined with weak instability might support a couple of shallow rotating cells capable of a brief tornado through tonight. ...Deep South Texas... Tropical Storm Fernand will continue to slowly approach the coast of northeastern Mexico overnight per the latest forecast from the National Hurricane Center. A gradual strengthening of low-level easterly flow on its northern periphery could support isolated low-topped supercell potential and possibly a brief tornado across parts of deep south TX through the overnight hours. ..Gleason.. 09/04/2019 Read more

No watches are valid as of Tue Sep 3 23:01:06 UTC 2019.

No Mesoscale Discussions are in effect as of Tue Sep 3 23:01:06 UTC 2019.

MD 1922 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN/CENTRAL IL...NORTHWEST/CENTRAL IN
Mesoscale Discussion 1922 NWS Storm Prediction Center Norman OK 0354 PM CDT Tue Sep 03 2019 Areas affected...Northern/Central IL...Northwest/Central IN Concerning...Severe potential...Watch possible Valid 032054Z - 032300Z Probability of Watch Issuance...40 percent SUMMARY...Increased thunderstorm activity is anticipated across the region over the next few hours. Some severe storms are possible. DISCUSSION...Recent surface analysis reveals a somewhat complex pattern across northern/central IL and northwest/north-central IN. Two outflow boundaries are apparent. One of these boundaries extends from about 35 mi north-northeast of LAF southeastward to the central IN/OH border. The other extends from near PPQ (in far west-central IL) northeastward into northwest IN, where it intersects the first outflow boundary mentioned. Air mass in the vicinity of these boundaries has not fully destabilized, with at least minimal convective inhibition still in place. Even so, increasing forcing for ascent is anticipated as a strong shortwave trough approaches. This strong forcing is apparent in the banded structure of the cloud features and recent radar signatures across northeast IL as well as storm development across west-central IN. Expectation is for the increased forcing for ascent, both attendant to the shortwave trough and along the cold front (which remains farther west from southern WI southwestward across IA), to eventually result in thunderstorm development across northern/central IL. Given the favorable environment, some severe storms are possible. The ongoing elevated activity is expected to persist across central IN before then moving into the more stable air mass to the north of the outflow boundary across northeast IN/northwest OH. Isolated hail and/or a strong wind gusts are possible with this storm. ..Mosier/Guyer.. 09/03/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...IND...LOT...ILX...DVN... LAT...LON 42308957 42438807 41678759 41458635 40728543 39498611 39398905 40329036 42308957 Read more

MD 1921 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN LOWER MI
Mesoscale Discussion 1921 NWS Storm Prediction Center Norman OK 0320 PM CDT Tue Sep 03 2019 Areas affected...Northern Lower MI Concerning...Severe potential...Watch unlikely Valid 032020Z - 032145Z Probability of Watch Issuance...20 percent SUMMARY...An isolated strong wind gust or two possible across northern portions of Lower MI during the next few hours. DISCUSSION...Recent visible satellite imagery shows a large area of cloudiness over all of northern Lower MI. This area of cloudiness has limited diurnal heating, keeping temperatures in the low 70s. This limited heating has resulted in a largely stable air mass despite advection of relatively steep mid-level lapse rates and dewpoints in the mid 60s. Strong forcing for ascent attendant to the approaching shortwave trough will likely result in sporadic deep convection capable of lightning and possibly a strong wind gust or two. Isolated nature of these storms (and the resulting severe threat) will likely preclude the need for a watch. ..Mosier/Guyer.. 09/03/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...APX...GRR... LAT...LON 44968594 45348545 45748454 45168340 44268357 43578438 43418497 43508636 44308635 44968594 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0305 PM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z The ISODRYT has been removed from northern Utah. Thunderstorms still appear likely in that location, however a continued upward trend in PWAT values and relatively slow storm motions near the center of the upper-level ridge increase the likelihood of wetting rainfall. High PWAT values (0.8+ inches) will also be an issue in northern Nevada. Storm motions here will be higher given the proximity of the incoming shortwave trough to the west. This may allow a few dry strikes early in the convective life cycle. There is increasing concern for a lightning activity during the evening and over portions of northern California during the evening/overnight. As the trough position has trended south, forecast soundings show increasing lift and elevated buoyancy. With dry heavy fuels, potential for lightning ignitions will exist. There is still uncertainty regarding coverage and also the southern extent of the threat. ISODRYT highlights for this area will be withheld for now. The elevated area in northern Montana was left unchanged. Locally elevated conditions may occur to the south of the highlighted area, which will impact ongoing fires in portions of central Montana. ..Wendt.. 09/03/2019 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Sep 03 2019/ ...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. ...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 0305 PM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z The ISODRYT has been removed from northern Utah. Thunderstorms still appear likely in that location, however a continued upward trend in PWAT values and relatively slow storm motions near the center of the upper-level ridge increase the likelihood of wetting rainfall. High PWAT values (0.8+ inches) will also be an issue in northern Nevada. Storm motions here will be higher given the proximity of the incoming shortwave trough to the west. This may allow a few dry strikes early in the convective life cycle. There is increasing concern for a lightning activity during the evening and over portions of northern California during the evening/overnight. As the trough position has trended south, forecast soundings show increasing lift and elevated buoyancy. With dry heavy fuels, potential for lightning ignitions will exist. There is still uncertainty regarding coverage and also the southern extent of the threat. ISODRYT highlights for this area will be withheld for now. The elevated area in northern Montana was left unchanged. Locally elevated conditions may occur to the south of the highlighted area, which will impact ongoing fires in portions of central Montana. ..Wendt.. 09/03/2019 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Sep 03 2019/ ...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. ...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 0305 PM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z The ISODRYT has been removed from northern Utah. Thunderstorms still appear likely in that location, however a continued upward trend in PWAT values and relatively slow storm motions near the center of the upper-level ridge increase the likelihood of wetting rainfall. High PWAT values (0.8+ inches) will also be an issue in northern Nevada. Storm motions here will be higher given the proximity of the incoming shortwave trough to the west. This may allow a few dry strikes early in the convective life cycle. There is increasing concern for a lightning activity during the evening and over portions of northern California during the evening/overnight. As the trough position has trended south, forecast soundings show increasing lift and elevated buoyancy. With dry heavy fuels, potential for lightning ignitions will exist. There is still uncertainty regarding coverage and also the southern extent of the threat. ISODRYT highlights for this area will be withheld for now. The elevated area in northern Montana was left unchanged. Locally elevated conditions may occur to the south of the highlighted area, which will impact ongoing fires in portions of central Montana. ..Wendt.. 09/03/2019 .PREV DISCUSSION... /ISSUED 0201 AM CDT Tue Sep 03 2019/ ...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. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Tue Sep 03 2019 Valid 032000Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER GREAT LAKES/MIDWEST... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of the Great Lakes and Midwest. A few tornadoes, large hail, and damaging winds remain possible. ...Discussion... Little change appears necessary to the ongoing outlook at this time, with the largest adjustment being to decrease the size of the MRGL and SLGT risk areas on the southern and western fringes. Otherwise, widespread cloud cover persists across a large portion of the SLGT risk area, which continues to temper destabilization, and fairly substantial capping is also evident from area 18z special RAOBs. These factors continue to cast uncertainty with respect to the degree of severe risk, and as such, upgrade to ENH risk (as was mentioned in prior outlooks) appears unwarranted at this time. Otherwise, the outlook appears to remain on track, with no other appreciable changes necessary at this time. ..Goss.. 09/03/2019 .PREV DISCUSSION... /ISSUED 1139 AM CDT Tue Sep 03 2019/ ...Midwest/Great Lakes... An upgrade to Enhanced Risk could still be warranted for portions of the region later today pending convective/observational trends. However, as mentioned in the prior (13Z) Outlook discussion, short-term guidance continues to generally sub-optimally depict and/or remains slow to adjust to the influence of ongoing convection, which casts some uncertainty regarding the convective scenario later today. This is principally with respect to the thermodynamic environment and related likelihood and north-northeastward extent of appreciable moistening and destabilization later today, coincident with a notable deep-layer wind field. Morning observations including 12Z sounding and WSR-88D VWP data sample deep-layer winds that are very strong by late-summer standards, particularly at a latitude around southern Lake Michigan and northward including Wisconsin/Michigan. Beneath a respectable elevated mixed layer, seasonably rich low-level moisture (with around 70F surface dewpoints) is prevalent at late morning across eastern Iowa, southern Wisconsin, western Illinois near and ahead of an eastward-advancing cold front. This moisture will steadily advect eastward today, with the morning convection/residual cloud cover potentially effectively reinforcing/delaying an eastward-shifting warm front toward and across Lower Michigan and northern Indiana. Boundary-layer heating will probably be of more limited duration with north/northeast extent across Lower Michigan, but will be greater with southwest extent into Illinois. A strongly unstable air mass should develop initially near Lake Michigan southwestward across Illinois, with greater uncertainty in the degree of buoyancy farther north across Lower Michigan. At least isolated, mid-to-late afternoon deep convective redevelopment will probably occur with the approach of a cold front from western Lower Michigan into northern Illinois, with deep-layer winds well-supportive (40-50 kt effective) of initial supercells. Hail/damaging wind potential aside, low-level shear/SRH will be maximized near the effective warm front and within the increasingly narrow warm sector with northward extent across Lower Michigan. Although short-term forecast uncertainty lingers as previously discussed, on presumed/probable air mass recovery a respectable potential does exist for a couple of tornadoes, including some possibility of a strong tornado, aside from an increasing risk for damaging winds this evening. Severe risks currently appear most probable to occur across northern Indiana and southern Lower Michigan, and possibly into northern/western Ohio late tonight. The severe threat should wane overnight as the primary shortwave trough becomes increasingly separated from the lingering buoyancy plume over the Midwest. ...East-central/northeast Florida Coast... Hurricane Dorian is forecast to move northward and remain offshore; reference NHC for the latest details. This will maintain most of the Florida Atlantic Coast in the tornado-unfavorable western periphery of Dorian. Nevertheless, some enlargement to the low-level hodograph combined with weak instability might support a couple of rotating cells capable of a brief tornado through tonight. ...Deep South Texas... Reference NHC for the latest details regarding Tropical Depression Seven, which may gradually strengthen/organize over the far western Gulf of Mexico. A modest low-level strengthening of easterly winds on its northern periphery could influence low-topped supercell potential and possibly some tornado risk into Wednesday. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Tue Sep 03 2019 Valid 032000Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER GREAT LAKES/MIDWEST... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of the Great Lakes and Midwest. A few tornadoes, large hail, and damaging winds remain possible. ...Discussion... Little change appears necessary to the ongoing outlook at this time, with the largest adjustment being to decrease the size of the MRGL and SLGT risk areas on the southern and western fringes. Otherwise, widespread cloud cover persists across a large portion of the SLGT risk area, which continues to temper destabilization, and fairly substantial capping is also evident from area 18z special RAOBs. These factors continue to cast uncertainty with respect to the degree of severe risk, and as such, upgrade to ENH risk (as was mentioned in prior outlooks) appears unwarranted at this time. Otherwise, the outlook appears to remain on track, with no other appreciable changes necessary at this time. ..Goss.. 09/03/2019 .PREV DISCUSSION... /ISSUED 1139 AM CDT Tue Sep 03 2019/ ...Midwest/Great Lakes... An upgrade to Enhanced Risk could still be warranted for portions of the region later today pending convective/observational trends. However, as mentioned in the prior (13Z) Outlook discussion, short-term guidance continues to generally sub-optimally depict and/or remains slow to adjust to the influence of ongoing convection, which casts some uncertainty regarding the convective scenario later today. This is principally with respect to the thermodynamic environment and related likelihood and north-northeastward extent of appreciable moistening and destabilization later today, coincident with a notable deep-layer wind field. Morning observations including 12Z sounding and WSR-88D VWP data sample deep-layer winds that are very strong by late-summer standards, particularly at a latitude around southern Lake Michigan and northward including Wisconsin/Michigan. Beneath a respectable elevated mixed layer, seasonably rich low-level moisture (with around 70F surface dewpoints) is prevalent at late morning across eastern Iowa, southern Wisconsin, western Illinois near and ahead of an eastward-advancing cold front. This moisture will steadily advect eastward today, with the morning convection/residual cloud cover potentially effectively reinforcing/delaying an eastward-shifting warm front toward and across Lower Michigan and northern Indiana. Boundary-layer heating will probably be of more limited duration with north/northeast extent across Lower Michigan, but will be greater with southwest extent into Illinois. A strongly unstable air mass should develop initially near Lake Michigan southwestward across Illinois, with greater uncertainty in the degree of buoyancy farther north across Lower Michigan. At least isolated, mid-to-late afternoon deep convective redevelopment will probably occur with the approach of a cold front from western Lower Michigan into northern Illinois, with deep-layer winds well-supportive (40-50 kt effective) of initial supercells. Hail/damaging wind potential aside, low-level shear/SRH will be maximized near the effective warm front and within the increasingly narrow warm sector with northward extent across Lower Michigan. Although short-term forecast uncertainty lingers as previously discussed, on presumed/probable air mass recovery a respectable potential does exist for a couple of tornadoes, including some possibility of a strong tornado, aside from an increasing risk for damaging winds this evening. Severe risks currently appear most probable to occur across northern Indiana and southern Lower Michigan, and possibly into northern/western Ohio late tonight. The severe threat should wane overnight as the primary shortwave trough becomes increasingly separated from the lingering buoyancy plume over the Midwest. ...East-central/northeast Florida Coast... Hurricane Dorian is forecast to move northward and remain offshore; reference NHC for the latest details. This will maintain most of the Florida Atlantic Coast in the tornado-unfavorable western periphery of Dorian. Nevertheless, some enlargement to the low-level hodograph combined with weak instability might support a couple of rotating cells capable of a brief tornado through tonight. ...Deep South Texas... Reference NHC for the latest details regarding Tropical Depression Seven, which may gradually strengthen/organize over the far western Gulf of Mexico. A modest low-level strengthening of easterly winds on its northern periphery could influence low-topped supercell potential and possibly some tornado risk into Wednesday. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Tue Sep 03 2019 Valid 032000Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER GREAT LAKES/MIDWEST... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon and evening across parts of the Great Lakes and Midwest. A few tornadoes, large hail, and damaging winds remain possible. ...Discussion... Little change appears necessary to the ongoing outlook at this time, with the largest adjustment being to decrease the size of the MRGL and SLGT risk areas on the southern and western fringes. Otherwise, widespread cloud cover persists across a large portion of the SLGT risk area, which continues to temper destabilization, and fairly substantial capping is also evident from area 18z special RAOBs. These factors continue to cast uncertainty with respect to the degree of severe risk, and as such, upgrade to ENH risk (as was mentioned in prior outlooks) appears unwarranted at this time. Otherwise, the outlook appears to remain on track, with no other appreciable changes necessary at this time. ..Goss.. 09/03/2019 .PREV DISCUSSION... /ISSUED 1139 AM CDT Tue Sep 03 2019/ ...Midwest/Great Lakes... An upgrade to Enhanced Risk could still be warranted for portions of the region later today pending convective/observational trends. However, as mentioned in the prior (13Z) Outlook discussion, short-term guidance continues to generally sub-optimally depict and/or remains slow to adjust to the influence of ongoing convection, which casts some uncertainty regarding the convective scenario later today. This is principally with respect to the thermodynamic environment and related likelihood and north-northeastward extent of appreciable moistening and destabilization later today, coincident with a notable deep-layer wind field. Morning observations including 12Z sounding and WSR-88D VWP data sample deep-layer winds that are very strong by late-summer standards, particularly at a latitude around southern Lake Michigan and northward including Wisconsin/Michigan. Beneath a respectable elevated mixed layer, seasonably rich low-level moisture (with around 70F surface dewpoints) is prevalent at late morning across eastern Iowa, southern Wisconsin, western Illinois near and ahead of an eastward-advancing cold front. This moisture will steadily advect eastward today, with the morning convection/residual cloud cover potentially effectively reinforcing/delaying an eastward-shifting warm front toward and across Lower Michigan and northern Indiana. Boundary-layer heating will probably be of more limited duration with north/northeast extent across Lower Michigan, but will be greater with southwest extent into Illinois. A strongly unstable air mass should develop initially near Lake Michigan southwestward across Illinois, with greater uncertainty in the degree of buoyancy farther north across Lower Michigan. At least isolated, mid-to-late afternoon deep convective redevelopment will probably occur with the approach of a cold front from western Lower Michigan into northern Illinois, with deep-layer winds well-supportive (40-50 kt effective) of initial supercells. Hail/damaging wind potential aside, low-level shear/SRH will be maximized near the effective warm front and within the increasingly narrow warm sector with northward extent across Lower Michigan. Although short-term forecast uncertainty lingers as previously discussed, on presumed/probable air mass recovery a respectable potential does exist for a couple of tornadoes, including some possibility of a strong tornado, aside from an increasing risk for damaging winds this evening. Severe risks currently appear most probable to occur across northern Indiana and southern Lower Michigan, and possibly into northern/western Ohio late tonight. The severe threat should wane overnight as the primary shortwave trough becomes increasingly separated from the lingering buoyancy plume over the Midwest. ...East-central/northeast Florida Coast... Hurricane Dorian is forecast to move northward and remain offshore; reference NHC for the latest details. This will maintain most of the Florida Atlantic Coast in the tornado-unfavorable western periphery of Dorian. Nevertheless, some enlargement to the low-level hodograph combined with weak instability might support a couple of rotating cells capable of a brief tornado through tonight. ...Deep South Texas... Reference NHC for the latest details regarding Tropical Depression Seven, which may gradually strengthen/organize over the far western Gulf of Mexico. A modest low-level strengthening of easterly winds on its northern periphery could influence low-topped supercell potential and possibly some tornado risk into Wednesday. Read more

MD 1920 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN/SOUTHERN WI
Mesoscale Discussion 1920 NWS Storm Prediction Center Norman OK 0157 PM CDT Tue Sep 03 2019 Areas affected...Eastern/Southern WI Concerning...Severe potential...Watch unlikely Valid 031857Z - 032100Z Probability of Watch Issuance...20 percent SUMMARY...Storm coverage is expected to increase over the next few hours along the front moving through eastern WI. A few severe storms are possible. DISCUSSION...Recent visible satellite imagery has shown increasingly deep cumulus towers along the cold front moving eastward across eastern WI. Cloudiness has limited diurnal heating and destabilization further south (across far southern WI and northern IL) but portions of eastern WI have reached the upper 70s/low 80s. Ample low-level moisture also exists, with dewpoints ranging from the low 70s across southern WI to the upper 60s just south of Green Bay. Steep mid-level lapse rates have also pushed into the region. All of this factors result in moderately buoyant thermodynamic environment. However, residual capping inversion may hinder overall updraft strength and contribute to a somewhat disorganized storm mode initially (i.e. during the next hour or so). Lift from the approaching shortwave trough should help cool these mid-level temperatures and allow for stronger, more persistent updrafts. Enhanced mid-level flow attendant to an approaching shortwave trough is contributing to strong vertical shear, with mesoanalysis estimated effective bulk shear from 50 to 60 kt. Once more persistent updrafts become established, a few more organized storms are possible. Primary severe threat is strong wind gusts. Uncertainty regarding storm coverage limits higher watch probability but trends will be monitored closely. ..Mosier/Guyer.. 09/03/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...MKX...ARX... LAT...LON 43098797 42678866 42699040 43788955 44698852 44948770 44788730 44178759 43898765 43098797 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEAST...THE SOUTHEASTERN U.S. COAST...AND DEEP SOUTH TEXAS... ...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. A brief tornado or two will also be possible over deep south Texas, as Tropical Depression 7 strengthens and moves gradually onshore over northeastern Mexico. Otherwise, isolated damaging gusts are possible Wednesday afternoon from the Middle Atlantic through New England. ...Synopsis... The upper pattern across the U.S. will be characterized by a large ridge, affecting much of the Rockies and into the Plains states. A weak upper low/trough is forecast to remain just off the West Coast, while a stronger short-wave trough progresses eastward across the Northeast. Meanwhile, Hurricane Dorian is forecast to advance slowly northward just off the Southeast U.S. Coast, while Tropical Depression #7 moves westward across the western Gulf of Mexico. At the surface, a cold front, accompanying the Northeast U.S. upper system, will advance across the Northeast through the period, while high pressure prevails across the central U.S. and into the Rockies. ...New England southwestward to the northern Chesapeake Bay vicinity... A cold front is forecast to advance across the Northeast Wednesday, ahead of a parent mid-level short-wave trough. While mid- to high-level cloud cover from remnant/prior storms is expected to hinder insolation/subsequent destabilization across parts of the area, enough instability should evolve during the afternoon to permit scattered to isolated storm development ahead of the advancing front. With a relatively strong, southwesterly/westerly flow field aloft expected atop the region, potential for fast-moving cells, and possibly a few semi-organized bands of storms, is apparent. While the overall severe risk still appears likely to be limited by modest destabilization potential during the afternoon, an upgrade to slight risk could be required in later forecasts if potential for slightly greater afternoon destabilization becomes apparent. ...Southeast U.S. Coast... Latest forecasts from the National Hurricane Center depict that Hurricane Dorian -- which should lie off the Florida Coast Wednesday morning -- will move northward/northwestward along the southeastern Atlantic Coast, to a position east of the southern South Carolina Coast late. With east to northeast low-level flow near the coast, north of the storm's center, veering slightly with height, a shear profile supportive of low-level rotation is expected. Therefore, the risk for a tornado or two will expand gradually northward in conjunction with Dorian's progression, reaching roughly the vicinity of the North Carolina/South Carolina border by sunrise Thursday. ...Deep south Texas... As Tropical Depression #7, now over the western Gulf of Mexico, moves westward with time, slow strengthening -- possibly to Tropical Storm intensity -- is forecast (please see the latest forecasts from the National Hurricane Center). With a corresponding increase in the wind field surrounding the low, low-level shear may be sufficient to support limited risk for a brief tornado spin-up or two -- which may linger through much of the period as the storm moves inland over northeast Mexico during latter stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/03/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEAST...THE SOUTHEASTERN U.S. COAST...AND DEEP SOUTH TEXAS... ...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. A brief tornado or two will also be possible over deep south Texas, as Tropical Depression 7 strengthens and moves gradually onshore over northeastern Mexico. Otherwise, isolated damaging gusts are possible Wednesday afternoon from the Middle Atlantic through New England. ...Synopsis... The upper pattern across the U.S. will be characterized by a large ridge, affecting much of the Rockies and into the Plains states. A weak upper low/trough is forecast to remain just off the West Coast, while a stronger short-wave trough progresses eastward across the Northeast. Meanwhile, Hurricane Dorian is forecast to advance slowly northward just off the Southeast U.S. Coast, while Tropical Depression #7 moves westward across the western Gulf of Mexico. At the surface, a cold front, accompanying the Northeast U.S. upper system, will advance across the Northeast through the period, while high pressure prevails across the central U.S. and into the Rockies. ...New England southwestward to the northern Chesapeake Bay vicinity... A cold front is forecast to advance across the Northeast Wednesday, ahead of a parent mid-level short-wave trough. While mid- to high-level cloud cover from remnant/prior storms is expected to hinder insolation/subsequent destabilization across parts of the area, enough instability should evolve during the afternoon to permit scattered to isolated storm development ahead of the advancing front. With a relatively strong, southwesterly/westerly flow field aloft expected atop the region, potential for fast-moving cells, and possibly a few semi-organized bands of storms, is apparent. While the overall severe risk still appears likely to be limited by modest destabilization potential during the afternoon, an upgrade to slight risk could be required in later forecasts if potential for slightly greater afternoon destabilization becomes apparent. ...Southeast U.S. Coast... Latest forecasts from the National Hurricane Center depict that Hurricane Dorian -- which should lie off the Florida Coast Wednesday morning -- will move northward/northwestward along the southeastern Atlantic Coast, to a position east of the southern South Carolina Coast late. With east to northeast low-level flow near the coast, north of the storm's center, veering slightly with height, a shear profile supportive of low-level rotation is expected. Therefore, the risk for a tornado or two will expand gradually northward in conjunction with Dorian's progression, reaching roughly the vicinity of the North Carolina/South Carolina border by sunrise Thursday. ...Deep south Texas... As Tropical Depression #7, now over the western Gulf of Mexico, moves westward with time, slow strengthening -- possibly to Tropical Storm intensity -- is forecast (please see the latest forecasts from the National Hurricane Center). With a corresponding increase in the wind field surrounding the low, low-level shear may be sufficient to support limited risk for a brief tornado spin-up or two -- which may linger through much of the period as the storm moves inland over northeast Mexico during latter stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/03/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Tue Sep 03 2019 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHEAST...THE SOUTHEASTERN U.S. COAST...AND DEEP SOUTH TEXAS... ...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. A brief tornado or two will also be possible over deep south Texas, as Tropical Depression 7 strengthens and moves gradually onshore over northeastern Mexico. Otherwise, isolated damaging gusts are possible Wednesday afternoon from the Middle Atlantic through New England. ...Synopsis... The upper pattern across the U.S. will be characterized by a large ridge, affecting much of the Rockies and into the Plains states. A weak upper low/trough is forecast to remain just off the West Coast, while a stronger short-wave trough progresses eastward across the Northeast. Meanwhile, Hurricane Dorian is forecast to advance slowly northward just off the Southeast U.S. Coast, while Tropical Depression #7 moves westward across the western Gulf of Mexico. At the surface, a cold front, accompanying the Northeast U.S. upper system, will advance across the Northeast through the period, while high pressure prevails across the central U.S. and into the Rockies. ...New England southwestward to the northern Chesapeake Bay vicinity... A cold front is forecast to advance across the Northeast Wednesday, ahead of a parent mid-level short-wave trough. While mid- to high-level cloud cover from remnant/prior storms is expected to hinder insolation/subsequent destabilization across parts of the area, enough instability should evolve during the afternoon to permit scattered to isolated storm development ahead of the advancing front. With a relatively strong, southwesterly/westerly flow field aloft expected atop the region, potential for fast-moving cells, and possibly a few semi-organized bands of storms, is apparent. While the overall severe risk still appears likely to be limited by modest destabilization potential during the afternoon, an upgrade to slight risk could be required in later forecasts if potential for slightly greater afternoon destabilization becomes apparent. ...Southeast U.S. Coast... Latest forecasts from the National Hurricane Center depict that Hurricane Dorian -- which should lie off the Florida Coast Wednesday morning -- will move northward/northwestward along the southeastern Atlantic Coast, to a position east of the southern South Carolina Coast late. With east to northeast low-level flow near the coast, north of the storm's center, veering slightly with height, a shear profile supportive of low-level rotation is expected. Therefore, the risk for a tornado or two will expand gradually northward in conjunction with Dorian's progression, reaching roughly the vicinity of the North Carolina/South Carolina border by sunrise Thursday. ...Deep south Texas... As Tropical Depression #7, now over the western Gulf of Mexico, moves westward with time, slow strengthening -- possibly to Tropical Storm intensity -- is forecast (please see the latest forecasts from the National Hurricane Center). With a corresponding increase in the wind field surrounding the low, low-level shear may be sufficient to support limited risk for a brief tornado spin-up or two -- which may linger through much of the period as the storm moves inland over northeast Mexico during latter stages of the period. ...MAXIMUM RISK BY HAZARD... Tornado: 2% - Marginal Wind: 5% - Marginal Hail: 5% - Marginal ..Goss.. 09/03/2019 Read more