Severe Storms

WW 588 TORNADO AL LA MS CW 141825Z - 150200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 588 NWS Storm Prediction Center Norman OK 1225 PM CST Wed Dec 14 2022 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southwest Alabama Southeast Louisiana Southern and Central Mississippi Coastal Waters * Effective this Wednesday afternoon and evening from 1225 PM until 800 PM CST. ...THIS IS A PARTICULARLY DANGEROUS SITUATION... * Primary threats include... Numerous tornadoes expected with a few intense tornadoes likely Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Numerous supercell thunderstorms have formed and will affect portions of the watch area through the afternoon and early evening. Strong winds aloft and ample instability will pose a risk of several tornadoes, including a few strong tornadoes. The tornado watch area is approximately along and 80 statute miles east and west of a line from 30 miles south southeast of Houma LA to 25 miles northeast of Meridian MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 587... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 23035. ...Hart Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CST Wed Dec 14 2022 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FLORIDA...COASTAL/SOUTHERN GEORGIA...AND COASTAL SOUTH CAROLINA... ...SUMMARY... Severe thunderstorms will be possible over portions of southern Georgia into northern Florida Thursday morning, and through the afternoon across parts of the Florida Peninsula. A few tornadoes and scattered damaging winds should be the main threats. ...Florida into Southern Georgia and the Carolinas... A large-scale upper cyclone encompassing much of the central and eastern CONUS will remain centered over the Upper Midwest and Great Lakes on Thursday. A lead mid-level perturbation is forecast to quickly shift eastward over the East Coast states/Mid-Atlantic through the day. While the primary surface low will remain over the Upper Midwest, a secondary low over GA/SC Thursday morning should develop quickly northeastward across the Carolinas and coastal southeastern VA by Thursday evening. A related cold front will sweep eastward across FL, GA, and the Carolinas through the day. A broken line of thunderstorms will likely be ongoing at the start of the period across parts of north FL into GA along or just ahead of the cold front. Mid to upper 60s surface dewpoints should be in place ahead of this activity, and modest daytime heating should support weak instability across the FL Peninsula into coastal GA and SC. Even though the enhanced low-level flow will gradually veer and weaken through the day, it should still be sufficiently strong to support updraft rotation and a threat for a few tornadoes as convection spreads eastward through the early afternoon. Scattered damaging winds may also occur before thunderstorms eventually weaken Thursday evening. Farther north, a warm front is forecast to lift northward across central/eastern NC through the day, but meager daytime heating and related instability should keep the overall severe threat rather isolated across this area. Better prospects for surface-based convection will probably remain just offshore the Outer Banks of NC. ..Gleason.. 12/14/2022 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1033 AM CST WED DEC 14 2022 ...Severe thunderstorms expected over parts of the Gulf Coast States this afternoon and tonight... * LOCATIONS... Southern Mississippi Southern Alabama Southeast Louisiana * HAZARDS... Several tornadoes, a few intense Isolated damaging winds * SUMMARY... Tornadoes (some strong) and damaging thunderstorm gusts are expected today and tonight across southern parts of Louisiana, Mississippi and Alabama, and portions of the Florida Panhandle. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. && ..Hart.. 12/14/2022 $$ Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1028 AM CST Wed Dec 14 2022 Valid 151200Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/14/2022 .PREV DISCUSSION... /ISSUED 0152 AM CST Wed Dec 14 2022/ ...Synopsis... A broad upper-level cyclone will slowly shift eastward out of the central U.S. and into the upper Midwest while slowly filling. High pressure will gradually intensify as it moves south out of Canada over the northern Plains. At the surface, weak northwesterly winds will keep temperatures cool and RH values modest. With recent precipitation and cooler temperatures, area fuels will be unfavorable for large-fire spread. Fire-weather concerns are low. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1025 AM CST Wed Dec 14 2022 Valid 141630Z - 151200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF SOUTHEAST LOUISIANA...SOUTHERN MISSISSIPPI...AND WESTERN/SOUTHERN ALABAMA... ...SUMMARY... Tornadoes (some strong) and damaging thunderstorm gusts are expected today and tonight across southern parts of Louisiana, Mississippi and Alabama, and portions of the Florida Panhandle. ...Active severe weather event is anticipated this afternoon and evening for portions of the central Gulf Coast states... ...LA/MS/AL... Morning water vapor imagery shows an intense and progressive shortwave trough rotating across OK/TX. This feature is expected to become negatively tilted this evening over AR, with strong large-scale forcing overspreading much of the mid/lower MS Valley. Strong southerly low-level winds have established a very moist and potentially unstable air mass over parts of LA/MS/AL, with dewpoints in the 70s and visible satellite showing considerable breaks in the low clouds. This should result in ample CAPE by mid-afternoon. A consensus of 12z CAM guidance indicates that discrete supercell development will commence this afternoon over southeast LA into southern MS. This activity will likely persist through the evening and track into western and southern AL. Forecast soundings show very strong low-level vertical shear and favorable deep-layer shear for tornadoes, along with sufficient CAPE for robust thunderstorms. Low-level winds are expected to strengthen further during the afternoon with the approach of the upper trough. Tornadoes, including the possibility of strong and long-track tornadoes, are the primary concern today. Given the consistent signal in 12z guidance for numerous supercells, the favorable CAPE/shear environment, and the impressive nature of the shortwave trough, have opted to upgrade to MDT risk for portions of the area. ..Hart/Bentley.. 12/14/2022 Read more

WW 0587 Status Updates
STATUS REPORT ON WW 587 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2030 ..BENTLEY..12/14/22 ATTN...WFO...MOB...LCH...LIX...JAN... STATUS REPORT FOR WT 587 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC023-129-141740- AL . ALABAMA COUNTIES INCLUDED ARE CHOCTAW WASHINGTON LAC001-005-007-023-033-037-039-045-047-053-055-063-077-091-093- 095-097-099-101-103-105-113-117-121-125-141740- LA . LOUISIANA PARISHES INCLUDED ARE ACADIA ASCENSION ASSUMPTION CAMERON EAST BATON ROUGE EAST FELICIANA EVANGELINE IBERIA IBERVILLE JEFFERSON DAVIS LAFAYETTE LIVINGSTON POINTE COUPEE ST. HELENA ST. JAMES ST. JOHN THE BAPTIST ST. LANDRY ST. MARTIN ST. MARY ST. TAMMANY TANGIPAHOA VERMILION WASHINGTON WEST BATON ROUGE WEST FELICIANA Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0955 AM CST Wed Dec 14 2022 Valid 141700Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/14/2022 .PREV DISCUSSION... /ISSUED 0150 AM CST Wed Dec 14 2022/ ...Synopsis... As a deep upper-level cyclone slowly fills over the northern Plains, cool temperatures and higher humidity are expected across much of the southern and central High Plains. Lingering gusty northwest flow may occasionally reach 15-20 mph through the afternoon in the wake of a cold front moving east across the MS Valley. However, cooler temperatures and increasing moisture will limit diurnal RH minimums. In addition, recent precipitation has tempered area fuels such that large-fire spread is unlikely. Thus, fire-weather concerns are not expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2015 CONCERNING TORNADO WATCH 582... FOR EAST/SOUTHEAST TX...NORTHWEST LA...SOUTHERN AR
Mesoscale Discussion 2015 NWS Storm Prediction Center Norman OK 0133 PM CST Tue Dec 13 2022 Areas affected...East/Southeast TX...Northwest LA...Southern AR Concerning...Tornado Watch 582... Valid 131933Z - 132130Z The severe weather threat for Tornado Watch 582 continues. SUMMARY...Threat for supercells capable of all severe hazards continues across Tornado Watch 582. A downstream Tornado Watch will likely be needed across southern AR, northwest LA, and east/southeast TX. DISCUSSION...Recent surface analysis places a triple point low about 20 miles east of PRX, with a cold front extending southwestward from this low through central TX. A warm front also extends southeastward from this low through northwest and central LA (delineated well by the 65 deg F isodrosotherm). Thunderstorm activity along the cold front has weakened over the last hour or so, while showers have increased throughout the warm sector. Most of these warm sector showers have not strengthened significantly. However, very recent trends have signaled some strengthening with the storms in Anderson, Houston, and Robertson Counties, evidenced by increasing reflectivity and lightning activity. Given their placement in the warm sector, some additional strengthen/maturing into supercells is possible. The warm front is expected to continue slowly lifting northward while the cold front advances eastward. This will take the warm sector farther east into more of east/southeast TX, northwest LA, and southern AR through this evening. As such an additional Tornado Watch will be needed for portions of the region within the next hour or so. Given the favorable parameter space, PDS wording is being considered. ..Mosier/Hart.. 12/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...LCH...SHV...HGX...FWD... LAT...LON 30739640 31859603 33499430 33859288 33259214 30999352 30249529 30739640 Read more

MD 2015 CONCERNING TORNADO WATCH 582... FOR EAST/SOUTHEAST TX...NORTHWEST LA...SOUTHERN AR
Mesoscale Discussion 2015 NWS Storm Prediction Center Norman OK 0133 PM CST Tue Dec 13 2022 Areas affected...East/Southeast TX...Northwest LA...Southern AR Concerning...Tornado Watch 582... Valid 131933Z - 132130Z The severe weather threat for Tornado Watch 582 continues. SUMMARY...Threat for supercells capable of all severe hazards continues across Tornado Watch 582. A downstream Tornado Watch will likely be needed across southern AR, northwest LA, and east/southeast TX. DISCUSSION...Recent surface analysis places a triple point low about 20 miles east of PRX, with a cold front extending southwestward from this low through central TX. A warm front also extends southeastward from this low through northwest and central LA (delineated well by the 65 deg F isodrosotherm). Thunderstorm activity along the cold front has weakened over the last hour or so, while showers have increased throughout the warm sector. Most of these warm sector showers have not strengthened significantly. However, very recent trends have signaled some strengthening with the storms in Anderson, Houston, and Robertson Counties, evidenced by increasing reflectivity and lightning activity. Given their placement in the warm sector, some additional strengthen/maturing into supercells is possible. The warm front is expected to continue slowly lifting northward while the cold front advances eastward. This will take the warm sector farther east into more of east/southeast TX, northwest LA, and southern AR through this evening. As such an additional Tornado Watch will be needed for portions of the region within the next hour or so. Given the favorable parameter space, PDS wording is being considered. ..Mosier/Hart.. 12/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...LCH...SHV...HGX...FWD... LAT...LON 30739640 31859603 33499430 33859288 33259214 30999352 30249529 30739640 Read more

WW 0582 Status Updates
STATUS REPORT ON WW 582 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 W TPL TO 30 W CRS TO 15 N CRS TO 30 WNW TYR TO 25 NNE DEQ. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2014 ..MOSIER..12/13/22 ATTN...WFO...SHV...LZK...TSA...FWD...HGX... STATUS REPORT FOR WT 582 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC057-061-081-091-109-113-133-131940- AR . ARKANSAS COUNTIES INCLUDED ARE HEMPSTEAD HOWARD LITTLE RIVER MILLER PIKE POLK SEVIER TXC001-037-063-067-073-145-159-161-183-203-213-225-289-293-309- 313-315-343-349-365-395-401-423-449-455-459-499-131940- TX . TEXAS COUNTIES INCLUDED ARE ANDERSON BOWIE CAMP CASS CHEROKEE FALLS FRANKLIN FREESTONE GREGG HARRISON HENDERSON HOUSTON LEON LIMESTONE MCLENNAN MADISON MARION MORRIS NAVARRO PANOLA ROBERTSON Read more

WW 0582 Status Updates
STATUS REPORT ON WW 582 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 W TPL TO 30 W CRS TO 15 N CRS TO 30 WNW TYR TO 25 NNE DEQ. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2014 ..MOSIER..12/13/22 ATTN...WFO...SHV...LZK...TSA...FWD...HGX... STATUS REPORT FOR WT 582 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC057-061-081-091-109-113-133-131940- AR . ARKANSAS COUNTIES INCLUDED ARE HEMPSTEAD HOWARD LITTLE RIVER MILLER PIKE POLK SEVIER TXC001-037-063-067-073-145-159-161-183-203-213-225-289-293-309- 313-315-343-349-365-395-401-423-449-455-459-499-131940- TX . TEXAS COUNTIES INCLUDED ARE ANDERSON BOWIE CAMP CASS CHEROKEE FALLS FRANKLIN FREESTONE GREGG HARRISON HENDERSON HOUSTON LEON LIMESTONE MCLENNAN MADISON MARION MORRIS NAVARRO PANOLA ROBERTSON Read more

WW 0582 Status Updates
STATUS REPORT ON WW 582 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 W TPL TO 30 W CRS TO 15 N CRS TO 30 WNW TYR TO 25 NNE DEQ. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2014 ..MOSIER..12/13/22 ATTN...WFO...SHV...LZK...TSA...FWD...HGX... STATUS REPORT FOR WT 582 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC057-061-081-091-109-113-133-131940- AR . ARKANSAS COUNTIES INCLUDED ARE HEMPSTEAD HOWARD LITTLE RIVER MILLER PIKE POLK SEVIER TXC001-037-063-067-073-145-159-161-183-203-213-225-289-293-309- 313-315-343-349-365-395-401-423-449-455-459-499-131940- TX . TEXAS COUNTIES INCLUDED ARE ANDERSON BOWIE CAMP CASS CHEROKEE FALLS FRANKLIN FREESTONE GREGG HARRISON HENDERSON HOUSTON LEON LIMESTONE MCLENNAN MADISON MARION MORRIS NAVARRO PANOLA ROBERTSON Read more

WW 582 TORNADO AR OK TX 131510Z - 132300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 582 NWS Storm Prediction Center Norman OK 910 AM CST Tue Dec 13 2022 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southwest Arkansas Southeast Oklahoma East Texas * Effective this Tuesday morning and afternoon from 910 AM until 500 PM CST. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms over north central Texas and southern Oklahoma will track eastward today, posing a risk of a few tornadoes, damaging winds, and hail. The tornado watch area is approximately along and 70 statute miles east and west of a line from 45 miles southeast of Waco TX to 20 miles north northeast of De Queen AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 581... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Hart Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1229 PM CST Tue Dec 13 2022 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2022 .PREV DISCUSSION... /ISSUED 0153 AM CST Tue Dec 13 2022/ ...Synopsis... Across the CONUS, the deep upper-level low over the Plains is forecast to slowly fill starting Wednesday. At the surface, dry and cool northwesterly flow is excepted over much of the southern High Plains and west TX. Snowfall and much colder temperatures associated with building high pressure will keep winds relatively light, temperatures cool and humidity high over fuels of limited receptiveness to large-fire spread. Thus, fire-weather concerns are minimal over much of the CONUS. ...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 1229 PM CST Tue Dec 13 2022 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 12/13/2022 .PREV DISCUSSION... /ISSUED 0153 AM CST Tue Dec 13 2022/ ...Synopsis... Across the CONUS, the deep upper-level low over the Plains is forecast to slowly fill starting Wednesday. At the surface, dry and cool northwesterly flow is excepted over much of the southern High Plains and west TX. Snowfall and much colder temperatures associated with building high pressure will keep winds relatively light, temperatures cool and humidity high over fuels of limited receptiveness to large-fire spread. Thus, fire-weather concerns are minimal over much of the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2014 CONCERNING TORNADO WATCH 582... FOR SOUTHWEST OK...SOUTHWEST AR...NORTHEAST/CENTRAL TX
Mesoscale Discussion 2014 NWS Storm Prediction Center Norman OK 1141 AM CST Tue Dec 13 2022 Areas affected...Southwest OK...Southwest AR...Northeast/Central TX Concerning...Tornado Watch 582... Valid 131741Z - 131945Z The severe weather threat for Tornado Watch 582 continues. SUMMARY...The threat for all severe hazards, including tornadoes, continues from far southeast OK/southwest AR across northeast TX into central TX. DISCUSSION...Recent surface analysis places a triple point low about 25 miles west of PRX, in the vicinity of the ongoing tornado-producing storm near Lamar County TX and Choctaw and McCurtain Counties in OK. Mesoscale enhancement of lift and shear is likely contributing to the persistence of this storm as it continues through a less favorable thermodynamic environment. A cold front extends southwestward from this low back through central TX. A few stronger storms have recently developed in the vicinity of this front over McLennan and Hill Counties. Undercutting character of the front suggests that hail is likely the predominant severe threat with these storms. Showers have also begun to deepen farther east in Freestone County and vicinity, with some lightning recently observed. These storms appear to be well placed within the warm sector for further intensification, although storm interactions could mitigate this process somewhat. Vertical shear remains strong and any storms that can persist and mature within this environment could become supercells capable of all severe hazards, including tornadoes. ..Mosier.. 12/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SHV...TSA...HGX...FWD... LAT...LON 31299759 33339574 34149512 33549375 31839431 30879617 31299759 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CST Tue Dec 13 2022 Valid 141200Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN LOUISIANA...SOUTHERN/CENTRAL MISSISSIPPI...SOUTHERN ALABAMA...AND THE WESTERN FLORIDA PANHANDLE... ...SUMMARY... Tornadoes and damaging winds are expected Wednesday over parts of southern Louisiana, southern/central Mississippi, southern Alabama and the western Florida Panhandle. A few strong tornadoes may occur. ...Lower Mississippi Valley into the Southeast... A large upper cyclone will encompass much of the central CONUS on Wednesday, with a rather strong mid-level jet expected to overspread much of the lower/mid MS Valley and the Southeast through the period. An embedded mid-level perturbation is forecast to advance across the southern Plains to the lower MS Valley/Mid-South by Wednesday evening. This feature should encourage a weak surface low to develop northeastward from coastal southern LA to western TN/KY in the same time frame. Rich low-level moisture will attempt to return northward through the day across the central Gulf Coast states ahead of a cold front, but persistent surface ridging should hinder the northward advance of the related surface warm front across central AL/GA. A broken line of thunderstorms will likely be ongoing at the start of the period Wednesday morning across parts of southern LA into southern/central MS in association with strong low-level warm advection. A threat for tornadoes and damaging winds should continue with this activity Wednesday morning, as embedded supercells encounter increasing low-level moisture and instability as filtered diurnal heating occurs. The thermodynamic environment across this region should gradually improve through the day, with MLCAPE perhaps reaching as high as 1000-1500 J/kg in a narrow zone ahead of the morning activity. Current expectations are for convection to gradually increase in coverage and intensity Wednesday afternoon from southeastern LA into southern MS. Deep-layer shear will be more than strong enough to support supercells, and a strengthening south-southwesterly low-level jet will aid updraft rotation as effective SRH increases and hodographs become enlarged. The threat for tornadoes will likely increase across this region as well Wednesday afternoon and evening, especially if convection can remain somewhat discrete ahead of the eastward-advancing cold front. A few strong tornadoes appear possible given the strength of the low-level flow, and as near surface winds potentially back to south-southeasterly as the surface low develops across MS. Any outflow boundary from the morning convection may serve to focus this strong tornado potential. Otherwise, scattered damaging winds and isolated large hail will also be a possibility as thunderstorms spread eastward across southern AL and the FL Panhandle Wednesday evening/night. The tornado threat will likely continue eastward across these areas as well, with both strong low-level and deep-layer shear present to organize updrafts. ..Gleason.. 12/13/2022 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CST Tue Dec 13 2022 Valid 141200Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN LOUISIANA...SOUTHERN/CENTRAL MISSISSIPPI...SOUTHERN ALABAMA...AND THE WESTERN FLORIDA PANHANDLE... ...SUMMARY... Tornadoes and damaging winds are expected Wednesday over parts of southern Louisiana, southern/central Mississippi, southern Alabama and the western Florida Panhandle. A few strong tornadoes may occur. ...Lower Mississippi Valley into the Southeast... A large upper cyclone will encompass much of the central CONUS on Wednesday, with a rather strong mid-level jet expected to overspread much of the lower/mid MS Valley and the Southeast through the period. An embedded mid-level perturbation is forecast to advance across the southern Plains to the lower MS Valley/Mid-South by Wednesday evening. This feature should encourage a weak surface low to develop northeastward from coastal southern LA to western TN/KY in the same time frame. Rich low-level moisture will attempt to return northward through the day across the central Gulf Coast states ahead of a cold front, but persistent surface ridging should hinder the northward advance of the related surface warm front across central AL/GA. A broken line of thunderstorms will likely be ongoing at the start of the period Wednesday morning across parts of southern LA into southern/central MS in association with strong low-level warm advection. A threat for tornadoes and damaging winds should continue with this activity Wednesday morning, as embedded supercells encounter increasing low-level moisture and instability as filtered diurnal heating occurs. The thermodynamic environment across this region should gradually improve through the day, with MLCAPE perhaps reaching as high as 1000-1500 J/kg in a narrow zone ahead of the morning activity. Current expectations are for convection to gradually increase in coverage and intensity Wednesday afternoon from southeastern LA into southern MS. Deep-layer shear will be more than strong enough to support supercells, and a strengthening south-southwesterly low-level jet will aid updraft rotation as effective SRH increases and hodographs become enlarged. The threat for tornadoes will likely increase across this region as well Wednesday afternoon and evening, especially if convection can remain somewhat discrete ahead of the eastward-advancing cold front. A few strong tornadoes appear possible given the strength of the low-level flow, and as near surface winds potentially back to south-southeasterly as the surface low develops across MS. Any outflow boundary from the morning convection may serve to focus this strong tornado potential. Otherwise, scattered damaging winds and isolated large hail will also be a possibility as thunderstorms spread eastward across southern AL and the FL Panhandle Wednesday evening/night. The tornado threat will likely continue eastward across these areas as well, with both strong low-level and deep-layer shear present to organize updrafts. ..Gleason.. 12/13/2022 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CST Tue Dec 13 2022 Valid 141200Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN LOUISIANA...SOUTHERN/CENTRAL MISSISSIPPI...SOUTHERN ALABAMA...AND THE WESTERN FLORIDA PANHANDLE... ...SUMMARY... Tornadoes and damaging winds are expected Wednesday over parts of southern Louisiana, southern/central Mississippi, southern Alabama and the western Florida Panhandle. A few strong tornadoes may occur. ...Lower Mississippi Valley into the Southeast... A large upper cyclone will encompass much of the central CONUS on Wednesday, with a rather strong mid-level jet expected to overspread much of the lower/mid MS Valley and the Southeast through the period. An embedded mid-level perturbation is forecast to advance across the southern Plains to the lower MS Valley/Mid-South by Wednesday evening. This feature should encourage a weak surface low to develop northeastward from coastal southern LA to western TN/KY in the same time frame. Rich low-level moisture will attempt to return northward through the day across the central Gulf Coast states ahead of a cold front, but persistent surface ridging should hinder the northward advance of the related surface warm front across central AL/GA. A broken line of thunderstorms will likely be ongoing at the start of the period Wednesday morning across parts of southern LA into southern/central MS in association with strong low-level warm advection. A threat for tornadoes and damaging winds should continue with this activity Wednesday morning, as embedded supercells encounter increasing low-level moisture and instability as filtered diurnal heating occurs. The thermodynamic environment across this region should gradually improve through the day, with MLCAPE perhaps reaching as high as 1000-1500 J/kg in a narrow zone ahead of the morning activity. Current expectations are for convection to gradually increase in coverage and intensity Wednesday afternoon from southeastern LA into southern MS. Deep-layer shear will be more than strong enough to support supercells, and a strengthening south-southwesterly low-level jet will aid updraft rotation as effective SRH increases and hodographs become enlarged. The threat for tornadoes will likely increase across this region as well Wednesday afternoon and evening, especially if convection can remain somewhat discrete ahead of the eastward-advancing cold front. A few strong tornadoes appear possible given the strength of the low-level flow, and as near surface winds potentially back to south-southeasterly as the surface low develops across MS. Any outflow boundary from the morning convection may serve to focus this strong tornado potential. Otherwise, scattered damaging winds and isolated large hail will also be a possibility as thunderstorms spread eastward across southern AL and the FL Panhandle Wednesday evening/night. The tornado threat will likely continue eastward across these areas as well, with both strong low-level and deep-layer shear present to organize updrafts. ..Gleason.. 12/13/2022 Read more

MD 2013 CONCERNING BLIZZARD FOR NORTHEAST COLORADO...SOUTHEAST WYOMING...AND THE NEBRASKA PANHANDLE
Mesoscale Discussion 2013 NWS Storm Prediction Center Norman OK 1114 AM CST Tue Dec 13 2022 Areas affected...northeast Colorado...southeast Wyoming...and the Nebraska Panhandle Concerning...Blizzard Valid 131714Z - 132015Z SUMMARY...A blizzard is ongoing across portions of the central High Plains with sustained winds of 30-35 mph and gusts to 50 mph, heavy snow, and visibility less than 1/4 mile. DISCUSSION...17Z surface analysis shows a ~990mb surface low near the northwest Kansas/southwest Nebraska border with a significant deformation zone to the west with moderate to heavy snowfall. In addition, a tight pressure gradient on the western periphery of this surface low has led to very strong winds of 30 to 40 mph with gusts over 50 mph. These conditions have combined for very low visibility with numerous observation sites at less than 1/4 mile. Expect blizzard conditions to continue to the west/northwest of this surface low as it lifts northeast through the day. This should expand blizzard conditions into western South Dakota and eastern Wyoming later this afternoon. ..Bentley.. 12/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...GLD...PUB...BOU...CYS... LAT...LON 40360489 41770452 42950279 43070197 42060084 40880183 39770150 38800153 38600251 39380419 39960471 40360489 Read more