monsoonman1 Posted January 21, 2017 Share Posted January 21, 2017 15% hatched tornado probabilities now for much of southern AL Link to comment Share on other sites More sharing options...
lj0109 Posted January 21, 2017 Share Posted January 21, 2017 New couplet moving across the Savannah River in to SC - Aiken/Allendale Counties Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 ACUS01 KWNS 211956 SWODY1 SPC AC 211955 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0155 PM CST SAT JAN 21 2017 VALID 212000Z - 221200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON INTO TONIGHT ACROSS PARTS OF THE AR-LA-MISS REGION... ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS PARTS OF SOUTHERN AND CENTRAL ALABAMA AND ADJACENT PORTIONS OF THE FLORIDA PANHANDLE INTO SOUTHWESTERN GEORGIA... ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SURROUNDING AREAS OF THE GULF INTO SOUTH ATLANTIC COAST STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SURROUNDING AREAS OF THE SOUTHEAST... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IMMEDIATELY SURROUNDING THE SLIGHT RISK AREA... ..SUMMARY SEVERE THUNDERSTORMS REMAIN POSSIBLE ACROSS PARTS OF THE SOUTHEAST LATE THIS AFTERNOON, AND ARE EXPECTED TO DEVELOP ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY INTO THE SOUTHEAST THIS EVENING THROUGH THE OVERNIGHT HOURS. THIS INCLUDES A RISK FOR SUPERCELLS CAPABLE OF PRODUCING TORNADOES, PARTICULARLY ACROSS PARTS OF SOUTHERN AND CENTRAL ALABAMA, AND ADJACENT PORTIONS OF THE FLORIDA PANHANDLE, INTO SOUTHWESTERN GEORGIA. ..20Z OUTLOOK UPDATE SEVERE WEATHER POTENTIAL HAS BEEN COMPLICATED CONSIDERABLY BY AT LEAST A COUPLE OF SHORT WAVES IMPULSES, EMERGING FROM A STRONG MID/UPPER JET WHICH CONTINUES TO MIGRATE INLAND ACROSS THE SOUTHERN TIER OF THE U.S., IN ADVANCE OF ONE MUCH MORE SIGNIFICANT PERTURBATION STILL EVOLVING NEAR THE SOUTHERN ROCKIES. THE LEAD IMPULSE IS NOW IN THE PROCESS OF SHIFTING ACROSS/NORTHEAST OF THE SOUTHERN APPALACHIANS. THIS FEATURE HAS PROVIDED SUPPORT FOR A SEVERE MESOSCALE CONVECTIVE SYSTEM WHICH MAINTAINS CONSIDERABLE STRENGTH AS IT SHIFTS ACROSS SOUTHERN GEORGIA AND PORTIONS OF THE LOWER SAVANNAH RIVER VALLEY, COINCIDENT WITH A 40-50 KT SOUTHWESTERLY 850 MB JET. SEVERE PROBABILISTIC LINES HAVE BEEN ADJUSTED SOME TO ACCOUNT FOR THE PROGRESSION OF THIS FEATURE. UPSTREAM, ANOTHER IMPULSE IS ALREADY IN THE PROCESS OF SHIFTING THROUGH THE ARK-LA-TEX REGION, WITH THE MAIN AMPLIFYING UPPER TROUGH NOT LIKELY TO REACH THE LOWER MISSISSIPPI VALLEY UNTIL LATE TONIGHT, THOUGH ANOTHER SMALLER SCALE IMPULSE OR TWO MAY STILL EMERGE FROM IT, AND PROGRESS TOWARD GULF COASTAL AREAS AHEAD OF IT. AT THE SAME TIME, THE BOUNDARY LAYER FROM THE VICINITY OF THE NORTH CENTRAL GULF COAST REGION INTO THE ARK-LA-TEX IS STILL IN THE PROCESS OF RECOVERING, AS A CONVECTIVE OUTFLOW BOUNDARY AND DEVELOPING WARM FRONTAL ZONE BEGIN TO ADVANCE NORTHEASTWARD. BASED ON THE VARIABILITY THAT HAS BEEN EVIDENT IN SHORT TERM MODEL FORECAST GUIDANCE, THE DETAILS OF THE POTENTIAL CONVECTIVE EVOLUTION ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE SOUTHEAST THROUGH THE REMAINDER OF THE PERIOD IS FAR FROM CERTAIN. HOWEVER, BASED ON CURRENT OBSERVATIONS AND MODEL OUTPUT, SEVERE CATEGORICAL AND PROBABILISTIC LINES ACROSS THE LOWER MISSISSIPPI VALLEY HAVE GENERALLY NOT BEEN CHANGED, AND APPEAR TO REFLECT POTENTIAL THAT CURRENTLY EXISTS. FARTHER EAST, CONFIDENCE CONTINUES TO INCREASE CONCERNING SEVERE WEATHER POTENTIAL ASSOCIATED WITH RESTRENGTHENING OF WEST SOUTHWESTERLY 850 MB FLOW (50+ KT) ACROSS PORTIONS OF SOUTHERN ALABAMA INTO SOUTHERN GEORGIA, LATE THIS EVENING INTO THE OVERNIGHT HOURS. AS THE BOUNDARY LAYER MOISTENS AND DESTABILIZES ACROSS THIS REGION, AND LOW-LEVEL HODOGRAPHS ENLARGE, SUPERCELLS CAPABLE OF PRODUCING TORNADOES (SOME STRONG) APPEAR INCREASINGLY LIKELY. Link to comment Share on other sites More sharing options...
lj0109 Posted January 21, 2017 Share Posted January 21, 2017 BULLETIN - EAS ACTIVATION REQUESTED Tornado Warning National Weather Service Charleston SC 258 PM EST SAT JAN 21 2017 The National Weather Service in Charleston has issued a * Tornado Warning for portions of... Screven County in southeastern Georgia... Allendale County in southeastern South Carolina... * Until 330 PM EST * At 258 PM EST, a severe thunderstorm capable of producing a tornado was located near Sylvania, moving northeast at 50 mph. Link to comment Share on other sites More sharing options...
Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 Quote ...20Z Outlook Update... Severe weather potential has been complicated considerably by at least a couple of short waves impulses, emerging from a strong mid/upper jet which continues to migrate inland across the southern tier of the U.S., in advance of one much more significant perturbation still evolving near the southern Rockies. The lead impulse is now in the process of shifting across/northeast of the southern Appalachians. This feature has provided support for a severe mesoscale convective system which maintains considerable strength as it shifts across southern Georgia and portions of the lower Savannah River Valley, coincident with a 40-50 kt southwesterly 850 mb jet. Severe probabilistic lines have been adjusted some to account for the progression of this feature. Upstream, another impulse is already in the process of shifting through the Ark-La-Tex region, with the main amplifying upper trough not likely to reach the lower Mississippi Valley until late tonight, though another smaller scale impulse or two may still emerge from it, and progress toward Gulf coastal areas ahead of it. At the same time, the boundary layer from the vicinity of the north central Gulf coast region into the Ark-La-Tex is still in the process of recovering, as a convective outflow boundary and developing warm frontal zone begin to advance northeastward. Based on the variability that has been evident in short term model forecast guidance, the details of the potential convective evolution across the lower Mississippi Valley into the Southeast through the remainder of the period is far from certain. However, based on current observations and model output, severe categorical and probabilistic lines across the lower Mississippi Valley have generally not been changed, and appear to reflect potential that currently exists. Farther east, confidence continues to increase concerning severe weather potential associated with restrengthening of west southwesterly 850 mb flow (50+ kt) across portions of southern Alabama into southern Georgia, late this evening into the overnight hours. As the boundary layer moistens and destabilizes across this region, and low-level hodographs enlarge, supercells capable of producing tornadoes (some strong) appear increasingly likely. https://gyazo.com/1028811f6db711d2a66aab0212ba03ac Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 21, 2017 Share Posted January 21, 2017 Maybe a slight CC lowering on that SC storm. Link to comment Share on other sites More sharing options...
Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 HRRR is looking really nasty by 00z Link to comment Share on other sites More sharing options...
monsoonman1 Posted January 21, 2017 Share Posted January 21, 2017 Per NWS Jackson twitter, Hattiesburg area tornado at least EF3, first one of the year. Link to comment Share on other sites More sharing options...
lj0109 Posted January 21, 2017 Share Posted January 21, 2017 BULLETIN - EAS ACTIVATION REQUESTED Tornado Warning National Weather Service Charleston SC 316 PM EST SAT JAN 21 2017 The National Weather Service in Charleston has issued a * Tornado Warning for portions of... Hampton County in southeastern South Carolina... Jasper County in southeastern South Carolina... * Until 345 PM EST * At 316 PM EST, a severe thunderstorm capable of producing a tornado was located 13 miles southwest of Lake Warren State Park, moving east at 50 mph. Link to comment Share on other sites More sharing options...
Jim Martin Posted January 21, 2017 Author Share Posted January 21, 2017 Damage from the tornado warned storm earlier near Sylvania... chschat 2017/01/21 3:14 PM iembot 6 N Woodcliff [Screven Co, GA] TRAINED SPOTTER reports TSTM WND DMG at 2:48 PM EST -- TRAINED SPOTTER REPORTED MULTIPLE TREES... ROAD SIGNS... AND POWERLINES DOWN WITH DAMAGE TO CHICKEN COOPS INCLUDING METAL ROOFS REMOVED WITH PORTIONS LEFT IN TREES NEAR THE INTERSECTION OF BAY BRACH ROAD AND BUTTERMILK ROAD. TIME IS ESTIMATED BASED ON RADAR. Link to comment Share on other sites More sharing options...
Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 Couple of impressive signatures starting to show up Link to comment Share on other sites More sharing options...
Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 Link to comment Share on other sites More sharing options...
lj0109 Posted January 21, 2017 Share Posted January 21, 2017 WATCH COUNTY NOTIFICATION FOR WATCH 13 NATIONAL WEATHER SERVICE CHARLESTON SC 321 PM EST SAT JAN 21 2017 THE NATIONAL WEATHER SERVICE HAS EXTENDED TORNADO WATCH 13 TO INCLUDE THE FOLLOWING AREAS UNTIL 7 PM EST THIS EVENING IN SOUTH CAROLINA THIS WATCH INCLUDES 2 COUNTIES IN SOUTHEAST SOUTH CAROLINA BERKELEY CHARLESTON THIS INCLUDES THE CITIES OF CHARLESTON, DANIEL ISLAND, GOOSE CREEK, MONCKS CORNER, MOUNT PLEASANT, AND NORTH CHARLESTON. Link to comment Share on other sites More sharing options...
Chinook Posted January 21, 2017 Share Posted January 21, 2017 A stronger rotational signature near Luray just developed between already-established tornado warnings. This sort of thing must drive the forecasters nuts! Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 21, 2017 Share Posted January 21, 2017 Deep TDS approaching Allendale Link to comment Share on other sites More sharing options...
Amped Posted January 21, 2017 Share Posted January 21, 2017 SPC upgrade SE Alabama to moderate. This is an impressive setup. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 back west but not quite into the other MOderate risk area I suspect we will have a meso for that area soon MESOSCALE DISCUSSION 0093 NWS STORM PREDICTION CENTER NORMAN OK 0234 PM CST SAT JAN 21 2017 AREAS AFFECTED...PORTIONS OF SOUTHERN MS...LA CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY VALID 212034Z - 212300Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...THE RISK FOR SEVERE THUNDERSTORMS CAPABLE OF LARGE HAIL, DAMAGING WINDS, AND TORNADOES WILL BE INCREASING THROUGH THE LATE AFTERNOON AND INTO THE EVENING. THE ISSUANCE OF A TORNADO WATCH IS LIKELY WITHIN THE NEXT FEW HOURS. DISCUSSION...THE ISALLOBARIC RESPONSE TO 2-HOUR PRESSURE FALLS ON THE ORDER OF 2-4 MB ACROSS THE LOWER MS VALLEY WILL BE THE CONTINUED NORTHWARD ADVANCE OF A WARM FRONT ANALYZED APPROXIMATELY WEST-EAST ACROSS SOUTHERN LA. THE AIR MASS SOUTH OF THIS BOUNDARY IS CHARACTERIZED BY SURFACE DEWPOINTS IN THE MIDDLE 60S TO AROUND 70F, SUPPORTING MODERATE TO LOCALLY STRONG BUOYANCY -- AIDED BY STEEP MIDLEVEL LAPSE RATES SAMPLED BY THE 18Z SLIDELL SOUNDING (AROUND 8 C/KM IN THE 700-500-MB LAYER). AS THIS AIR MASS CONTINUES TO SPREAD NORTHWARD WITHIN A MODEST WARM-ADVECTION REGIME WELL IN ADVANCE OF STRONGER DEEP ASCENT FARTHER WEST, DIURNALLY REDUCED CAPPING AND MODEST ASCENT WILL LIKELY SUPPORT AN INCREASE IN SURFACE-BASED THUNDERSTORM DEVELOPMENT -- ESPECIALLY DURING THE LATE AFTERNOON AND EVENING AS MORE VIGOROUS ASCENT APPROACHES. INITIAL SHALLOW CONVECTIVE TOWERS ARE ALREADY EVOLVING ALONG THE WARM FRONTAL ZONE ACROSS PARTS OF SOUTHERN LA, IN PROXIMITY TO POCKETS OF STRONGER INSOLATION, PER VISIBLE IMAGERY. WHILE THERE IS SOME UNCERTAINTY REGARDING THE TIMING OF MORE ROBUST CONVECTIVE DEVELOPMENT GIVEN THE AFOREMENTIONED CAPPING, EFFECTIVE SHEAR AROUND 45-60 KT WILL LIKELY SUPPORT SUPERCELL STRUCTURES. INITIALLY, LARGE HAIL WILL BE LIKELY, THOUGH ELONGATING/INCREASINGLY CURVED LOW-LEVEL HODOGRAPHS INTO THE EVENING HOURS SUGGEST THAT THE TORNADO RISK WILL LIKELY INCREASE. DAMAGING WINDS WILL ALSO BE POSSIBLE IN CONJUNCTION WITH SMALL-SCALE, CONGEALING CONVECTIVE CLUSTERS. Link to comment Share on other sites More sharing options...
Superstorm93 Posted January 21, 2017 Share Posted January 21, 2017 Pretty impressive pressure falls as the SPC noted. Steep lapse rates, good CAPE, great shear, and strong UL dynamics suggest that this will be a long night. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 Mesoscale Discussion 0092 NWS Storm Prediction Center Norman OK 0233 PM CST Sat Jan 21 2017 Areas affected...Portions of northwest LA...northeast TX...southern AR...far southeast OK Concerning...Severe potential...Tornado Watch likely Valid 212033Z - 212300Z Probability of Watch Issuance...95 percent SUMMARY...The risk for severe thunderstorms capable of producing tornadoes, damaging winds, and very large hail is increasing this afternoon, and Tornado Watch issuance is likely within the next few hours. DISCUSSION...A warm front continues advancing northward from portions of east-central TX through southern LA, within a warm-advection plume preceding midlevel troughing over the South-Central States. Embedded within broader-scale midlevel cyclonic flow, water vapor loops indicate a smaller-scale impulse advancing northeastward toward the lower Sabine Valley. Ascent associated with these features is expected to support thunderstorm development from portions of northeast TX through west-central LA -- particularly after 22Z -- with activity subsequently spreading east-northeastward/eastward into the evening hours. Initial boundary-layer cumulus development is already noted across portions of east-central TX, southeast of Corsicana. Ample low-level moisture south of the warm front, marked by surface dewpoints in the middle 60s, will continue to build northward in response to southerly low-level mass fluxes promoted by the approaching upstream trough. With a well-defined elevated mixed layer sampled by the 18Z Shreveport sounding featuring steep lapse rates in the 800-550-mb layer, moderate instability will continue to develop northward into the zone of developing convection. With 45-60 kt of effective shear, and an anticipated initial discrete and semi-discrete convective mode, significantly severe hail will be possible with supercell structures. The risk for damaging winds will increase as convection organizes into smaller-scale clusters with embedded bowing/rotating convective elements. While not particularly strong, low-level flow will be increasing through the evening. The resultant enlargement of low-level hodographs will foster an increasing tornado risk, especially with convection evolving in proximity to the warm frontal zone and given the steep midlevel lapse rates. ..Cohen/Hart.. 01/21/2017 Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 21, 2017 Share Posted January 21, 2017 Two TDs W of Ashton Link to comment Share on other sites More sharing options...
Chinook Posted January 21, 2017 Share Posted January 21, 2017 CLX radar detected low-altitude 70-80 kt winds toward the radar. (base velocity) Two wind damage reports near there. Link to comment Share on other sites More sharing options...
lj0109 Posted January 21, 2017 Share Posted January 21, 2017 BULLETIN - EAS ACTIVATION REQUESTED Tornado Warning National Weather Service Columbia SC 350 PM EST SAT JAN 21 2017 The National Weather Service in Columbia has issued a * Tornado Warning for... East central Barnwell County in central South Carolina... Northwestern Bamberg County in central South Carolina... West central Orangeburg County in central South Carolina... * Until 415 PM EST * At 350 PM EST, a severe thunderstorm capable of producing a tornado was located over Blackville, or 8 miles northeast of Barnwell, moving east at 45 mph. Link to comment Share on other sites More sharing options...
OhioWX Posted January 21, 2017 Share Posted January 21, 2017 Unwarned tornado SE of Ashton, SC Link to comment Share on other sites More sharing options...
southmdwatcher Posted January 21, 2017 Share Posted January 21, 2017 Hot temperatures and dry dewpoints all across south Texas and northeastern Mexico right now. San Antonio 86/33, Laredo 93/33, Corpus Christi 92/38, Brownsville 93/39, Monterrey MX, 89/28, Ciudad Victoria MX 97/34, Tampico MX 95/50. That should set up quite a sizeable EML. Link to comment Share on other sites More sharing options...
Indystorm Posted January 21, 2017 Share Posted January 21, 2017 Storms starting to fire sw of NOLA and near Shreveport. And so it begins for this round. Tor watches issued. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 17 tornado reports since 12z I suspect that will really increase by 12z also 18z NAM very bullish tommrow too Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 TOR warned cell now in NE Texas Link to comment Share on other sites More sharing options...
monsoonman1 Posted January 21, 2017 Share Posted January 21, 2017 TDS for a few scans on the cell west of Jefferson, TX. Link to comment Share on other sites More sharing options...
MattPetrulli Posted January 21, 2017 Share Posted January 21, 2017 Tornado on that tail end storm unwarned currently. Link to comment Share on other sites More sharing options...
janetjanet998 Posted January 21, 2017 Share Posted January 21, 2017 getting a very bad feeling about this not liking all te discrete stuff developing along the retreating warm front over LA Link to comment Share on other sites More sharing options...
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