kevinbente Posted March 23, 2016 Share Posted March 23, 2016 While it is the 4km NAM, that model along with the less, but still notable 12km NAM are both showing a decent chance of severe weather and potentially a tornado threat in Alabama and surrounding areas on Thursday, March 24th. It seems right now, if this setup wants to be more significant, the surface low should want to slow down a bit so surface winds would be more backed in the area. Also, CAPE values generally range from around 1000 J/kg on the 12km NAM/GFS to 1500-2000 on the 4km NAM. Regardless of this, the 4km NAM shows discrete supercells in central Alabama Thursday afternoon. Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted March 23, 2016 Share Posted March 23, 2016 Forbes: Link to comment Share on other sites More sharing options...
Disc Posted March 23, 2016 Share Posted March 23, 2016 There's beginning to look like a decent threat for severe weather across the deep south tomorrow. As of now (12z NAM) has a mixed mode of storms moving across AL from 21z to 03z tomorrow. The instability appears to be there, but the wind profile isn't screaming tornado to me as of now. Looking like a line of broken line of storms with embedded supercells -- Any discrete cells will have tornadic potential. Best place right now appears to be central C AL during the late afternoon into the evening. Link to comment Share on other sites More sharing options...
Jon Posted March 23, 2016 Share Posted March 23, 2016 SPC update for Day 2: ...SUMMARY... SEVERE THUNDERSTORMS WITH A FEW TORNADOES...WIND DAMAGE AND ISOLATED LARGE HAIL WILL BE POSSIBLE ON THURSDAY ACROSS PARTS OF THE TENNESSEE VALLEY AND CENTRAL GULF COAST STATES. ...TN VALLEY/CNTRL GULF COAST STATES... AN UPPER-LEVEL TROUGH WILL BECOME LESS AMPLIFIED ON THURSDAY...MOVING EWD ACROSS THE OZARKS AND INTO THE MID MS VALLEY. AT THE SFC...A LOW WILL MOVE INTO THE SRN GREAT LAKES REGION AS A COLD FRONT ADVANCES QUICKLY EWD INTO THE LOWER AND MID MS VALLEY. A BROKEN LINE OF THUNDERSTORMS SHOULD BE ONGOING AHEAD OF THE FRONT AT THE START OF THE PERIOD. THE NRN PART OF THE LINE MAY REMAIN INTACT INTO THE AFTERNOON...BEING SUPPORTED BY A 50 TO 60 KT LOW-LEVEL JET AND LARGE-SCALE ASCENT ASSOCIATED WITH AN UPPER-LEVEL TROUGH IN THE MID MS VALLEY. AS INSTABILITY INCREASES DURING THE DAY...THE LINE IS EXPECTED TO REDEVELOP FROM WRN TN SWD INTO CNTRL MS AND MOVE EWD ACROSS THE SLIGHT RISK AREA. FORECAST SOUNDINGS AT 21Z/THU FROM TUPELO NEWD INTO MIDDLE TN SHOW MLCAPE OF 100O TO 1500 J/KG WITH MID-LEVEL LAPSE RATES NEAR 7.5 C/KM AND STRONG DEEP-LAYER SHEAR PROFILES. 0-6 KM SHEAR IS FORECAST TO BE FROM 55 TO 65 KT WITH 0-3 KM STORM RELATIVE HELICITIES IN THE 300 TO 400 M2/S2 RANGE. THIS SHOULD SUPPORT ISOLATED SUPERCELL DEVELOPMENT AND POSSIBLY A FEW TORNADOES WITH CELLS ALONG THE MORE ORGANIZED PARTS OF THE LINE AND WHERE GAPS DEVELOP WITHIN THE LINE. SUPERCELLS WITH ISOLATED LARGE HAIL WILL BE POSSIBLE IN AREAS THAT DESTABILIZE THE MOST. THE STRONG LOW-LEVEL FLOW WILL ALSO BE FAVORABLE FOR WIND DAMAGE WITH ORGANIZED MULTICELL LINE SEGMENTS THAT DEVELOP ALONG AND AHEAD OF THE FRONT. Via the 4km NAM.. Not much on other models though we'll see if the threat holds. Birmingham, AL valid 00z Fri Link to comment Share on other sites More sharing options...
mackerel_sky Posted March 23, 2016 Share Posted March 23, 2016 The system seems to have sped up by a few hours! A few days ago, it was looking like arrival time around 10-midnight, now looks around 8 pm, so might be some decent storms in NEGa and western Carolinas, around sunset and still have some heating to feed off of ! Link to comment Share on other sites More sharing options...
Solak Posted March 23, 2016 Share Posted March 23, 2016 US National Weather Service Peachtree City Georgia 11 mins · A line of strong to severe thunderstorms is possible Thursday afternoon and evening across the outlook area. Large hail, damaging wind gusts, frequent lightning and locally heavy rainfall are the main threats. Please keep monitoring the forecast for any changes! Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted March 23, 2016 Share Posted March 23, 2016 BMX updated their severe weather outlook to include an "elevated" risk area; their equivalent to an enhanced risk. Link to comment Share on other sites More sharing options...
ClicheVortex2014 Posted March 23, 2016 Share Posted March 23, 2016 BMX says models are trending toward more instability. They say strong tornadoes are possible. AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE BIRMINGHAM AL406 PM CDT WED MAR 23 2016.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT.MAIN FOCUS IN THE SHORT TERM IS THE SEVERE WEATHER THREAT FORTOMORROW AND TOMORROW NIGHT. LATEST MODELS HAVE BEEN TRENDING UPWARDWITH INSTABILITY...BULK SHEAR...AND HELICITY VALUES. THEREFORECONFIDENCE IS INCREASING IN THE SEVERE WEATHER THREAT. CENTRALALABAMA WILL BE IN THE RIGHT ENTRANCE REGION OF A 100 KT 300 MB JETSTREAK PROVIDING SYNOPTIC SCALE FORCING FOR ASCENT. AN UPPER-LEVELLOW/SHORTWAVE TROUGH WILL BE LIFTING FROM THE CENTRAL PLAINS TO THEGREAT LAKES. ROUNDING THE BASE OF THE TROUGH WILL BE A 65-70 KT MID-LEVEL JET STREAK THAT WILL MOVE ACROSS CENTRAL ALABAMA. THIS WILLRESULT IN 0-6 KM BULK SHEAR VALUES OF 55-65+ KTS. THE STRONGEST 850MB LOW LEVEL JET WINDS WILL BE LIFTING NORTH OF CENTRAL ALABAMA BUT0-1KM SHEAR VALUES WILL STILL BE STRONG...AROUND 25-30 KTS. VEERINGWINDS WITH HEIGHT WILL RESULT IN 0-3 KM SRH VALUES OF 300 TO 400M2/S2 WHICH IS AN INCREASE OVER PREVIOUS MODEL RUNS. DEW POINTS WILLINCREASE INTO THE LOW 60S WITH SOME GUIDANCE INDICATING DEWPOINTS APPROACHING THE MID 60S. STEEP MID-LEVEL LAPSE RATES OF6.5 TO 7 C/KM WILL ALSO OVERSPREAD THE WARM SECTOR. WITH THESESTEEP MID- LEVEL LAPSE RATES NOT MUCH HEATING WILL BE REQUIRED FORDESTABILIZATION. CAPE VALUES HAVE INCREASED IN MODEL GUIDANCE FROMPREVIOUS RUNS WITH MOST GUIDANCE INDICATING CAPE NOW IN THE 1000-1500 J/KG RANGE...WITH THE HIGHEST VALUES IN SOUTHWEST AND WEST-CENTRAL CENTRAL ALABAMA...AND SOME GUIDANCE INDICATES VALUES EVENHIGHER. CONVECTION WILL INITIATE ALONG THE FRONT AND POTENTIALLYALSO ALONG CONFLUENCE LINES AHEAD OF THE FRONT. THE STRONG 0-6 KMSHEAR ORIENTED FROM THE WEST-SOUTHWEST FAVORS SUPERCELLDEVELOPMENT INITIALLY...EVOLVING INTO A BROKEN LINE OF SUPERCELLSAND POSSIBLY LINE SEGMENTS. THREATS WILL INCLUDE TORNADOES BASEDON THE SRH VALUES AND INSTABILITY...DAMAGING WINDS IN ANY BOWINGSEGMENTS THAT DEVELOP...AND LARGE HAIL GIVEN THE MID-LEVEL LAPSERATES. THE FLOODING RISK REMAINS LOW GIVEN THE PROGRESSIVE NATUREOF THE SYSTEM.LIKE WITH MANY EVENTS THERE ARE SOME POTENTIAL LIMITINGFACTORS...MAINLY IF DESTABILIZATION CAN OCCUR BEHIND SHOWERSDEVELOPING IN ISENTROPIC LIFT LATE TONIGHT AND TOMORROW MORNING ANDPOSSIBLE REMNANTS OF CONVECTION DEVELOPING UPSTREAM TONIGHT. THEDEGREE OF UPPER-LEVEL FORCING MAY ALSO BE A LIMITING FACTOR.HOWEVER...THE GENERAL CONSENSUS OF MODEL GUIDANCE INDICATES ROBUSTCONVECTION DEVELOPING AND MOVING EASTWARD DURING THE AFTERNOON ANDEVENING. WITH THE INSTABILITY AND SHEAR PARAMETERS IN PLACE...THEPOTENTIAL IMPACTS WARRANT BUMPING UP THE CONFIDENCE LEVEL IN THE HWOAND ADDING AN ELEVATED RISK IN OUR SEVERE WEATHER IMPACT GRAPHICS.BASED ON THE PARAMETERS AND SUPERCELL STORM MODE...WILL ALSO HAVE TOCLOSELY MONITOR THE POTENTIAL FOR STRONG TORNADOES. THE ELEVATEDRISK MAY BE EXPANDED EASTWARD IN FUTURE UPDATES AS THE EVOLUTION OFTHE CONVECTION INTO THE EVENING HOURS BECOMES CLEARER. THE THREAT INTHE FAR NW COUNTIES IS A BIT CONDITIONAL DEPENDING ON WHEN STORMSDEVELOP IN THE AFTERNOON BUT WILL KEEP AN ELEVATED RISK THERE ASWELL. Link to comment Share on other sites More sharing options...
PGM Posted March 24, 2016 Share Posted March 24, 2016 Any thoughts on how the widespread convection in the bmx area will effect the severe threat later? Link to comment Share on other sites More sharing options...
Solak Posted March 24, 2016 Share Posted March 24, 2016 Any thoughts on how the widespread convection in the bmx area will effect the severe threat later? Looks like any severe threat has shifted South closer to the Gulf... ...SUMMARY... SEVERE STORMS REMAIN A THREAT ACROSS THE NORTHEAST GULF COAST INTO THIS EVENING. A FEW STRONG TO SEVERE STORMS ALSO MAY OCCUR NORTHWARD THROUGH THE OHIO VALLEY INTO LOWER MICHIGAN. ...GULF COAST TO TN VALLEY REGION... THE GREATEST SEVERE WEATHER THREAT THROUGH THE REST OF THE AFTERNOON TO EARLY EVENING IS EXPECTED TO BE CONFINED TO THE NORTHEAST GULF COAST REGION...ALONG AND AHEAD OF THE EASTWARD-MOVING BOW/QLCS /CURRENTLY LOCATED IN SOUTH AL TO THE FAR WESTERN FL PANHANDLE/. THE ENVIRONMENT DOWNSTREAM IS DESTABILIZING SOME WITH NORTHWARD EXTENT ACROSS THE REST OF THE FL PANHANDLE INTO SOUTHWEST GA. GIVEN THIS LATTER FACTOR AND THE EASTWARD MOVEMENT OF THE BOW/QLCS...THE SEVERE PROBABILITIES AND CATEGORICAL RISK AREAS HAVE BEEN SHIFTED EAST ACCORDINGLY. MEANWHILE...WEAK DESTABILIZATION IN THE WAKE OF THE QLCS AND AHEAD OF THE COLD FRONT MAY PROVE FAVORABLE FOR ADDITIONAL STRONG TO SEVERE STORMS...GIVEN THE PRESENCE OF STRONG EFFECTIVE BULK SHEAR ACROSS THE CENTRAL GULF COAST/LOWER MS VALLEY. Link to comment Share on other sites More sharing options...
PGM Posted March 24, 2016 Share Posted March 24, 2016 Looks like any severe threat has shifted South closer to the Gulf... Alright, thanks Link to comment Share on other sites More sharing options...
metalicwx366 Posted March 24, 2016 Share Posted March 24, 2016 Looks like the potential for strong to severe thunderstorms is increasing here. Earlier runs of HRRR didn't get the squall line past the AL/GA border. Now they maintain it till it reaches coastal GA/FL. Line still looks good as well. Still expect the line to weaken as it moves into a more stable environment and loss of daytime heating. Link to comment Share on other sites More sharing options...
Solak Posted March 24, 2016 Share Posted March 24, 2016 Nice Meso low south of Columbus, GA http://radar.weather.gov/radar_lite.php?product=N0R&rid=EOX&loop=yes Link to comment Share on other sites More sharing options...
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