SVR Potential 3/10 - 3/12

[tennessee storm09]

tomorrow looks like a nice dry slot by after lunch, should get plenty breaks from the clouds.  with sunshine breaking through instability will increase quickly. if we can get decent directional wind shear, we might just get our first tast of soome isolated naders at least. especially nw miss. and further south.

[Charles L.]

tomorrow looks like a nice dry slot by after lunch, should get plenty breaks from the clouds.  with sunshine breaking through instability will increase quickly. if we can get decent directional wind shear, we might just get our first tast of soome isolated naders at least. especially nw miss. and further south.

I agree. As you head further east and SE, the higher those chances go. The Jackson, MS NWS office (JAN?) has good right to be "nervous" or hyped up about this event. 1-2 tornadoes look very possible tomorrow, IMO. And I would give it about 50/50 we see a handful (5).

[toastido]

I'm not overly impressed thus far with the threat, but the SREF says things could get bumpy around 4pm tomorrow for the lower MS Valley..  

[Charles L.]

I would love to be out in the field chasing this setup over in MO, AR, KS, or OK.

SPC has a 10% tornado risk zone out for them and a 30% hatched hail threat.

SPC thinks once these cells begin firing...it will not take them long to turn severe and those run the risk for bringing isolated tornadoes more so then when all this convection turns linear later on tonight.

[Charles L.]

This is what LMK has for Thursday's risk...sounds like more then a "See Text" day to me if we do see that clearing take place.

BY THURSDAY AFTERNOON...LATEST DETERMINISTIC MODELS SHOW QUITE
SUBSTANTIAL CLEARING TAKING PLACE BY EARLY AFTERNOON IN THE WESTERN
SECTIONS OF THE FA.  IF THIS OCCURS...COMBINATION OF INCREASING COLD
TEMPS ALOFT AND A RAPID WARMING OF THE SURFACE WOULD RESULT IN
MODEST DESTABILIZATION IN AREAS WEST OF INTERSTATE 65.  AS THIS
CLEARING TAKES PLACE...SOUTHWEST PBL FLOW LOOKS TO BE STRONG ENOUGH
TO ALLOW MOISTURE TO POOL ALONG AN ADVANCING SFC BOUNDARY THAT
ENTERS WESTERN KY BY EARLY AFTERNOON.  LATEST HIGH RES NAM-WRF
SOLUTIONS SHOW THIS QUITE WELL WITH A SECONDARY LINE OF CONVECTION
DEVELOPING ACROSS WEST KY AND THEN SPREADING EASTWARD.  DEPENDING ON
THE AMOUNT OF CLEARING AND DESTABILIZATION...SOME OF THESE STORMS
COULD BE ON THE STRONG TO SEVERE SIDE.  GUSTY WINDS AND LARGE HAIL
WOULD LIKELY BE THE PRIMARY SEVERE WEATHER THREATS.  HOWEVER...GIVEN
THE STRONG WIND FIELDS...BULK SHEAR IN THE LOWER ATMOSPHERE IS MORE
THAT SUFFICIENT TO SUPPORT A FEW ISOLATED TORNADOES.

[servocrow]

WKRN's Jeff Ray talked about secondary round tomorrow..this is text from tomorrow's SWODY2:

...MIDWEST/LOWER OH VALLEY TO TN VALLEY DURING THE DAY...
   VERTICALLY STACKED CYCLONE IS EXPECTED TO REMAIN QUASI-STATIONARY
   OVER THE LOWER/MIDDLE MO RIVER VALLEY ON THURSDAY. BANDS OF
   SHOWERS/TSTMS WILL SPREAD NORTHEASTWARD /WITH PERHAPS A MARGINAL
   ELEVATED HAIL THREAT/ EARLY IN THE DAY ACROSS MUCH OF THE REGION VIA
   A LEAD SHORTWAVE TROUGH/WARM ADVECTION REGIME. IN THE WAKE OF THIS
   ACTIVITY...MODEST DESTABILIZATION SHOULD OCCUR MID/LATE AFTERNOON
   ALONG/IMMEDIATELY AHEAD OF A SURFACE OCCLUSION...WHERE LOWER 50S F
   SURFACE DEWPOINTS WILL EXIST BENEATH A NORTHEAST ADVANCING DRY
   SLOT/PLUME OF STEEP MID LEVEL LAPSE RATES. AS SUCH...ADDITIONAL
   STRONG/SEVERE LOW-TOPPED TSTM DEVELOPMENT APPEARS POSSIBLE BY
   MID/LATE AFTERNOON ACROSS THE MIDWEST/LOWER OH VALLEY TO THE TN
   VALLEY. SEVERE HAIL/PERHAPS A BRIEF TORNADO WOULD LIKELY BE THE
   PRIMARY HAZARDS...WITH ANY SUCH THREAT TENDING TO WANE BY AROUND
   SUNSET.

Waiting to post SWODY1 stuff after the 8:30 AM update...

[servocrow]

OHX:

.PREV DISCUSSION... /ISSUED 359 AM CST WED MAR 10 2010/

SHORT TERM...A MOIST AIR MASS REMAINS IN PLACE ACROSS THE MID
STATE, WITH LOW CLOUDS PREVAILING AREA-WIDE. WINDS EARLY THIS
MORNING WERE OUT OF THE SOUTH AT 5 TO 10 MPH. TEMPERATURES AT
300 AM WERE IN THE MID 50S, WHICH SETS THE STAGE FOR A PRETTY
DECENT WARM-UP TODAY, ESPECIALLY ACROSS THE NORTH WHERE LOW CLOUDS
ARE EXPECTED TO BREAK BY THE AFTERNOON. EXPECT HIGHS TO SURGE TO AROUND
70 IN THE PARTLY SUNNY AREAS THIS AFTERNOON, AND EXPECT NASHVILLE
TO HIT THE 70 DEGREE MARK AGAIN TODAY, WITH LOWER 70S LIKELY AROUND
CLARKSVILLE. AS THE SUN BREAKS THROUGH, EXPECT SOUTH WINDS TO
BECOME RATHER GUSTY, SOMETIMES GUSTING TO BETWEEN 25 AND 30 MPH.

SHOWERS AND ISOLATED THUNDERSTORMS WILL BE LIKELY IN THE
SOUTHEASTERN AREAS, WHERE ATMOSPHERIC MOISTURE WILL BE DEEPEST,
WITH LESSER CHANCES FURTHER NORTH.

CLOSED UPPER LOW TO OUR WEST KICKS OUT A POTENT SHORTWAVE TONIGHT,
WHICH APPROACHES THE MID STATE FROM THE SOUTHWEST AND PRODUCES SHOWERS
AND THUNDERSTORMS IN OUR SOUTHWESTERN COUNTIES BY SUNRISE THURSDAY.
PRECIPITABLE WATER AHEAD OF THIS TROUGH WILL BE AROUND ONE INCH AND
EXPECT STORM TOTALS OVER OUR AREA TO AVERAGE BETWEEN ONE HALF AND
THREE QUARTERS OF AN INCH BETWEEN LATE TONIGHT AND THURSDAY AFTERNOON.

SPC HAS PLACED EXTREME WESTERN MIDDLE TENNESSEE IN A SLIGHT RISK
FOR SEVERE THUNDERSTORMS TONIGHT, AND BELIEVE THE MAIN THREAT WILL
BE FOR LARGE HAIL AND STRONG STRAIGHT LINE WINDS. 0-3KM HELICITIES
WILL BE BETWEEN 150 AND 200 M2/S2, WHICH SUGGESTS AT LEAST A SMALL
POSSIBILITY FOR ISOLATED TORNADOES AS WELL.

[servocrow]

MEG

546 AM CST WED MAR 10 2010

.DISCUSSION... /ISSUED 449 AM CST WED MAR 10 2010/

AN ACTIVE WEATHER PERIOD IS ANTICIPATED ACROSS THE MID SOUTH LATER
THIS AFTERNOON THROUGH TONIGHT WITH THE POTENTIAL FOR SEVERE
THUNDERSTORMS AND LOCALLY HEAVY RAINFALL.

AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUES TO LIFT NORTHWARD
FROM CENTRAL MISSISSIPPI INTO SOUTHEAST PORTIONS OF THE FORECAST
AREA EARLY THIS MORNING. THIS ACTIVITY WAS OCCURRING WITHIN A
WARM ADVECTION REGIME WITH INCREASED LIFT ASSOCIATED WITH A LOW
LEVEL JET AS WELL AS POSITIONING WITHIN A DIFFLUENT UPPER PATTERN
ASSOCIATED WITH THE LEFT EXIT REGION OF A POWERFUL 170KT UPPER LEVEL
SUBTROPICAL JET STREAK MOVING ALONG THE GULF COAST. EXPECT THIS
ACTIVITY TO CONTINUE THROUGH THE EARLY AFTERNOON HOURS AND HAVE
MAINTAINED LIKELY TO CATEGORICAL POPS IN THIS REGION. THIS
ENHANCED LIFT SHOULD PULL SLOWLY EAST THROUGH THE DAY WITH POP
CHANCES DECREASING TEMPORARILY ACROSS THIS AREA LATER THIS
AFTERNOON.

THE BIGGER WEATHER STORY WILL BE WITH THE APPROACH OF A POTENT
UPPER LEVEL SHORTWAVE LATER THIS EVENING AND OVERNIGHT. CURRENTLY
THIS WEATHER FEATURE IS LOCATED OVER NEW MEXICO. THIS STRONG
SHORTWAVE IS FORECAST TO RACE NORTHEASTWARD THROUGH THE DAY AND
BECOME NEGATIVELY TILTED AS IT MOVES INTO NORTHEAST OKLAHOMA THIS
EVENING AND INTO THE MID MISSISSIPPI VALLEY OVERNIGHT. IN
ADDITION...DEEPENING SURFACE LOW PRESSURE SHOULD LIFT RAPIDLY
NORTHEAST FROM CENTRAL OKLAHOMA TO WESTERN MISSOURI OVERNIGHT.

MUCH OF THE MID SOUTH WILL REMAIN EMBEDDED WITHIN AN EXPANDING
WARM SECTOR WITH DEWPOINTS NOW RANGING FROM THE MID 50S ACROSS
EASTERN SECTIONS TO LOWER 60S ACROSS NORTHWEST MISSISSIPPI. LOW
LEVEL MOISTURE WILL REMAIN IN PLACE THROUGH THE DAY AS
TEMPERATURES RISE INTO THE LOW AND MID 70S...AS LOW LEVEL STRATUS
MIXES OUT LATER THIS MORNING AND SKIES BECOME PARTLY SUNNY BY THIS
AFTERNOON ACROSS THE NORTHWEST HALF OF THE AREA. THE ATMOSPHERE IS
EXPECTED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON AND EVENING
WITH SBCAPES RANGING FROM 1500-2500 J/KG AND LI/S BETWEEN -4C AND
-6C. THE GREATEST INSTABILITY SHOULD REMAIN ACROSS THE WESTERN
HALF OF THE MID SOUTH...DECREASING WITH EASTWARD EXTENT. MID LEVEL
LAPSE RATES WILL ALSO STEEPEN SIGNIFICANTLY TO LESS THAN 8C/KM AS
MID LEVEL HEIGHT FALLS BEGIN TO OVERSPREAD WESTERN PORTIONS OF THE
REGION THIS EVENING IN RESPONSE TO A 80KT MID LEVEL JET STREAK
PUNCHING INTO THE OZARKS. THE MID SOUTH SHOULD REMAIN ALONG THE
SOUTHERN PERIPHERY OF THIS MID LEVEL JET...BUT THIS SHOULD HELP TO
INCREASE DEEP LAYER SHEAR TO IN EXCESS OF 45KT ACROSS MUCH OF THE
REGION THIS EVENING. IN ADDITION...0-1KM HELICITY VALUES SHOULD
INCREASE TO GREATER THAN 150 M2/S2 BY LATE THIS AFTERNOON.

ALTHOUGH THE ATMOSPHERE BECOMES MODERATELY UNSTABLE THIS
AFTERNOON...IT APPEARS THAT A MID LEVEL CAPPING INVERSION MAY
PERSIST UNTIL THE BETTER FORCING ASSOCIATED WITH THE SHORTWAVE
MOVES INTO THE AREA THIS EVENING. ALTHOUGH...STRONG SURFACE HEATING
WILL WORK TO ERODE THE CAPPING INVERSION THIS AFTERNOON AND THIS
WILL NEED TO BE MONITORED CLOSELY AS ISOLATED CONVECTION THAT CAN
DEVELOP THIS AFTERNOON WOULD RAPIDLY BECOME SEVERE CONSIDERING THE
KINEMATIC AND THERMODYNAMIC ENVIRONMENT. THE LATEST 06Z NAM MODEL
HINTS AT LATE AFTERNOON CONVECTION DEVELOPING ALONG THE
MISSISSIPPI RIVER DELTA. AT THIS TIME...PREFER TO FAVOR THE IDEA
THAT MOST OF THE CONVECTION WILL HOLD OFF UNTIL AFTER SUNSET
ACROSS THE WESTERN HALF OF THE FORECAST AREA AS GREATER HEIGHT
FALLS ASSOCIATED WITH THE SHORTWAVE IMPINGE UPON THE REGION. ONCE
CONVECTION DEVELOPS IT WILL HAVE THE POTENTIAL TO BECOME SEVERE
CONSIDERING THE DEGREE OF INSTABILITY AND SHEAR AVAILABLE. IT
APPEARS THAT THE CONVECTIVE MODE MAY BEGIN AS SUPERCELLS WEST OF
THE MISSISSIPPI RIVER THIS EVENING. CONVECTION SHOULD EVENTUALLY
EVOLVE EVOLVE INTO A QUASI-LINEAR CONVECTIVE LINE (SQUALL-LINE)
WITH EMBEDDED SUPERCELLS. THIS WILL POSE THE POTENTIAL FOR
DAMAGING WINDS...LARGE HAIL...AND ISOLATED TORNADOES. PLAN TO
CONTINUE TO HIGHLIGHT THE SEVERE THREAT IN THE LATEST HWO

[servocrow]

NWS STORM PREDICTION CENTER NORMAN OK
   0658 AM CST WED MAR 10 2010
   
   VALID 101300Z - 111200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN PARTS OF THE CNTRL/SRN
   PLNS SE TO THE CNTRL GULF CST...
   
   ...SYNOPSIS...
   AN ACTIVE/COMPLEX SVR WEATHER PATTERN WILL EXIST OVER THE S CNTRL
   U.S. THROUGH EARLY THU...WITH SEVERAL DISTINCT EPISODES/MODES OF SVR
   TSTMS EXPECTED FROM ERN PARTS OF THE CNTRL/SRN PLNS TO THE MID/LWR
   MS VLYS.
   
   POTENT NM UPR LOW WILL TRACK ENE INTO N CNTRL OK THIS EVE...BEFORE
   TURNING NE INTO NW MO EARLY THU AS UPSTREAM TROUGH AMPLIFIES SE
   ACROSS THE SWRN DESERTS.  FARTHER S...FAST/NEARLY ZONAL SUBTROPICAL
   JET WILL PERSIST FROM THE TX BIG BEND TO THE NRN GULF OF MEXICO.
   
   AT THE SFC...LOW NOW OVER THE TX PANHANDLE SHOULD MOVE SLOWLY E INTO
   CNTRL OK BY THIS EVE...BEFORE CONTINUING NE INTO NRN MO EARLY THU.
   COLD FRONT EXTENDING S FROM THE LOW WILL ACCELERATE E ACROSS OK AND
   TX TODAY...AND OVERTAKE DRY LINE/CONFLUENCE ZONE LEFT FROM PREVIOUS
   UPR SYSTEM NOW IN IA.  THE COMBINED BOUNDARY SHOULD CONTINUE RAPIDLY
   E/NE ACROSS AR/MO TONIGHT AND EARLY THU...AND MORE SLOWLY E ACROSS
   LA/MS.
   
   ...NE TX/ERN OK/SE KS INTO MO/AR AND THE MS VLY TODAY/TONIGHT...
   LOW-LVL MOISTENING WILL CONTINUE NWD AHEAD OF MERGING COLD FRONT/DRY
   LINE TODAY/TONIGHT...WITH SFC DEWPOINTS IN THE UPR 50S F EXPECTED BY
   LATE AFTN OVER ERN OK/AR.  A SEPARATE AREA OF RELATIVELY MOIST AIR
   WILL SPREAD N FROM THE AR/MS DELTA INTO SE MO AND WRN KY/TN.
   COUPLED WITH SFC HEATING AND COOL MID LVL TEMPERATURES...SETUP
   SHOULD YIELD SBCAPE OF 1000-1500 J/KG IN AR...AND VALUES AOA 1000
   J/KG FROM ERN OK INTO SRN MO/W TN.
   
   COMBINATION OF DESTABILIZATION AND STRONG ASCENT AHEAD OF NM UPR
   VORT SHOULD SUPPORT VIGOROUS STORM DEVELOPMENT ALONG AND AHEAD OF
   THE FRONT FROM SE KS THROUGH ERN OK INTO NE TX BY MID/LATE AFTN.
   THE STORMS SHOULD CONSOLIDATE INTO BROKEN BANDS AND MOVE/DEVELOP
   E/NE INTO MO/AR BY EARLY EVE.
   
   BAND OF 80+ KT SSWLY 500 MB FLOW SHIFTING ENE ATOP LOW-LVL SLY FLOW
   WILL BE FAVORABLE FOR SUPERCELLS.  HOWEVER...SUBSTANTIAL
   SPATIAL/TEMPORAL VARIATION OF WIND FIELD AHEAD OF COMPACT UPR
   VORT...AND NW-TO-SE VARIATION OF MOISTURE AVAILABILITY ACROSS REGION
   COMPLICATE FORECAST OF DOMINANT STORM MODE.  NEVERTHELESS...OVERALL
   COMBINATION OF STRENGTHENING INSTABILITY...SHEAR...AND LIFT SUGGEST
   STRONG LIKELIHOOD FOR SVR WEATHER...ESPECIALLY LARGE HAIL.
   TORNADOES ALSO WILL BE POSSIBLE...NOT ONLY WITH THE MORE DISCRETE
   STORMS THIS AFTN...BUT ALSO WITH BROKEN BANDS/LEWPS OVER AR/MO AND
   PERHAPS WRN TN TONIGHT/EARLY THU AS THE ACTIVITY ENCOUNTERS
   INCREASING MOISTURE MOVING N UP THE MS RVR VLY.
   
   ...N CNTRL OK INTO SRN KS THIS AFTN/EVE...
   LOW-TOPPED TSTMS EXPECTED TO FORM IMMEDIATELY N/NE OF MAIN UPR VORT
   CROSSING CNTRL OK THIS AFTN...WHERE SUSTAINED/DEEP CONVERGENCE WILL
   EXIST NEAR ASSOCIATED SFC LOW.  THESE STORMS SHOULD MOVE/DEVELOP NE
   INTO PARTS OF SRN KS BY EARLY EVE.  COMBINATION OF VERY COOL AIR
   ALOFT /AOA MINUS 24 C AT 500 MB/ AND AMPLE SHEAR FOR ROTATING
   UPDRAFTS WILL SUPPORT A THREAT FOR LARGE HAIL.  TORNADOES MAY ALSO
   OCCUR...ESPECIALLY IN ZONE OF BACKED LOW-LVL FLOW ALONG STNRY FRONT
   EXTENDING NE FROM SFC LOW.  THE SVR THREAT SHOULD DIMINISH TONIGHT
   AS STORMS FARTHER S AND E STABILIZE INFLOW AIR...AND DIURNAL COOLING
   OCCURS.
   
   ...CNTRL/E TX MIDDAY THROUGH EVE...
   SATELLITE AND SFC OBS SHOW LOW-LVL MOISTURE SPREADING STEADILY NNW
   ACROSS E CNTRL AND S CNTRL TX ATTM AS CONFLUENCE ZONE/DRY LINE FROM
   YESTERDAY RETURNS N/W AHEAD OF NM UPR VORT.  STORMS MAY FORM ALONG
   THE CONFLUENCE ZONE OVER CNTRL TX LATER THIS MORNING OR EARLY THIS
   AFTN IN RESPONSE TO INCREASING MOISTURE...DAYTIME HEATING AND
   GLANCING INFLUENCE OF NM VORT.  THE STORMS SHOULD MOVE E TOWARD THE
   ARKLATEX AND SE TX LATER TODAY AS COLD FRONT ACCELERATES EWD ON S
   SIDE OF THE UPR TROUGH.  ALTHOUGH PW DATA SUGGEST THAT TOTAL
   MOISTURE AVAILABILITY WILL REMAIN SOMEWHAT LIMITED /BELOW .75
   IN/...SUFFICIENT DESTABILIZATION SHOULD OCCUR TO SUPPORT A THREAT
   FOR SVR WIND/HAIL...ESPECIALLY IN E TX.
   
   ...CNTRL GULF CST STATES...
   SCTD TO BROKEN TSTMS WILL PERSIST OVER PARTS OF SRN LA/MS AND AL 
   TODAY...IN AREA OF SUSTAINED LOW-LVL CONFLUENCE/WAA BENEATH BROADLY
   DIFFLUENT UPR FLOW.  ALTHOUGH THIS ACTIVITY INITIALLY WILL BE
   SLIGHTLY ELEVATED...WARMING/MOISTENING OF BOUNDARY LAYER SUGGESTS
   THAT SOME OF THE STORMS COULD BECOME NEARLY SFC-BASED WITH TIME AS
   THEY EVOLVE INTO ONE OR MORE REGENERATIVE CLUSTERS.  COUPLED WITH 40
   KT 500 MB WSWLY FLOW AND 30 KT SSWLY LLJ...THE THREAT FOR SVR
   WEATHER /MAINLY IN THE FORM OF TORNADOES...HAIL AND HEAVY RAIN/ MAY
   SLOWLY INCREASE THROUGH THE DAY.  THIS THREAT MAY FURTHER INCREASE
   THIS EVE OR EARLY THU FROM SE LA INTO SRN MS...SRN AL...AND THE FL
   PANHANDLE AS LOW-LVL SLY FLOW STRENGTHENS AHEAD OF E TX/LA COLD
   FRONT.  DESPITE NEARLY MOIST ADIABATIC PROFILES...FAVORABLE
   VEERING/INCREASING WINDS WITH HEIGHT AND PROXIMITY OF STRONG
   SUBTROPICAL JET COULD SUPPORT SUPERCELLS AND TORNADOES.
   

[Eric]

I think central AR is the "green zone" for thsi event.  There could be a rogue tornado or two in KS/OK near the surface low, but I think the better kinematics are to the southwest of the low.  The 4.0km WRF-NMM radar simulation wants to paint discrete activity, granted not a lot, across the Little Rock area between 5-6pm:



Here's the skew-T for that timeframe:



Some values taken from the skew-T-
Lifted indices of -4.4.  Not great, but marginal...
0-3km SRH values of ~200 m2/s2
CAPE values of ~1400 j/kg
Lapse rates of -8.0 C/km, with 850-500 lapse rates of 7.0 C/km
Winds are out of the south at the surface, but turn to the E-SE around 500mb

Here is the progged CAPE values across AR...



Surface dew points look to be within 55-60F across AR....



...while surface temps look to be within a 65-70F range.



As the surface low gets closer to AR, it'll bring with it a dry slot which should aid in thunderstorm development.  You can clearly see the dry slot in the model below and the one following...





Whatever thunderstorms that do develop will also be aided by a pretty good breeze at 500mb...



Given the data, strong winds and hail do appear to be the main threat, but given the kinematics and thermodynamics at play, there could be several reports of tornadoes across AR today.  For our general area, we could see a few rumbles of thunder from a decaying squall line that looks to pass through here during the overnight hours.  The severe chances should minimize, perhaps even disappear, as the sun goes down, but the hail chances and the possibilities of gusty winds should remain.

[Curt]

Lots of low clouds this morning which, if they dont break, may limit instability. Per satellite from LIT, they may be breaking up in a couple of hours.

http://aviationweather.gov/adds/satellite/displaySat.php?region=LIT&isingle=multiple&itype=vis

[Eric]

MESOSCALE DISCUSSION 0166
   NWS STORM PREDICTION CENTER NORMAN OK
   1221 PM CST WED MAR 10 2010
   
   AREAS AFFECTED...CNTRL/SRN MS...W-CNTRL/SRN AL
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
   
   VALID 101821Z - 101945Z
   
   THREAT FOR LARGE HAIL AND ISOLATED TORNADOES WILL INCREASE THIS
   AFTERNOON WITH A TORNADO WATCH LIKELY BECOMING NEEDED.
   
   LOW-TOPPED CONVECTION HAS SHOWN A GRADUAL INCREASE IN
   COVERAGE/INTENSITY ACROSS SERN MS/SWRN AL NWWD INTO CNTRL MS.
   CONTINUED DIURNAL HEATING WITH SURFACE TEMPERATURES WARMING INTO THE
   MIDDLE 70S AND FURTHER DESTABILIZATION SHOULD SUPPORT ISOLATED TO
   SCATTERED TSTM DEVELOPMENT DURING THE AFTERNOON. WITH REGION LYING
   ON THE ERN FRINGE OF STEEP MID-LEVEL LAPSE RATES /PER UPSTREAM
   MORNING RAOBS AND LATEST OBJECTIVE ANALYSIS/...SEVERE HAIL WOULD
   LIKELY BE THE PRIMARY THREAT. HOWEVER...30-35 KT SWLY FLOW AT 1 KM
   AGL /PER REGIONAL VWP DATA/ WILL BE SUFFICIENT FOR LOW-LEVEL STORM
   ROTATION...AND SHOULD BE AUGMENTED BE AMBIENT SHEAR ALONG BAROCLINIC
   BOUNDARY LYING ROUGHLY FROM AROUND 40 SW CBM TO NEAR MGM AS OF 18Z.
   GIVEN THE RICHNESS OF BOUNDARY LAYER MOISTURE WITH MEAN MIXING
   RATIOS AROUND 12-13 G/KG /REF 18Z LIX RAOB/...ISOLATED TORNADOES
   APPEAR PROBABLE.
   
   ..GRAMS.. 03/10/2010

[Eric]

JAN AFD from late morning...

THE ENVIRONMENT WILL BE QUITE VOLATILE BY LATE AFTERNOON WITH MLCAPE
RANGING FROM 1200-1700 J/KG. LAPSE RATES WILL BE VERY STEEP WITH
VERTICAL TOTALS 28-29C. THE CAPPING INVERSION WILL OFFER A "LOADED
GUN" TYPE SOUNDING FOR SOME IF NOT MOST OF THE CWA. THIS WILL BE
BASICALLY LYING IN WAIT FOR THE BETTER ASCENT TO GET THINGS TO FIRE.
IT APPEARS THAT THE COMBINATION OF THE ABV FACTORS WILL LIKELY KEEP
THE INITIAL ACTIVITY MORE ON THE ISO/SCT SIDE. THIS IS USUALLY THE
WORST CASE SCENARIO AS THE FEW STORMS THAT DO EXIST...ARE VERY NASTY
AND WILL BE THOSE DISCRETE SUPERCELL STORMS. IF THEY MANAGE TO
DEVELOP...EXPECT VERY LARGE HAIL WITH GOLF BALL TO BASEBALL SIZE
POSSIBLE. SAYING THIS...I WANT TO EXPRESS THAT THERE IS AN EQUAL
CHANGE THAT THE CAPPING MAY REMAIN TOO STRONG AND STORMS WAIT EVEN
LONGER TO DEVELOP. THIS IS VERY CONDITIONAL AND I`M JUST LAYING OUT
THE POTENTIAL IF WE CAN ACTUALLY GET STORMS TO FIRE. AS FOR
TIMING...IT IS BECOMING MORE LIKELY THAT STORMS WILL WAIT UNTIL AT
LEAST 4 PM OR LATER TO GET GOING. ACTUALLY...PRIME TIME MAY BE
BETWEEN 8 PM AND 4 AM. AS FOR THE OTHER SVR RISKS...LIGHTNING WILL BE
SUBSTANTIAL WITH ANY STORM DUE TO THE COLD AIR ALOFT AND UPPER JET
STRUCTURE. THE TORNADO RISK WILL INCREASE AS THE NIGHT GOES ON AS THE
LOW LEVEL JET AND INCREASING LOW LEVEL SHEAR INCREASE. AT THIS
TIME...LOCATIONS ALONG AND EAST OF A BROOKHAVEN TO LOUISVILLE LINE
APPEAR TO HAVE THE GREATEST TORNADO RISK FROM LATE EVE TO 4-5 AM.
THERE IS A RISK THAT A STRONG TORNADO MAY OCCUR AS WELL. DAMAGING
WINDS WILL ALSO BE POSSIBLE...ESPECIALLY WITH ANY ACTIVITY ACROSS THE
W HALF AS THE DRY AIR ALOFT WILL SUPPORT STRONGER DOWNDRAFTS. I ALSO
WANTED TO MENTION THAT MOST OF THE AREA COULD SEE A FEW ROUNDS OF
STORMS. THIS RISK IS GREATEST ACROSS THE E HALF.

FINALLY...AS THE MAIN PUSH OF LIFT MOVES OVER...THE GREATEST STORM
ACTIVITY WILL OCCUR ACROSS THE E HALF OF THE CWA FROM 10 PM TO 4-5
AM. EXPECT ALL THE STORM ACTIVITY TO BE EAST OF THE REGION BY 6 AM.

THERE ALSO EXIST SOME HVY RAIN/FLASH FLOODING POTENTIAL. THIS IS
MAINLY DUE TO THE PAST 24HR RAINFALL. THIS WILL EXIST ACROSS SOME THE
EASTERN AREAS AND WILL HIGHLY DEPEND ON HOW THE NEW STORM ACTIVITY
LATER TONIGHT WILL SETUP. WE WILL BE LOOKING INTO THE POSSIBILITY FOR
A FF WATCH FOR SOME OF THE EAST WITH THE AFTERNOON FORECAST.

Nocturnal activity?     "Loaded gun"?     Not bad for our first "real" threat of the severe weather season...

[beneficii]

Sun out with widespread 1500+ J/kg SBCAPE reaching Memphis.

[servocrow]

Scary nocturnal threats...Great explanations throughout the morning, Eric..Thanks!!