SWODY1
SPC AC 140608
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0108 AM CDT FRI MAR 14 2008
VALID 141200Z - 151200Z
..THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF OK AND SRN KS
INTO THE LOWER MS AND TN VALLEYS...
..SYNOPSIS...
INITIAL SHORTWAVE TROUGH CURRENTLY MOVING INTO THE MS VALLEY REGION
WILL CONTINUE EAST THROUGH THE SERN STATES...REACHING THE CAROLINAS
OVERNIGHT. SECONDARY IMPULSE OVER NWRN GULF WILL MOVE EAST INTO NRN
FL DURING THE DAY. AN UPSTREAM LOW AMPLITUDE SHORTWAVE TROUGH WITH
ATTENDANT STRONG MID LEVEL JET WILL REACH THE SRN PLAINS BY FRIDAY
EVENING. WEAK SURFACE LOW IS FORECAST TO SHIFT EWD INTO THE MID
ATLANTIC IN ASSOCIATION WITH LEAD IMPULSE WITH TRAILING FRONT
EXTENDING SWWD THROUGH THE TN VALLEY...LOWER MS VALLEY AND OK. WRN
PORTIONS OF THIS FRONT WILL STALL AS CYCLOGENESIS COMMENCES AND THE
SLY LOW LEVEL JET STRENGTHENS IN RESPONSE TO APPROACHING WAVE. THE
DRYLINE WILL EXTEND SWD FROM THE LOW THROUGH ERN TX.
..N CNTRL OK THROUGH SRN KS EWD INTO THE LOWER MS AND TN VALLEYS...
PARTIALLY MODIFIED GULF AIR WITH DEWPOINTS MOSTLY IN THE 50S IN OK
AND NRN AR...BUT WITH SOME LOW 60S OVER THE SRN PARTS OF THE LOWER
MS VALLEY WILL RESIDE SOUTH OF THE FRONT BENEATH VERY STEEP MID
LEVEL LAPSE RATES. HOWEVER...MUCH OF THIS WARM SECTOR WILL BE CAPPED
MUCH OF THE DAY DUE TO PRESENCE OF EML. THE ATMOSPHERE WILL
GRADUALLY DESTABILIZE AS THE BOUNDARY LAYER WARMS DURING THE DAY AND
AS STRENGTHENING LOW LEVEL JET ADVECTS MOISTURE NWD BENEATH COLD MID
LEVEL TEMPERATURES DURING THE EVENING WITH -20C AT 500 MB AND MUCAPE
AROUND 1500 J/KG LIKELY. INCREASING FORCING FOR ASCENT ATTENDING
EXIT REGION OF EWD ADVANCING UPPER JET AND STRENGTHENING LOW LEVEL
JET WILL RESULT IN INCREASING POTENTIAL FOR SURFACE BASED STORMS IN
VICINITY OF THE FRONT FROM NRN OK...SRN KS EWD INTO PART OF AR. BULK
SHEAR PROFILES OF 50 + KT WILL SUPPORT SUPERCELLS WITH STORMS THAT
MANAGE TO DEVELOP. PRIMARY THREAT WILL BE ISOLATED LARGE HAIL AND
POSSIBLY DAMAGING WIND GUSTS. AN ISOLATED TORNADO OR TWO CANNOT BE
RULED OUT...ESPECIALLY DURING THE EVENING FROM NERN OK INTO PARTS OF
AR BEFORE THE BOUNDARY LAYER DECOUPLES WHERE STRENGTHENING LOW LEVEL
JET WILL RESULT IN LARGE LOW LEVEL HODOGRAPHS.
THUNDERSTORM POTENTIAL IS EXPECTED TO INCREASE OVERNIGHT WHERE THE
STRENGTHENING LOW LEVEL JET WILL INCREASE LIFT NORTH OF THE FRONT.
THIS ACTIVITY WILL BECOME INCREASINGLY ELEVATED...BUT COLD AIR
ALOFT...STEEP MID LEVEL LAPSE RATES AND BULK SHEAR SUPPORTIVE OF
SUPERCELLS WILL CONTRIBUTE TO A THREAT OF LARGE HAIL. ACTIVITY WILL
LIKELY EXPAND EWD INTO PARTS OF THE TN VALLEY OVERNIGHT.
..N CNTRL FL...
IMPULSE OVER THE GULF WILL GRADUALLY SHIFT EWD INTO FL BY AFTERNOON.
THUNDERSTORM POTENTIAL WILL INCREASE AND MODELS INDICATE A STRONG
SWLY LOW LEVEL JET WILL ACCOMPANY THIS FEATURE AND CONTRIBUTE TO THE
NEWD ADVECTION OF RICHER LOW LEVEL MOISTURE INTO PARTS OF FL. LOW
LEVEL HODOGRAPHS WILL SUPPORT POTENTIAL FOR SUPERCELLS AND BOWING
SEGMENTS WITH A THREAT FOR ISOLATED DAMAGING WIND AND PERHAPS
ISOLATED TORNADOES. AT THIS TIME...PRIMARY UNCERTAINTY IS HOW MUCH
BOUNDARY LAYER RECOVERY WILL OCCUR IN ASSOCIATION WITH THIS FEATURE.
SO RISK IN THIS AREA APPEARS SOMEWHAT CONDITIONAL. IF IT BEGINS TO
APPEAR SUFFICIENT MOISTURE RETURN AND DESTABILIZATION WILL DEVELOP
OVER FL AN UPGRADE TO SLIGHT RISK MIGHT BE NECESSARY IN LATER
UPDATES.
..SERN U.S...
SCATTERED CONVECTION WILL LIKELY CONTINUE EWD THROUGH PARTS OF THE
SERN STATES FROM EARLY FRIDAY INTO THE AFTERNOON IN ASSOCIATION WITH
LEAD SHORTWAVE TROUGH. CURRENT THINKING IS MOST OF THIS ACTIVITY
WILL BEGIN TO OUTRUN THE LOW LEVEL MOISTURE RETURN AND MAY REMAIN AT
LEAST SLIGHTLY ELEVATED. DESTABILIZATION WILL OCCUR IN WAKE OF THE
CONVECTION...BUT SUBSIDENCE IN WAKE OF LEAD WAVE AND LACK OF A LOW
LEVEL FOCUS SUGGEST IT MAY BE DIFFICULT TO INITIATE STORMS UPSTREAM.
HOWEVER...AS THE BOUNDARY LAYER DESTABILIZES UPSTREAM OF EXISTING
ACTIVITY...INCREASING WSWLY UNSTABLE INFLOW COULD RESULT IN SOME
INTENSIFICATION OF EXISTING STORMS WITH PRIMARY THREAT BEING HAIL.
.DIAL.. 03/14/2008
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