DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 221249
SWODY1
SPC AC 221247

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0647 AM CST SAT FEB 22 2014

VALID 221300Z - 231200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
UPPER-AIR PATTERN THIS PERIOD WILL BE CHARACTERIZED BY HUDSON BAY
VORTEX...LEADING BROADLY CYCLONIC FLOW ACROSS GREAT MAJORITY OF
CONUS. THAT FLOW WILL BE INTERSPERSED WITH VERY LOW-AMPLITUDE
PERTURBATIONS AND ACCOMPANYING/ELONGATED VORTICITY BANNERS...BUT NO
SUBSTANTIAL SHORTWAVES.

AT SFC...FRONTAL ZONE ASSOCIATED WITH HUDSON BAY VORTEX HAS STALLED
FROM CENTRAL FL PENINSULA WSWWD ACROSS CENTRAL GULF. FRONTOLYSIS IS
FCST OVER WRN GULF WHILE MIDDLE-ERN GULF AND FL SEGMENTS WEAKEN AND
RETREAT NWD MORE SLOWLY. SEPARATE AREA OF SFC BAROCLINICITY OVER TX
PANHANDLE...OK AND AR WILL REMAIN DISPLACED FROM CONVECTIVE
POTENTIAL DAY-1.

...CENTRAL GULF COAST AND LOWER DELTA REGIONS...
SCATTERED TSTMS ARE FCST TO DEVELOP OVERNIGHT -- MAINLY AFTER 6Z --
INCREASING IN COVERAGE AS REGIME SPREADS/SHIFTS EWD ALONG LA/MS/AL
COASTS TOWARD WRN FL PANHANDLE. MOST VIGOROUS CELLS MAY OFFER HAIL
NEAR SVR LIMITS...HOWEVER THREAT APPEARS TOO MRGL/ISOLATED FOR
CATEGORICAL RISK.

TONIGHT...LOW-LEVEL TRAJECTORIES FROM S OF FRONT SHOULD BEGIN TO
ADVECT CONVECTIVELY SUPPORTIVE MOISTURE OVER RELATIVELY
STABLE/LOW-THETAE BOUNDARY LAYER NEAR COAST. MOIST FETCH SHOULD
SATURATE SOUNDINGS IN 850-900 MB LAYER...BENEATH SUFFICIENTLY STEEP
MIDLEVEL LAPSE RATES TO PROMOTE 500-1000 J/KG MUCAPE...LOCALLY
HIGHER. PARCELS WILL BE LIFTED ISENTROPICALLY TO RESULTING
LFC...AMIDST EFFECTIVE SHEAR MAGNITUDES MOSTLY IN 30-40 KT RANGE.

...FL PENINSULA...
WIDELY SCATTERED TO SCATTERED TSTMS ARE EXPECTED TODAY IN CLUSTERS.
A FEW OF THESE TSTMS MAY PRODUCE STG GUSTS...HOWEVER OVERALL
INTENSITY/ORGANIZATION OF WIND RISK WILL BE LIMITED BY LACK OF MORE
ROBUST SHEAR/BUOYANCY VALUES. MOISTURE-CHANNEL IMAGERY AND MOST
PROGS INDICATE NO SUBSTANTIAL UPPER-AIR SUPPORT OR SUPPRESSION OF
CONVECTIVE POTENTIAL...WHICH WILL BE DRIVEN MAINLY BY AREAS OF
LOW-LEVEL LIFT.

SFC FRONTAL ZONE...ALONG WITH SEA BREEZES...DIFFERENTIAL-HEATING
LINES AND OUTFLOW BOUNDARIES S OF FRONT...WILL BE PRIMARY FOCI FOR
CONVECTIVE INITIATION. ASIDE FROM ONGOING CONVECTION OVER CENTRAL
FL...TSTMS SHOULD FORM THIS AFTN...AS DIURNAL/DIABATIC HEATING ACTS
ON THOSE BOUNDARIES IN PRESENCE OF WEAK CINH. THAT HEATING WITH SFC
DEW POINTS UPPER 60S/LOWER 70S F SHOULD BE SUFFICIENT TO OFFSET
SMALL LAPSE RATES ALOFT FOR MLCAPE TO REACH 1000-1500 J/KG RANGE.
WEAK LOW-LEVEL WIND SPEEDS WILL KEEP HODOGRAPHS SMALL...THOUGH 60-70
KT ANVIL-LEVEL WLYS SHOULD AID IN VENTING UPPER REACHES OF TSTMS.

..EDWARDS/DEAN.. 02/22/2014

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.