DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 241235
SWODY1
SPC AC 241233

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0633 AM CST MON FEB 24 2014

VALID 241300Z - 251200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
UPPER-AIR PATTERN WILL BE CHARACTERIZED BY PERSISTENT/BROAD CYCLONIC
FLOW OVER MUCH OF CENTRAL/ERN CONUS. STG UPPER-LEVEL CYCLONE -- NOW
EVIDENT IN MOISTURE-CHANNEL IMAGERY OVER NERN PAC AND CENTERED INVOF
38N148W -- IS FCST TO EJECT NEWD...AS DOWNSTREAM RIDGE AMPLIFIES
FROM NWRN MEX UP W COAST STATES AND BC/YUKON. PRIMARY SHORTWAVE
TROUGH -- CURRENTLY EVIDENT OVER SRN PORTIONS SK/MB BORDER WWD
ACROSS SRN AB -- IS FCST TO MOVE SEWD ACROSS DAKOTAS BY 00Z THEN
PIVOT/ACCELERATE EWD ACROSS WI TO LOWER MI BY END OF PERIOD. IN SRN
STREAM...MOISTURE-CHANNEL LOOPS INDICATE WEAK PERTURBATION OVER SERN
NM...W TX PERMIAN BASIN AND COAHUILA. THIS FEATURE IS RESOLVED TO
SOME EXTENT BY 6Z OPERATIONAL NAM/SPECTRAL MODELS...WHICH PROG SRN
PORTION TO MOVE ACROSS NRN GULF BETWEEN UPPER TX COAST AND FL
COASTAL BEND DURING 00Z-12Z TIME FRAME.

AT SFC...RESIDUAL/DIFFUSE AND QUASISTATIONARY FRONTAL ZONE WAS
EVIDENT FROM S FL NWWD ACROSS NERN GULF THEN WWD ACROSS MOSTLY SHELF
WATERS TO LOWER TX COAST. THAT FRONT WILL BE OVERTAKEN FROM W-E BY
COLD FRONT NOW MOVING SEWD ACROSS GA...SRN AL...SRN LA AND S-CENTRAL
TX. COMBINED FRONTAL ZONE SHOULD STALL ACROSS NWRN GULF AND S
TX...RETURNING NWD AS WARM FRONT OVERNIGHT OVER TX.

...CENTRAL/ERN FL PENINSULA...
WIDELY SCATTERED TSTMS MAY DEVELOP THIS AFTN ALONG
SEA-BREEZE/CONVERGENCE ZONE OVER ERN PENINSULA...BENEATH DEEP-LAYER
WLYS...AND AFTER PASSAGE OF CLOUD DEBRIS FROM MORNING ACTIVITY OVER
GULF. ALTHOUGH E-COAST CONVERGENCE ZONE SHOULD CONCENTRATE BULK OF
CONVECTIVE POTENTIAL...FRONT AND/OR OUTFLOW/DIFFERENTIAL-HEATING
BOUNDARIES FROM EARLY CONVECTION ALSO MIGHT FOSTER SECONDARY TSTM
INITIATION. FCST SOUNDINGS SUGGEST DIABATIC SFC HEATING AND MID-60S
TO LOW-70S F SFC DEW POINTS WILL BE SUFFICIENT TO YIELD AROUND
1000-1500 J/KG MLCAPE ALONG I-95 CORRIDOR IN CENTRAL FL...BUT WITH
MORE PRONOUNCED AND POTENTIALLY BUOYANCY-LIMITING MIDLEVEL STABLE
LAYER FARTHER S.

WEAK NEAR-SFC WIND SPEEDS WILL KEEP BOUNDARY-LAYER HODOGRAPHS
SMALL...HOWEVER CONCENTRATIONS OF VORTICITY ALONG CONVERGENCE LINE
MAY BRIEFLY SUPPORT STORM ROTATION. MULTICELLS SHOULD BE
PREDOMINANT MODE...SOME OF WHICH MAY BECOME ORGANIZED AMIDST 70-KT
ANVIL-LEVEL FLOW AND 30-40 KT EFFECTIVE SHEAR MAGNITUDES. FCST
SOUNDINGS REASONABLY SUGGEST SHALLOW INVERTED-V THERMODYNAMIC
PROFILES IN BOUNDARY LAYER AND SEASONALLY COLD AIR ALOFT -- E.G. -10
TO -12 C AT 500 MB. GIVEN THESE CONDITIONS...ISOLATED/MRGLLY SVR
HAIL AND/OR ISOLATED DAMAGING GUSTS MAY OCCUR.

...N TX...RED RIVER REGION TO ARKLATEX...
ISOLATED TO WIDELY SCATTERED ELEVATED TSTMS MAY DEVELOP LATE
OVERNIGHT -- E.G. INITIALLY AFTER 06Z AND MOSTLY AFTER 09Z -- IN
ZONE OF ELEVATED LOW-LEVEL WAA AND MRGL MOISTURE. UPPER-LEVEL
SUPPORT WILL BE MINIMAL BY THAT TIME...WITH SRN-STREAM PERTURBATION
WELL E OF AREA AND NO SUBSTANTIAL FEATURES EVIDENT UPSTREAM.
HOWEVER...PLANAR PROGS AND TIME SERIES OF FCST SOUNDINGS SUGGEST
GRADUAL INCREASE IN BOTH THETAE AND RH OF AIR MASS AROUND 850 MB
OVERNIGHT. MINIMALLY INHIBITED MUCAPE OF 300-700 J/KG SHOULD
DEVELOP BY 09-12Z TIME FRAME...ROOTED AROUND 850 MB...WITH
CONVECTION SUPPORTED BY ISENTROPIC LIFT TO LFC. DEEP SHEAR AND
BUOYANCY EACH APPEAR TOO MODEST FOR SVR THREAT.

...S TX...
ISOLATED TO WIDELY SCATTERED TSTMS MAY SPREAD ENEWD FROM NUEVO LEON
AND/OR REDEVELOP TODAY AHEAD OF MEXICAN LOBE OF AFOREMENTIONED
SHORTWAVE TROUGH...AFFECTING PORTIONS S TX. WEAKENING OF INITIALLY
ROBUST EML-RELATED CINH IS EVIDENT WITH SWD EXTENT AND WITH TIME
TODAY ACROSS S TX...ALONG WITH UPPER 60S TO LOW 70S F SFC DEW POINTS
AND POCKETS OF STG SFC HEATING MAINLY AHEAD OF FRONT. ALTHOUGH NLY
COMPONENT OF PREFRONTAL FLOW WILL LIMIT CONVERGENCE...SOME FRONTAL
LIFT MAY COMBINE WITH SFC HEATING IN SUPPORTING UPDRAFT DEVELOPMENT.
ISOLATED TSTMS ALSO MAY DEVELOP BEHIND FRONT. OVERALL COVERAGE
SHOULD BE LIMITED BY LACK OF MORE ROBUST LIFT AGAINST ANTECEDENT EML
CINH.

..EDWARDS/BOTHWELL.. 02/24/2014

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