SWODY3
SPC AC 210818
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0218 AM CST MON NOV 21 2011
VALID 231200Z - 241200Z
...SYNOPSIS...
IN MID-UPPER LEVELS...STG SHORTWAVE TROUGH NOW OVER CA SHOULD MOVE
ENEWD ACROSS OH VALLEY AND MID-SOUTH REGIONS...PHASING WITH
NRN-STREAM PERTURBATION OVER LOWER GREAT LAKES REGION AROUND
BEGINNING OF PERIOD AND EXTENDING SWWD ACROSS MS. TROUGH SHOULD
MOVE OFFSHORE MOST OF ATLC COAST EXCEPT NEW ENGLAND DURING
24/00Z-24/06Z TIME FRAME.
RELATED SFC CYCLONE SHOULD MOVE EWD FROM INTERIOR MID-ATLANTIC
REGION ACROSS NEW ENGLAND EARLY IN PERIOD...WHILE TRAILING COLD
FRONT CROSSES APPALACHIANS/PIEDMONT. FRONT SHOULD MOVE OFFSHORE
JUST AHEAD OF MID-UPPER TROUGH.
...MID-ATLANTIC...TIDEWATER AND COASTAL PLAIN...
BAND OF MOSTLY LOW-TOPPED CONVECTION IS PROBABLE INVOF SFC COLD
FRONT...WITH CONDITIONAL POTENTIAL FOR DAMAGING CONVECTIVE GUSTS.
THOUGH WINDS WILL BE LARGELY UNIDIRECTIONAL IN NATURE...STG
DEEP-LAYER SPEED SHEAR IS EXPECTED...ESPECIALLY FROM TIDEWATER AREA
NWD. MEANWHILE...WEAK LOW-MIDDLE LEVEL LAPSE RATES WILL LIMIT
BUOYANCY...MORE SO FROM VA NWD THAN OVER CAROLINAS/GA. FRONTAL
TIMING DIFFERENCES AMONG MODELS ARE MESOSCALE IN NATURE...BUT STILL
CRUCIAL FOR DETERMINING WHETHER FOREGOING BOUNDARY LAYER WILL
DESTABILIZE ENOUGH TO SUPPORT SVR POTENTIAL PRIOR TO FROPA IN
MID-ATLANTIC AND CAROLINAS. SPECTRAL INDICATES NO...BUT REPRESENTS
FAST OUTLIER COMPARED TO OPERATIONAL NAM AND BULK OF SREF MEMBERS.
EVEN WITH SLOWER CONSENSUS FROPA...STRONGEST ISALLOBARIC FORCING
WILL REMAIN WELL NE OF FAVORABLY MOIST BOUNDARY LAYER WHILE MOVING
AWAY...RESULTING IN SUBSTANTIAL WLY COMPONENT TO PREFRONTAL SFC
WINDS...AND ACCORDINGLY REDUCED LOW-LEVEL SHEAR/CONVERGENCE. GIVEN
THESE CAVEATS...WILL INTRODUCE JUST MRGL UNCONDITIONAL SVR
PROBABILITIES ATTM.
..EDWARDS.. 11/21/2011
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.
No comments:
Post a Comment