SWODY1
SPC AC 151953
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0253 PM CDT TUE MAR 15 2011
VALID 152000Z - 161200Z
...NO SVR TSTM AREAS FORECAST...
.CHANGE TO PREV FORECAST...
1/ ADD GENERAL TSTM PROBABILITIES TO NCNTRL/NERN TX
OTHERWISE...ONGOING FORECAST ON TARGET.
...NCNTRL/NERN TX...
OVERLAY OF 12Z MAF WITH DFW SOUNDING INDICATES MARGINAL ELEVATED
INSTABILITY HAS EVOLVED AS INHIBITION WEAKENS AND THE 850-700 MB
MOISTENS OWING TO LIFT FROM A WEAK UPPER IMPULSE. EXPECT LOW
PROBABILITIES OF TSTMS TO EXTEND DOWNSTREAM INTO NERN TX THROUGH
THIS EVENING.
..RACY.. 03/15/2011
.PREV DISCUSSION... /ISSUED 1122 AM CDT TUE MAR 15 2011/
...PACIFIC NW...
THE EXIT REGION OF AN INTENSE UPPER-LEVEL JET STREAK OVER THE ERN
PACIFIC WILL DEVELOP INLAND DURING THE D1 PERIOD...ADVANCING THROUGH
NRN CA/SRN ORE ENEWD TO THE NRN HIGH PLAINS BY WED MORNING. A
SHORT-WAVE TROUGH LOCATED ON THE CYCLONIC SIDE OF UPPER JET IS
FORECAST TO REACH THE WA/ORE COASTS BY 16/00Z...CONTRIBUTING TO A
DOWNSTREAM CORRIDOR OF SIGNIFICANT HEIGHT FALLS/DYNAMIC FORCING FOR
ASCENT WHICH WILL PROGRESSIVELY OVERSPREAD THE REGION TODAY.
EARLY VISIBLE SATELLITE IMAGERY INDICATES THAT WIDESPREAD CLOUDINESS
WILL LIMIT THE DEGREE OF DIABATIC HEATING WITHIN THE BOUNDARY LAYER.
HOWEVER...SUBSTANTIAL MIDLEVEL COOLING AND RESULTANT STEEPENING OF
LAPSE RATES WILL RESULT IN WEAK AIR MASS DESTABILIZATION /I.E.
MLCAPE VALUES OF 100-200 J PER KG/ LATER TODAY FROM THE COAST INLAND
TOWARD THE COLUMBIA BASIN. GIVEN THE STRONG...LARGELY
UNIDIRECTIONAL WSWLY DEEP-LAYER SHEAR FORECAST...THE POTENTIAL WILL
EXIST FOR EMBEDDED BOWING STRUCTURES CAPABLE OF LOCALLY STRONG WIND
GUSTS...SOME HAIL AND PERHAPS A BRIEF TORNADO. THIS SEVERE WEATHER
POTENTIAL IS EXPECTED TO DIMINISH BY MID/LATE EVENING AS THE
BOUNDARY LAYER COOLS/STABILIZES.
...ERN GULF COAST INTO MID ATLANTIC STATES...
MIDLEVEL LOW OVER THE LOWER OH VALLEY THIS MORNING WILL WEAKEN
CONSIDERABLY OVER THE NEXT 24-HR WHILE LIFTING NEWD THROUGH THE
UPPER OH VALLEY WITHIN BROADER CYCLONIC FLOW REGIME IN PLACE OVER
THE ERN THIRD OF THE NATION. ASSOCIATED SURFACE LOW WILL LIKEWISE
WEAKEN WHILE TRAVERSING SAME GENERAL AREA WITH TRAILING COLD FRONT
ADVANCING TOWARD THE ATLANTIC COAST. WEDGE FRONT SITUATED ACROSS
CNTRL PARTS OF GA/SC AS OF LATE MORNING WILL RETREAT
NWD...POTENTIALLY REACHING THE TIDEWATER REGION LATE TONIGHT.
BASED ON CURRENT VISIBLE SATELLITE IMAGERY AND LATEST MODEL
GUIDANCE...IT APPEARS THAT DIURNAL TSTM DEVELOPMENT WILL REMAIN
FAVORED WITHIN NARROW AXIS OF RELATIVELY HIGHER THETA-E AIR IN PLACE
AHEAD OF COLD FRONT OVER SERN AL...THE FL PNHDL INTO SRN /AND
EVENTUALLY/ CNTRL GA. GIVEN THE WEAK LAPSE RATES AND MARGINAL
BOUNDARY LAYER MOISTURE CONTENT...NO SEVERE WEATHER IS EXPECTED.
THEREAFTER...SOME POTENTIAL WILL EXIST FOR TSTM DEVELOPMENT ALONG
RETREATING WEDGE FRONT OVER THE TIDEWATER AREA LATER TONIGHT INTO
WED MORNING. MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE STRONGER
FORCING FOR ASCENT AND MORE FAVORABLE VERTICAL SHEAR WILL REMAIN
DISPLACED TO THE N OF WHERE ANY WEAK SURFACE-BASED INSTABILITY MAY
DEVELOP.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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