[MCD] SWOMCD

Fri Dec 1 16:36:46 UTC 2006

ACUS11 KWNS 011638
SWOMCD
SPC MCD 011638 
CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-011845-

MESOSCALE DISCUSSION 2261
NWS STORM PREDICTION CENTER NORMAN OK
1038 AM CST FRI DEC 01 2006

AREAS AFFECTED...PORTIONS PA...WRN/SRN NY...DE...ERN
WV...NJ...MD...NRN/CENTRAL VA...DC.

CONCERNING...SEVERE THUNDERSTORM WATCH 874...

VALID 011638Z - 011845Z

BROKEN BAND OF LOW-TOPPED CONVECTION -- INCLUDING SPORADIC TSTMS --
IS FCST TO CONTINUE MOVING ENEWD 40-45 KT ACROSS WW AREA...AND
PERHAPS ADJACENT PORTIONS WRN NY AND WRN/CENTRAL VA.  ACTIVITY
CONSISTS OF SEVERAL QUASI-LINEAR SEGMENTS THAT ARE DISCRETE AT 50
DBZ REFLECTIVITY LEVELS.  SEVERAL REPORTS OF DAMAGE FROM NON-TSTM
GUSTS -- BUT STILL CONVECTIVE IN ORIGIN -- HAVE BEEN RECEIVED FROM
WRN PA AND NRN WV WITH THIS ACTIVITY.  EXPECT SVR POTENTIAL TO
PERSIST EWD THROUGH WW AND ALSO EXTEND INTO PORTIONS SRN NY..ERN PA
AND NJ WITHIN 3-4 HOURS.  ADDITIONAL WW MAY BE REQUIRED FOR THOSE
AREAS ADJACENT TO WW 874.

SFC MESOANALYSIS SHOWS MAIN CYCLONE OVER WRN LE...OCCLUDED FRONT EWD
ACROSS LE TO TRIPLE POINT NEAR WRN TIP NY.  WARM FRONT CONTINUES EWD
INVOF NY/PA BORDER THEN ENEWD ACROSS SERN NY TO JUST S ALB...THEN
EXTREME SRN VT.  PRIND WARM FRONT WILL LIFT SLOWLY NWD ACROSS WRN NY
AND SPREAD NEUTRALLY TO MRGLLY UNSTABLE WARM SECTOR INTO ELM/BGM/ALB
AND PERHAPS ITH/GFL AREAS.  GIVEN STRONG STATIC STABILITY EVIDENT N
OF WARM FRONT...THIS BOUNDARY SHOULD SERVE AS NRN BOUND OF SVR WIND
POTENTIAL.  WAA AND WEAK SFC DIABATIC HEATING E OF FRONT WILL
DESTABILIZE PRE-STORM BOUNDARY LAYER SOMEWHAT...RESULTING IN PATCHY
MUCAPES 100-400 J/KG...SOME OF WHICH WILL REACH INTO ICING LAYERS
SUITABLE FOR LIGHTNING PRODUCTION.  GIVEN INTENSITY OF KINEMATIC
FIELDS JUST ABOVE SFC AND POTENTIAL FOR DOWNWARD MOMENTUM
TRANSFER...DAMAGING GUST POTENTIAL WILL EXIST ALMOST ANYWHERE WITHIN
THIS ACTIVITY...BUT WILL BE ENHANCED LOCALLY INVOF LEWP/BOW
FORMATIONS THAT SHOULD DEVELOP WITHIN THOSE SEGMENTS.  QLCS-TYPE
TORNADIC SPINUP ALSO CANNOT BE RULED OUT.

..EDWARDS.. 12/01/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...BUF...CTP...LWX...RNK...PBZ...RLX...

38228023 39687965 41687937 42357950 42417718 42687540
42937387 42667335 41797352 40457397 39837405 39427428
38957482 38757538 38047789 37927995 