MESO: Mesoscale Discussion 1672

ACUS11 KWNS 210109
SWOMCD
SPC MCD 210109
MEZ000-210245-

MESOSCALE DISCUSSION 1672
NWS STORM PREDICTION CENTER NORMAN OK
0809 PM CDT WED JUL 20 2011

AREAS AFFECTED...NRN/CNTRL MAINE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 210109Z - 210245Z

WHILE THE THREAT FOR A DMGG WIND GUST OR TWO CANNOT BE ENTIRELY
RULED OUT DURING THE NEXT HOUR OR TWO IN ASSOCIATION WITH ONGOING
CONVECTION...THE OVERALL SVR THREAT ACROSS NRN/CNTRL MAINE IS
DIMINISHING. WHILE CONVECTIVE TRENDS WILL CONTINUE TO BE
MONITORED...THE ISSUANCE OF A WW IS UNLIKELY.

CONVECTION THAT FORMED INVOF A BAROCLINIC ZONE DRAPED ACROSS SERN
CANADA ATTENDANT TO AN EWD-MIGRATING...MID-LEVEL SHORTWAVE TROUGH
EVOLVED INTO A LINE SEGMENT. THIS FEATURE CURRENTLY STRETCHES FROM
PORTIONS OF SRN AROOSTOOK COUNTY INTO FAR ERN PISCATAQUIS
COUNTY...AND IS MOVING ESEWD AROUND 45-50 KT. CARIBOU WSR-88D TRENDS
SUGGEST THAT THIS LINE IS BECOMING INCREASINGLY DISORGANIZED...AS IT
CROSSES A SHALLOW BAROCLINIC ZONE THAT MARKS THE GRADIENT BETWEEN
STABLE MARINE-LAYER TRAJECTORIES FROM THE WRN ATLANTIC TO ITS EAST
AND MARGINAL INSTABILITY TO ITS WEST. THIS WEAKENING TREND IS ALSO
CONSISTENT WITH THE RECENT DOWNWARD TREND IN OBSERVED CG FLASH
RATES. AS INFLOW TO ONGOING CONVECTION BECOMES INCREASINGLY
STABLE...IT WILL LIKELY CONTINUE TO LOSE ITS VIGOR PRIOR TO EXITING
THE UNITED STATES. FURTHERMORE...MID-LEVEL HEIGHT RISES IN THE WAKE
OF THE AXIS OF THE SHORTWAVE TROUGH /PER MULTI-DETERMINISTIC MODEL
GUIDANCE/ ALSO INDICATE A LESSENING THREAT FOR CONVECTIVE SUSTENANCE
OR UPSTREAM DEVELOPMENT. REGARDLESS...WITH 48 KT OF 0-6-KM BULK
SHEAR PER CARIBOU VWP...THE LINE MAY RETAIN SOME ORGANIZED
CONVECTIVE CHARACTERISTICS AND YIELD A LOCALIZED THREAT FOR STRONG
WIND GUSTS...AIDED BY MODEST DCAPE VALUES IN PLACE ALONG WITH
STORM-SCALE EFFECTS. WHILE A DMGG WIND GUST OR TWO CANNOT BE RULED
OUT...THE OVERALL THREAT WILL BE SUBSTANTIALLY TEMPERED BY THE
AFOREMENTIONED INHIBITING FACTORS FOR CONVECTION.

..COHEN.. 07/21/2011

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

ATTN...WFO...CAR...GYX...

LAT...LON 46407028 46896956 46926871 46586782 46176749 45556736
44946778 44756877 44847016 45547061 46407028

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.