Monday, July 13, 2009

MESO: Mesoscale Discussion 1548

ACUS11 KWNS 131811
SWOMCD
SPC MCD 131810
MTZ000-131945-

MESOSCALE DISCUSSION 1548
NWS STORM PREDICTION CENTER NORMAN OK
0110 PM CDT MON JUL 13 2009

AREAS AFFECTED...PARTS OF CNTRL/ERN MT

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 131810Z - 131945Z

THE THREAT FOR SEVERE STORMS CAPABLE OF MAINLY DAMAGING WINDS AND
LARGE HAIL IS EXPECTED TO INCREASE ACROSS AREA THIS AFTERNOON AND A
WW WILL LIKELY BE REQUIRED PRIOR TO 20Z.

WIDELY SCATTERED TSTMS ARE GRADUALLY INTENSIFYING INVOF SURFACE COLD
FRONT OVER PONDERA...CHOUTEAU AND BROADWATER COUNTIES MT WITHIN ZONE
OF DEEP ASCENT IN ADVANCE OF STRONG SHORT WAVE TROUGH. MODIFICATION
OF 17Z GREAT FALLS SOUNDING FOR 75/50 SURFACE CONDITIONS YIELDS
AROUND 1000 J/KG OF SBCAPE WITHIN STEEP LAPSE RATE ENVIRONMENT. 12Z
HIGH-RESOLUTION MODEL DATA SUGGESTS THAT STORMS SHOULD INCREASE IN
COVERAGE THIS AFTERNOON...EVENTUALLY EVOLVING INTO ONE OR MULTIPLE
BOWING LINE SEGMENTS WHICH WOULD TRACK EWD INTO ERN MT BY THIS
EVENING. SHOULD THIS EVOLUTION OCCUR...DAMAGING WIND GUSTS AND HAIL
WOULD BE THE PRIMARY SEVERE THREATS.

FARTHER E...A SEPARATE CLUSTER OF TSTMS MAY ORGANIZE THIS AFTERNOON
OVER SERN MT IN ADVANCE OF A WEAKER LEAD IMPULSE. HERE...BOUNDARY
LAYER IS MORE MOIST WITH LOCALLY BACKED SURFACE WINDS /INVOF
PRE-FRONTAL TROUGH/ BOOSTING DEEP-LAYER SHEAR TO 40-50 KT. SHOULD
STORMS DEVELOP IN WAKE OF INITIAL CONVECTIVE LINE DEPARTING CARTER
CO...THE POTENTIAL WILL EXIST FOR SUPERCELL STRUCTURES CAPABLE OF
HAIL...DAMAGING WINDS AND PERHAPS A COUPLE OF TORNADOES.

..MEAD.. 07/13/2009

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

ATTN...WFO...BYZ...GGW...TFX...

LAT...LON 45901058 46941080 47941079 48721089 48910944 48750757
47940646 45780440 45270493 45220732 45290939 45901058

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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: