SWOMCD
SPC MCD 141842
MNZ000-IAZ000-SDZ000-142015-
MESOSCALE DISCUSSION 1557
NWS STORM PREDICTION CENTER NORMAN OK
0142 PM CDT TUE JUL 14 2009
AREAS AFFECTED...ERN SD INTO W-CNTRL/SWRN MN AND NWRN IA
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 141842Z - 142015Z
THE THREAT FOR SEVERE STORMS IS EXPECTED TO INCREASE THIS AFTERNOON
ACROSS DISCUSSION AREA. A WW WILL LIKELY BE REQUIRED BEFORE 20Z.
18Z MESOANALYSIS INDICATED A SURFACE LOW NE OF ABR WITH A TRAILING
COLD FRONT EXTENDING SSWWD TO JUST W OF A HON-MHE LINE. A WARM
FRONT/OUTFLOW COMPOSITE BOUNDARY STRETCHED ESEWD FROM THE LOW INTO
W-CNTRL MN /S OF AXN/ BEFORE CURVING MORE SSEWD THROUGH S-CNTRL MN
INTO CNTRL IA. WHILE CONSIDERABLE LOW CLOUDINESS HAS PREVAILED
ACROSS SYSTEM WARM SECTOR OVER ERN SD TODAY...BREAKS IN THE CLOUDS
COUPLED WITH THE NWD TRANSPORT OF RICHER BOUNDARY LAYER MOISTURE ARE
CONTRIBUTING TO THE MOST RAPID AIR MASS DESTABILIZATION FROM
YKN-FSD-BKX EWD THROUGH SWRN INTO CNTRL MN...PER 3-HR T/TD TRENDS.
CURRENT RUC OBJECTIVE FIELDS SUGGEST THAT WARM SECTOR AIR MASS IS
NOW MODERATELY UNSTABLE WITH MLCAPE OF 1000-2000 J/KG WITH
DECREASING CONVECTIVE INHIBITION.
A SHORT CONVECTIVE LINE SEGMENT IS IN THE PROCESS OF DEVELOPING
ALONG COLD FRONT AS OF 1830Z OVER SWRN CLARK...SERN SPINK INTO CNTRL
BEADLE COUNTIES IN ERN SD. BASED ON WATER VAPOR IMAGERY...IT
APPEARS THAT THE STRONGER FORCING FOR ASCENT ASSOCIATED WITH
UPSTREAM TROUGH IS BEGINNING TO ACT ON DESTABILIZING WARM SECTOR.
EXPECT AN INCREASE IN STORM COVERAGE AND INTENSITY ALONG FRONTAL
ZONE THIS AFTERNOON AS IT PROGRESSES EWD THROUGH ERN SD. TIME
TRENDS IN THE NELIGH NEB PROFILER AND FSD VWP INDICATE GRADUALLY
VEERING WINDS IN THE LOW LEVELS...RESULTING IN INCREASINGLY STRAIGHT
HODOGRAPHS WHICH WILL SUPPORT THE DEVELOPMENT OF LINE SEGMENTS
AND/OR SPLITTING SUPERCELLS WITH THE PRIMARY THREATS BEING LARGE
HAIL AND DAMAGING WINDS.
FARTHER E ALONG WARM FRONT IN CNTRL MN...COLLOCATION OF BACKED
SURFACE WINDS AND SLY 30-40 KT LLJ WILL RESULT IN RELATIVELY STRONG
LOW-LEVEL SHEAR. ANY MORE DISCRETE STORMS WHICH CAN DEVELOP
UPSTREAM OF SURFACE WARM FRONT WILL POSE A TORNADO THREAT WHILE
APPROACHING THIS BOUNDARY LATER THIS AFTERNOON INTO EVENING.
..MEAD.. 07/14/2009
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MPX...DMX...FSD...ABR...
LAT...LON 43659746 44889741 45399666 45609608 45489516 45079448
44029437 43149472 42629573 42669649 43099715 43659746
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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