Sunday, May 30, 2010

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 301947
SWODY1
SPC AC 301946

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0246 PM CDT SUN MAY 30 2010

VALID 302000Z - 311200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF CNTRL/NCNTRL
OK AND SCNTRL/SERN KS...

ONLY APPRECIABLE CHANGE TO ONGOING FORECAST: BETTER DEFINE WRN EDGE
OF SLIGHT RISK OVER OK.

...KS/OK...
19Z MESOANALYSIS PLACES A MESOLOW OVER NWRN OK WITH A COLD FRONT N
THROUGH KP28-KOMA AND S TO KCSM-KLBB THEN ARCING NWWD ALONG THE NM
HIGH PLAINS.

CONVECTIVE INITIATION OCCURRING OVER KS ALONG THE FRONT WILL
CONTINUE SWWD IN A ZIPPER-LIKE FASHION INTO NWRN OK IN THE 20-22Z
TIME FRAME AMIDST MLCAPES 2000-3000 J/KG. STRONG DEEP LAYER SHEAR
EXISTS ALONG COOL SIDE OF THE FRONT...BUT MAGNITUDE OF LAPSE RATES
WILL RESULT IN VIGOROUS UPDRAFTS AND THE POSSIBILITY OF LARGE HAIL
AND HIGH WINDS WITH MULTICELLS/BRIEF SUPERCELL STRUCTURES. ACTIVITY
WILL LIKELY CONGEAL INTO A LOOSELY-ORGANIZED MCS AND LINGER OVER
SERN KS AND NCNTRL/CNTRL OK LATER IN THE EVENING...POSSIBLY
BACKBUILDING ALONG SWRN FLANKS OVERNIGHT. SVR THREATS SHOULD
GRADUALLY WANE AFTER 03Z OR SO.

REMAINDER OF THE FORECAST UNCHANGED./RACY

..RACY/HALES/JEWELL.. 05/30/2010

.PREV DISCUSSION... /ISSUED 1120 AM CDT SUN MAY 30 2010/

EVOLVING ZONAL FLOW MUCH OF CONUS AS COLD UPPER SYSTEM SHIFTS INTO
SRN CANADA AND HEIGHTS GENERALLY RISE OVER THE CENTRAL U.S. WEAK
STALLED CUT-OFF LOW OVER MS WILL BEGIN DRIFTING NEWD AND WEAKEN
FURTHER.

COLD FRONT TRAILING SWWD FROM SURFACE LOW NRN MN THRU WRN IA TO NWRN
OK AND ERN NM WILL BE THE FOCUS FOR THE RATHER LOW END SEVERE
CONCERN TODAY.

...KS/OK...
A MOIST AND MDTLY UNSTABLE WARM SECTOR IS IN PLACE ACROSS KS/OK IN
ADVANCE OF THE COLD FRONT. DAYTIME HEATING WILL RAISE SURFACE TEMPS
TO NEAR OR ABOVE 90F BY MID AFTERNOON WHICH EFFECTIVELY REMOVES THE
CONVECTIVE INHIBITION AND RESULTS IN MLCAPES AOA 2000 J/KG.

SCATTERED THUNDERSTORMS WILL DEVELOP VICINITY FRONTAL ZONE FROM ERN
KS SWWD INTO SWRN OK BY MID/LATE AFTERNOON AND MOVE/PROPAGATE RATHER
SLOWLY E/SEWD THRU THE EVENING. AS THE SHEAR PROFILES DROP BELOW
ABOUT 20KT THE PRIMARY MECHANISM FOR SEVERE STORMS WILL BE THE
COMBINATION OF RELATIVELY STEP MID LEVEL LAPSE RATES...AOA
7C/KM...AND THE UNSTABLE AIR MASS. STRONGEST UPDRAFTS SHOULD SUPPORT
LARGE HAIL AND LOCAL DAMAGING DOWNBURST WINDS.

ANY SEVERE THREAT SHOULD DIMINISH QUICKLY WITH LOSS OF HEATING BY
THIS EVENING.

...MN/WI...
A SHORTWAVE TROUGH PROGRESSING EAST NORTHEASTWARD ACROSS THE
NORTHERN PLAINS/UPPER MS VALLEY TODAY WILL HELP TO INITIATE ISOLATED
AFTERNOON THUNDERSTORMS ACROSS PARTS OF MN/WI/IA...AGAIN VICINITY OF
THE COLD FRONT. MODEL SOLUTIONS SUGGEST CONVECTION WILL BE
ISOLATED...AND FORECAST SOUNDINGS SHOW WEAK MID LEVEL LAPSE RATES
AND CAPE. A FEW INTENSE STORMS CAPABLE OF GUSTY WINDS AND HAIL ARE
POSSIBLE...BUT ORGANIZED SEVERE ACTIVITY IS NOT PRESENTLY
ANTICIPATED.

...SOUTHEAST...
A WEAK UPPER LOW REMAINS OVER MS THIS MORNING...WITH AMPLE LOW AND
MID LEVEL MOISTURE SURROUNDING THE SYSTEM. THUNDERSTORMS ARE
EXPECTED TO DEVELOP ONCE AGAIN BY EARLY AFTERNOON...ESPECIALLY TO
THE EAST OF THE LOW CENTER ACROSS PARTS OF MS/AL/TN/GA. THE MID
LEVEL COLD POOL HAS BEEN SLOWLY WARMING WITH THIS
SYSTEM...SUGGESTING A DECREASING HAIL THREAT. NEVERTHELESS...A FEW
STORMS CAPABLE OF GUSTY/DAMAGING WINDS REMAIN POSSIBLE.

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