SWODY2
SPC AC 181727
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1227 PM CDT SUN MAY 18 2008
VALID 191200Z - 201200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE MID
MS/LOWER OH VALLEYS...
...SYNOPSIS...
UPPER RIDGE IN THE WEST WILL SHIFT EWD ON MONDAY TOWARD THE ROCKIES
AND BEGIN TO UNDERGO WEAKENING AS AN UPSTREAM AMPLIFYING PACIFIC
TROUGH APPROACHES THE PACIFIC NW/WRN CANADA. ERN U.S. TROUGH IS
EXPECTED TO BECOME LESS AMPLIFIED AS HEIGHTS RISE ACROSS THE SRN
PLAINS TO LOWER MS VALLEY AND GREAT LAKES VORTEX TRACKS NEWD ACROSS
NEW ENGLAND. THIS EVOLVING FLOW PATTERN WILL RESULT IN AN ELEVATED
MIXED LAYER SPREADING EWD ACROSS THE PLAINS TO THE MID MS/TN VALLEYS
AND GULF COAST STATES.
A COUPLE OF MID LEVEL IMPULSES WITHIN NWLY FLOW ALONG ERN PERIPHERY
OF ROCKIES RIDGE...AND NOW LOCATED OVER WRN MT AND ERN BC...WILL BE
THE IMPETUS FOR TSTM/SEVERE WEATHER THREAT ON DAY 2 ACROSS THE MID
MS/LOWER OH VALLEYS AND IN SRN MN/IA...RESPECTIVELY.
...PARTS OF MID MS/LOWER OH VALLEYS...
SURFACE LOW/FRONTAL SYSTEM ATTENDANT TO THE LEAD SHORT WAVE TROUGH
WILL TRACK ESEWD FROM ERN KS TO SERN MO/LOWER OH VALLEY BY LATE
MONDAY AFTERNOON. SURFACE DEWPOINTS IN THE UPPER 50S TO AROUND 60
CURRENTLY RESIDE ACROSS THE SRN PLAINS TO LOWER MS VALLEY. THIS
MOISTURE IS FORECAST TO RETURN NWD AS LOW LEVEL WINDS BACK TO SLY IN
RESPONSE TO THE APPROACHING MID LEVEL IMPULSE/SURFACE LOW. THIS
COMBINED WITH STEEP MID LEVEL LAPSE RATES/EML SPREADING EWD WILL
RESULT IN MODERATE INSTABILITY FROM PARTS OF THE OZARKS EWD INTO THE
LOWER OH VALLEY. THIS EML IS EXPECTED TO INHIBIT TSTM DEVELOPMENT
UNTIL LATE MONDAY AFTERNOON ACROSS SERN MO/LOWER OH VALLEY. BY THAT
TIME PERIOD...INHIBITION SHOULD WEAKEN ALONG ERN EXTENT OF THE EML
AS ASCENT INCREASES WITHIN ENTRANCE REGION OF MID LEVEL JET LOCATED
OVER THE OH VALLEY...AND WAA INCREASES ALONG NOSE OF 40-50 KT SWLY
LLJ. TSTMS DEVELOPING OVER SERN MO/SRN IL LATE MONDAY AFTERNOON/
EARLY EVENING WILL BE LOCATED WITHIN AN AREA OF MODERATE INSTABILITY
WITH EFFECTIVE BULK SHEAR UP TO 50 KT SUPPORTING ORGANIZED STORMS/
SUPERCELLS. STEEP LAPSE RATES WILL FAVOR THE POTENTIAL FOR HAIL...
WHILE STRONG VEERING WINDS WITH HEIGHT SUGGEST THE POTENTIAL FOR
ISOLATED TORNADOES. ALTHOUGH INSTABILITY WEAKENS BY LATER MONDAY
EVENING...STRENGTHENING WLY LLJ TO 50+ KT ACROSS TN/KY WOULD SUGGEST
A CONTINUED DAMAGING WIND THREAT THROUGH PART OF THE EVENING.
...SRN MN/IA...
ALTHOUGH INSTABILITY IS EXPECTED TO BE WEAK ACROSS THIS REGION ON
MONDAY DUE TO LOW SURFACE DEWPOINTS...ASCENT ATTENDANT TO A SECOND
STRONGER SHORT WAVE TROUGH TRACKING SEWD WITHIN NWLY FLOW ALOFT WILL
SUPPORT TSTM DEVELOPMENT. EFFECTIVE BULK SHEAR OF 25-40 KT SHOULD
SUPPORT A FEW STRONGER TO SEVERE STORMS WITH ISOLATED HAIL/STRONG
WIND GUSTS POSSIBLE.
..PETERS.. 05/18/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment