SWODY3
SPC AC 290730
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT THU APR 29 2010
VALID 011200Z - 021200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE LOWER MS
VALLEY...TN AND OH VALLEYS...
...SYNOPSIS...
UPPER PATTERN WILL REMAIN CHARACTERIZED BY A BROAD DOUBLE VORTEX
POSITIVE TILT UPPER TROUGH SATURDAY. A SIGNIFICANT IMPULSE WILL LIFT
NEWD THROUGH THE GREAT LAKES EARLY SATURDAY. ANOTHER SHORTWAVE
TROUGH INITIALLY OVER NRN MEXICO SATURDAY MORNING WILL EJECT NEWD
REACHING THE MID MS VALLEY OVERNIGHT. FRONTAL BOUNDARY WILL LIKELY
BECOME QUASI-STATIONARY FROM THE GREAT LAKES SWWD THROUGH ERN TX. A
SURFACE WAVE IS FORECAST TO DEVELOP AND LIFT NEWD ALONG THE FRONT
THROUGH THE LOWER AND MID MS VALLEYS IN ASSOCIATION WITH EJECTING
SRN BRANCH JET STREAK. THIS WILL ACCELERATE EWD SRN PORTIONS OF THE
FRONT INTO THE LOWER MS VALLEY OVERNIGHT.
...LOWER MS...TN AND OH VALLEYS...
BOUNDARY LAYER WINDS WILL TEMPORARILY WEAKEN DURING THE DAY AS
INITIAL LOW LEVEL JET LIFTS NWD INTO SRN ONTARIO IN ASSOCIATION WITH
LEAD SHORTWAVE TROUGH. HOWEVER...MODERATE SLY FLOW WILL PERSIST OVER
THE LOWER MS VALLEY MAINTAINING INFLUX OF RICH GULF MOISTURE.
WIDESPREAD CLOUDS AND ONGOING CONVECTION WILL LIMIT DIABATIC WARMING
OF THE BOUNDARY LAYER WITH MLCAPE GENERALLY BELOW 1000 J/KG EXCEPT
OVER THE LOWER MS VALLEY REGION WHERE RICHER GULF MOISTURE WILL
PERSIST. AT THIS POINT...UNCERTAINTY EXISTS REGARDING EVOLUTION OF
ONGOING CONVECTION. HOWEVER...DEEP LAYER FLOW/VERTICAL SHEAR WILL
REMAIN SUFFICIENT THROUGHOUT THE DAY FOR A THREAT OF ORGANIZED
SEVERE STORMS. THE SEVERE THREAT MAY INCREASE FROM LATE AFTERNOON
INTO THE OVERNIGHT INITIALLY OVER THE LOWER MS VALLEY AS THE LOW
LEVEL JET STRENGTHENS IN RESPONSE TO EJECTING IMPULSE. STORMS WILL
LIKELY REDEVELOP AHEAD OF EWD ADVANCING COLD FRONT. DEEP LAYER SHEAR
AND HODOGRAPHS WILL BECOME SUPPORTIVE OF ORGANIZED STORMS WITH A
THREAT OF DAMAGING WIND AND ISOLATED TORNADOES CONDITIONAL UPON
SUFFICIENT SURFACE BASED INSTABILITY. THREAT WILL EXPAND NEWD ALONG
MIGRATORY LOW-LEVEL JET TOWARD THE OH VALLEY OVERNIGHT.
..DIAL.. 04/29/2010
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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