-Weather Watch possible…
Posted by David Cole on July 13, 2009
Posted: July 13- 10:06am
MESOSCALE DISCUSSION 1544
NWS STORM PREDICTION CENTER NORMAN OK
0932 AM CDT MON JUL 13 2009
AREAS AFFECTED…CNTRL/SRN MS INTO SWRN AL
CONCERNING…SEVERE POTENTIAL…WATCH POSSIBLE
VALID 131432Z – 131600Z
TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY TODAY WITH
THE THREAT FOR LOCALLY DAMAGING WIND GUSTS. CONVECTIVE TRENDS ARE
BEING MONITORED FOR A POSSIBLE WW.
PRE-FRONTAL TSTMS ARE GRADUALLY INTENSIFYING THIS MORNING FROM
PORTIONS OF ERN AR SEWD THROUGH NRN MS INTO CNTRL AL. THIS ACTIVITY
IS APPARENTLY BEING FORCED BY LOW-LEVEL WAA REGIME PRESENT OVER THE
LOWER MS VALLEY. MODIFICATION OF 12Z SOUNDING DATA FOR CURRENT
SURFACE OBSERVATIONS INDICATES THAT IMMEDIATE INFLOW AIR MASS IS
ALREADY MODERATELY UNSTABLE WITH MLCAPE 2000-2500 J/KG AND
DECREASING CONVECTIVE INHIBITION.
WHILE NOT OVERLY STRONG…REGIONAL VWPS SHOW A BELT OF 30-35 KT
WINDS IN THE MIDLEVELS. THIS HIGHER MOMENTUM FLOW HAS DESCENDED TO
AS LOW AS 2-3 KM AGL PER CURRENT MEM PROFILE. THIS MODEST FLOW IN
CONJUNCTION WITH THE MODERATE UNSTABLE ENVIRONMENT SHOULD SUPPORT A
GENERAL INCREASE IN STORM INTENSITY TODAY WITH THE STRONGEST
ACTIVITY LIKELY BEING FOCUSED ALONG LEADING EDGE OF COMPOSITE
OUTFLOW BOUNDARY. LOCALLY DAMAGING WIND GUSTS WILL BE THE PRIMARY
SEVERE WEATHER HAZARD WITH THESE STORMS.
