SUMMARY…STRONG SYNOPTIC FORCING AND STRONG MST FLUX THOUGH
PROGRESSIVE NATURE MAY POSE LOCALIZED FLASH FLOODING THREAT FOR
TRAINING CONVECTION.DISCUSSION…GOES-E WV LOOP DENOTES A CONSOLIDATING SHORTWAVE
FEATURE ALONG THE CENTRAL TX COAST LIFTING NORTHEAST WITH ENHANCED
COOLING CONVECTIVE CLUSTERS SPLIT BETWEEN THE EXITING 120 KT POLAR
JET STREAK ACROSS THE CENTRAL AR AND THE FLATTENING 120 KT
SUBTROPICAL JET STREAK DRAPED ACROSS THE NORTHWEST GULF. AS THE
DPVA FROM THE SHORTWAVE CONTINUES TO APPROACH THE DUAL JET
FORCING…A WEAK SURFACE WAVE AND 7-85MB WAVE WILL BEGIN TO
CONSOLIDATE FROM SW TX INTO CENTRAL LA. THIS WILL INVOKE
STRENGTHENING SWLY LLJ FROM 45KTS THAT WILL PRODUCE STRONG WAA AND
BEGIN TO LIFT WARM FRONT FROM S LA/COASTAL MS
NORTHEAST…INCREASING MST FLUX AND CONVERGENCE ENHANCING ONGOING
CONVECTION ACROSS SW MS BACK TO CENTRAL LA.AROUND 12-13Z…THE 7-85MB WAVE WILL BECOME QUITE MATURE WITH 850
LLJ INCREASING TO 65KTS AND ENHANCING LOCALIZED TPWS IN THE 1.75″
RANGE AND SUFFICIENT INSTABILITY FOR ROBUST UPDRAFTS WITH
INCREASING RAINFALL EFFICIENCY AS RATES UP TO 2″/HR ARE LIKELY.
ALTHOUGH THE WAVE WILL BE PROGRESSIVE ACROSS LA/CENTRAL
MS…UNIDIRECTIONAL WIND PROFILES AND ORIENTATION OF THE WARM
FRONT CONVECTION SHOULD BE FAVORABLE FOR A SEVERAL HOUR TRAINING
ENVIRONMENT ACROSS CENTRAL MS INTO W AL TOWARD 14Z. HI-RES CAMS
SHOW GENERAL AGREEMENT WITH THE EVOLUTION SUGGESTED WITH SOME
NORTH-SOUTH DISPLACEMENTS WHILE SUGGESTING 2-4″ TOTALS OVER THE
NEXT 6HRS POSSIBLE. CURRENT TRENDS AND ENVIRONMENTAL SETUP
SUGGEST RECENT RUNS OF THE HRRR AND 00Z NMMB/ARW PRESENT THE MOST
LIKELY SCENARIO/TRACK THROUGH THE ARW MAY BE A BIT TOO
PROGRESSIVE.FURTHER SOUTH ALONG THE TRAILING COLD FRONT GREATER UNCERTAINTY
EXISTS AS THE LINE MAY BE FAVORABLY ORIENTED TO UPSTREAM INFLOW
THAT MAY SUPPORT A BACKBUILDING ENVIRONEMENT ACROSS SOUTHEAST LA.
HOWEVER EQUALLY POSSIBLE IS THAT HEIGHT FALLS AND PROGRESSIVE
UPSTREAM FLOW WOULD SUGGEST A SURGING COLD FRONT ACROSS SE
LA/COASTAL MS. GIVEN THE FFG VALUES ARE ALSO HIGHER HERE THE
LIKELIHOOD OF FLASH FLOODING SEEMS TOO LOW TO INCLUDE INTO THE MPD
AREA OF CONCERN AT THIS TIME BUT THE THREAT PARTICULARLY ACROSS
THE URBAN CORRIDOR OF NEW ORLEANS WILL REQUIRE SOME ADDITIONAL
VIGILANCE.
