MESOSCALE PRECIPITATION DISCUSSION 0066
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
202 AM EST THU MAR 10 2016
 
AREAS AFFECTED...SE TEXAS...W LOUISIANA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 100702Z - 101232Z
 
SUMMARY...SHORTWAVE/SURFACE WAVE PROVIDING LIFT/INSTABILITY AND
MST TRANSPORT TO REINVIGORATE DEEP CONVECTION ACROSS AREA
CURRENTLY EXPERIENCING FLASH FLOODING FURTHER COMPOUNDING AN
ALREADY DANGEROUS AND LIFE THREATENING SITUATION. 

DISCUSSION...A VIGOUROUS SHORTWAVE AND LEADING NOSE OF JET STREAK
HAS ADVANCED TO THE CENTRAL PORTION OF THE WESTERN GULF OF MEXICO.
 RADAR AND SURFACE ANALYSIS INDICATES SURFACE INFLECTION WITH
BULGED/BOWED COLD FRONT ADVANCING NORTHWARD.  SURFACE PRESSURE
FALLS AND ISALLOBARIC WIND ENHANCEMENT WILL INCREASE LOW LEVEL
SOUTHERLY JET IN EXCESS OF 60KTS AT 850MB FOCUSED TOWARD THE
GALVESTON BAY AND EASTWARD BY 9-10Z...COINCIDENT WITH TPWS OF 2.0"
AND CAPES FORECAST NEAR 2500-3000 J/KG PER 00Z ARW/NMMB AND NSSL
WRF SHOULD SUPPORT STRENGTHENING CONVECTION NEAR AND EAST OF THE
FRONTAL ZONE CURRENTLY ORIENTED SW TO NE ACROSS SE TX INTO CENTRAL
LA WITH RATES OF 2-3"/HR LIKELY WITHIN A GENERAL N-S TRAINING
PROFILE WITH REPEAT DEVELOPMENT ALONG THE FRONTAL ZONE THAT WILL
SLOWLY ADVANCE FROM WEST TO EAST BY 12Z INTO W LA...WITH THE
POTENTIAL FOR AN ADDITIONAL 3-6" NEAR THE FRONT.  GIVEN STRENGTH
OF LOW LEVEL FLOW/MST FLUX... CONVECTION WILL ISENTROPICALLY LIFT
INTO EAST CENTRAL TX...N LA AS THE SHORTWAVE ADVANCES
NORTHWARD...ALONG WITH PERIPHERAL ASCENT PROVIDED BY RIGHT
ENTRANCE DYNAMICS FROM 130-140 KT ANTICYCLONICALLY CURVED POLAR
JET OVER THE MO RIVER VALLEY...EVEN MODERATE SHIELD PRECIPITATION
WILL BE HIGHLY EFFICIENT OVER AREAS THAT HAVE RECEIVED OVER 12"
PLUS IN THE LAST TWO DAYS NEAR/ALONG THE I-20
CORRIDOR...COMPOUNDING ONGOING FLOODING IN THIS VICINITY AS WELL.  

FURTHER WEST ACROSS SE TX...THE ADVANCING WAVE WILL HAVE A NICE
TROWAL WITH SOME EMBEDDED CONVECTIVE ELEMENTS WITHIN THEM...THOUGH
NOT FULLY ROOTED NEAR THE SURFACE...THIS WAVE WILL PROVIDE STRONG
ASCENT AT THE LEFT EXIT OF THE APPROACHING MID-LEVEL JET
STREAK/DRYING SEEN ACROSS THE WESTERN GULF.  GIVEN SOME STEEPER
LAPSE RATES...THESE STRONGER THE CELLS WILL SUPPORT RATES UP TO
1.5-2"/HR BUT SHOULD BE QUICKER MOVING...AND POSE ONLY SHORT TERM
FF CONCERNS IF CROSSING LOWERED AREAS WITH LOWERED FFG VALUES DUE
TO PRIOR ROUNDS OF CONVECTION OVER THE LAST DAY OR SO.  THE
WESTERN CELLS ALONG THIS AXIS SHOULD SLOW AND SHEAR MOISTURE BACK
TOWARD THE UPPER LOW WITHIN THE DEFORMATION ZONE WILL PROVIDE SOME
MODERATE RAINFALL AT TIMES ACROSS CENTRAL TX THOUGH NOT LIKELY
ENOUGH TO SUPPORT FLOODING CONCERNS ATTM. 


GALLINA

ATTN...WFO...CRP...EWX...FWD...HGX...JAN...LCH...SHV...

ATTN...RFC...LMRFC...WGRFC...

LAT...LON   32669377 32479182 31509169 30819200 29799265 
            29769342 29469452 28919526 28469640 29329666 
            30299641 31049570 32079496