MESOSCALE PRECIPITATION DISCUSSION 0076
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
343 AM EST FRI MAR 11 2016
 
AREAS AFFECTED...SE LOUISIANA...S MISSISSIPPI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 110900Z - 111400Z
 
SUMMARY...CONTINUED FRACTURED CONVECTION ALONG PRECIPITATION
COOLED BOUNDARY ACROSS SE LA/S MS IN ADVANCE OF DEEPER CONVECTION
ALONG COLD FRONT ADVANCING NE WITH RATES UP TO 2.0"/HR LIKELY
COMPOUNDING ONGOING FLASH FLOOD SITUATION.

DISCUSSION...SURFACE ANALYSIS AND RADAR MOSAIC CONTINUE TO
INDICATE A REINFORCED BOUNDARY ACROSS S MS THROUGH LAKE
PONTCHARTRAIN AND INTERSECTING WITH A BOWED COLD FRONT JUST NORTH
OF VERMILLION BAY.  AHEAD OF THE DEEP CONVECTION...DEEP SOUTHERLY
WITH 40-45KT 850MB PER VWP NETWORK CONTINUING TO SUPPORT
ISENTROPIC ASCENT ACROSS THE BOUNDARY FOR THE NEXT FEW HOURS IN
ADVANCE OF THE FRONT.  CELLS WILL REMAIN FRACTURED LIKE THE LAST
FEW HOURS...BUT WILL CONTINUE TO RAIN OUT NORTHWARD OF THE
BOUNDARY OVER THE SAME AREAS OF E LA AND S MS COMPOUNDING ONGOING
FLASH FLOODING IN THAT VICINITY. 

FURTHER WEST/SOUTH...WV LOOP/SATELLITE DERIVED WINDS PLACE NOSE OF
100+ KT UPPER LEVEL JET MOVING THROUGH BAY OF CAMPECHE INTO THE
WEST CENTRAL GULF BECOMING SLIGHTLY DIFFLUENT OVER THE SE TX/LA
COAST...IR/SWIR DENOTES DEEP CONVECTION TO -70C CONTINUING TO
EXPAND ALONG THE COLD FRONT AS IT SLOWLY ADVANCES...WITH TWO
SIGNIFICANT CLUSTERS BEGINNING TO MERGE SOUTH OF MARSH
ISLAND...SUPPORTED BY 20KTS OF SFC WESTERLIES CONVERGING WITH
25KTS OF SELY FLOW ON THE WARM SIDE.  ALL THIS SUPPORTS INCREASED
MST CONVERGENCE TO OVERCOME WEAK MUCINH AND TAPPING 1000-1500 J/KG
MUCAPES FOR VIGOROUS DEEP CONVECTION..WHICH IS WELL DISPLAYED BY
RECENT EXPANSION/INTENSITY OF LIGHTNING STRIKES.   TPWS INCREASING
OVER 2" SUPPORTING RAIN RATES OF 2.5-3"/HR IN THE DEEPEST CORES
WHICH WILL BE NEARING TERREBONNE PARISH BY 10-11Z...WHILE NORTH OF
THE INTERSECTION...RATES UP TO 2"/HR ARE LIKELY AS WELL.  DEEP
UNIDIRECTIONAL FLOW WITHIN THE CLOUD BARING LAYER WILL SUPPORT
SOME TRAINING SOUTH TO NORTH AS THE FRONT SLOWLY PROGRESSES
EAST...LEADING TO A SWATH OF 2-3" TOTALS ACROSS MUCH OF E LA BY
14Z.  ALONG WITH ONGOING 2"+ (LOCALLY HIGHER DUE TO FRACTURED
NATURE) OF THE PRE-FRONTAL ISENTROPIC RAINFALL...SHOULD CONTINUE
SIGNIFICANT FLOODING CONDITIONS IN THAT VICINITY.  

GALLINA

ATTN...WFO...JAN...LCH...LIX...MOB...

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

LAT...LON   32518891 31998857 31178842 30468877 29708925 
            29358917 29138893 28888924 29208972 29049017 
            28979079 29149136 29369164 29489205 29469239 
            29569273 29729280 30929168 31809091 32498968