MESOSCALE PRECIPITATION DISCUSSION 0550
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
730 AM EDT FRI AUG 12 2016
 
AREAS AFFECTED...CENTRAL/SOUTHERN MS...CENTRAL/SOUTHERN LA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 121130Z - 121730Z
 
SUMMARY...EXTREMELY HEAVY RAINFALL ONGOING ACROSS FAR SOUTHWEST MS
AND SOUTHEAST LA WILL RESULT IN SIGNIFICANT RUNOFF AND/OR FLASH
FLOODING THROUGH THIS MORNING.

DISCUSSION...DEEP CONVECTION CONTINUES TO DEVELOP AND CONCENTRATE
ITSELF THIS MORNING AROUND THE SOUTHERN FLANK OF A LOW TO MID
LEVEL AREA OF LOW PRESSURE SITUATED OVER FAR SOUTHWEST MS. CLOUD
TOP TEMPERATURES HAVE BEEN APPROACHING -80C NEAR THE MS/LA BORDER
AREA TO THE NORTHEAST OF BATON ROUGE...AND IN THIS AREA....VERY
INTENSE RAINFALL IS ONGOING WITH RAINFALL RATES OF 3 TO 3.5
INCHES/HR. OVER THE LAST 24 HOURS...SOME AREAS HAVE LOCALLY SEEN
OVER 10 INCHES OF RAIN BASED ON DUAL-POL RADAR ESTIMATES.

VERY INTENSE RAINFALL WILL CONTINUE THIS MORNING OVER PORTIONS OF
ESPECIALLY SOUTHWEST MS CLOSE INTO THE LOW CENTER ITSELF...AND
ACROSS SOUTH-CENTRAL AND SOUTHEAST LA AS CONFLUENT LOW LEVEL FLOW
AND GREATER INSTABILITY AROUND THE SOUTHERN FLANK OF THE LOW
CIRCULATION PERSISTS.

THE GLOBAL MODELS FROM 00Z INCLUDING THE UKMET/GFS AND ECMWF ONCE
AGAIN SUGGEST SOME STRENGTHENING OF THIS LOW CENTER...ESPECIALLY
IN THE 850/700 MB LAYER THROUGH THE MORNING HOURS.
CONSEQUENTLY...STRONGER LOW TO MID LEVEL FORCING IS EXPECTED TO
ENSUE WHICH WILL ALLOW ONGOING CONVECTION TO REMAIN SUSTAINABLE
AND POSSIBLE INTENSIFY A BIT FURTHER WITH STRONGER CONVECTIVE
BANDS IN PARTICULAR SETTING UP AROUND THE SOUTHWEST SIDE OF THE
CIRCULATION CENTER.

HIRES GUIDANCE LED BY THE 00Z ARW/NMMB SOLUTIONS SUGGEST
ADDITIONAL RAINFALL AMOUNTS BETWEEN 12Z AND 18Z APPROACHING 10
INCHES OVER PARTS OF SOUTH-CENTRAL LA WHICH SEEMS REASONABLE AT
THIS TIME. THESE MODELS THOUGH ARE LIKELY UNDERDONE OVER PARTS OF
SOUTHWEST MS AND SOUTHEAST LA WHERE CONVECTIVE BANDS ONGOING ARE
ALREADY PRODUCING VERY HEAVY RAINFALL.

LIFE-THREATENING RUNOFF AND/OR FLASH FLOODING IS EXPECTED WITH
SUCH INTENSE RAINFALL RATES AND STORM TOTALS GOING THROUGH THE
MORNING HOURS.

ORRISON

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

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

LAT...LON   32609045 32358982 31918957 31388944 30638878 
            30138888 29638927 29478945 29168985 29099070 
            29339141 29459165 29539247 29829299 30209311 
            30609284 30989221 31239203 31969162 32419104