MESOSCALE PRECIPITATION DISCUSSION 0162
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
318 AM EDT SUN JUN 29 2014
 
AREAS AFFECTED...NERN ARKANSAS INTO NWRN MISSISSIPPI AND WRN
TENNESSEE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 290715Z - 291215Z
 
SUMMARY...PERSISTENT...MOIST INFLOW ACROSS A REMNANT OUTFLOW
BOUNDARY IS EXPECTED TO INCREASE THE COVERAGE OF ELEVATED
CONVECTION OVER THE NEXT FEW HOURS. WIND PROFILES SUPPORT TRAINING
OF CELLS FROM PORTIONS OF ARKANSAS ENEWD TOWARD THE MISSISSIPPI
RIVER POSSIBLY LEADING TO FLASH FLOODING PROBLEMS THROUGH 12Z.

DISCUSSION...07Z SURFACE ANALYSIS PLACED A REMNANT OUTFLOW
BOUNDARY ESEWD ACROSS OKLAHOMA INTO S-CNTRL ARKANSAS SEPARATING
TEMPERATURES GENERALLY BETWEEN 75-80 F AND DEWPOINTS IN THE LOW TO
MID 70S SOUTHWEST OF THIS BOUNDARY FROM TEMPERATURE/DEWPOINTS 5-10
F COOLER ACROSS CNTRL/NERN ARKANSAS ON THE COOL SIDE OF THE
BOUNDARY. 00Z RAOBS INDICATED A SOMEWHAT BROAD 30-40 KT SWLY JET
BETWEEN 850 AND 700 MB POINTING NORTHEAST ACROSS THE ARKLATEX WITH
A NARROW CORRIDOR OF LOW DEWPOINT DEPRESSIONS THROUGH MUCH OF THE
COLUMN NOTED AT SHV AND LZK. ALSO NOTED WERE WET BULB ZERO HEIGHTS
BETWEEN 13 AND 14 KFT AT THESE TWO RAOB SITES.

THE HIGH MOISTURE CONTENT OF THE AIR...NOTED BY CURRENT GPS
PRECIPITABLE WATER VALUES OVER 2 INCHES OVER MUCH OF
ARKANSAS...SHOULD LEAD TO EFFICIENT RAINFALL PRODUCTION AND
RAINFALL RATES OF 1-2 IN/HR. CURRENT FLASH FLOOD GUIDANCE OF 2-3
INCHES IN 3 HRS SHOULD BE MET WITH THE PERSISTENT NATURE OF
TRAINING CELLS AT LEAST ON A REGIONAL BASIS GIVEN THE SOMEWHAT
SHOWERY NATURE OF THE CURRENT CELLS.

THIS SCENARIO IS FORECAST BY A MAJORITY OF THE 00Z HI-RES
MODELS...ALTHOUGH THEY DIFFER ON TIMING AND PLACEMENT. WHILE
LIKELY OVERDONE...BUT JUST FOR REFERENCE...THE WRF
NMM...ARW...PARALLEL NAM CONEST...NSSL WRF...AND SPC WRF INDICATE
5-7 INCHES IN 6 HOURS BY 15Z TODAY ACROSS E-CNTRL ARKANSAS.

OTTO

ATTN...WFO...MEG...JAN...LZK...TSA...

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

LAT...LON   36239135 36198995 34988950 33859097 34389360 34919451
            35629420 36039281 36239135