EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
908 PM EDT MON JUN 17 2013
...VALID 03Z TUE JUN 18 2013 - 00Z WED JUN 19 2013...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 WSW AND 10 NNW LZU 35 SSW RMG 25 WNW BHM CBM 40 ENE GWO
30 N GWO 15 WSW UTA 30 ESE M19 15 E ARG 25 E POF 40 S EHR
30 SSE FTK 25 NNE LOZ 6V3 10 WSW HLX 15 SE UKF 10 ENE EHO
10 ESE GYH 20 WSW AND.
...LOWER-MID MS VLY INTO THE TN/LOWER OH VALLEYS...
LOCALLY EXCESSIVE RAINFALL ASSCD AHEAD OF WELL-DEFINED MCV ACROSS
THE PTNS OF THE MID MS VLY WILL EVENTUALLY EXPAND E-SE INTO THE TN
AND LOWER OH VALLEYS THIS EVENING AND TONIGHT. THIS AS A 30-40 KT
SWRLY ELEVATED INFLOW (LLJ CENTERED ~850 MB) WILL FOCUS ACROSS
THESE AFOREMENTIONED AREAS OVERNIGHT...THANKS IN LARGE PART TO THE
APPROACHING MCV...WHILE AT THE SAME TIME THE LARGE-SCALE DYNAMICAL
FORCING BECOMES MORE FAVORABLE PER THE INCREASING UPPER LEVEL
AGEOS DIVERGENCE AND LOW-MID LEVEL FRONTOGENESIS AHEAD OF THIS MCV
AND WITHIN THE RIGHT ENTRANCE REGION OF THE THE JET STREAK N-NE OF
THE AREA. 24 HR AREAL-AVERAGE AMOUNTS OF 1-2+ INCHES ARE EXPECTED
ACROSS THE TN VLY AND INTO SRN KY (00Z 6/18 - 00Z 6/19)...WITH THE
HIGHEST AMOUNTS ACROSS WRN AND CEN TN. THE POTENTIAL WILL EXIST
FOR AS MUCH AS 3-4 INCHES WITHIN A 3 HOUR PERIOD OVERNIGHT FROM
THE AR/MO/TN BORDER EAST THROUGH MUCH OF TN AND SRN KY.
...TEXAS...
BROKEN LINE OF CONVECTION DEVELOPING THIS AFTN IN THE LEE OF THE
ROCKIES/ACROSS THE HIGH PLAINS IS EXPECTED TO EVOLVE INTO AN MCS
(EVENTUAL MCV) OVERNIGHT...WHICH ALONG WITH ACCOMPANYING SWATH OF
HEAVIER RAINFALL...MOST MODELS (INCLUDING HIGH RES RUNS) HAVE
MOVING INTO NORTH-CENTRAL TX OR BASICALLY ALONG/S OF THE CURRENT
SFC FRONTAL POSITION. MSTR FLUX CONVERGENCE INTO THIS REGION WILL
GET A BOOST WITH THE STRENGTHENING SOUTHERLY LLVL
INFLOW...COINCIDING WITH A WESTWARD-EXPANDING AXIS OF HIGHER PW'S
(~1.75") AND SUFFICIENTLY DEEP LAYER INSTABILITY (BEST LI'S AOB
-6C). WHILE HIGHEST AREAL-AVERAGE RAINFALL AMOUNTS ARE EXPECTED
TO RANGE CLOSER TO 1 TO 1.5" OVER THIS AREA...THE POTENTIAL EXISTS
FOR LOCALLY HIGHER (EXCESSIVE) AMOUNTS OF AS MUCH AS 3-4 INCHES IN
A 3 HOUR TIMEFRAME TONIGHT. AS A RESULT...ISOLATED RUNOFF
PROBLEMS WILL BE POSSIBLE.
HURLEY