MESOSCALE PRECIPITATION DISCUSSION 0247
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1015 AM EDT FRI JUN 19 2015
 
AREAS AFFECTED...SERN MO...EXTREME NERN AR...SRN IL...SRN
IN...SWRN OH...WRN AND NRN KY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 191414Z - 192014Z
 
SUMMARY...HEAVY RAIN THREAT WITH TROPICAL DEPRESSION BILL
SPREADING EASTWARD THROUGH THIS AFTERNOON.  

DISCUSSION...TROPICAL DEPRESSION BILL IS CENTERED OVER
NORTHEASTERN ARKANSAS THIS MORNING AND CONTINUES TO MOVE
EAST-NORTHEASTWARD. CONVECTION IN THE SPIRAL BANDS ASSOCIATED WITH
BILL IS AT A DIURNAL MINIMUM THIS MORNING -- BUT SHOULD BEGIN TO
EXPAND AND INTENSIFY BY EARLY AFTERNOON AS INSTABILITY INCREASES.
A NEARLY STATIONARY FRONTAL BOUNDARY IS POSITIONED TO THE NORTH OF
BILL -- EXTENDING FROM SOUTHERN MISSOURI EASTWARD TO SOUTHERN
IN/OH. A LOW-LEVEL JET EAST OF THE CENTER OF BILL OF 30-45 KTS IS
FOCUSING SHOWERS AND THUNDERSTORMS GENERALLY ALONG THE MISSISSIPPI
RIVER THIS MORNING -- AND IS RESULTING IN ADDITIONAL SHOWERS AND
THUNDERSTORMS IN THE VICINITY AND NORTH OF THE FRONTAL BOUNDARY
AND A MID/UPPER-LEVEL DEFORMATION ZONE.

HI-RES MODELS ARE IN GENERAL AGREEMENT ON AN INCREASE IN BANDED
CONVECTION EAST OF BILL THIS AFTERNOON -- AS WELL AS IN IN THE
VICINITY OF THE FRONTAL BOUNDARY (AIDED BY THE LOW-LEVEL JET).
MUCAPES ARE FORECAST TO INCREASE INTO THE 1000-2000 J/KG RANGE
ACROSS MOST OF THE MISSISSIPPI AND OHIO VALLEYS. PWAT VALUES ARE
ALSO FORECAST TO INCREASE INTO THE 2-2.25" RANGE -- 2 TO 3
STANDARD DEVIATIONS ABOVE AVERAGE. GIVEN THESE PARAMETERS -- WOULD
EXPECT THE POTENTIAL FOR RAINFALL RATES OF 2"/HOUR IN THE HEAVIEST
CONVECTION. ADDITIONAL RAINFALL TOTALS OF 2-4" ARE POSSIBLE THRU
20Z. GIVEN RELATIVELY LOW FLASH FLOOD GUIDANCE VALUES OVER
PARTICULARLY THE NORTHERN PORTIONS OF THE OUTLINED AREA -- FLASH
FLOODING IS POSSIBLE. 


RYAN

ATTN...WFO...ILN...ILX...IND...LMK...LSX...MEG...OHX...PAH...
SGF...

ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...

LAT...LON   39958580 39758436 38838376 38198457 38198613 
            37868693 37298745 36658800 36358822 35868876 
            35448968 35539020 36239008 36798980 37229024 
            37259140 37759198 38629113 38749111 39528947 
            39798762