Graphic for MPD #0134
MESOSCALE PRECIPITATION DISCUSSION 0134
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
721 AM EDT SAT APR 22 2017

AREAS AFFECTED...EASTERN TN...SOUTHEAST KY...EXT SOUTHWEST VA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 221130Z - 221700Z

SUMMARY...WEAKENING CONVECTION THOUGH WITH MODERATE SHIELD
PRECIPITATION MOVING INTO AREA OF SENSITIVE GROUND CONDITIONS
STILL MAY POSE ISOLATED FLASH FLOOD THREAT THROUGH EARLY MORNING.

DISCUSSION...WV DEPICTS WEAK HEIGHT FALLS/SHORTWAVE PRESSING
EASTWARD ACROSS THE LOWER OHIO RIVER VALLEY CURRENTLY CORRALLING
AND CONCENTRATING THE NARROW MOISTURE STREAM ACROSS N MS/NW AL
INTO CENT AND E TN IN ADVANCE OF A WAVY FRONTAL ZONE. INSTABILITY
IS NEARLY FULLY EXHAUSTED WITH ONLY A NARROW RIBBON OF 100-250
J/KG OF ELEVATED MUCAPE EXISTING ACROSS CENT/E TN.  STILL THIS IS
SUFFICIENT TO MAINTAIN WEAK CONVECTIVE ELEMENTS ALONG THE FRONTAL
BOUNDARY THOUGH THERE IS A TRANSITION OF THE CELLS TOWARD GREATER
ELEVATED NATURE OR SLIGHTLY ANAFRONTAL.  STILL WITH FAIRLY DEEP
SATURATED PROFILES WITH TPWS OF 1.3 TO 1.5"...THESE WEAK CELLS ARE
STILL CAPABLE OF RATES OF .75-1.0"/HR AND GIVEN THE ORIENTATION OF
THE FRONTAL ZONE WITH THE INCREASING NORTHERLY COMPONENT OF THE
CELL MOTION THERE MAY BE A NARROW CORRIDOR OF TRAINING CELLS AS
WEAK SHOWERS HAVE DEVELOPED DOWNSTREAM ACROSS THE CUMBERLAND
PLATEAU THROUGH TO THE APPALACHIANS OF FAR W VA.  THOUGH WITH THE
DPVA ALOFT AND NARROWING BUT NEARLY UNIDIRECTIONAL MST TRANSPORT
THERE SHOULD BE SOME EXPANSION/MAINTENANCE OF THE BROAD MODERATE
SHIELD PRECIPITATION ACROSS NE TN AND SE KY...WITH EXPECTATIONS OF
1-2".  THIS WOULD FALL OVER 3-6HRS WHICH WOULD BE VERY CLOSE TO
THE LOW FFG VALUES ACROSS THE CUMBERLAND PLATEAU AND SE KY.  STILL
THE THREAT OVERALL IS ON THE LOWER SIDE AND THEREFORE THE THREAT
OF FLASH FLOODING IS ONLY CONSIDERED POSSIBLE THROUGH THE EARLY
MORNING. 

GALLINA

ATTN...WFO...JKL...LMK...MRX...OHX...RLX...

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

LAT...LON   37718283 37498220 36448190 35718399 35418597
            36188621 37308409


Last Updated: 721 AM EDT SAT APR 22 2017