MESOSCALE PRECIPITATION DISCUSSION 0421
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
634 PM EDT MON JUL 04 2016
 
AREAS AFFECTED...WEST VIRGINIA...EXT W MARYLAND...W VIRGINIA...E
KENTUCKY...EXT NE TENNESSEE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 042230Z - 050230Z
 
SUMMARY...INGREDIENTS FOR HVY RAINFALL PRESENT OVER AREA OF
SATURATED SOILS AND PRONE HYDROLOGIC CONDITIONS FOR FLASH FLOODING.

DISCUSSION...RADAR MOSAIC ALONG WITH SATELLITE LOOP INDICATING TWO
STRONGER VORTICITY CENTERS ALONG BROADER SHEAR AXIS FROM PA TO
ARK; THE LEAD WAVE CURRENTLY IN SE OH IS AT THE NOSE OF DEEP
MOISTURE CHANNEL WITH TPWS AOA 2" EXTENDING BACK ALONG THE OHIO
RIVER INTO W KY/TN ATTM.  THIS WAVE IS ALSO COINSIDENT WITH THE A
NE EXTENDING BULGE IN THE SURFACE FRONT WITH STRONG SURFACE-850
MST TRANSPORT VECTORS PRESENTING EXCELLENT UPGLIDE FOR DEEPER
CONVECTIVE INITIATION.  THIS ARE HAS BEEN LIMITED IN SOLAR
INSOLATION FOR SURFACE HEATING TO STEEPEN LAPSE RATES FOR STRONG
INSTABILITY...LIMITING SOME OF THE EFFECTIVENESS FROM THE
MID-LEVEL AND UPPER LEVEL FORCING OF THE VORT CENTER AND
DIVERGENCE ALOFT.  STILL CELLS ARE IN THE 1"/HR RANGE MOVING INTO
MORE COMPLEX TERRAIN AND LOWER FFG VALUES ACROSS WV/W MD.  THE
TRAILING BAND OF CONVECTION IS ALSO DEVELOPING IN SLIGHTLY BETTER
SURFACE CONDITIONS FOR VERTICAL GROWTH OVER CENTRAL WV...THIS
ORIENTATION EXTENDING BACK TOWARD TOWARD THE NEXT ADVANCING WAVE
MAY PROVIDE BEST FF THREAT GIVEN HIGHER PROABILITIES FOR TRAINING
OF THIS NEW DEVELOPMENT. 

THE SECOND WAVE CURRENT OVER N KY SOUTH OF CINCINNATI METRO IS A
BIT STRONGER AND AMPLIFIED AND AS SUCH IS SUPPORTIVE OF STRONGER
WESTERLIES SOUTH OF THE WAVE TO ADVANCE THE MST CONVERGENCE ZONE
WITH DEEPER CONVECTION ACROSS E KY.. WITH MLCAPES IN THE 1000-1500
J/KG RANGE BUT SLIGHTLY LESS MST...TPWS IN THE 1.75 RANGE...STILL
SHOULD BE SUFFICIENT FOR QUICK BURSTS OF INTENSE RAINFALL CAPABLE
OF APPROACHING THE LOW NEAR 1.0" FFG IN THE VICINITY.  THOUGH THE
LOW LEVEL FLOW OUT OF THE WSW IS FAIRLY PARALLEL TO ORIENTATION OF
THE RIDGE LINES...THE AMOUNT OF MOISTURE AND FORCING MAY LEAD TO
LOCALIZED FF CONCERNS. 

LIKEWISE TO THE WAVE TO THE NORTH...THE SLACKENED WESTERLY FLOW AT
THE PERIPHERY OF THE VORT MAY ALLOW FOR THE SOUTHERN PORTION OF
THE CONVERGENCE ZONE TO ORIENT MORE WESTERLY IN ADVANCE OF NEXT
WEAK WAVE IN W TN...SUPPORTING A CORRIDOR OF TRAINING IN THE
VICINITY OF THE KY/TN BORDER...CONFIDENCE REMAINS MARGINAL FOR
THIS SCENARIO TO UNFOLD...BUT IF IT DOES...FF THREAT WOULD BE
INCREASED LATER THIS EVENING INTO TONIGHT MUCH LIKE WESTERN
KY...OVERNIGHT YESTERDAY. 

GALLINA

ATTN...WFO...CTP...JKL...LMK...LWX...MRX...OHX...PBZ...RLX...
RNK...

ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...

LAT...LON   39778018 39777880 39407828 38117874 36798058 
            36268272 36248309 36268424 36408588 36728607 
            36998576 37128494 37278395 37628343 38178329 
            38468249 39178107 39738067