MESOSCALE PRECIPITATION DISCUSSION 0317
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
822 PM EDT MON JUL 06 2015
 
AREAS AFFECTED...NORTHERN ILLINOIS...NORTHWEST INDIANA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 070021Z - 070621Z
 
SUMMARY...MULTIPLE ROUNDS OF STRONG AND EFFICIENT RAINFALL
PRODUCING CELLS COULD LEAD TO POSSIBLE  FLASH FLOOD CONDITIONS. 

DISCUSSION...VERY STRONG COLD FRONT MARCHES ACROSS THE CENTRAL
U.S. AHEAD OF AN UPPER LEVEL TROF WITH EMBEDDED SHORTWAVES ALONG
IT.  THE BASE OF THE TROF SHORTWAVE CONTINUE TO PRESS OUT OF
NEBRASKA/KANSAS INTO NORTHERN MISSOURI. ANOTHER VORT LOBE IS
ANALYZED OVER NORTHEAST IOWA INTO WISCONSIN WITH A VERY TIGHT
NARROW RIDGE DOWNSTREAM FROM SOUTHWEST MICHIGAN INTO THE OZARKS. 
THIS LEADS TO A FLAT FLOW PATTERN PARALLEL TO AN E-W OUTFLOW
BOUNDARY THAT WAS EJECTED FROM THE EARLY MORNING CONVECTION ACROSS
THE DISCUSSION AREA.  A LEADING CONVECTIVE AREA CURRENTLY OVER
NORTH CENTRAL ILLINOIS WILL BECOME AFFECTED BY THE RIDGE A BIT
MORE SLOWING ITS FORWARD PROGRESS WHILE ALLOWING FOR CELLS MOTIONS
TO TURN SOUTH INTO THE MORE DIFFLUENT FLOW INTO NORTHWEST INDIANA.
 WHILE THE SECOND CONVECTIVE COMPLEX ALONG THE FLATTER FLOW IN THE
SHORTWAVE RIDGING BETWEEN THE VORT LOBES IS ORIENTING MORE
EAST-WEST ALLOWING FOR SOUTHERLY LOW LEVEL INFLOW TO BE MORE
PERPENDICULAR TO TRACK OF THE CELLS.  THIS WILL PUMP 3000 J/KG
CAPES AND MID-70S DEWPOINT AIR INTO THE SECOND COMPLEX MAKING IT
HIGHLY EFFICIENT WITH RAIN RATES IN EXCESS OF 2"/HR.  WITH THE
FIRST ROUND LAYING DOWN SOME DESCENT TOTALS...THE MORE EFFICIENT
SECOND ROUND HAS A HIGHER POTENTIAL FOR FLASH FLOODING.   

GALLINA

ATTN...WFO...DVN...ILX...IND...IWX...LOT...LSX...

ATTN...RFC...NCRFC...OHRFC...

LAT...LON   42218855 41828760 41618731 41598615 40928683 
            40148800 40018948 40239142 41049155 41809063