MESOSCALE PRECIPITATION DISCUSSION 0275
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
904 PM EDT FRI AUG 15 2014
 
AREAS AFFECTED......MISSOURI... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 160104Z - 160604Z
 
SUMMARY...FLASH FLOODING WILL BECOME INCREASINGLY POSSIBLE THIS
EVENING AND OVERNIGHT AS DEEP CONVECTION INCREASES AND
BACKBUILDING OCCURS. 

DISCUSSION...00Z KOAX AND KTOP RAOBS SHOW DEEP MOISTURE PROFILES
CONTAINING PW VALUES NEAR OR IN EXCESS OF 2 INCHES AND STRONGLY
VEERING WINDS.  ALTHOUGH LAPSE RATES ARE NEARLY MOIST
ADIABATIC...STEEPER LAPSE ARE ADVECTING FROM UPSTREAM.  RADAR
IMAGERY SHOWS GRADUALLY GROWING CONVECTION OVER NORTHWEST MISSOURI
WHICH IS CONSISTENT WITH THE MAJORITY OF MODEL GUIDANCE AS THE
SHORTWAVE TROUGH APPROACHES.

18Z RUNS OF THE NAM CONUS NEST AND GFS HAVE SHIFTED THEIR AXES OF
MAXIMUM QPF SOUTHWARD OVERNIGHT AND ARE NOW ALIGNED WITH THE
MAJORITY OF HI-RES GUIDANCE THAT DEPICTS THE POTENTIAL FOR SEVERAL
OR MORE INCHES OF RAINFALL.  THE RAINFALL ACROSS NORTHERN MISSOURI
HAS ALREADY PROMOTED AN ACCELERATION OF INFLOW...AND EXPECT IT TO
ONLY INCREASE AS THE LOW LEVEL JET DEVELOPS.
  
GIVEN THE POTENTIAL FOR A 50 KNOT LOW LEVEL JET OVERNIGHT...EXPECT
CONVECTION TO CONTINUE INCREASING NORTH OF THE STATIONARY FRONT
WITH INCREASING LIKELIHOOD FOR NEARLY STATIONARY OR BACKBUILDING
DEVELOPMENT.  ALSO GIVEN PW VALUES NEAR 2 INCHES...RAINFALL RATES
OF AT LEAST 1 INCH PER HOUR SEEM LIKELY...WITH THE POTENTIAL FOR 2
TO 2.5 INCHES PER HOUR QUITE POSSIBLE.  SOME HI-RES RUNS DEPICT
THE POTENTIAL FOR 4 TO 8 INCHES OF RAINFALL ACROSS PARTS OF N.
MISSOURI.  WHILE NOT EXPECTED BASIN-WIDE...
SIMILAR AMOUNTS LOCALLY ARE QUITE POSSIBLE...AND WOULD LEAD TO
FLASH FLOODING.

JAMES

ATTN...WFO...LSX...SGF...DMX...EAX...OAX...TOP...

ATTN...RFC...ABRFC...MBRFC...NCRFC...

LAT...LON   39399578 40289601 40659455 40399284 39669152 38719145
            38259293 38769483 39399578