MESOSCALE PRECIPITATION DISCUSSION 0865
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
730 PM EDT THU OCT 05 2017

AREAS AFFECTED...SOUTHEAST NEB...NORTHEAST KS...NORTHERN MO

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

VALID 052330Z - 060530Z

SUMMARY...STRENGTHENING DEEP MOISTURE CONVERGENCE WITHIN FAVORABLE
TRAINING PROFILE SUPPORTS THREAT FOR FLASH FLOODING INTO THE EARLY
OVERNIGHT.

DISCUSSION...23Z SURFACE ANALYSIS SHOWS A WEAK INFLECTION ACROSS
SOUTHEAST NEB ALLOWING FOR SOME SELY BACKED FLOW ALONG WITH
STRENGTHENING SOUTHERLY FLOW WEST OF THE INFECTION CONVERGING
NEARLY 180 DEGREES WITH WEAK NORTHERLY FLOW.  WARM SECTOR IS
REPRESENTED BY LOW 70S TDS (THAT IS GENERALLY SATURATED THROUGH
7H)  WITH SOME SURFACE HEATING ALLOWING FOR MODEST INSTABILITY OF
1000+ J/KG MLCAPES.  ABOVE THE BOUNDARY LAYER...850-7H FLOW VEERS
NICELY FROM THE SURFACE SUPPORTING GENERAL CONFLUENCE ALONG/EAST
OF THE INFLECTION PROVIDING STRONGER MST FLUX DOWNSTREAM WHILE
ALSO SUPPORTING A WEST TO EAST MEAN CELL MOTION ALLOWING FOR THE
POTENTIAL FOR TRAINING.  CURRENT REGIONAL RADAR REFLECTIVITY
MOSAIC AS WELL AS 10.3UM GOES-16 CONUS LOOP SHOW A STEADY
CONVECTIVE INCREASE MAINLY ALONG THE FRONT IN SE NEB WITH COOLING
TOPS AND BUBBLING CUMULIFORM NATURE TO THE COMPLEX ACROSS GAGE TO
RICHARDSON COUNTY. AN ADDITIONAL MORE VIGOROUS CELL IN DAVIESS
COUNTY MO CAPABLE OF RAIN RATES IN THE 1.5"/HR RANGE HELPING TO
SET THE STAGE BY WETTING THE SOILS. 

THE INFLECTION IS BETWEEN TWO SHORTWAVE FEATURES THAT ARE CLOSE
ENOUGH TO SUPPORT THE TRAINING PROFILE WHILE ALSO PROVIDING SOME
DPVA ASCENT AND STRENGTHENING OF THE LLJ/SURFACE WIND FIELD JUST
AFTER DUSK.  AS SUCH THE COMPLEX IS EXPECTED TO INCREASE IN
COVERAGE AND INTENSITY WHILE ALLOWING FOR SLACKED PROPAGATION
VECTORS SUPPORTING UPSTREAM REDEVELOPMENT AS WELL.  THIS IS
UNFOLDING QUITE SIMILAR TO HI-RES CAM SOLUTIONS OF THE 18Z
NAM-CONEST, RECENT RAP SOLUTIONS AND ARW2/NSSL-WRF (THOUGH A BIT
FURTHER NORTH OF THE LATTER).  GLOBAL GUIDANCE SUPPORT ALSO
PROVIDES SOME ADDITIONAL CONFIDENCE FROM THE 18Z NAM AND 12Z
ECMWF.  AVAILABLE MOISTURE FLUX AND SATURATED LOW LEVEL PROFILE
(TPWS AOA 2") SHOULD SUPPORT WARM CLOUD/EFFICIENT PROCESSES THAT
MAY BE UNDERESTIMATED BY REGIONAL WSR-88DS...AND IN THE RANGE OF
1.5-2"/HR.  AS SUCH TOTALS OF 3-4" WITH ISOLATED HIGHER TOTALS ARE
POSSIBLE LEADING TO THE THREAT OF FLASH FLOODING THROUGH 06Z. 

GALLINA

ATTN...WFO...EAX...OAX...TOP...

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

LAT...LON   40569302 40259238 39779307 39569486 39579652
            39889729 40429674 40539530