Flash Flood Guidance
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692
AWUS01 KWNH 301229
FFGMPD
KSZ000-NEZ000-301528-

MESOSCALE PRECIPITATION DISCUSSION 0505
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
828 AM EDT SAT JUL 30 2016

AREAS AFFECTED...CENTRAL TO SOUTHEASTERN NE/NORTH-CENTRAL KS...

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

VALID 301228Z - 301528Z

SUMMARY...A CONVECTIVE COMPLEX WHICH ERUPTED DURING THE EARLY
MORNING HOURS HAS DROPPED HEAVY RAINFALL OVER SECTIONS OF CENTRAL
NE. THIS ORGANIZED CLUSTER OF THUNDERSTORMS HAVE A HISTORY OF
PRODUCING 1 TO 2 INCH HOURLY RATES. GRADUAL SOUTH-SOUTHEASTWARD
EXPANSION IS LIKELY AS THE CONVECTION SLIDES DOWN THE INSTABILITY
GRADIENT.

DISCUSSION...WITHIN THE NORTHWESTERLY FLOW REGIME ACROSS THE
CENTER OF THE COUNTRY...A WEAK PERTURBATION HAS IGNITED DEEP
CONVECTION OVER THE CENTER OF NE. THE VAD WIND PROFILER OUT OF
KUEX...HASTINGS NE...SHOWED SUFFICIENT INFLOW INTO THIS COMPLEX
WITH 20 TO 25 KNOT FLOW GENERALLY OUT OF THE 165 TO 170 DEGREE
DIRECTION. SUCH INFLOW HAS ACTUALLY PICKED UP A TAD IN THE PAST 15
MINUTES. THIS ACTIVITY SEEMS TO BE TRAVERSING ALONG THE
INSTABILITY GRADIENT AS DEPICTED BY THE 11Z RAP OBJECTIVE
ANALYSIS. RECENT RADAR IMAGERY AND SURFACE OBSERVATIONS HAVE SHOWN
A FEW ROBUST PRECIPITATION CORES DROPPING VERY HEFTY AMOUNTS.
WHILE DUAL-POL HOURLY ESTIMATES ARE OVERDONE DUE TO LIKELY HAIL
CONTAMINATION...OBSERVED DATA INDICATED 1 TO 2 INCH AMOUNTS ARE
OCCURRING (JOHNSTOWN AND EVELYN SHARP FIELD AIRPORT...NE).

UNFORTUNATELY...RECENT CAMS HAVE BEEN LITTLE TO NO HELP RESOLVING
THIS ACTIVITY. ALL OF THE RECENT HRRR CYCLES SHOWED THE COMPLEX
ALREADY WEAKENING WHICH IS NOT CASE GIVEN COOLING TOPS ON THE
SOUTHWESTERN FLANK OF THE COMPLEX.


RUBIN-OSTER

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GID...LBF...OAX...TOP...

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

LAT...LON   41769878 41429757 39939677 39539762 40119840
            41469922



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