Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 221946
SWOMCD
SPC MCD 221945
NEZ000-SDZ000-WYZ000-222045-

MESOSCALE DISCUSSION 1360
NWS STORM PREDICTION CENTER NORMAN OK
0245 PM CDT FRI JUL 22 2016

AREAS AFFECTED...FAR ERN WY / SWRN SD / NRN NEB PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 221945Z - 222045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED LARGE HAIL/SEVERE GUST THREAT WILL LIKELY
DEVELOP THIS AFTERNOON.  RELATIVELY LIMITED SEVERE STORM COVERAGE
WILL SEEMINGLY PRECLUDE A SEVERE THUNDERSTORM WATCH.  CONVECTIVE
TRENDS WILL BE MONITORED.

DISCUSSION...VISIBLE-SATELLITE IMAGERY LOOP AND SURFACE OBSERVATIONS
CONFIRM VERY STRONG HEATING HAS OCCURRED TODAY AND HAS ACTED TO
PRECONDITION A WEAKENING IN THE CAP AND EROSION OF MLCINH EARLY THIS
AFTERNOON.  WEAK FORCING FOR ASCENT ASSOCIATED WITH A SHORTWAVE
IMPULSE MOVING ACROSS ERN PORTIONS OF WY INTO WRN SD PER WATER-VAPOR
IMAGERY HAS AIDED STORM DEVELOPMENT.  RADAR MOSAIC SHOWS WIDELY
SCATTERED THUNDERSTORMS DEVELOPING IN A NW TO SE BAND FROM NIOBRARA
COUNTY WY SEWD INTO THE NRN NEB PANHANDLE.

VERY LARGE TEMP-DEWPOINT SPREADS RANGING FROM 45-55 DEG F RESULTING
IN NEARLY DRY-ADIABATIC LAPSE RATES ON THE WRN EDGE OF THE MOISTURE
RESERVOIR --WHICH IS LOCATED OVER THE SANDHILLS AND CNTRL SD-- WILL
FACILITATE EFFICIENT DOWNBURSTS VIA EVAPORATIVE COOLING.  AS STORMS
ACQUIRE LARGE CORES...AN ISOLATED RISK FOR SEVERE GUSTS WILL
CORRESPONDINGLY INCREASE.  LARGE HAIL IS ALSO POSSIBLE WITH THE
STRONGER UPDRAFTS MANAGING TO SUSTAIN MORE THAN BRIEF ROTATION.

..SMITH/WEISS.. 07/22/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LBF...UNR...CYS...

LAT...LON   43900329 42820203 42020214 41780309 43030453 43610411
            43900329




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