Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 241951
SWOMCD
SPC MCD 241950
NDZ000-MTZ000-242045-

MESOSCALE DISCUSSION 1459
NWS STORM PREDICTION CENTER NORMAN OK
0250 PM CDT THU JUL 24 2014

AREAS AFFECTED...N-CNTRL AND NERN MT...NWRN ND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 241950Z - 242045Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THREAT FOR DMGG WINDS AND HAIL IS FORECAST TO INCREASE
THROUGH THE AFTERNOON ACROSS N-CNTRL AND NERN MT. IT IS UNCERTAIN
WHETHER TSTM COVERAGE AND ACCOMPANYING SPATIAL EXTENT OF THESE
THREATS WILL BE SUFFICIENT FOR A WW...BUT TRENDS ARE BEING
MONITORED.

DISCUSSION...A SEASONABLY STRONG UPPER TROUGH IS QUICKLY PROGRESSING
EWD ACROSS THE NRN ROCKIES...WITH BAND OF STRONGEST FORCING FOR
ASCENT AND UPPER DIVERGENCE NOTED ACROSS N-CNTRL MT INTO SWRN SK PER
RECENT WATER VAPOR IMAGERY. ISOLATED SHOWERS/TSTMS HAVE BEEN
DEVELOPING WITHIN THIS BAND OF ASCENT BETWEEN CTB AND HVR...BUT
APPEAR TO BE LOCATED TO THE W OF A SFC COLD FRONT. THE AIR MASS
DOWNSHEAR FROM THIS AREA INTO NERN MT IS CHARACTERIZED BY RICHER
LOW-LEVEL MOISTURE /E.G. SFC DEWPOINTS IN THE UPPER 50S TO LOWER 60S
F/...AND CONTINUES TO DESTABILIZE AMIDST STRONG HEATING. THE SPECIAL
18Z SOUNDING FROM GGW MODIFIED FOR 19Z SFC OBS IS YIELDING AROUND
1000 J/KG OF CAPE...WITH STEEP MIDLEVEL LAPSE RATES WITHIN AN EML
PLUME ALSO NOTED.

WITH DEEP-LAYER FORCING FOR ASCENT LARGELY POST-FRONTAL ATTM...AND
THE PRESENCE OF WEAK CINH ACROSS THE REGION...FOCUS FOR NEW
CONVECTIVE DEVELOPMENT IS SOMEWHAT UNCLEAR...AND LENDS UNCERTAINTY
ABOUT TSTM COVERAGE THROUGH THE LATE AFTERNOON AND EARLY EVENING.
HOWEVER...SUBSTANTIAL EFFECTIVE SHEAR /50-60 KT/ WILL BE MORE THAN
SUFFICIENT FOR A FEW SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL. A
DMGG WIND THREAT IS ALSO POSSIBLE GIVEN STEEP LOW-LEVEL LAPSE
RATES...BUT A MORE WIDESPREAD THREAT MAY BE LIMITED BY ISOLATED
COVERAGE AND DISCRETE/CLUSTER CONVECTIVE MODES. TRENDS ARE BEING
MONITORED FOR A POSSIBLE WW...WHICH MAY INCLUDE PARTS OF N-CNTRL AND
NERN MT...AND POSSIBLY NWRN ND.

..ROGERS/WEISS.. 07/24/2014

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

ATTN...WFO...BIS...GGW...TFX...

LAT...LON   48950284 48390276 47610334 47050499 46910577 46970796
            47080966 47051015 47761029 48961024 48950284



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