Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 261844
SWOMCD
SPC MCD 261844
UTZ000-AZZ000-NVZ000-262045-

MESOSCALE DISCUSSION 1765
NWS STORM PREDICTION CENTER NORMAN OK
0144 PM CDT FRI SEP 26 2014

AREAS AFFECTED...ERN NV...WRN UT...AND EXTREME NWRN AZ

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 261844Z - 262045Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INCREASE IN COVERAGE FROM ERN
NV...WRN UT INTO EXTREME NWRN AZ. A FEW OF THE STORMS COULD PRODUCE
ISOLATED DOWNBURST WINDS AND LARGE HAIL THROUGH EARLY EVENING.
TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

DISCUSSION...STRONG DIABATIC WARMING OVER THE HIGHER TERRAIN HAS
RESULTED IN AN INCREASE IN BOUNDARY LAYER CUMULUS ALONG MOIST AXIS
FROM ERN NV...WRN UT INTO NWRN AZ. LATEST OBJECTIVE ANALYSIS SHOWS
AN AXIS OF MLCAPE RANGING FROM 1500 J/KG OVER SERN NV AND NWRN AZ TO
AOB 500 J/KG OVER NERN NV AND NWRN UT. WV IMAGERY INDICATES A STRONG
AND PROGRESSIVE VORTICITY MAXIMUM ROTATING THROUGH THE BASE OF AN
UPPER TROUGH AND APPROACHING THE CNTRL CA COAST WITH ASSOCIATED
UPPER JET FROM CNTRL CA THROUGH WRN NV. DEEPER FORCING FOR ASCENT
AND STRONGER WINDS ALOFT ACCOMPANYING THIS FEATURE WILL STAY WEST OF
PRIMARY MOIST AXIS THIS AFTERNOON. HOWEVER...DIFFERENTIAL HEATING
OVER THE HIGHER TERRAIN SHOULD CONTRIBUTE TO THUNDERSTORM INITIATION
DURING THE NEXT COUPLE HOURS. WHILE STRONGER WIND PROFILES AND
VERTICAL SHEAR ARE INITIALLY NOT PHASED WELL WITH THE INSTABILITY
AXIS...AN INCREASE IN SHEAR IS EXPECTED TOWARD EARLY EVENING AS THE
SHORTWAVE TROUGH CONTINUES EWD. THE PHASING ISSUES AND MODEST
MID-LEVEL LAPSE RATES COULD SERVE AS OVERALL LIMITING FACTORS FOR A
MORE ROBUST SEVERE EVENT. NEVERTHELESS...STORMS WILL HAVE THE
POTENTIAL TO ORGANIZE AND DEVELOP MID-LEVEL UPDRAFT ROTATION AS THEY
INTERACT WITH THE INCREASINGLY SHEARED ENVIRONMENT LATER THIS
AFTERNOON AND EVENING.

..DIAL/MEAD.. 09/26/2014

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

ATTN...WFO...SLC...VEF...LKN...

LAT...LON   36501562 39021531 40481450 39781337 36651324 35711444
            36501562




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