Severe Storm Outlook Narrative (AC)
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968
ACUS11 KWNS 292233
SWOMCD
SPC MCD 292232
AZZ000-300100-

MESOSCALE DISCUSSION 1440
NWS STORM PREDICTION CENTER NORMAN OK
0532 PM CDT FRI JUL 29 2016

AREAS AFFECTED...PORTIONS OF SRN/CNTRL AZ

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 292232Z - 300100Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A RISK FOR ISOLATED DAMAGING WIND GUSTS SHOULD INCREASE
THROUGH THE EVENING HOURS. THIS SEVERE THREAT WILL PROBABLY REMAIN
TOO ISOLATED TO WARRANT WW ISSUANCE...BUT CONVECTIVE TRENDS WILL BE
MONITORED.

DISCUSSION...ISOLATED CONVECTION HAS DEVELOPED OVER THE HIGHER
TERRAIN OF E-CNTRL AZ AND W-CNTRL NM THIS AFTERNOON. AN UPPER RIDGE
REMAINS OVER THE SRN GREAT BASIN AND ADJACENT SWRN CONUS PER RECENT
WATER-VAPOR SATELLITE IMAGERY...AND ELY MID-LEVEL WINDS SHOULD
ENCOURAGE THIS ISOLATED CONVECTION TO DEVELOP/MOVE WWD INTO THE
LOWER TERRAIN OF CNTRL/SRN AZ THROUGH THE EARLY EVENING HOURS. 12Z
SOUNDINGS FROM PHOENIX AND TUCSON SHOW AMPLE PWAT VALUES OF 1.66 AND
1.57 INCHES...RESPECTIVELY...AND SFC DEWPOINTS ARE HOLDING IN THE
UPPER 50S TO LOWER 60S PER 22Z OBSERVATIONS.

WITH STRONG DIURNAL HEATING OCCURRING TODAY...SFC TEMPERATURES HAVE
WARMED INTO THE MID 90S TO UPPER 100S IN LOWER ELEVATIONS...WITH
RESULTANT MLCAPE INCREASING FROM AROUND 1000 J/KG E TO APPROXIMATELY
2000 J/KG W ACROSS THE MCD AREA. STEEP LOW-LEVEL LAPSE RATES GIVEN A
WELL-MIXED BOUNDARY LAYER SHOULD PROMOTE STRONGER CONVECTIVE
DOWNDRAFT WINDS TO THE SFC...AND ISOLATED DAMAGING WIND GUSTS SHOULD
BE THE MAIN SEVERE THREAT THROUGH THIS EVENING. DCAPE ESTIMATES
RANGING FROM 1600-2000 J/KG PER 22Z RAP MESOANALYSIS ALSO SUPPORT
THE DAMAGING-WIND THREAT IN LOWER ELEVATIONS OF CNTRL/SRN AZ. A
SECONDARY THREAT FOR LARGE HAIL MAY ALSO EXIST WITH INITIAL
CONVECTION IN THE HIGHER TERRAIN.

THE MID-LEVEL FLOW IS NOT OVERLY STRONG PER LATEST RAP FORECAST AND
OBSERVED AREA 12Z SOUNDINGS...WHICH MAY TEND TO SLOW THUNDERSTORM
PROPAGATION OFF THE HIGHER TERRAIN UNTIL LATER THIS EVENING. VARIOUS
CAM GUIDANCE SUGGESTS AT LEAST SOME POTENTIAL FOR UPSCALE GROWTH
INTO A WWD/SWWD-MOVING LINE APPROACHING THE PHOENIX METRO AREA
AROUND 02-04Z...WHICH MAY POSE A GREATER DAMAGING WIND THREAT THAN
CURRENTLY EXPECTED. IF THIS CONSOLIDATION WERE TO OCCUR...WW
ISSUANCE PROBABILITIES WOULD INCREASE.

..GLEASON/EDWARDS.. 07/29/2016

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

ATTN...WFO...TWC...FGZ...PSR...

LAT...LON   31541186 33401259 34071244 34701115 34180973 33440911
            32530908 31340962 31271108 31541186




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