Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 241854
FFGMPD
NMZ000-AZZ000-242300-

MESOSCALE PRECIPITATION DISCUSSION 0553
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
253 PM EDT MON JUL 24 2017

AREAS AFFECTED...EASTERN & SOUTHERN AZ...SOUTHWEST NM

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

VALID 241850Z - 242300Z

SUMMARY...DAYTIME HEATING AND HIGH MOISTURE AVAILABILITY LEADING
TO CONVECTIVE DEVELOPMENT THAT POSES A FLASH FLOOD THREAT DUE TO
HIGH RAINFALL RATES UP TO 2"/HR

DISCUSSION...MAIN MCV/SHORTWAVE CONTINUES TO SLIDE NORTH-NORTHWEST
OUT OF W AZ TOWARD THE COLORADO RIVER VALLEY BETWEEN E CA/S
NV...ONGOING CONVECTION ACROSS THE CENTRAL AZ VALLEY ALONG THE
CONVERGENCE BANDS ALLOWED FOR MILD SUPPRESSION ACROSS EASTERN AND
SOUTHEASTERN AZ ALLOWING FOR EARLY MORNING HEATING TO INCREASE
INSTABILITY IN EXCESS OF 1000 J/KG.  THOUGH FLOW IS GENERALLY
WEAKER THAN EARLY MORNING 7H ENHANCED SOUTHEASTERLY JET THERE
STILL REMAINS SUFFICIENT 10-15KT FLOW THAT IS REMAINS GENERALLY
CONVERGENT PARTICULARLY ALONG THE EASTERN QUADRANT BAND OF THE
WAVE ITSELF.  THIS CONVERGENCE IS MANIFESTING IN CONVECTION
LIFTING NORTHEAST ACROSS GILA COUNTY LIKELY TO MELD/MERGE WITH
OROGRAPHICALLY ENHANCED CONVECTION ALONG ALONG THE EASTERN SIDE OF
THE MOGOLLON RIM.

THE WEAKER FLOW/CONVERGENCE ALLOWS FOR CONVECTION TO BECOME
OUTFLOW DOMINANT BUT NOT BEFORE OVERTURNING AND TAKING AVAILABLE
MOISTURE TOWARD VERY INTENSE RAIN RATES.  12Z SOUNDINGS OUT OF
FGZ, PHX AND TUS ALSO SUGGEST VERY LITTLE SUB-CLOUD
EVAPORATION...AND AS SUCH AVAILABLE TPWS THAT ARE NEAR RECORD
VALUES (1.25-1.4" ON THE HIGH PLATEAU AND AOA 2" ACROSS SE AZ)
SHOULD SUPPORT SIMILAR RATES AND POTENTIAL SIMILAR HOURLY TOTALS.
AS SUCH THERE IS A GOOD POTENTIAL FOR FLASH FLOODING PARTICULARLY
IN COMPLEX TERRAIN NEAR/BELOW THE MOGOLLON RIM AS WELL AS THE
MOUNTAIN RANGES OF S & SE AZ AND SW NM.

ALSO HAVE INCLUDED AREAS OF THE SOUTHERN/SOUTHEASTERN VALLEY FOR
CELLS MOVING SLOWLY NORTHWARD OUT OF PIMA COUNTY AS ANY ADDITIONAL
RAIN IS LIKELY TO EXACERBATE ONGOING FLOODING CONCERNS IN THAT
AREA.

GALLINA

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

ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC...

ATTN...RFC...CBRFC...WGRFC...

LAT...LON   35511088 35330980 34780918 33200884 32450822
            31870785 31800822 31350822 31360905 31421017
            31861127 32111253 32421305 32981260 33661151
            35161155


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