Area Forecast Discussion
Issued by NWS Flagstaff, AZ

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FXUS65 KFGZ 291649
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
949 AM MST WED JUL 29 2015

.SYNOPSIS...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON AND EVENING ACROSS AREAS SOUTH OF A LINE FROM PRESCOTT
TO SHOW LOW TO WINDOW ROCK...WITH A SLIGHT CHANCE ELSEWHERE. FROM
THURSDAY THROUGH NEXT TUESDAY...EXPECT DAILY CHANCES FOR SHOWERS
AND THUNDERSTORMS FOR ALL OF NORTHERN ARIZONA.

&&

.DISCUSSION...SHOWER ACTIVITY CONTINUED OVERNIGHT AND INTO THIS
MORNING MOSTLY FROM THE MOGOLLON RIM SOUTH. AS COMPARED TO
YESTERDAY, LOW LEVEL MOISTURE HAS INCREASED, WITH OBSERVED DEW
POINTS ABOVE 50F GENERALLY SOUTH OF A LINE FROM BAGDAD TO
FLAGSTAFF TO WINDOW ROCK. MODEL DATA SUGGESTS MOISTURE WILL
CONTINUE TO SPREAD NORTHWARD TODAY.

THIS MORNINGS UPPER AIR SOUNDING FROM NEAR FLAGSTAFF SHOWS A
STRONG CAPPING INVERSION IN PLACE JUST ABOVE 500 MB. THIS MAY
LIMIT SHOWER AND THUNDERSTORM ACTIVITY THERE, BUT FURTHER SOUTH,
WHERE THE HIGHEST LOW LEVEL MOISTURE EXISTS, THERE ARE BETTER
CHANCES FOR OVERCOMING ANY CONVECTIVE INHIBITION.

IN THE UPPER LEVELS, AN INVERTED TROUGH IS FORECAST TO CROSS THE
SOUTHWESTERN PORTIONS OF THE REGION. IN ADDITION TO SPREADING
MOISTURE NORTHWARD, THIS FEATURE MAY SUPPLY SOME WEAK LIFT ACROSS
NORTHERN GILA AND YAVAPAI COUNTIES THIS AFTERNOON AND EVENING. THIS
TROUGH IS ALSO EXPECT TO CAUSE ABOUT 30 KNOTS OF DEEP LAYER BULK
SHEAR IN YAVAPAI COUNTY TODAY. WILL WATCH THIS AREA CLOSELY.

THUNDERSTORM STEERING FLOW IS LIGHT TODAY AND WILL GENERALLY BE
FROM THE EAST. THE MAIN HAZARDS FROM TODAY`S STORMS WILL BE SMALL
HAIL, LOCALIZED HEAVY RAINFALL AND FREQUENT LIGHTNING. THE
GREATEST POTENTIAL FOR SEVERE WEATHER WILL BE SOUTH OF THE
MOGOLLON RIM IN YAVAPAI AND NORTHERN GILA COUNTIES - WHERE THE
BEST COMBINATION OF INSTABILITY AND SHEAR EXISTS.

THE ONLY UPDATES TO TODAY`S FORECAST WERE TO INCREASE THE POPS
SOUTH OF THE MOGOLLON RIM, MAINLY IN YAVAPAI COUNTY. THIS MORNINGS
SHORT TERM MODEL GUIDANCE SUGGESTS YAVAPAI COUNTY MAY EXPERIENCE
SCATTERED THUNDERSTORM COVERAGE. THIS MAKES SENSE GIVEN THE ABOVE
ANALYSIS.

&&

.PREV DISCUSSION /330 AM MST/... PROGS ARE SHOWING AN INVERTED
TROUGH MOVING NORTHWESTWARD THROUGH THE PHX AREA THIS EVENING.
PRECIP CHANCES HAVE BEEN INCREASED ACROSS SRN YAVAPAI AND NORTHERN
GILA COUNTIES THIS EVENING.

FROM THURSDAY THROUGH TUESDAY...SOUTHERLY FLOW IN THE MID LEVELS
IS EXPECTED TO CONTINUE ACROSS NORTHERN AZ. PW VALUES INCREASE
SHARPLY ON THURSDAY ACROSS THE AREA AND THEN LEVEL OUT THROUGH
SATURDAY. THUS PRECIP CHANCES ARE ABOVE CLIMATOLOGY FOR THESE DAYS
AND SOME HEAVY RAINERS ARE POSSIBLE. PRECIP CHANCES THEN DROP TO
CLIMO VALUES FROM SUNDAY THROUGH TUESDAY.

&&

.AVIATION...FOR THE 18Z PACKAGE...ISOLATED SHOWERS THIS MORNING
GENERALLY SOUTH OF A KSEZ-KSJN LINE...WITH PRIMARILY VFR EXPECTED.
SCATTERED SHRA/TSRA TO DEVELOP DURING THE EARLY AFTERNOON...MOST
NUMEROUS SOUTH OF A KPRC-KSOW-KRQE LINE...WITH ISOLATED MVFR/IFR
AND GUSTS UP TO 25 KTS NEAR STRONGER STORMS. THE CHANCE FOR
SHRA/TSRA WILL CONTINUE THROUGH THE EVENING HOURS...ESPECIALLY SE
OF A KFLG-KRQE LINE. AVIATION DISCUSSION NOT UPDATED FOR
AMENDMENTS.

&&

.FIRE WEATHER...MONSOON MOISTURE AND ASSOCIATED THUNDERSTORM
ACTIVITY WILL CONTINUE TO INCREASE ACROSS CENTRAL AND EASTERN
ARIZONA TODAY WITH NORTHWESTERN PORTIONS OF THE STATE EXPECTED TO
REMAIN DRY. MOISTURE CONTINUES TO INCREASE TONIGHT LEADING TO
GREATER THUNDERSTORM CHANCES AREA-WIDE ON THURSDAY.
LIGHTNING...LOCALLY HEAVY RAIN...AND SMALL HAIL WILL BE THE MAIN
HAZARDS.

FRIDAY THROUGH SUNDAY...A MORE TYPICAL SUMMER MONSOON PATTERN WILL
PERSIST THROUGH THE WEEKEND WITH DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/DL
AVIATION...JJ
FIRE WEATHER...MCS


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



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