Area Forecast Discussion
Issued by NWS Phoenix, AZ

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FXUS65 KPSR 012054
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
155 PM MST SUN FEB 1 2015

&&

.SYNOPSIS...
THE COMBINATION OF LINGERING MOISTURE...CLEAR SKIES...AND LIGHT
WINDS WILL ALLOW PATCHY FOG TO DEVELOP ONCE AGAIN TONIGHT ACROSS
SOUTH CENTRAL ARIZONA. HIGH PRESSURE THAT IS FORECAST TO BUILD
INLAND ACROSS THE DESERT SOUTHWEST WILL THEN BRING DRY WEATHER AND A
WARMING TREND...ALONG WITH MOSTLY CLEAR SKIES TO THE REGION THROUGH
THE UPCOMING WORK WEEK...WITH HIGHS APPROACHING 80 DEGREES ACROSS
THE LOWER DESERTS BY THE END OF THE WEEK.

&&

.DISCUSSION...

AFTER A VERY FOGGY MORNING...MOST OF OUR CWA IS NOW SEEING MOSTLY
CLEAR SKIES AT THIS HOUR...WITH JUST SOME PATCHY FOG AND LOW CLOUDS
STILL SEEN ON SATELLITE IMAGERY OVER PINAL COUNTY...WHICH WILL
LIKELY BURN OFF OVER THE NEXT HOUR OR SO. AMPLE SUNSHINE THIS
AFTERNOON...ALONG WITH SOMEWHAT WARMER AIR ALOFT IS EXPECTED TO
ALLOW TEMPERATURES TO RECOVER INTO THE UPPER 60S AT MOST LOWER
DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA...WITH 70S ACROSS SW
AZ AND SE CA.

AS FAR AS THE FORECAST FOR TONIGHT IS CONCERNED...ONCE AGAIN THE
POSSIBILITY OF FOG WILL BE THE MAIN ISSUE. THE COMBINATION OF A
STILL-MOIST BOUNDARY LAYER/SOIL MOISTURES...LIGHT WINDS...AND CLEAR
SKIES IS EXPECTED TO ALLOW TEMPERATURES TODAY TO FALL VERY CLOSE TO
THE DEWPOINT VALUES ACROSS SOUTH-CENTRAL ARIZONA...WHICH WOULD ALLOW
FOG TO ONCE AGAIN FORM TOWARDS MORNING. HOWEVER...STRONG SUBSIDENCE
ALOFT IS EXPECTED TO BEGIN TO PUSH DRIER AIR DOWNWARD AND COMPRESS
THE BOUNDARY LAYER BY LATE TONIGHT...WHICH SHOULD HELP TO INHIBIT
FOG FORMATION SOMEWHAT. AT THIS POINT...CURRENT THINKING IS THAT
PATCHY FOG WILL FORM...BUT SHOULD...FOR THE MOST PART...NOT BECOME
ANYWHERE AS DENSE AS WE SAW THIS MORNING...AND CLEAR EARLIER...IN
THE 16-17Z TIMEFRAME. ONCE THIS FOG CLEARS...ABUNDANT SUNSHINE AND
FURTHER WARMING ALOFT IS EXPECTED TO ALLOW TEMPERATURES TO RISE
ABOVE 70F ACROSS THE SOUTH-CENTRAL DESERTS ON MONDAY AFTERNOON.

AS FAR AS THE REST OF THE WEEK IS CONCERNED...MODEL GUIDANCE
REMAINS VERY CONSISTENT IN CALLING FOR DRY AND WARMER CONDITIONS
THROUGH THE ENTIRE WEEK...AND INTO NEXT WEEKEND...AS A STRONG UPPER
LEVEL HIGH PRESSURE RIDGE STEADILY BUILDS INTO THE DESERT SOUTHWEST.
AS THE RIDGE BUILDS...THERE WILL BE PERIODS OF HIGH CLOUDS SPREADING
THROUGH THE RIDGE AND ACROSS THE DESERTS...BUT OVERALL WE SHOULD SEE
MOSTLY SUNNY DAYS AND MOSTLY CLEAR NIGHTS. HIGH TEMPS ARE FORECAST
TO CLIMB INTO THE MID TO UPPER 70S BY TUESDAY...THEN RISE FURTHER
AND INTO THE UPPER 70S TO LOW 80S ACROSS THE WARMER DESERTS BY
FRIDAY. IF THE WARMER EURO MODEL IS RIGHT...H5 HEIGHTS ARE FORECAST
TO RISE IN EXCESS OF 585DM OVER THE SOUTHWEST AZ AND SERN CA DESERTS
BY THIS WEEKEND...WHICH WOULD ALLOW HIGH TEMPS TO REACH INTO THE MID
TO UPPER 80S ACROSS THE WARMER LOWER DESERTS. AT THIS POINT...HAVE
JUST GONE WITH A MODEL BLEND...WHICH IS STILL PUSHING LOWER DESERT
HIGHS INTO THE LOW TO MID 80S.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...

WILL SEE SOME AFTERNOON CU DEVELOPMENT AFTER 21Z...BUT COVERAGE
SHOULD REMAIN FEW TO SCATTERED WITH BASES AROUND 5-6K FEET AND THEN
CLEARING SHORTLY AFTER SUNSET. LIGHT WESTERLY WINDS THIS AFTERNOON
WILL TURN EASTERLY LATER THIS EVENING AND REMAIN LESS THAN 8 KTS
THROUGH MONDAY MORNING. THERE IS THE POTENTIAL FOR ANOTHER ROUND OF
FOG LATE TONIGHT INTO MONDAY MORNING...BUT NOT ANTICIPATING ANY
DENSE FOG THIS TIME AND CONFIDENCE IN OCCURRENCE IS STILL SOMEWHAT
LOW. BEST TIME FRAME FOR ANY VSBY IMPACTS AT TERMINALS WOULD BE
BETWEEN 11Z-16Z.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO AVIATION IMPACTS FOR SOUTHEAST CALIFORNIA AS SKIES WILL REMAIN
CLEAR THROUGH MONDAY MORNING. SFC WINDS WILL RETAIN A LIGHT
NORTHERLY COMPONENT...THOUGH WILL BECOME VARIABLE AT TIMES AS THE
UNDER A WEAK PRESSURE GRADIENT.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
WARMER TEMPERATURES ARE EXPECTED ACROSS THE REGION THIS WEEK ALONG
WITH DRIER AIR. DESPITE THIS...AFTERNOON HUMIDITIES WILL ONLY DROP
INTO THE 15-25 PERCENT RANGE EACH AFTERNOON WITH GOOD OVERNIGHT
RECOVERIES EXPECTED. NO MAJOR WIND EVENTS ARE ANTICIPATED WITH WINDS
FOLLOWING THE TYPICAL DIURNAL PATTERNS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...DENSE FOG ADVISORY UNTIL NOON TODAY FOR AZZ021>023-025>028.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA/CB
AVIATION...KUHLMAN
FIRE WEATHER...LEINS




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