Area Forecast Discussion
Issued by NWS Tucson, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KTWC 131533
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
833 AM MST SAT SEP 13 2014

.SYNOPSIS...STRONG AND GUSTY EAST WINDS TODAY ALONG WITH SEVERAL
DEGREES OF COOLING. ISOLATED SHOWERS AND THUNDERSTORMS OVER THE
WEEKEND. THE CHANCE FOR THUNDERSTORMS WILL INCREASE DURING THE
UPCOMING WEEK AS MOISTURE INCREASES ACROSS THE AREA FROM THE SOUTH.
THERE IS A POTENTIAL FOR PERIODS OF SIGNIFICANT RAINFALL FROM
TUESDAY THROUGH THURSDAY.

&&

.DISCUSSION...THE MAIN WEATHER STORY TODAY WILL BE GUSTY EAST WINDS
AS A TIGHT SURFACE PRESSURE GRADIENT REMAINS IN PLACE. LESS
THUNDERSTORM ACTIVITY TODAY COMPARED TO YESTERDAY...BUT STILL
LOOKING AT ISOLATED THUNDERSTORMS DEVELOPING THIS AFTERNOON AND THIS
EVENING. CURRENT FORECAST LOOKED ON TRACK...SO PLEASE REFER TO THE
PREVIOUS DISCUSSION ATTACHED IN THIS PRODUCT FOR MORE DETAILS. NO
UPDATES ANTICIPATED THIS MORNING.

&&

.AVIATION...VALID THRU 14/18Z.
STATIONARY FRONTAL BOUNDARY WILL LINGER JUST EAST OF THE KSAD TO
KDUG LINE THROUGH MOST OF THE PERIOD. THIS WILL KEEP THE TIGHTENED
PRESSURE GRADIENT IN PLACE WHICH WILL RESULT IN EASTERLY SFC FLOW AT
ALL TERMINALS. GENERALLY SPEAKING WINDS WILL REMAIN BELOW 12 KTS
THOUGH FAIRLY ROBUST LOW LEVEL JET EXIST. THEREFORE...THERE REMAINS
SOME THREAT OF GUSTY WINDS MIXING DOWN. THESE CONDITIONS WILL LIKELY
BE PRESENT AT MOST TERMINALS THRU TO 21Z TODAY. THEN AS THE JET
ERODES WINDS WILL GENERALLY BE SUSTAINED AT OR AROUND 12KTS. DURING
THE AFTERNOON TODAY THE FOCUS WILL SHIFT TO CB/TS
DEVELOPMENT...WHICH GIVEN THE INVERTED V SOUNDING PROFILES WILL
BRING THE POTENTIAL FOR ERRATIC OUTFLOW WINDS AND GUST. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STATIONARY FRONT WILL LINGER NEAR THE NEW MEXICO
STATE LINE THROUGHOUT MOST OF TODAY BEFORE RETREATING TO THE EAST
SOME FOR SUNDAY. THIS WILL KEEP A FAIRLY TIGHT PRESSURE GRADIENT IN
PLACE FOR THE AREA...WHICH WILL KEEP THE ELEVATED EASTERLY FLOW IN
PLACE. THERE WILL ALSO BE A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS
ACROSS THE AREA FOR THIS WEEKEND. THEN THE FOCUS WILL SHIFT TO
HURRICANE ODILE...WHICH WILL USHER IN SOME DEEPER MOISTURE EARLY
NEXT WEEK. THIS MOISTURE IS EXPECT TO BE IN PLACE ALL WEEK THOUGH
THE BEST DAY FOR WETTING RAINS WILL LIKELY BE TUE/WED. GUIDANCE HAS
AN UPPER TROUGH EDGING IN TO THE WEST COAST BY LATE WEEK WHICH
SHOULD BE COME IN PHASE WITH ODILE WHICH WILL HELP USHER CONTINUAL
MOISTURE INTO THE REGION AS ODILE WEAKENS OFF THE CENTRAL BAJA
COAST.

&&

.PREV DISCUSSION...WEAKENING FRONTAL BOUNDARY BACKING IN FROM NEW
MEXICO WILL CONTINUE TO WASH OUT THIS MORNING NEAR THE NEW MEXICO
BORDER AS A STRONG EASTERLY FLOW KICKS IN ACROSS SOUTHEAST ARIZONA
THIS MORNING. WE`LL PROBABLY SEE LESS THUNDERSTORM COVERAGE TODAY ON
THE OTHER SIDE OF THE BOUNDARY THROUGH MOST EASTERN
AREAS...INCLUDING COCHISE AND SOUTHERN GRAHAM COUNTIES.
MEANWHILE...WESTERN AREAS HAVE SEEN A NICE PUSH OF MOISTURE FROM THE
EARLIER OUTFLOWS AS WELL AS FROM THE SOUTH. WITH THIS IN MIND...WE
EXPECT CONVECTION WILL FOCUS ON AREAS SOUTH TO SOUTHWEST OF TUCSON
THIS AFTERNOON AS WELL AS THE WHITE MOUNTAINS INCLUDING NORTHERN
GREENLEE COUNTY. STRONG AND GUSTY EAST TO SOUTHEAST WINDS THIS
MORNING...DIMINISHING SOMEWHAT THIS AFTERNOON AS THE GRADIENT
ASSOCIATED WITH THE WEAKENING BOUNDARY RELAXES.

RIDGE AXIS PHASES OVERHEAD EARLY IN THE NEW WEEK. AFTER COOLER AIR
FILTERS IN FROM THE EAST TODAY...EXPECT TEMPERATURES TO BOUNCE BACK
TO NEAR CLIMO BY MONDAY. WE SHOULD KEEP ENOUGH MOISTURE AROUND FOR
ISOLATED THUNDERSTORM COVERAGE AS THIS HAPPENS.

FROM TUESDAY THROUGH MOST OF THE REST OF THE WEEK WE SHOULD SEE
SIGNIFICANT INFLUENCES FROM ODILE. AS OF 2 AM ODILE HAD INTENSIFIED
TO HURRICANE STRENGTH AND WAS LOCATED ABOUT 200 MILES SSW OF
MANZANILLO MEXICO AT 16.4N 105.6W...MOVING NW AT 5 MPH. INITIALLY
ODILE WILL BE IN A GREAT POSITION TO ASSIST ANOTHER SURGE LATE
SUNDAY INTO MONDAY AS THE OFFICIAL FORECAST TRACK PUTS IT NEAR THE
SOUTHERN TIP OF BAJA. WE SHOULD SEE A RAMP UP IN THUNDERSTORM
COVERAGE BY TUESDAY AS THIS OCCURS AND MID LEVEL CONDITIONS AND
INSTABILITIES STILL RETAIN NON TROPICAL INFLUENCES. MOISTURE WILL
PROBABLY BE QUITE DEEP AND WELL ABOVE CLIMO BY WEDNESDAY BUT WE MAY
ALSO BE SEEING MORE TROPICAL INFLUENCES ON OUR
STABILITY...INCREASING RAIN EFFICIENCY BUT BECOMING MORE RELIANT ON
EXTERNAL FEATURES FOR A TRIGGER.

BY LATE WEDNESDAY INTO THURSDAY THE ECMWF DIGS A TROUGH INTO A
POSITION NEAR THE WEST COAST TO GREATLY ENHANCE THE POTENTIAL FOR
STORMS WHILE AT THE SAME TIME DRAWING THE DECAYED REMNANTS OF ODILE
INTO SOUTHERN ARIZONA THURSDAY AND THURSDAY NIGHT. THAT`S PRETTY FAR
OUT STILL...BUT LATEST ENSEMBLE MEAN AND NORMALIZED SPREAD FOR THE
SECOND HALF OF NEXT WEEK ARE LOOKING GOOD WITH FAVORABLE TRENDS. THE
GFS IS A LITTLE FURTHER WEST WITH SOME FEATURES WHILE STILL MANAGING
TO BRING POPS WELL ABOVE CLIMO TO SOUTHEAST ARIZONA. EITHER WAY WE
ARE RAMPING UP THE POP FORECAST WITH HINTS IN AN EXTENDED QPF
FORECAST OF ELEVATED STORM TOTAL RAINFALL VALUES. THIS AGREES WELL
WITH LATEST 7 DAY QPF OUTLOOKS FROM THE WPC.

BOTTOM LINE IS GUSTY EAST WINDS TODAY WITH ISOLATED THUNDERSTORM
COVERAGE INTO MONDAY. INCREASING CONVECTION COVERAGE AND INTENSITY
TUESDAY WITH BEST CHANCES OF PERIODS OF HEAVY PRECIP WEDNESDAY INTO
EARLY FRIDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

MEYER/MEADOWS







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.