588
FXUS65 KTWC 030925
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 AM MST THU OCT 3 2013

.SYNOPSIS...A TROUGH BRUSHING BY NORTH OF THE AREA WILL BRING SOME
BREEZINESS LATER TODAY INTO FRIDAY...ALONG WITH SEVERAL DEGREES OF
COOLING FRIDAY INTO SATURDAY.

&&

.DISCUSSION...STILL RATHER DRY WESTERLY FLOW ACROSS SOUTHEAST
ARIZONA THIS MORNING...BUT STARTING TO GAIN A SOUTHERLY INFLECTION
TO THE FLOW THAT WILL DRAW SOME THIN PATCHES OF MAINLY CIRRUS LEVEL
MOISTURE BRUSHING BY FROM THE SOUTH AND EVEN SOME SHALLOW SURFACE
DEWPT INCREASES. FURTHER INCREASE IN SOUTHWESTERLY GRADIENT AS A
STRONG SYSTEM PUSHES INTO THE REGION WELL NORTH OF US SHOULD SEE A
FEW AFTERNOON GUSTS IN WIND PRONE LOCATIONS AND HIGHER ELEVATIONS
WITH BREEZY LEVELS IN SPOTS THIS AFTERNOON AND FRIDAY AFTERNOON.
OTHERWISE...THE MAIN STORM TRACK IS HIGHER LATITUDE FOR BREEZY
CONDITIONS AT TIMES AND A COOLING TREND FRIDAY AND SATURDAY FOR
SOUTHEAST ARIZONA. COOLEST OVERNIGHT LOWS BEHIND THE SAGGING
TROUGHINESS FOR OUR PART OF THE STATE SATURDAY NIGHT INTO SUNDAY
MORNING WITH 40S EAST TO 50S WEST.

STRONG BUT SHORT PERIOD RIDGE PHASES IN QUICKLY FROM THE WEST SUNDAY
AND MONDAY WITH RAPID BUT PROBABLY BRIEF WARMING TREND. REASONABLE
MEASURE OF PREDICTABILITY WITH ECMWF SOLUTION BRINGING ANOTHER
TROUGH INTO THE REGION THE FIRST HALF OF NEXT WEEK. POTENTIAL GOOD
FOR A DEEPER TRACK THAN ADVERTISED BY GFS OR PARTIAL SPLIT BY THAT
POINT WITH GFS ENSEMBLE HINTING AT BETTER STACKING OF RIDGE
UPSTREAM. WE`LL START TO TREND TEMPS DOWN A LITTLE AND BLEND IN SOME
IDEAS FROM ECMWF OUTPUT AROUND THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...SKC-SCT CLOUDS AT OR ABOVE 20K FT AGL THRU EARLY FRIDAY
OR 04/09Z. SURFACE WIND GENERALLY LESS THAN 10 KTS THIS
MORNING...THEN SURFACE WIND SWLY-WLY 10-15 KTS WITH GUSTS TO 22 KTS
THIS AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...LOW PRESSURE WILL MOVE ACROSS THE CENTRAL ROCKIES AS
THE WORK WEEK COMES TO A CLOSE. INCREASED SOUTHWESTERLY TO WESTERLY
SURFACE WINDS WILL OCCUR ACROSS SE AZ TODAY AND FRIDAY BUT DRY
CONDITIONS WILL PERSIST. COOLING TREND FRIDAY AND SATURDAY...WITH
TEMPERATURES SEVERAL DEGREES BELOW AVERAGE BY SATURDAY BEFORE
RETURNING TO NEAR SEASONAL NORMALS EARLY NEXT WEEK.

&&

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

&&

$$

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MEYER/RASMUSSEN