000
FXUS65 KPSR 032230
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
330 PM MST WED DEC 3 2008
.SYNOPSIS...
A WEAK UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION
THURSDAY NIGHT AND FRIDAY AND GIVE SOME HIGH CLOUDS TO THE AREA.
OTHERWISE...HIGH PRESSURE ALOFT WILL DOMINATE THE SOUTHWEST UNITED
STATES INTO EARLY NEXT WEEK...PRODUCING MOSTLY CLEAR TO PARTLY
CLOUDY SKIES...NEAR-NORMAL HIGH TEMPERATURES AND COOL NIGHTS.
&&
.DISCUSSION...
MODELS HAVE FINALLY ALL COME INTO A DECENT AGREEMENT REGARDING WX
EVENTS THE NEXT SEVERAL DAYS. AFTER A WEAK SHORTWAVE PUSHES THRU
FROM THE GREAT BASIN LATE THURSDAY INTO FRIDAY...HIGH PRESSURE ALONG
THE WEST COAST WILL CONTINUE A DRY NWLY FLOW OVER THE DESERT SW. THE
UPPER CUTOFF LOW THAT HAS BEEN PROGGED TO DEVELOP OFF THE WEST COAST
BY THE VARIOUS MEDIUM RANGE MODELS IS NOW BEING HANDLED SIMILARLY.
THAT IS...SHORTWAVE NOW BREAKING OFF FROM THE NRN BRANCH OF THE WLYS
OFF THE PAC NW COAST WILL CLOSE OFF AND GET CAUGHT UP UNDER THE
AMPLIFYING RIDGE. THIS WILL KEEP THE UPPER LOW WELL OFF THE COAST
WELL INTO NEXT WEEK. ALL ADJACENT OFFICES ARE NOW IN AGREEMENT WITH
THE ABOVE SCENARIO. HAVE THEREFORE BACKED OFF ON POPS TO SINGLE
DIGITS AND LOWERED AMOUNT OF SKY COVER SUNDAY AND MONDAY. IN
ADDITION...WE WARMED UP THE MAX TEMPS AND COOLED OFF NIGHTTIME LOWS
OVER THE EXTENDED. BOTTOM LINE...IT NOW APPEARS LIKE A DRY AND
UNEVENTFUL SEVEN DAYS AHEAD.
&&
.AVIATION...
VFR CONDITIONS WITH LIGHT DIURNAL WINDS AND CLOUDS AT OR ABOVE 20K
FT WILL CONTINUE THROUGH AT LEAST MID DAY THURSDAY.
KPHX WINDS ARE EXPECTED TO REMAIN UNDER 7KT THROUGH THE NEXT 24
HOURS...FAVORING DIURNAL FLUCTUATIONS WITH A WESTERLY COMPONENT
AFTER 23 UTC AND THEN AN EASTERLY COMPONENT EARLY THURSDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
UPPER LEVEL HIGH PRESSURE CENTERED OFF THE PACIFIC COAST WILL BEGIN
TO WEAKEN AND SHIFT EASTWARD BY THE WEEKEND...WITH A CUTOFF LOW
PRESSURE DEVELOPING OFF THE COAST OF CALIFORNIA. A MODEST INCREASE
IN MOISTURE MAY TAKE PLACE SUNDAY OR MONDAY...ACCOMPANIED WITH A
SLIGHT CHANCE OF SHOWERS DURING THIS PERIOD. THERE IS STILL A GREAT
DEAL OF UNCERTAINTY WITH REGARDS TO THE POSITION OF THE CUTOFF
LOW...SO PRECIPITATION CHANCES REMAIN LOW ATTM. TEMPERATURES WILL
REMAIN SLIGHTLY ABOVE NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...ESTLE
AVIATION...WANEK
FIRE WEATHER...ROGERS
