SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NWS PHOENIX AZ
AFDPSR 905 PM MST SAT FEB 2 2002
.SYNOPSIS...
CLOUDS DECREASED BY LATE SATURDAY AS A WEAK LOW PRESSURE AREA MOVED
EAST. DRY WEATHER AND NEAR NORMAL DAYTIME HIGHS...WITH A SMALL
DAY-TO-DAY WARMUP...ARE EXPECTED THROUGH MONDAY. WEAK LOW PRESSURE
WILL PERSIST OVER THE SOUTHWEST UNITED STATES AND BAJA CALIFORNIA.
ABOVE-NORMAL TEMPERATURES...AND CONTINUED DRY WEATHER...ARE FORECAST
TUESDAY THROUGH THURSDAY AS A RIDGE OF HIGH PRESSURE DEVELOPS OVER
THE WESTERN UNITED STATES. SLIGHTLY COOLER TEMPERATURES AND SOME
BREEZES CAN BE EXPECTED FRIDAY AND SATURDAY AS A RATHER STRONG
WEATHER SYSTEM PASSES BY TO OUR NORTH.
.DISCUSSION...
WATER VAPOR AND IR LOOPS SHOW CONTINUED DECREASE IN MSTR ABOVE 15K
FEET AS 300MB JET CORE...120+ KTS...REMAINS OVER SW U.S. NOT
SURPRISINGLY...QUITE A FEW MODERATE TURBULENCE REPORTS FROM AIRCRAFT
AROUND AZ TODAY. HUGE PLUME OF SUBTROPICAL MOISTURE STILL AFFECTING
SE AZ...EVEN SOME RAIN THIS EVENING AT DUG AND NOG. AT 00Z TUS
SOUNDING SHOWED THE MOISTURE WELL...AS PRECIP WATER JUMPED WAY UP.
BOTH ETA/NGM HAD THE SW FLOW AT 500MB...BUT ETA LOOKED BETTER WITH
MORE AMPLIFICATION THAN NGM. LATEST ETA ALSO PICKS UP THE SBTRPCL
LOW SOUTH OF 30N AND LIFTS IT NE BY SUNDAY NIGHT/MONDAY. COMPARED TO
PREVIOUS RUN...ETA IS A BIT SLOWER WITH THIS SYSTEM AS CALIF RIDGE
BECOMES VERY POS TILTED.
SURFACE WARMING TODAY WAS MOST APPARENT OUT WEST...CALIF ZONES WERE
UP 5 TO 7 DEGS. IN FACT IMPERIAL/EL CENTRO RECOVERED TO 66 AND BLH
HAD A 64. EASTERN ZONES...WITH THEIR OVERCAST ALL DAY DROPPED AN
AVERAGE OF 2F DEG FROM FRIDAY.
UPPER RIDGE WILL BE THE MAIN FEATURE TO WATCH NEXT SEVERAL DAYS. NO
SIGNIFICANT CLOUDS EXPECTED WITH POS TILT RIDGE SETTING UP ACROSS
CALIF/NV BY 48HRS. QUICK LOOK AT PARTIAL AVN RUN SUPPORTS THIS
SCENARIO. WINDS WILL LIKELY BE A PLAYER...AND MID SHIFT FORECASTER
MAY WANT TO LOOK AT NEED FOR BREEZY WORDING. SIPPLE
.PSR...NONE.