FXUS65 KTWC 050907
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
207 AM MST SUN FEB 5 2012

.SYNOPSIS...EXPECT DRY CONDITIONS WITH A WARMING TREND TODAY THROUGH
TUESDAY. A FEW SHOWERS MAY OCCUR WEDNESDAY THROUGH THURSDAY AS A
PACIFIC LOW PRESSURE SYSTEM APPROACHES THE AREA. EXPECT A RETURN TO
WARMER AND DRY CONDITIONS BY LATE IN THE WEEK AND INTO NEXT WEEKEND.

&&

.DISCUSSION...WATER VAPOR IMAGERY SHOWS AN UPPER LOW CURRENTLY
SPINNING OVER NORTHEAST NEVADA AND NORTHWEST UTAH. THIS HAS RESULTED
IN DRY WESTERLY FLOW ALOFT OVER THE DESERT SOUTHWEST.

IR SATELLITE IMAGERY SHOWS ONLY A FEW PATCHES OF MID TO HIGH LEVEL
CLOUDINESS ALONG THE ARIZONA/NEW MEXICO BORDER AND THESE ARE MOVING
TO THE EAST.

MODELS PROG THE AFOREMENTIONED UPPER LOW TO MOVE SLOWLY EAST TO A
POSITION OVER THE CONJUNCTION OF UTAH/WYOMING/COLORADO THROUGH EARLY
MONDAY MORNING. THIS LOW FINALLY TRANSITIONS INTO AN OPEN WAVE AND
MOVES INTO THE CENTRAL PLAINS BY TUESDAY. MEANWHILE...SHORTWAVE
RIDGING WILL SLIDE OVER THE REGION BEHIND THIS LOW MONDAY NIGHT AND
TUESDAY.

ANOTHER APPROACHING UPPER LOW IS PROGGED TO MOVE DOWN THE WEST COAST
AND THE BAJA PENINSULA WEDNESDAY AND THURSDAY. EVEN THOUGH THE LOW
IS EXPECTED TO MOVE PRETTY FAR TO THE SOUTH...WE SHOULD STILL HAVE
ENOUGH MOISTURE THIS FAR NORTH TO JUSTIFY AT LEAST SLIGHT CHANCE
POPS AREA WIDE AND CHANCE POPS ALONG THE INTERNATIONAL BORDER MAINLY
WEDNESDAY NIGHT.

THE SYSTEM SHOULD BE FAR ENOUGH TO THE SOUTH AND EAST ON THURSDAY TO
KEEP ONLY SLIGHT CHANCE POPS MAINLY ALONG THE NEW MEXICO BORDER.

BY FRIDAY RIDGING WILL BUILD IN FROM THE WEST FOR A RETURN TO DRY
AND WARMER WEATHER.

HIGHS ARE GENERALLY EXPECTED TO BE 2 TO 4 DEGS ABOVE NORMAL TODAY
THROUGH TUESDAY...THEN AROUND 4 TO 6 DEGS BELOW NORMAL FOR
WEDNESDAY. FOR THURSDAY AND FRIDAY HIGHS ARE EXPECTED TO BE NEAR
NORMAL AND 4 TO 6 DEGS ABOVE NORMAL FOR SATURDAY. LOWS WILL BE
AROUND 2 TO 4 DEGS BELOW NORMAL FOR MONDAY MORNING...THEN NEAR
NORMAL FOR TUESDAY AND 2 TO 4 DEGS ABOVE NORMAL FOR WEDNESDAY.
THEREAFTER...LOWS NEAR NORMAL.

&&

.AVIATION...SCT CLOUDS AOA 20K FT AGL THRU 06/12Z. AS SURFACE HIGH
PRESSURE SETS UP OVER THE FRONT RANGE OF THE ROCKIES...EXPECT E-SE
WINDS 10-20 KTS WITH LOCAL GUSTS TO 25 KTS THROUGH AROUND
06/03Z...ESPECIALLY IN AREAS THAT ARE SUSCEPTIBLE TO EAST WINDS...
LIKE THE TUCSON AIRPORT. AFT 06/03Z WINDS SHOULD BE LESS THAN 12
KNOTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WITH A WARMING TREND OCCURRING TODAY
THROUGH TUESDAY. LOCALLY GUSTY EAST WINDS MAY OCCUR TODAY DUE TO A
TIGHT SURFACE PRESSURE GRADIENT. WIND SPEEDS ARE EXPECTED TO REMAIN
BELOW CRITICAL FIRE WEATHER CRITERIA. HOWEVER...FIELD CREWS ARE
ENCOURAGED TO MONITOR SUBSEQUENT FORECASTS. THEREAFTER... THERE IS A
SLIGHT CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS WEDNESDAY
THROUGH THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES THE AREA. DRY
CONDITIONS ARE FORECAST NEXT FRIDAY AND SATURDAY.

&&

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

$$

WEATHER.GOV/TUCSON




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