Area Forecast Discussion
Issued by NWS Tucson, AZ

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FXUS65 KTWC 210350 CCA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
850 PM MST MON APR 20 2015

.SYNOPSIS...DRY WEATHER IS EXPECTED TUESDAY AND WEDNESDAY WITH NEAR
NORMAL TEMPERATURES AND A SOUTHWEST BREEZE.  A LOW PRESSURE SYSTEM
WILL BRING COOLER TEMPERATURES AND A CHANCE OF SHOWERS THURSDAY AND
EARLY FRIDAY WITH GUSTY WINDS THURSDAY.  THEN DRIER WEATHER IS
EXPECTED FOR THE WEEKEND WITH NEAR NORMAL TEMPERATURES.

&&

.DISCUSSION...SATELLITE IMAGERY WAS STILL SHOWING SOME CLOUDS
HANGING AROUND LATE THIS EVENING...BUT THE OVERALL TREND WAS FOR
CLEARING OVERNIGHT. OTHERWISE...THE CURRENT FORECAST LOOKED ON TRACK
WITH SOME CHANGES IN THE WEATHER ANTICIPATED THIS WEEK. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 22/06Z.
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SCT-LOCALLY BKN CLOUDS
AROUND 12K FT AGL BECOMING MOSTLY CLEAR OVERNIGHT. WINDS WILL BE
LIGHT AND TERRAIN DRIVEN OVERNIGHT BEFORE INCREASING ONCE AGAIN
TUESDAY MORNING. EXPECT SLY TO SWLY WINDS TO INCREASE AFT 21/16Z TO
12-18 KTS WITH GUSTS TO 28 KTS WITH THE STRONGEST SPEEDS NEAR THE
INTERNATIONAL BORDER. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.   FRENCH

&&

.FIRE WEATHER...DRY CONDITIONS ARE EXPECTED THROUGH WEDNESDAY AS A
LOW PRESSURE SYSTEM DEVELOPS OFF THE SOUTHERN CALIFORNIA COAST. THIS
LOW WILL GENERATE A SOUTH TO SOUTHWEST WIND ACROSS THE AREA
THROUGHOUT THE WEEK WITH WIND SPEEDS INCREASING EACH AFTERNOON.

SPOTTY AND BRIEF RED FLAG CONDITIONS ARE POSSIBLE MAINLY NEAR THE
INTERNATIONAL BORDER BOTH TUESDAY AND WEDNESDAY. EXPECT
SOUTHWESTERLY 20-FT WINDS OF 15-20 MPH AND GUSTS OF 30-35 MPH DURING
THE AFTERNOON HOURS AND RELATIVE HUMIDITY IN THE 10-15 PERCENT
RANGE. WINDS WILL BE STRONGEST ON THURSDAY...WITH SPEEDS OF 20-25
MPH AND GUSTS TO 40 MPH. HOWEVER...MOISTURE LEVELS WILL BE ON THE
INCREASE BEGINNING THURSDAY MORNING AS THE LOW PASSES THROUGH AND
BRINGS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA.
THEREFORE...WIDESPREAD RED FLAG CONDITIONS WILL BE MARGINAL AT BEST
WITH RELATIVE HUMIDITY IN THE 15-20% RANGE. DRY CONDITIONS EXPECTED
TO RETURN FRIDAY EVENING AND LAST THROUGH THIS COMING WEEKEND WITH
NEAR-NORMAL TEMPERATURES AND LESS WIND.   FRENCH

&&

.PREV DISCUSSION...BY TUESDAY AN UPPER LOW WILL HAVE DEVELOPED OFF
THE SOUTHERN CALIFORNIA COAST WITH SWLY MID LEVEL FLOW OVER THE
AREA.  THIS WILL BEGIN TO ADVECT SLIGHTLY COOLER AIR OVER THE REGION
FROM 600-800 MBS WHICH WILL ALLOW FOR FEW DEGREES OF COOLING TUESDAY
MOST AREAS...BASICALLY BACK DOWN TO NORMAL.  THE BIGGER EFFECT WILL
BE SOMEWHAT STRONGER SW WINDS FOR THE AFTERNOON HOURS AS WE MIX
OUT.  NOTHING EXCEPTIONAL...JUST A GOOD BREEZE WHICH WILL BE
STRONGEST NEAR THE MEXICO BORDER.

THEN A NEAR REPEAT FOR WEDNESDAY AS THE UPPER LOW OFF THE WEST COAST
RELOADS WITH ANOTHER SHOT OF ENERGY ROLLING DOWN THE BACKSIDE OF THE
SYSTEM.  WITH CONTINUED SLIGHT COOLING IN THE MID LEVELS HIGH TEMPS
SHOULD END UP ANOTHER DEGREE OR TWO COOLER THAN TUESDAY WITH
SIMILAR SW WINDS IN THE AFTERNOON.  ANY NOTICEABLE STRENGTH
DIFFERENCE IN THE WINDS FROM TUESDAY IS A BIT CHALLENGING TO DISCERN
AT THIS POINT.

THE BIG CHANGES TAKE PLACE THURSDAY INTO FRIDAY AS THIS UPPER LOW
BEGINS TO EJECT TO THE NE ACROSS ARIZONA.  AS A RESULT IT WILL BE A
GOOD DEAL COOLER /7-10 DEGREES COOLER THAN NORMAL/...WINDIER WITH A
THREAT OF SHOWERS BY LATE THURSDAY.  THE SHOWER THREAT IS HIGHEST
NORTH AND OVER THE MOUNTAINS BUT CAN`T RULE OUT A SHOWER ANYWHERE
LATER THURSDAY THROUGH THURSDAY NIGHT.  THE SYSTEM WILL BE LIFTING
OUT OF THE REGION FRIDAY LEAVING A FEW SHOWERS POSSIBLE MAINLY NORTH
OF TUCSON...COOL TEMPERATURES AND A BREEZY WEST WIND.

CONDITIONS WILL IMPROVE OVER THE WEEKEND BUT WITH LINGERING
TROUGHINESS OVER THE REGION WE SHOULD REMAIN JUST A BIT COOLER THAN
NORMAL WITH A SMALL THREAT OF A SHOWER OR TWO OVER THE WHITE
MOUNTAINS SATURDAY.  WARMER TEMPERATURES LIKELY EARLY NEXT WEEK.
CERNIGLIA

&&

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

&&

$$

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