Area Forecast Discussion
Issued by NWS Tucson, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

000
FXUS65 KTWC 120357
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
857 PM MST FRI APR 11 2014

.SYNOPSIS...A PACIFIC WEATHER SYSTEM WILL BRING STRONG GUSTY WINDS
ALONG WITH POSSIBLE AREAS OF BLOWING DUST SATURDAY. NOT QUITE AS
WARM OVER THE WEEKEND AND A FEW SHOWERS POSSIBLE IN FAR EAST CENTRAL
MOUNTAINS...OTHERWISE CONTINUED DRY. WARMING TREND EARLY IN THE NEW
WEEK.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 12/00Z UPPER-AIR PLOTS SHOW A
PACIFIC TROUGH MAKING ITS WAY INTO SOUTHERN CALIFORNIA AT THIS TIME.
ZONAL FLOW SOUTH AND SOUTHEAST OF THIS SYSTEM IS SPREADING MID AND
HIGH LEVEL CLOUDINESS ACROSS MUCH OF MEXICO...AS WELL AS SOUTHERN
ARIZONA. THE INHERITED PARTLY CLOUDY TO MOSTLY CLOUDY WORDING FOR
SKY CONDITION FOR THE REMAINDER OF TONIGHT SEEMS REASONABLE...SO NO
CHANGES ARE PLANNED.

THIS SYSTEM WILL MOVE ACROSS THE DESERT SOUTHWEST SATURDAY RESULTING
IN AN INCREASE IN WINDS WHICH HAVE PROMPTED BOTH A WIND ADVISORY FOR
MUCH OF COCHISE COUNTY...BUT ALSO SOUTHERN PARTS OF GRAHAM COUNTY
AND EASTERN PORTIONS OF SANTA CRUZ COUNTY FROM 11 AM TO 7 PM MST
SATURDAY. THESE EXPECTED GUSTY WINDS COMBINED WITH ANTICIPATED VERY
LOW MINIMUM RELATIVE HUMIDITY VALUES WILL RESULT IN FIRE WEATHER
CONCERNS AS WELL. FOR MORE DETAILS SEE THE FIRE WEATHER SECTION
BELOW.

AS OF 03Z (8 PM MST)...TEMPERATURES ACROSS THE REGION RANGED FROM
THE MID 70S TO THE MID 80S...WITH THE TUCSON INTL AIRPORT REPORTING
A TEMP OF 84 DEGS AFTER REACHING AN AFTERNOON HIGH OF 94 DEGS...
WHICH WAS 13 DEGS ABOVE NORMAL FOR THIS DATE...BUT ALSO JUST 1
DEGREE SHY OF THE RECORD HIGH TEMP FOR TODAY. SO FAR THE CURRENT
READINGS SEEM TO BE ON TRACK WITH THE INHERITED OVERNIGHT LOW
TEMPS...BUT WILL CONTINUE TO MONITOR AND MAKE ADJUSTMENTS IF NEEDED.

FOR DETAILS REGARDING THE FORECAST BEYOND TONIGHT...PLEASE REFER TO
THE PREVIOUS DISCUSSION BELOW.

&&

.AVIATION...VALID THRU 13/06Z.  A WEAKENING LOW PRESSURE SYSTEM NEAR
SOUTHERN CALIFORNIA WILL CONTINUE TO SPREAD MID AND HIGH-LEVEL
CLOUDINESS ACROSS SE AZ INTO SATURDAY.  EXPECT SCT CLOUDS AT 12-15K
FT AGL AND BKN-OVC CLOUDS ABOVE 20K FT AGL TONIGHT AND SATURDAY
MORNING.  SURFACE WIND WILL EASE TO LESS THAN 10 KTS AFT 12/05Z THEN
INCREASE TO SW 15-25 KTS WITH HIGHER GUSTS AFT 12/18Z.  AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A RED FLAG WARNING IS IN EFFECT FROM LATE SATURDAY
MORNING THROUGH SATURDAY EVENING FOR MOST OF FIRE ZONES 151 AND 152
AND THE SOUTHERN PORTION OF 153.  THE COMBINATION OF STRONG AND
GUSTY WEST WINDS...VERY LOW RELATIVE HUMIDITIES...AND A HIGH TO VERY
HIGH FIRE DANGER RATING ARE EXPECTED TO PRODUCE CRITICAL FIRE
WEATHER CONDITIONS.  THE STRONGEST WINDS...COCHISE COUNTY...ARE
EXPECTED TO BE IN THE 20-30 MPH RANGE WITH GUSTS OF 40+ MPH WITH
LOWER VALUES FURTHER WEST.  MINIMUM HUMIDITY LEVELS WILL BE A BIT
HIGHER THAN TODAY BUT WILL STILL BOTTOM OUT BELOW 10 PERCENT.

ANOTHER SYSTEM DROPPING SE ACROSS THE GREAT BASIN SUNDAY NIGHT WILL
BRING NEAR RED FLAG CONDITIONS TO THE NORTHEAST PART OF THE AREA
THANKS TO A NW BREEZE AND LOW RH VALUES.  THIS WOULD AFFECT ZONE
153 AND THE NORTHERN THIRD OF ZONE 152 AND WILL NEED TO BE WATCHED.

BEYOND THAT...WARM AND DRY WITH MORE TYPICAL DIURNAL AFTERNOON
BREEZES ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK.  CERNIGLIA

&&

.PREVIOUS DISCUSSION...MAIN STORY FOR OUR PART OF THE STATE
CONTINUES TO FOCUS ON ENHANCED GRADIENT FROM THE LOW AS IT OPENS UP
AND PUSHES THROUGH SOUTHERN ARIZONA SATURDAY. MID AND UPPER LEVEL
CLOUD MAY INITIALLY DELAY MIXING WITH STRONGEST WINDS AFTER NOON OR
1 PM MST SATURDAY WITH A PARTIAL CLEARING TREND FROM THE WEST DURING
THE LATE MORNING AND EARLY AFTERNOON HOURS. WITH THIS IN MIND WE
HAVE ISSUED A WIND ADVISORY FOR WIND PRONE EASTERN AREAS EAST AND
SOUTHEAST OF TUCSON. ALSO A RED FLAG WARNING FOR MOST OF OUR AREA AS
OUTLINED IN THE FIRE WEATHER SECTION BELOW.

DECENT MID LEVEL MOISTURE AHEAD OF THE IMPULSE SATURDAY...BUT LOW
LEVELS WILL STRUGGLE TO SEE MUCH MOISTURE EVEN WITH TEMPORARY
SURFACE STREAMLINES FROM THE GULF. WE COULD MANAGE A FEW LIGHT
SHOWERS IN EAST CENTRAL MOUNTAINS WITH PATCHY VIRGA ELSEWHERE. SOME
GRADIENT ENHANCEMENT IN ESPECIALLY EASTERN AREAS SUNDAY AS A
STRONGER IMPULSE CARVES INTO THE REGION NORTH OF US.

RIDGE PHASING IN MONDAY AND TUESDAY LOSES AMPLITUDE AS NORTHERN TIER
ENERGY HELPS MASSAGE THE PATTERN INTO A MORE ZONAL FLOW. ENERGY MAY
BRUSH BY CLOSE ENOUGH FOR BREEZY WINDS AT TIMES AROUND MID WEEK.

ANOTHER WEAK IMPULSE DIRTYING UP THE MEAN LOW AMPLITUDE RIDGE
POSITION LATE NEXT WEEK. TOUGH TO WRING MUCH IN THE WAY OF
SIGNIFICANT MOISTURE OR PRECIP OUT OF IT.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    RED FLAG WARNING SATURDAY FROM 11AM THROUGH 9PM
     FOR AZZ151-152 AND SOUTHERN AZZ153.
    WIND ADVISORY SATURDAY FROM 11AM THROUGH 7PM FOR
     AZZ503-507>509-511>513.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

CURRENT DISCUSSION/AVIATION...MOLLERE
PREVIOUS DISCUSSION/FIRE WEATHER...MEYER/CERNIGLIA






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.