Area Forecast Discussion
Issued by NWS Tucson, AZ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KTWC 230359
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
855 PM MST MON DEC 22 2014

.SYNOPSIS...DRY WITH MOSTLY CLEAR SKIES TO START THE WEEK. A WEAK
COLD FRONT WILL MOVE THROUGH TONIGHT...BRINGING COOLER TEMPERATURES
ESPECIALLY EAST OF TUCSON. A STORM SYSTEM DIGGING INTO THE FOUR
CORNERS AREA THURSDAY AND FRIDAY WILL BRING A FEW SHOWERS...MAINLY
NEAR THE EASTERN MOUNTAINS.

&&

.DISCUSSION...NORTHERLY FLOW WITH A MOISTURE STARVED COLD FRONT
PUSHING THROUGH NORTHEAST ARIZONA TONIGHT...TRACKING TOWARD OUR AREA
TOMORROW MORNING. SEASONABLY COLDER TEMPERATURES BEHIND THE FRONT
TOMORROW AND TUESDAY NIGHT INTO WEDNESDAY MORNING.

TROUGH FOR THE END OF THE WEEK MIGHT SEE A BIT MORE ENERGY SPLITTING
INTO THE BASE AT A LATITUDE THAT COULD BRING A CHANCE OF SHOWERS
INTO OUR NECK OF THE WOODS. LATEST 00Z NAMDNG5 TRENDS HINTING AT
THIS NOW ALONG WITH THE 12Z ECMWF. SOME SMALL ADJUSTMENTS LEANING IN
THIS DIRECTION.

&&

.AVIATION...VALID THRU 24/04Z.
MAINLY CLEAR SKIES THROUGH THE FORECAST PERIOD. NORTHWEST WINDS 10
TO 15 KTS WITH AN OCCASIONAL GUST TO 20 KTS THROUGH ABOUT
22/06Z...MAINLY SOUTH AND EAST OF KTUS. WINDS WILL THEN BE LESS THAN
10 KTS OVERNIGHT AND BECOME MORE NORTH-NORTHEAST AS A DRY COLD FRONT
PASSES THROUGH THE AREA. AS MIXING INCREASES
TUESDAY...NORTH-NORTHEAST WINDS WILL INCREASE TO 10-20 KTS WITH
HIGHER GUSTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY WITH A
FEW RAIN AND SNOW SHOWERS MAINLY NEAR THE EASTERN MOUNTAINS LATE
CHRISTMAS DAY THROUGH FRIDAY. OTHERWISE...WINDS DIMINISHING TONIGHT
EXCEPT FOR THE HIGHER TERRAIN WHERE BREEZES WILL CONTINUE OVERNIGHT.
BREEZY TO LOCALLY WINDY CONDITIONS AGAIN ON TUESDAY...WITH WINDS
FROM A MORE NLY/NELY DIRECTION. DEW POINTS WILL DROP SIGNIFICANTLY
FOLLOWING A FRONTAL PASSAGE FROM THE NORTH ON TUESDAY RESULTING IN
LOWERING HUMIDITY LEVELS. GUSTY WINDS WILL RETURN AGAIN ON THURSDAY.

&&

.PREV DISCUSSION...CURRENTLY CLEAR SKIES AND NEAR NORMAL
TEMPERATURES MAKE FOR A GREAT AFTERNOON/EVENING IN SOUTHEASTERN
ARIZONA. MIXING DOWN NORTHWEST FLOW ALOFT IS BRINGING BREEZY
CONDITIONS TO MAINLY EASTERN PORTIONS TODAY...WINDS WILL DIMINISH
AFTER SUNSET WITH THE EXCEPTION OF THE GILA VALLEY AREA STAYING
BREEZY INTO TONIGHT.

SATELLITE AND MODEL DATA SHOW A RIDGE OF HIGH PRESSURE AMPLIFYING
JUST OFF THE WESTERN U.S. COAST. AS THE RIDGE AXIS TILTS EAST THE
LONG WAVE TROUGH TO THE EAST WILL DEEPEN...TIGHTENING GRADIENTS AND
CHANGING UPPER LEVEL FLOW TO A MORE NORTHERLY ORIENTATION. A
BACKDOOR COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA OVERNIGHT
TONIGHT BRINGING DRY AIR...MUCH COOLER TEMPERATURES AND A SHIFT IN
SURFACE WINDS TO NORTHEASTERLY. EXPECT BREEZY CONDITIONS AGAIN
TUESDAY...WITH GUSTY WINDS MIXING DOWN THROUGHOUT THE DAY. EXPECT
WINDS TO GENERALLY OUT OF THE NORTH TO NORTHEAST.

TEMPERATURES THROUGH WEDNESDAY MORNING WILL FOR THE MOST PART BE
WITHIN A FEW DEGREES BELOW NORMAL. BY WEDNESDAY MORNING...COOL DRY
AIR WILL BE FIRMLY IN PLACE AND LOW TEMPERATURES ARE EXPECTED TO
DROP BY AROUND 5 DEGREES AROUND THE GREATER TUCSON AREA...AND UP TO
7 TO 10 DEGREES IN EASTERN PORTIONS SUCH AS SAFFORD OR DOUGLAS. THIS
COULD POTENTIALLY CAUSE SOME FREEZING CONCERNS FOR SOME AREAS.
EASTERLY WINDS OVERNIGHT TUESDAY INTO WEDNESDAY MORNING MAY CAUSE
SOME DOWNSLOPE WARMING...POTENTIALLY KEEPING TEMPERATURES UP IN SOME
AREAS.

THE RIDGE AXIS WILL THEN PASS OVERHEAD WEDNESDAY NIGHT BRINGING A
NICE BUMP IN TEMPERATURES BEFORE THE NEXT SYSTEM MOVES IN FOR
CHRISTMAS AND FRIDAY. AT THIS TIME MODELS SHOW IT SKIRTING THE
NORTHERN PORTION OF THE STATE...EVEN SO...SOME RAIN/SNOW SHOWERS
WILL BE POSSIBLE WITH THIS SYSTEM...THOUGH AT THIS TIME IT LOOKS TO
BE MOSTLY LIMITED TO THE WHITE MOUNTAINS. SOME MODEL DISAGREEMENT
EXISTS ON THE EXTENT OF THE MOISTURE BROUGHT INTO THE AREA WITH THIS
SYSTEM...THIS COULD POTENTIALLY CHANGE SHOWER COVERAGE AS MODELS
STRUGGLE TO LOCK ONTO A SOLUTION.

&&

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

&&

$$

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

MEYER





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