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000
FXUS65 KPSR 211710
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1009 AM MST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
IR SATELLITE IMAGERY REVEALS HIGH CLOUDS CONTINUE TO SPILL ACROSS
MOST OF THE WESTERN CONUS THIS MORNING...AS THE EASTERN PACIFIC
RIDGE CONTINUES TO AMPLIFY OFF THE WEST COAST. REGIONAL UPPER AIR
PLOTS INDICATE 582-588DM 500MB HEIGHTS JUST OFF THE SOUTHERN
CALIFORNIA COAST...WITH A RATHER POTENT 140-160KT UPPER LEVEL JET
PUNCHING ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES. THE
JET AND ATTENDANT SHORT WAVE TROUGH IS PROGGED TO STRENGTHEN/DEEPEN
AS IT BEGINS TO SLIDE INTO THE CENTRAL CONUS/NORTHERN PLAINS LATER
THIS EVENING AND MONDAY. SURFACE CONDITIONS ACROSS OUR CWA ARE ONCE
AGAIN COOL AND DRY...BUT THE CLOUD COVER DID KEEP TEMPS UP A FEW
DEGREES OVERNIGHT COMPARED TO YESTERDAY MORNING. DIURNAL DEW POINT
TEMP TRENDS HAVE DIPPED SLIGHTLY BUT WILL STILL HOVER IN THE 30S-40S
ACROSS OUR CWA TODAY...SO DAYTIME HIGHS WILL TOP OUT A BIT WARMER...
IN THE UPPER 60S TO LOW 70S ACROSS THE LOWER DESERT ELEVATIONS.

THE OFFSHORE RIDGE WILL CONTINUE TO STRENGTHEN THROUGH MIDWEEK...BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE AND CLOUD COVER WILL BE MINIMAL.
TEMPERATURES ARE EXPECTED TO WARM A FEW DEGREES MONDAY/TUESDAY...
BUT NOT TO THE DEGREE IF RIDGE AXIS WERE TO MOVE OVERHEAD. ANY
WARMING TO TEMPERATURES TUESDAY WILL PROBABLY BE OFFSET AS A WEAK
BACKDOOR COLD FRONT FROM THE EXPANDING CENTRAL CONUS TROUGH WILL
FINALLY MOVE INTO OUR FORECAST AREA. THIS FRONT WILL BE DRY AND
WILL RESULT IN SLIGHTLY COOLER TEMPERATURES AND INCREASED WINDS
ACROSS SOUTH CENTRAL ARIZONA...WITH NO CHANCE OF RAIN. THE COOLER
TEMPERATURES WILL REMAIN IN PLACE THROUGH WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN





000
FXUS65 KPSR 211710
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1009 AM MST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
IR SATELLITE IMAGERY REVEALS HIGH CLOUDS CONTINUE TO SPILL ACROSS
MOST OF THE WESTERN CONUS THIS MORNING...AS THE EASTERN PACIFIC
RIDGE CONTINUES TO AMPLIFY OFF THE WEST COAST. REGIONAL UPPER AIR
PLOTS INDICATE 582-588DM 500MB HEIGHTS JUST OFF THE SOUTHERN
CALIFORNIA COAST...WITH A RATHER POTENT 140-160KT UPPER LEVEL JET
PUNCHING ACROSS THE PACIFIC NORTHWEST INTO THE NORTHERN ROCKIES. THE
JET AND ATTENDANT SHORT WAVE TROUGH IS PROGGED TO STRENGTHEN/DEEPEN
AS IT BEGINS TO SLIDE INTO THE CENTRAL CONUS/NORTHERN PLAINS LATER
THIS EVENING AND MONDAY. SURFACE CONDITIONS ACROSS OUR CWA ARE ONCE
AGAIN COOL AND DRY...BUT THE CLOUD COVER DID KEEP TEMPS UP A FEW
DEGREES OVERNIGHT COMPARED TO YESTERDAY MORNING. DIURNAL DEW POINT
TEMP TRENDS HAVE DIPPED SLIGHTLY BUT WILL STILL HOVER IN THE 30S-40S
ACROSS OUR CWA TODAY...SO DAYTIME HIGHS WILL TOP OUT A BIT WARMER...
IN THE UPPER 60S TO LOW 70S ACROSS THE LOWER DESERT ELEVATIONS.

THE OFFSHORE RIDGE WILL CONTINUE TO STRENGTHEN THROUGH MIDWEEK...BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE AND CLOUD COVER WILL BE MINIMAL.
TEMPERATURES ARE EXPECTED TO WARM A FEW DEGREES MONDAY/TUESDAY...
BUT NOT TO THE DEGREE IF RIDGE AXIS WERE TO MOVE OVERHEAD. ANY
WARMING TO TEMPERATURES TUESDAY WILL PROBABLY BE OFFSET AS A WEAK
BACKDOOR COLD FRONT FROM THE EXPANDING CENTRAL CONUS TROUGH WILL
FINALLY MOVE INTO OUR FORECAST AREA. THIS FRONT WILL BE DRY AND
WILL RESULT IN SLIGHTLY COOLER TEMPERATURES AND INCREASED WINDS
ACROSS SOUTH CENTRAL ARIZONA...WITH NO CHANCE OF RAIN. THE COOLER
TEMPERATURES WILL REMAIN IN PLACE THROUGH WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN





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000
FXUS65 KFGZ 211654
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
954 AM MST SUN DEC 21 2014

.SYNOPSIS...
PATCHY LOW CLOUDS AND FOG WILL AFFECT THE NORTHEAST ARIZONA
VALLEYS THIS MORNING. OTHERWISE...FAIR WEATHER...A FEW CLOUDS AND
GRADUALLY WARMING TEMPERATURES ARE EXPECTED THROUGH MONDAY. A DRY
COLD FRONT WILL BRING MUCH COLDER TEMPERATURES AND GUSTY NORTHEAST
WINDS MONDAY NIGHT THROUGH TUESDAY. MILD TEMPERATURES ARE FORECAST
FOR WEDNESDAY...THEN BREEZY AND COOLER WEATHER RETURNS FOR
CHRISTMAS DAY AND FRIDAY.

&&

.DISCUSSION...
NO BIG CHANGES THIS MORNING. MAIN FOCUS OF SHORT-TERM FORECAST
WILL BE LOW CLOUDS AND FOG ACROSS NORTHEASTERN VALLEYS...AND ITS
LIMITING IMPACT ON MAXIMUM DAYTIME TEMPS. MAY REDUCE TEMPS A BIT
IN THESE AREAS LATER THIS MORN.

&&

.PREVIOUS DISCUSSION /415 AM MST/...
NORTHWESTERLY FLOW ALOFT WILL CONTINUE TODAY...WITH DRY CONDITIONS
AND GRADUALLY WARMING TEMPERATURES. SOME AREAS OF LOW CLOUDS AND
PATCHY FOG WILL AFFECT NORTHEAST AZ VALLEY AREAS THIS
MORNING...BUT SHOULD DECREASE BY THIS AFTERNOON...POSSIBLY
RETURNING AGAIN TONIGHT. OTHERWISE...LOOK FOR PERIODS OF HIGH
CLOUDS IN THE NORTHWEST FLOW.

LATE MONDAY INTO TUESDAY...A TROUGH DIVING THROUGH THE CENTRAL
ROCKIES TO THE PLAINS STATES WILL PUSH A RATHER STRONG COLD
FRONT INTO ARIZONA. HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO
THE NORTHEAST CORNER OF THE STATE MONDAY...BUT THE MAIN IMPACT IS
LIKELY TO BE GUSTY NORTHEAST WINDS AND SIGNIFICANTLY COLDER
TEMPERATURES BY MONDAY NIGHT AND TUESDAY. THE STRONG PRESSURE
GRADIENTS OVER ARIZONA WILL BE DUE TO A DEEP LOW OVER THE PLAINS
STATES AND RIDGING OFF THE WEST COAST. WIND PROFILES SUGGEST THAT
WIND SPEEDS IN THE 9-12 THOUSAND FOOT MSL LAYER WILL REACH 40-65KT
MONDAY NIGHT AND TUESDAY MORNING...BRINGING THE POTENTIAL FOR
STRONG WINDS OVER AND JUST SOUTH OF THE MOUNTAINS...INCLUDING THE
SAN FRANCISCO PEAKS AND THE NORTH SIDE OF FLAGSTAFF. AFTERNOON
HIGHS ON TUESDAY WILL BE 10-15 DEGREES COOLER THAN MONDAY...AND
THE WINDS WILL MAKE IT FEEL EVEN COLDER. TEMPERATURES SHOULD
MODERATE BY WEDNESDAY AS THE TROUGH SHIFTS EAST.

FOR CHRISTMAS DAY AND FRIDAY...THE NEXT TROUGH MOVES ACROSS THE
WESTERN UNITED STATES...BUT MODEL TRENDS CONTINUE TO KEEP MOST
IF NOT ALL OF THE MOISTURE WITH THE SYSTEM TO OUR NORTH. KEPT JUST
A SLIGHT CHANCE OF SHOWERS FOR CHRISTMAS DAY WITH NEAR NORMAL
TEMPERATURES. COOLER BUT FAIR WEATHER EXPECTED FRIDAY. NEXT
WEEKEND LOOKS DRY WITH MODERATING TEMPERATURES AS THE TROUGH MOVES
EAST.

&&

.AVIATION...
FOR THE 18Z PACKAGE...WIDESPREAD IFR TO VLIFR CONDITIONS IN LOW
CLOUDS AND FOG ARE PRESENT IN THE LITTLE COLORADO RIVER THIS
MORNING. CONDITIONS ARE EXPECTED TO IMPROVE THROUGH THE DAY TODAY
WITH DAYTIME HEATING...BUT WILL LIKELY RETURN AGAIN OVERNIGHT
AFFECTING KINW. VFR CONDITIONS ARE FORECAST ELSEWHERE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.........KD/JJ
AVIATION.......RICKEY

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF







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000
FXUS65 KTWC 211547
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
845 AM MST SUN DEC 21 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL TODAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR NORTH FOR THE
END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION FOR THE WHITE
MOUNTAINS.

&&

.DISCUSSION...LOTS OF MAINLY HIGH CLOUDS OVER THE AREA THIS MORNING
UNDER N-NW FLOW ALOFT. THESE CLOUDS WILL BE AROUND TODAY RESULTING
IN A MIX OF PARTLY TO MOSTLY CLOUDY CONDITIONS. HIGHS WILL BE AT OR
SLIGHTLY WARMER THAN SATURDAY. DETAILS ABOUT THE REMAINDER OF THE 7
DAY FORECAST CAN BE FOUND IN THE PREVIOUS DISCUSSION BELOW.

&&

.AVIATION...VALID THRU 22/18Z.
BKN-SCT HIGH CLOUDS ABOVE 20K FT. SURFACE WIND WILL BE DIURNAL AND
GENERALLY LESS THAN 10 KTS THROUGH THE PERIOD. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY WITH A
SLIGHT CHANCE OF SOME RAIN AND SNOW SHOWERS OVER THE WHITE MOUNTAINS
CHRISTMAS DAY THROUGH FRIDAY. A PASSING WEATHER SYSTEM WILL KICK UP
A NORTHWEST BREEZE MONDAY AFTERNOON ACROSS EASTERN AREAS ESPECIALLY
THE GILA VALLEY. THE WINDS WILL SETTLE DURING THE EVENING EXCEPT
ACROSS THE HIGHER TERRAIN AND THE GILA VALLEY WHERE THEY WILL
CONTINUE THROUGH MUCH OF MONDAY NIGHT. THIS WILL BE FOLLOWED BY A
NORTHERLY BREEZE ON TUESDAY AND A LIGHTER EAST BREEZE WEDNESDAY.
THEN THE SYSTEM ARRIVING LATE IN THE WEEK WILL GENERATE A SOUTHWEST
TO WEST BREEZE THURSDAY AND FRIDAY AFTERNOONS. DEW POINTS WILL DROP
FOLLOWING THE LATE MONDAY SYSTEM THEN DROP FURTHER AFTER THE SYSTEM
LATE IN THE WEEK RESULTING IN LOWERING HUMIDITY LEVELS FROM WHAT WE
HAVE SEEN LATELY.

&&

.PREV DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS
SHOW A TROUGH THAT EXTENDS FROM THE CENTRAL PLAINS THROUGH WEST
TEXAS. MEANWHILE...A RIDGE RESIDES OVER THE PACIFIC WATERS WITH
NORTH TO NORTHWEST FLOW ALOFT OVER ARIZONA BETWEEN THESE TWO SYSTEMS
AS EVIDENCED BY THE WIND PROFILE FROM LAST EVENINGS KTWC 21/00Z
SOUNDING. IR SATELLITE IMAGERY SHOWS PERIODS OF MOSTLY HIGH CLOUDS
SPILLING OVER THE TOP OF THE RIDGE ACROSS THE GREAT BASIN AND INTO
PORTIONS OF THE DESERT SOUTHWEST...RESULTING IN PARTLY CLOUDY SKIES
AS A RESULT OF INTERMITTENT BATCHES OF CLOUDS THAT ARE EXPECTED TO
MOVE BY FROM TIME TO TIME TODAY.

MODELS CONTINUE TO SHOW THIS DRY NORTHERLY FLOW ACROSS ARIZONA
THROUGH MONDAY WITH A VORT LOBE MOVING ACROSS THE FOUR CORNERS
REGION AND WESTERN NEW MEXICO LATE MONDAY THROUGH EARLY TUESDAY AS
THE PARENT LOW ASSOCIATED WITH THIS FEATURE SLOWLY MOVES THROUGH THE
MIDWEST AND GREAT LAKES REGION. AS THIS OCCURS THE BULK OF THE
MOISTURE ASSOCIATED WITH THE SYSTEM WILL REMAIN NORTH AND EAST OF
ARIZONA FOR A CONTINUED DRY FORECAST...ALTHOUGH SOME INCREASE IN
WINDS IS EXPECTED MONDAY AFTERNOON...ESPECIALLY BETWEEN TUCSON AND
THE NEW MEXICO BORDER. TEMPERATURES WILL DROP SEVERAL DEGREES ON
TUESDAY WITH THE PASSAGE OF THIS SYSTEM. ONCE THIS SYSTEM MOVES TO
THE EAST LATE TUESDAY AND EARLY WEDNESDAY...STRONG PACIFIC RIDGING
BEHIND THIS SYSTEM WILL REMAIN OVER THE PACIFIC WATERS WELL WEST OF
THE BAJA PENINSULA...BUT WITH THE RIDGE AXIS EXTENDING NORTHEAST
ACROSS CALIFORNIA INTO THE GREAT BASIN AND NORTHERN ROCKIES ON
WEDNESDAY.

BY LATE WEDNESDAY INTO THURSDAY A PACIFIC SYSTEM IS PROGGED TO MOVE
THROUGH THE PACIFIC NORTHWEST...THEN MAKE ITS WAY INTO THE CENTRAL
ROCKIES BY LATE IN THE DAY ON THURSDAY. THIS SYSTEM WAS PROGGED TO
BE DEEPER AND A BIT WETTER ACCORDING TO EARLIER MODEL RUNS OF THE
ECMWF...BUT IT HAS BACKED OFF ON THIS SCENARIO AND IS NOW MORE IN
LINE WITH THE GFS...WHICH SHOWS THE SYSTEM BRUSHING BY TO OUR NORTH
LATE IN THE WEEK. ONCE AGAIN...MOISTURE WITH THIS SYSTEM IS EXPECTED
TO BE LIMITED AND MOSTLY RESIDING TO THE NORTHEAST OF ARIZONA. THAT
SAID...I MADE SOME MINOR TWEAKS TO THE POP GRIDS FOR THE THURSDAY
THROUGH FRIDAY TIME FRAME...BUT IT STILL LOOKS LIKE JUST A SLIGHT
CHANCE OF SHOWERS OVER THE WHITE MOUNTAINS FOR THAT PERIOD OF TIME.

FOR TUCSON...HIGH TEMPERATURES GENERALLY NEAR TO SLIGHTLY ABOVE
NORMAL TODAY... THEN 3 TO 5 DEGS ABOVE NORMAL FOR MONDAY. NEAR
NORMAL FOR TUESDAY...THEN 3 TO 5 DEGS ABOVE NORMAL AGAIN FOR
WEDNESDAY AND THURSDAY. THEREAFTER...HIGHS NEAR NORMAL. LOW
TEMPERATURES 2 TO 3 DEGS ABOVE NORMAL MONDAY AND TUESDAY
MORNINGS...THEN NEAR NORMAL WEDNESDAY MORNING. SLIGHTLY ABOVE NORMAL
THURSDAY AND FRIDAY...THEN SLIGHTLY BELOW NORMAL FOR SATURDAY
MORNING.

&&

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

&&

$$

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






000
FXUS65 KPSR 211159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN DEC 21 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN








000
FXUS65 KPSR 211159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN DEC 21 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN








000
FXUS65 KPSR 211159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN DEC 21 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN








000
FXUS65 KPSR 211159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN DEC 21 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN








000
FXUS65 KPSR 211159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN DEC 21 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN









000
FXUS65 KPSR 211159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN DEC 21 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...

EXPECT PERIODS OF HIGH CLOUDS INTO MONDAY WITH NORTH AND NORTHWEST
FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS THIS AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST ON TUESDAY. THE SYSTEM
WILL BE DRY AND HUMIDITIES WILL DROP DRAMATICALLY TUESDAY AFTERNOON.
THE SYSTEM WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE
OF ENHANCED WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER
SYSTEM MOVES THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS
ONLY A VERY SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.
&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...KUHLMAN
FIRE WEATHER...AJ/KUHLMAN








000
FXUS65 KFGZ 211118
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
415 AM MST SUN DEC 21 2014

.SYNOPSIS...
PATCHY LOW CLOUDS AND FOG WILL AFFECT THE NORTHEAST ARIZONA VALLEYS
THIS MORNING. OTHERWISE...FAIR WEATHER...A FEW CLOUDS AND GRADUALLY
WARMING TEMPERATURES ARE EXPECTED THROUGH MONDAY. A DRY COLD FRONT
WILL BRING MUCH COLDER TEMPERATURES AND GUSTY NORTHEAST WINDS MONDAY
NIGHT THROUGH TUESDAY. MILD TEMPERATURES ARE FORECAST FOR
WEDNESDAY...THEN BREEZY AND COOLER WEATHER RETURNS FOR CHRISTMAS DAY
AND FRIDAY.
&&

.DISCUSSION...NORTHWESTERLY FLOW ALOFT WILL CONTINUE TODAY...WITH
DRY CONDITIONS AND GRADUALLY WARMING TEMPERATURES. SOME AREAS OF LOW
CLOUDS AND PATCHY FOG WILL AFFECT NORTHEAST AZ VALLEY AREAS THIS
MORNING...BUT SHOULD DECREASE BY THIS AFTERNOON...POSSIBLY RETURNING
AGAIN TONIGHT. OTHERWISE...LOOK FOR PERIODS OF HIGH CLOUDS IN THE
NORTHWEST FLOW.

LATE MONDAY INTO TUESDAY...A TROUGH DIVING THROUGH THE CENTRAL
ROCKIES TO THE PLAINS STATES WILL PUSH A RATHER STRONG COLD FRONT
INTO ARIZONA. HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO THE
NORTHEAST CORNER OF THE STATE MONDAY...BUT THE MAIN IMPACT IS LIKELY
TO BE GUSTY NORTHEAST WINDS AND SIGNIFICANTLY COLDER TEMPERATURES BY
MONDAY NIGHT AND TUESDAY. THE STRONG PRESSURE GRADIENTS OVER ARIZONA
WILL BE DUE TO A DEEP LOW OVER THE PLAINS STATES AND RIDGING OFF THE
WEST COAST. WIND PROFILES SUGGEST THAT WIND SPEEDS IN THE 9-12
THOUSAND FOOT MSL LAYER WILL REACH 40-65KT MONDAY NIGHT AND TUESDAY
MORNING...BRINGING THE POTENTIAL FOR STRONG WINDS OVER AND JUST
SOUTH OF THE MOUNTAINS...INCLUDING THE SAN FRANCISCO PEAKS AND THE
NORTH SIDE OF FLAGSTAFF. AFTERNOON HIGHS ON TUESDAY WILL BE 10-15
DEGREES COOLER THAN MONDAY...AND THE WINDS WILL MAKE IT FEEL EVEN
COLDER. TEMPERATURES SHOULD MODERATE BY WEDNESDAY AS THE TROUGH
SHIFTS EAST.

FOR CHRISTMAS DAY AND FRIDAY...THE NEXT TROUGH MOVES ACROSS THE
WESTERN UNITED STATES...BUT MODEL TRENDS CONTINUE TO KEEP MOST IF
NOT ALL OF THE MOISTURE WITH THE SYSTEM TO OUR NORTH. KEPT JUST A
SLIGHT CHANCE OF SHOWERS FOR CHRISTMAS DAY WITH NEAR NORMAL
TEMPERATURES. COOLER BUT FAIR WEATHER EXPECTED FRIDAY. NEXT WEEKEND
LOOKS DRY WITH MODERATING TEMPERATURES AS THE TROUGH MOVES EAST.

&&

.AVIATION...FOR THE 12Z PACKAGE...EXPECT MOSTLY VFR CONDITIONS
OUTSIDE OF NORTHEASTERN ARIZONA VALLEYS TODAY. LOW STRATUS CLOUDS
AND FOG WILL LINGER IN THE LITTLE COLORADO RIVER VALLEY FROM PAGE TO
WINSLOW WITH IFR TO LIFR CONDITIONS THROUGH THE MORNING HOURS. THE
EXTENT OF STRATUS AND FOG COVERAGE WILL DIMINISH IN THE AFTERNOON
AND THEN EXPAND AGAIN AFTER SUNSET. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....JJ
AVIATION...BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 211118
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
415 AM MST SUN DEC 21 2014

.SYNOPSIS...
PATCHY LOW CLOUDS AND FOG WILL AFFECT THE NORTHEAST ARIZONA VALLEYS
THIS MORNING. OTHERWISE...FAIR WEATHER...A FEW CLOUDS AND GRADUALLY
WARMING TEMPERATURES ARE EXPECTED THROUGH MONDAY. A DRY COLD FRONT
WILL BRING MUCH COLDER TEMPERATURES AND GUSTY NORTHEAST WINDS MONDAY
NIGHT THROUGH TUESDAY. MILD TEMPERATURES ARE FORECAST FOR
WEDNESDAY...THEN BREEZY AND COOLER WEATHER RETURNS FOR CHRISTMAS DAY
AND FRIDAY.
&&

.DISCUSSION...NORTHWESTERLY FLOW ALOFT WILL CONTINUE TODAY...WITH
DRY CONDITIONS AND GRADUALLY WARMING TEMPERATURES. SOME AREAS OF LOW
CLOUDS AND PATCHY FOG WILL AFFECT NORTHEAST AZ VALLEY AREAS THIS
MORNING...BUT SHOULD DECREASE BY THIS AFTERNOON...POSSIBLY RETURNING
AGAIN TONIGHT. OTHERWISE...LOOK FOR PERIODS OF HIGH CLOUDS IN THE
NORTHWEST FLOW.

LATE MONDAY INTO TUESDAY...A TROUGH DIVING THROUGH THE CENTRAL
ROCKIES TO THE PLAINS STATES WILL PUSH A RATHER STRONG COLD FRONT
INTO ARIZONA. HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO THE
NORTHEAST CORNER OF THE STATE MONDAY...BUT THE MAIN IMPACT IS LIKELY
TO BE GUSTY NORTHEAST WINDS AND SIGNIFICANTLY COLDER TEMPERATURES BY
MONDAY NIGHT AND TUESDAY. THE STRONG PRESSURE GRADIENTS OVER ARIZONA
WILL BE DUE TO A DEEP LOW OVER THE PLAINS STATES AND RIDGING OFF THE
WEST COAST. WIND PROFILES SUGGEST THAT WIND SPEEDS IN THE 9-12
THOUSAND FOOT MSL LAYER WILL REACH 40-65KT MONDAY NIGHT AND TUESDAY
MORNING...BRINGING THE POTENTIAL FOR STRONG WINDS OVER AND JUST
SOUTH OF THE MOUNTAINS...INCLUDING THE SAN FRANCISCO PEAKS AND THE
NORTH SIDE OF FLAGSTAFF. AFTERNOON HIGHS ON TUESDAY WILL BE 10-15
DEGREES COOLER THAN MONDAY...AND THE WINDS WILL MAKE IT FEEL EVEN
COLDER. TEMPERATURES SHOULD MODERATE BY WEDNESDAY AS THE TROUGH
SHIFTS EAST.

FOR CHRISTMAS DAY AND FRIDAY...THE NEXT TROUGH MOVES ACROSS THE
WESTERN UNITED STATES...BUT MODEL TRENDS CONTINUE TO KEEP MOST IF
NOT ALL OF THE MOISTURE WITH THE SYSTEM TO OUR NORTH. KEPT JUST A
SLIGHT CHANCE OF SHOWERS FOR CHRISTMAS DAY WITH NEAR NORMAL
TEMPERATURES. COOLER BUT FAIR WEATHER EXPECTED FRIDAY. NEXT WEEKEND
LOOKS DRY WITH MODERATING TEMPERATURES AS THE TROUGH MOVES EAST.

&&

.AVIATION...FOR THE 12Z PACKAGE...EXPECT MOSTLY VFR CONDITIONS
OUTSIDE OF NORTHEASTERN ARIZONA VALLEYS TODAY. LOW STRATUS CLOUDS
AND FOG WILL LINGER IN THE LITTLE COLORADO RIVER VALLEY FROM PAGE TO
WINSLOW WITH IFR TO LIFR CONDITIONS THROUGH THE MORNING HOURS. THE
EXTENT OF STRATUS AND FOG COVERAGE WILL DIMINISH IN THE AFTERNOON
AND THEN EXPAND AGAIN AFTER SUNSET. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....JJ
AVIATION...BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KTWC 210913
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 AM MST SUN DEC 21 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL TODAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR NORTH FOR THE
END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION FOR THE WHITE
MOUNTAINS.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS SHOW A
TROUGH THAT EXTENDS FROM THE CENTRAL PLAINS THROUGH WEST TEXAS.
MEANWHILE...A RIDGE RESIDES OVER THE PACIFIC WATERS WITH NORTH TO
NORTHWEST FLOW ALOFT OVER ARIZONA BETWEEN THESE TWO SYSTEMS AS
EVIDENCED BY THE WIND PROFILE FROM LAST EVENINGS KTWC 21/00Z
SOUNDING. IR SATELLITE IMAGERY SHOWS PERIODS OF MOSTLY HIGH CLOUDS
SPILLING OVER THE TOP OF THE RIDGE ACROSS THE GREAT BASIN AND INTO
PORTIONS OF THE DESERT SOUTHWEST...RESULTING IN PARTLY CLOUDY SKIES
AS A RESULT OF INTERMITTENT BATCHES OF CLOUDS THAT ARE EXPECTED TO
MOVE BY FROM TIME TO TIME TODAY.

MODELS CONTINUE TO SHOW THIS DRY NORTHERLY FLOW ACROSS ARIZONA
THROUGH MONDAY WITH A VORT LOBE MOVING ACROSS THE FOUR CORNERS
REGION AND WESTERN NEW MEXICO LATE MONDAY THROUGH EARLY TUESDAY AS
THE PARENT LOW ASSOCIATED WITH THIS FEATURE SLOWLY MOVES THROUGH THE
MIDWEST AND GREAT LAKES REGION. AS THIS OCCURS THE BULK OF THE
MOISTURE ASSOCIATED WITH THE SYSTEM WILL REMAIN NORTH AND EAST OF
ARIZONA FOR A CONTINUED DRY FORECAST...ALTHOUGH SOME INCREASE IN
WINDS IS EXPECTED MONDAY AFTERNOON...ESPECIALLY BETWEEN TUCSON AND
THE NEW MEXICO BORDER. TEMPERATURES WILL DROP SEVERAL DEGREES ON
TUESDAY WITH THE PASSAGE OF THIS SYSTEM. ONCE THIS SYSTEM MOVES TO
THE EAST LATE TUESDAY AND EARLY WEDNESDAY...STRONG PACIFIC RIDGING
BEHIND THIS SYSTEM WILL REMAIN OVER THE PACIFIC WATERS WELL WEST OF
THE BAJA PENINSULA...BUT WITH THE RIDGE AXIS EXTENDING NORTHEAST
ACROSS CALIFORNIA INTO THE GREAT BASIN AND NORTHERN ROCKIES ON
WEDNESDAY.

BY LATE WEDNESDAY INTO THURSDAY A PACIFIC SYSTEM IS PROGGED TO MOVE
THROUGH THE PACIFIC NORTHWEST...THEN MAKE ITS WAY INTO THE CENTRAL
ROCKIES BY LATE IN THE DAY ON THURSDAY. THIS SYSTEM WAS PROGGED TO
BE DEEPER AND A BIT WETTER ACCORDING TO EARLIER MODEL RUNS OF THE
ECMWF...BUT IT HAS BACKED OFF ON THIS SCENARIO AND IS NOW MORE IN
LINE WITH THE GFS...WHICH SHOWS THE SYSTEM BRUSHING BY TO OUR NORTH
LATE IN THE WEEK. ONCE AGAIN...MOISTURE WITH THIS SYSTEM IS EXPECTED
TO BE LIMITED AND MOSTLY RESIDING TO THE NORTHEAST OF ARIZONA. THAT
SAID...I MADE SOME MINOR TWEAKS TO THE POP GRIDS FOR THE THURSDAY
THROUGH FRIDAY TIME FRAME...BUT IT STILL LOOKS LIKE JUST A SLIGHT
CHANCE OF SHOWERS OVER THE WHITE MOUNTAINS FOR THAT PERIOD OF TIME.

FOR TUCSON...HIGH TEMPERATURES GENERALLY NEAR TO SLIGHTLY ABOVE
NORMAL TODAY... THEN 3 TO 5 DEGS ABOVE NORMAL FOR MONDAY. NEAR
NORMAL FOR TUESDAY...THEN 3 TO 5 DEGS ABOVE NORMAL AGAIN FOR
WEDNESDAY AND THURSDAY. THEREAFTER...HIGHS NEAR NORMAL. LOW
TEMPERATURES 2 TO 3 DEGS ABOVE NORMAL MONDAY AND TUESDAY
MORNINGS...THEN NEAR NORMAL WEDNESDAY MORNING. SLIGHTLY ABOVE NORMAL
THURSDAY AND FRIDAY...THEN SLIGHTLY BELOW NORMAL FOR SATURDAY
MORNING.

&&

.AVIATION...VALID THRU 22/126Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN HIGH CLOUDS ABOVE
20K FT.  SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS
THROUGH THE PERIOD.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY WITH A
SLIGHT CHANCE OF SOME RAIN AND SNOW SHOWERS OVER THE WHITE MOUNTAINS
CHRISTMAS DAY THROUGH FRIDAY.  A PASSING WEATHER SYSTEM WILL KICK UP
A NORTHWEST BREEZE MONDAY AFTERNOON ACROSS EASTERN AREAS ESPECIALLY
THE GILA VALLEY.  THE WINDS WILL SETTLE DURING THE EVENING EXCEPT
ACROSS THE HIGHER TERRAIN AND THE GILA VALLEY WHERE THEY WILL
CONTINUE THROUGH MUCH OF MONDAY NIGHT.  THIS WILL BE FOLLOWED BY A
NORTHERLY BREEZE ON TUESDAY AND A LIGHTER EAST BREEZE WEDNESDAY.
THEN THE SYSTEM ARRIVING LATE IN THE WEEK WILL GENERATE A SOUTHWEST
TO WEST BREEZE THURSDAY AND FRIDAY AFTERNOONS.  DEW POINTS WILL DROP
FOLLOWING THE LATE MONDAY SYSTEM THEN DROP FURTHER AFTER THE SYSTEM
LATE IN THE WEEK RESULTING IN LOWERING HUMIDITY LEVELS FROM WHAT WE
HAVE SEEN LATELY. CERNIGLIA

&&

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

&&

$$

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PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...CERNIGLIA







000
FXUS65 KTWC 210913
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 AM MST SUN DEC 21 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL TODAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR NORTH FOR THE
END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION FOR THE WHITE
MOUNTAINS.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS SHOW A
TROUGH THAT EXTENDS FROM THE CENTRAL PLAINS THROUGH WEST TEXAS.
MEANWHILE...A RIDGE RESIDES OVER THE PACIFIC WATERS WITH NORTH TO
NORTHWEST FLOW ALOFT OVER ARIZONA BETWEEN THESE TWO SYSTEMS AS
EVIDENCED BY THE WIND PROFILE FROM LAST EVENINGS KTWC 21/00Z
SOUNDING. IR SATELLITE IMAGERY SHOWS PERIODS OF MOSTLY HIGH CLOUDS
SPILLING OVER THE TOP OF THE RIDGE ACROSS THE GREAT BASIN AND INTO
PORTIONS OF THE DESERT SOUTHWEST...RESULTING IN PARTLY CLOUDY SKIES
AS A RESULT OF INTERMITTENT BATCHES OF CLOUDS THAT ARE EXPECTED TO
MOVE BY FROM TIME TO TIME TODAY.

MODELS CONTINUE TO SHOW THIS DRY NORTHERLY FLOW ACROSS ARIZONA
THROUGH MONDAY WITH A VORT LOBE MOVING ACROSS THE FOUR CORNERS
REGION AND WESTERN NEW MEXICO LATE MONDAY THROUGH EARLY TUESDAY AS
THE PARENT LOW ASSOCIATED WITH THIS FEATURE SLOWLY MOVES THROUGH THE
MIDWEST AND GREAT LAKES REGION. AS THIS OCCURS THE BULK OF THE
MOISTURE ASSOCIATED WITH THE SYSTEM WILL REMAIN NORTH AND EAST OF
ARIZONA FOR A CONTINUED DRY FORECAST...ALTHOUGH SOME INCREASE IN
WINDS IS EXPECTED MONDAY AFTERNOON...ESPECIALLY BETWEEN TUCSON AND
THE NEW MEXICO BORDER. TEMPERATURES WILL DROP SEVERAL DEGREES ON
TUESDAY WITH THE PASSAGE OF THIS SYSTEM. ONCE THIS SYSTEM MOVES TO
THE EAST LATE TUESDAY AND EARLY WEDNESDAY...STRONG PACIFIC RIDGING
BEHIND THIS SYSTEM WILL REMAIN OVER THE PACIFIC WATERS WELL WEST OF
THE BAJA PENINSULA...BUT WITH THE RIDGE AXIS EXTENDING NORTHEAST
ACROSS CALIFORNIA INTO THE GREAT BASIN AND NORTHERN ROCKIES ON
WEDNESDAY.

BY LATE WEDNESDAY INTO THURSDAY A PACIFIC SYSTEM IS PROGGED TO MOVE
THROUGH THE PACIFIC NORTHWEST...THEN MAKE ITS WAY INTO THE CENTRAL
ROCKIES BY LATE IN THE DAY ON THURSDAY. THIS SYSTEM WAS PROGGED TO
BE DEEPER AND A BIT WETTER ACCORDING TO EARLIER MODEL RUNS OF THE
ECMWF...BUT IT HAS BACKED OFF ON THIS SCENARIO AND IS NOW MORE IN
LINE WITH THE GFS...WHICH SHOWS THE SYSTEM BRUSHING BY TO OUR NORTH
LATE IN THE WEEK. ONCE AGAIN...MOISTURE WITH THIS SYSTEM IS EXPECTED
TO BE LIMITED AND MOSTLY RESIDING TO THE NORTHEAST OF ARIZONA. THAT
SAID...I MADE SOME MINOR TWEAKS TO THE POP GRIDS FOR THE THURSDAY
THROUGH FRIDAY TIME FRAME...BUT IT STILL LOOKS LIKE JUST A SLIGHT
CHANCE OF SHOWERS OVER THE WHITE MOUNTAINS FOR THAT PERIOD OF TIME.

FOR TUCSON...HIGH TEMPERATURES GENERALLY NEAR TO SLIGHTLY ABOVE
NORMAL TODAY... THEN 3 TO 5 DEGS ABOVE NORMAL FOR MONDAY. NEAR
NORMAL FOR TUESDAY...THEN 3 TO 5 DEGS ABOVE NORMAL AGAIN FOR
WEDNESDAY AND THURSDAY. THEREAFTER...HIGHS NEAR NORMAL. LOW
TEMPERATURES 2 TO 3 DEGS ABOVE NORMAL MONDAY AND TUESDAY
MORNINGS...THEN NEAR NORMAL WEDNESDAY MORNING. SLIGHTLY ABOVE NORMAL
THURSDAY AND FRIDAY...THEN SLIGHTLY BELOW NORMAL FOR SATURDAY
MORNING.

&&

.AVIATION...VALID THRU 22/126Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN HIGH CLOUDS ABOVE
20K FT.  SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS
THROUGH THE PERIOD.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY WITH A
SLIGHT CHANCE OF SOME RAIN AND SNOW SHOWERS OVER THE WHITE MOUNTAINS
CHRISTMAS DAY THROUGH FRIDAY.  A PASSING WEATHER SYSTEM WILL KICK UP
A NORTHWEST BREEZE MONDAY AFTERNOON ACROSS EASTERN AREAS ESPECIALLY
THE GILA VALLEY.  THE WINDS WILL SETTLE DURING THE EVENING EXCEPT
ACROSS THE HIGHER TERRAIN AND THE GILA VALLEY WHERE THEY WILL
CONTINUE THROUGH MUCH OF MONDAY NIGHT.  THIS WILL BE FOLLOWED BY A
NORTHERLY BREEZE ON TUESDAY AND A LIGHTER EAST BREEZE WEDNESDAY.
THEN THE SYSTEM ARRIVING LATE IN THE WEEK WILL GENERATE A SOUTHWEST
TO WEST BREEZE THURSDAY AND FRIDAY AFTERNOONS.  DEW POINTS WILL DROP
FOLLOWING THE LATE MONDAY SYSTEM THEN DROP FURTHER AFTER THE SYSTEM
LATE IN THE WEEK RESULTING IN LOWERING HUMIDITY LEVELS FROM WHAT WE
HAVE SEEN LATELY. CERNIGLIA

&&

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

&&

$$

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PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...CERNIGLIA







000
FXUS65 KTWC 210913
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 AM MST SUN DEC 21 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL TODAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR NORTH FOR THE
END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION FOR THE WHITE
MOUNTAINS.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS SHOW A
TROUGH THAT EXTENDS FROM THE CENTRAL PLAINS THROUGH WEST TEXAS.
MEANWHILE...A RIDGE RESIDES OVER THE PACIFIC WATERS WITH NORTH TO
NORTHWEST FLOW ALOFT OVER ARIZONA BETWEEN THESE TWO SYSTEMS AS
EVIDENCED BY THE WIND PROFILE FROM LAST EVENINGS KTWC 21/00Z
SOUNDING. IR SATELLITE IMAGERY SHOWS PERIODS OF MOSTLY HIGH CLOUDS
SPILLING OVER THE TOP OF THE RIDGE ACROSS THE GREAT BASIN AND INTO
PORTIONS OF THE DESERT SOUTHWEST...RESULTING IN PARTLY CLOUDY SKIES
AS A RESULT OF INTERMITTENT BATCHES OF CLOUDS THAT ARE EXPECTED TO
MOVE BY FROM TIME TO TIME TODAY.

MODELS CONTINUE TO SHOW THIS DRY NORTHERLY FLOW ACROSS ARIZONA
THROUGH MONDAY WITH A VORT LOBE MOVING ACROSS THE FOUR CORNERS
REGION AND WESTERN NEW MEXICO LATE MONDAY THROUGH EARLY TUESDAY AS
THE PARENT LOW ASSOCIATED WITH THIS FEATURE SLOWLY MOVES THROUGH THE
MIDWEST AND GREAT LAKES REGION. AS THIS OCCURS THE BULK OF THE
MOISTURE ASSOCIATED WITH THE SYSTEM WILL REMAIN NORTH AND EAST OF
ARIZONA FOR A CONTINUED DRY FORECAST...ALTHOUGH SOME INCREASE IN
WINDS IS EXPECTED MONDAY AFTERNOON...ESPECIALLY BETWEEN TUCSON AND
THE NEW MEXICO BORDER. TEMPERATURES WILL DROP SEVERAL DEGREES ON
TUESDAY WITH THE PASSAGE OF THIS SYSTEM. ONCE THIS SYSTEM MOVES TO
THE EAST LATE TUESDAY AND EARLY WEDNESDAY...STRONG PACIFIC RIDGING
BEHIND THIS SYSTEM WILL REMAIN OVER THE PACIFIC WATERS WELL WEST OF
THE BAJA PENINSULA...BUT WITH THE RIDGE AXIS EXTENDING NORTHEAST
ACROSS CALIFORNIA INTO THE GREAT BASIN AND NORTHERN ROCKIES ON
WEDNESDAY.

BY LATE WEDNESDAY INTO THURSDAY A PACIFIC SYSTEM IS PROGGED TO MOVE
THROUGH THE PACIFIC NORTHWEST...THEN MAKE ITS WAY INTO THE CENTRAL
ROCKIES BY LATE IN THE DAY ON THURSDAY. THIS SYSTEM WAS PROGGED TO
BE DEEPER AND A BIT WETTER ACCORDING TO EARLIER MODEL RUNS OF THE
ECMWF...BUT IT HAS BACKED OFF ON THIS SCENARIO AND IS NOW MORE IN
LINE WITH THE GFS...WHICH SHOWS THE SYSTEM BRUSHING BY TO OUR NORTH
LATE IN THE WEEK. ONCE AGAIN...MOISTURE WITH THIS SYSTEM IS EXPECTED
TO BE LIMITED AND MOSTLY RESIDING TO THE NORTHEAST OF ARIZONA. THAT
SAID...I MADE SOME MINOR TWEAKS TO THE POP GRIDS FOR THE THURSDAY
THROUGH FRIDAY TIME FRAME...BUT IT STILL LOOKS LIKE JUST A SLIGHT
CHANCE OF SHOWERS OVER THE WHITE MOUNTAINS FOR THAT PERIOD OF TIME.

FOR TUCSON...HIGH TEMPERATURES GENERALLY NEAR TO SLIGHTLY ABOVE
NORMAL TODAY... THEN 3 TO 5 DEGS ABOVE NORMAL FOR MONDAY. NEAR
NORMAL FOR TUESDAY...THEN 3 TO 5 DEGS ABOVE NORMAL AGAIN FOR
WEDNESDAY AND THURSDAY. THEREAFTER...HIGHS NEAR NORMAL. LOW
TEMPERATURES 2 TO 3 DEGS ABOVE NORMAL MONDAY AND TUESDAY
MORNINGS...THEN NEAR NORMAL WEDNESDAY MORNING. SLIGHTLY ABOVE NORMAL
THURSDAY AND FRIDAY...THEN SLIGHTLY BELOW NORMAL FOR SATURDAY
MORNING.

&&

.AVIATION...VALID THRU 22/126Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN HIGH CLOUDS ABOVE
20K FT.  SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS
THROUGH THE PERIOD.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY WITH A
SLIGHT CHANCE OF SOME RAIN AND SNOW SHOWERS OVER THE WHITE MOUNTAINS
CHRISTMAS DAY THROUGH FRIDAY.  A PASSING WEATHER SYSTEM WILL KICK UP
A NORTHWEST BREEZE MONDAY AFTERNOON ACROSS EASTERN AREAS ESPECIALLY
THE GILA VALLEY.  THE WINDS WILL SETTLE DURING THE EVENING EXCEPT
ACROSS THE HIGHER TERRAIN AND THE GILA VALLEY WHERE THEY WILL
CONTINUE THROUGH MUCH OF MONDAY NIGHT.  THIS WILL BE FOLLOWED BY A
NORTHERLY BREEZE ON TUESDAY AND A LIGHTER EAST BREEZE WEDNESDAY.
THEN THE SYSTEM ARRIVING LATE IN THE WEEK WILL GENERATE A SOUTHWEST
TO WEST BREEZE THURSDAY AND FRIDAY AFTERNOONS.  DEW POINTS WILL DROP
FOLLOWING THE LATE MONDAY SYSTEM THEN DROP FURTHER AFTER THE SYSTEM
LATE IN THE WEEK RESULTING IN LOWERING HUMIDITY LEVELS FROM WHAT WE
HAVE SEEN LATELY. CERNIGLIA

&&

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

&&

$$

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PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...CERNIGLIA







000
FXUS65 KTWC 210913
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 AM MST SUN DEC 21 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL TODAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR NORTH FOR THE
END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION FOR THE WHITE
MOUNTAINS.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS SHOW A
TROUGH THAT EXTENDS FROM THE CENTRAL PLAINS THROUGH WEST TEXAS.
MEANWHILE...A RIDGE RESIDES OVER THE PACIFIC WATERS WITH NORTH TO
NORTHWEST FLOW ALOFT OVER ARIZONA BETWEEN THESE TWO SYSTEMS AS
EVIDENCED BY THE WIND PROFILE FROM LAST EVENINGS KTWC 21/00Z
SOUNDING. IR SATELLITE IMAGERY SHOWS PERIODS OF MOSTLY HIGH CLOUDS
SPILLING OVER THE TOP OF THE RIDGE ACROSS THE GREAT BASIN AND INTO
PORTIONS OF THE DESERT SOUTHWEST...RESULTING IN PARTLY CLOUDY SKIES
AS A RESULT OF INTERMITTENT BATCHES OF CLOUDS THAT ARE EXPECTED TO
MOVE BY FROM TIME TO TIME TODAY.

MODELS CONTINUE TO SHOW THIS DRY NORTHERLY FLOW ACROSS ARIZONA
THROUGH MONDAY WITH A VORT LOBE MOVING ACROSS THE FOUR CORNERS
REGION AND WESTERN NEW MEXICO LATE MONDAY THROUGH EARLY TUESDAY AS
THE PARENT LOW ASSOCIATED WITH THIS FEATURE SLOWLY MOVES THROUGH THE
MIDWEST AND GREAT LAKES REGION. AS THIS OCCURS THE BULK OF THE
MOISTURE ASSOCIATED WITH THE SYSTEM WILL REMAIN NORTH AND EAST OF
ARIZONA FOR A CONTINUED DRY FORECAST...ALTHOUGH SOME INCREASE IN
WINDS IS EXPECTED MONDAY AFTERNOON...ESPECIALLY BETWEEN TUCSON AND
THE NEW MEXICO BORDER. TEMPERATURES WILL DROP SEVERAL DEGREES ON
TUESDAY WITH THE PASSAGE OF THIS SYSTEM. ONCE THIS SYSTEM MOVES TO
THE EAST LATE TUESDAY AND EARLY WEDNESDAY...STRONG PACIFIC RIDGING
BEHIND THIS SYSTEM WILL REMAIN OVER THE PACIFIC WATERS WELL WEST OF
THE BAJA PENINSULA...BUT WITH THE RIDGE AXIS EXTENDING NORTHEAST
ACROSS CALIFORNIA INTO THE GREAT BASIN AND NORTHERN ROCKIES ON
WEDNESDAY.

BY LATE WEDNESDAY INTO THURSDAY A PACIFIC SYSTEM IS PROGGED TO MOVE
THROUGH THE PACIFIC NORTHWEST...THEN MAKE ITS WAY INTO THE CENTRAL
ROCKIES BY LATE IN THE DAY ON THURSDAY. THIS SYSTEM WAS PROGGED TO
BE DEEPER AND A BIT WETTER ACCORDING TO EARLIER MODEL RUNS OF THE
ECMWF...BUT IT HAS BACKED OFF ON THIS SCENARIO AND IS NOW MORE IN
LINE WITH THE GFS...WHICH SHOWS THE SYSTEM BRUSHING BY TO OUR NORTH
LATE IN THE WEEK. ONCE AGAIN...MOISTURE WITH THIS SYSTEM IS EXPECTED
TO BE LIMITED AND MOSTLY RESIDING TO THE NORTHEAST OF ARIZONA. THAT
SAID...I MADE SOME MINOR TWEAKS TO THE POP GRIDS FOR THE THURSDAY
THROUGH FRIDAY TIME FRAME...BUT IT STILL LOOKS LIKE JUST A SLIGHT
CHANCE OF SHOWERS OVER THE WHITE MOUNTAINS FOR THAT PERIOD OF TIME.

FOR TUCSON...HIGH TEMPERATURES GENERALLY NEAR TO SLIGHTLY ABOVE
NORMAL TODAY... THEN 3 TO 5 DEGS ABOVE NORMAL FOR MONDAY. NEAR
NORMAL FOR TUESDAY...THEN 3 TO 5 DEGS ABOVE NORMAL AGAIN FOR
WEDNESDAY AND THURSDAY. THEREAFTER...HIGHS NEAR NORMAL. LOW
TEMPERATURES 2 TO 3 DEGS ABOVE NORMAL MONDAY AND TUESDAY
MORNINGS...THEN NEAR NORMAL WEDNESDAY MORNING. SLIGHTLY ABOVE NORMAL
THURSDAY AND FRIDAY...THEN SLIGHTLY BELOW NORMAL FOR SATURDAY
MORNING.

&&

.AVIATION...VALID THRU 22/126Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN HIGH CLOUDS ABOVE
20K FT.  SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS
THROUGH THE PERIOD.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY WITH A
SLIGHT CHANCE OF SOME RAIN AND SNOW SHOWERS OVER THE WHITE MOUNTAINS
CHRISTMAS DAY THROUGH FRIDAY.  A PASSING WEATHER SYSTEM WILL KICK UP
A NORTHWEST BREEZE MONDAY AFTERNOON ACROSS EASTERN AREAS ESPECIALLY
THE GILA VALLEY.  THE WINDS WILL SETTLE DURING THE EVENING EXCEPT
ACROSS THE HIGHER TERRAIN AND THE GILA VALLEY WHERE THEY WILL
CONTINUE THROUGH MUCH OF MONDAY NIGHT.  THIS WILL BE FOLLOWED BY A
NORTHERLY BREEZE ON TUESDAY AND A LIGHTER EAST BREEZE WEDNESDAY.
THEN THE SYSTEM ARRIVING LATE IN THE WEEK WILL GENERATE A SOUTHWEST
TO WEST BREEZE THURSDAY AND FRIDAY AFTERNOONS.  DEW POINTS WILL DROP
FOLLOWING THE LATE MONDAY SYSTEM THEN DROP FURTHER AFTER THE SYSTEM
LATE IN THE WEEK RESULTING IN LOWERING HUMIDITY LEVELS FROM WHAT WE
HAVE SEEN LATELY. CERNIGLIA

&&

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

&&

$$

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PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...CERNIGLIA







000
FXUS65 KPSR 210819
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
119 AM MST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THURSDAY...A FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
QUITE A BIT OF HIGH CLOUD COVER ACROSS THE AREA ASSOCIATED WITH
STRONG ONSHORE FLOW ACROSS NORTHERN CALIFORNIA. MUCH LIKE LAST
NIGHT...THIS HAS SLOWED THE TYPICAL DIURNAL DROP IN TEMPERATURES AND
READINGS ACROSS THE LOWER DESERTS WERE GENERALLY IN THE MID 40S AS
OF 08Z. WINDS WERE LIGHT.

OFFSHORE RIDGING WILL CONTINUE TO STRENGTHEN THROUGH MID WEEK BUT
THE RIDGE AXIS WILL REMAIN OFFSHORE. TEMPERATURES WILL WARM SOMEWHAT
BUT NOT TO THE DEGREE IF THE +2 TO +3 STDEV RIDGE AXIS WAS OVERHEAD.
LOOKING AT HIGHS TODAY AND TOMORROW IN THE UPPER 60S WHICH IS JUST
SLIGHTLY ABOVE AVERAGE FOR LATE DECEMBER. ON TUESDAY A WEAK BACKDOOR
FRONT WILL SLIDE THROUGH THE AREA FROM THE NORTHEAST RESULTING IN
SLIGHTLY COOLER TEMPERATURES ALONG WITH INCREASED BREEZINESS...BUT
NO CHANCE OF RAIN. COOLER TEMPERATURES WILL REMAIN IN PLACE THROUGH
WEDNESDAY.

LOOKING AHEAD TO THURSDAY AND BEYOND...MODELS ARE BACK IN AGREEMENT
ONCE AGAIN INDICATING THE PRESENCE OF A LONGWAVE TROUGH MOVING
THROUGH THE FOUR CORNERS...JUST BRUSHING PARTS OF ARIZONA IN THE
PROCESS. ACROSS THE LOWER AZ AND SE CA DESERTS A TROUGH OF THIS
NATURE SHOULD HAVE A MINIMAL IMPACT ON OUR WEATHER...SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS BUT THAT`S ABOUT IT. FROM
THERE...BROAD NORTHWESTERLY FLOW IS EXPECTED TO PREVAIL INTO NEXT
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ





000
FXUS65 KTWC 210350
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
850 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...LATEST WV IMAGERY WAS SHOWING NW FLOW ALOFT SETTLING
IN OVER ARIZONA AS A WEAK SHORTWAVE TROUGH WAS EXITING AND MOVING
EASTWARD ACROSS NEW MEXICO AND INTO WEST TEXAS. IR IMAGERY WAS
INDICATING THAT SKIES WERE PARTLY TO MOSTLY CLOUDY OVER MUCH OF THE
REGION WITH A BATCH OF MAINLY CIRRUS FILTERING IN FROM THE NORTH.
AFTER REACHING A HIGH OF 63F TODAY...KTUS WAS DOWN TO 48F AT 0330Z.
TEMPERATURES AROUND SOUTHEASTERN ARIZONA RANGED FROM THE UPPER 30S
TO LOW 50S IN MOST VALLEY LOCATIONS WITH COOLER TEMPERATURES IN THE
MOUNTAINS. EXPECT SCATTERED TO BROKEN MAINLY HIGH LEVEL CLOUDS TO
PERSIST OVERNIGHT TONIGHT AND INTO TOMORROW AS RIDGING BEGINS TO
BUILD IN FROM THE WEST. TEMPERATURES TOMORROW WILL BE A FEW DEGREES
WARMER THAN WHAT WAS ACHIEVED TODAY AS HEIGHTS INCREASE SLIGHTLY.
FORECAST LOOKS TO BE ON TRACK FOR THIS EVENING AND NO UPDATES ARE
NEEDED. PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR MORE
INFORMATION.

&&

.AVIATION...VALID THRU 22/06Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN MAINLY HIGH CLOUDS.
SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

.PREV DISCUSSION...AS A LARGE RIDGE OF HIGH PRESSURE SETS UP ACROSS
THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON THE EASTERN SIDE
OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND GRADUALLY RISING
HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT UPTICK IN DAYTIME
TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE NEAR NORMAL SUNDAY
AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE WILL BE SOME MAINLY
THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

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

&&

$$

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

DISCUSSION...FRENCH
PREV DISCUSSION...GL






000
FXUS65 KTWC 210350
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
850 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...LATEST WV IMAGERY WAS SHOWING NW FLOW ALOFT SETTLING
IN OVER ARIZONA AS A WEAK SHORTWAVE TROUGH WAS EXITING AND MOVING
EASTWARD ACROSS NEW MEXICO AND INTO WEST TEXAS. IR IMAGERY WAS
INDICATING THAT SKIES WERE PARTLY TO MOSTLY CLOUDY OVER MUCH OF THE
REGION WITH A BATCH OF MAINLY CIRRUS FILTERING IN FROM THE NORTH.
AFTER REACHING A HIGH OF 63F TODAY...KTUS WAS DOWN TO 48F AT 0330Z.
TEMPERATURES AROUND SOUTHEASTERN ARIZONA RANGED FROM THE UPPER 30S
TO LOW 50S IN MOST VALLEY LOCATIONS WITH COOLER TEMPERATURES IN THE
MOUNTAINS. EXPECT SCATTERED TO BROKEN MAINLY HIGH LEVEL CLOUDS TO
PERSIST OVERNIGHT TONIGHT AND INTO TOMORROW AS RIDGING BEGINS TO
BUILD IN FROM THE WEST. TEMPERATURES TOMORROW WILL BE A FEW DEGREES
WARMER THAN WHAT WAS ACHIEVED TODAY AS HEIGHTS INCREASE SLIGHTLY.
FORECAST LOOKS TO BE ON TRACK FOR THIS EVENING AND NO UPDATES ARE
NEEDED. PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR MORE
INFORMATION.

&&

.AVIATION...VALID THRU 22/06Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN MAINLY HIGH CLOUDS.
SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

.PREV DISCUSSION...AS A LARGE RIDGE OF HIGH PRESSURE SETS UP ACROSS
THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON THE EASTERN SIDE
OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND GRADUALLY RISING
HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT UPTICK IN DAYTIME
TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE NEAR NORMAL SUNDAY
AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE WILL BE SOME MAINLY
THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

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

&&

$$

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

DISCUSSION...FRENCH
PREV DISCUSSION...GL







000
FXUS65 KTWC 210350
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
850 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...LATEST WV IMAGERY WAS SHOWING NW FLOW ALOFT SETTLING
IN OVER ARIZONA AS A WEAK SHORTWAVE TROUGH WAS EXITING AND MOVING
EASTWARD ACROSS NEW MEXICO AND INTO WEST TEXAS. IR IMAGERY WAS
INDICATING THAT SKIES WERE PARTLY TO MOSTLY CLOUDY OVER MUCH OF THE
REGION WITH A BATCH OF MAINLY CIRRUS FILTERING IN FROM THE NORTH.
AFTER REACHING A HIGH OF 63F TODAY...KTUS WAS DOWN TO 48F AT 0330Z.
TEMPERATURES AROUND SOUTHEASTERN ARIZONA RANGED FROM THE UPPER 30S
TO LOW 50S IN MOST VALLEY LOCATIONS WITH COOLER TEMPERATURES IN THE
MOUNTAINS. EXPECT SCATTERED TO BROKEN MAINLY HIGH LEVEL CLOUDS TO
PERSIST OVERNIGHT TONIGHT AND INTO TOMORROW AS RIDGING BEGINS TO
BUILD IN FROM THE WEST. TEMPERATURES TOMORROW WILL BE A FEW DEGREES
WARMER THAN WHAT WAS ACHIEVED TODAY AS HEIGHTS INCREASE SLIGHTLY.
FORECAST LOOKS TO BE ON TRACK FOR THIS EVENING AND NO UPDATES ARE
NEEDED. PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR MORE
INFORMATION.

&&

.AVIATION...VALID THRU 22/06Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN MAINLY HIGH CLOUDS.
SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

.PREV DISCUSSION...AS A LARGE RIDGE OF HIGH PRESSURE SETS UP ACROSS
THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON THE EASTERN SIDE
OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND GRADUALLY RISING
HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT UPTICK IN DAYTIME
TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE NEAR NORMAL SUNDAY
AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE WILL BE SOME MAINLY
THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

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

&&

$$

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

DISCUSSION...FRENCH
PREV DISCUSSION...GL






000
FXUS65 KTWC 210350
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
850 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...LATEST WV IMAGERY WAS SHOWING NW FLOW ALOFT SETTLING
IN OVER ARIZONA AS A WEAK SHORTWAVE TROUGH WAS EXITING AND MOVING
EASTWARD ACROSS NEW MEXICO AND INTO WEST TEXAS. IR IMAGERY WAS
INDICATING THAT SKIES WERE PARTLY TO MOSTLY CLOUDY OVER MUCH OF THE
REGION WITH A BATCH OF MAINLY CIRRUS FILTERING IN FROM THE NORTH.
AFTER REACHING A HIGH OF 63F TODAY...KTUS WAS DOWN TO 48F AT 0330Z.
TEMPERATURES AROUND SOUTHEASTERN ARIZONA RANGED FROM THE UPPER 30S
TO LOW 50S IN MOST VALLEY LOCATIONS WITH COOLER TEMPERATURES IN THE
MOUNTAINS. EXPECT SCATTERED TO BROKEN MAINLY HIGH LEVEL CLOUDS TO
PERSIST OVERNIGHT TONIGHT AND INTO TOMORROW AS RIDGING BEGINS TO
BUILD IN FROM THE WEST. TEMPERATURES TOMORROW WILL BE A FEW DEGREES
WARMER THAN WHAT WAS ACHIEVED TODAY AS HEIGHTS INCREASE SLIGHTLY.
FORECAST LOOKS TO BE ON TRACK FOR THIS EVENING AND NO UPDATES ARE
NEEDED. PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR MORE
INFORMATION.

&&

.AVIATION...VALID THRU 22/06Z.
VFR CONDITIONS AT ALL TERMINALS WITH SCT TO BKN MAINLY HIGH CLOUDS.
SURFACE WIND WILL BE DIURNAL AND GENERALLY LESS THAN 10 KTS THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

.PREV DISCUSSION...AS A LARGE RIDGE OF HIGH PRESSURE SETS UP ACROSS
THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON THE EASTERN SIDE
OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND GRADUALLY RISING
HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT UPTICK IN DAYTIME
TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE NEAR NORMAL SUNDAY
AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE WILL BE SOME MAINLY
THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

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

&&

$$

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

DISCUSSION...FRENCH
PREV DISCUSSION...GL







000
FXUS65 KPSR 210305
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
805 PM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
CONSIDERABLE HIGH CLOUDS CONTINUED TO STREAM INTO THE REGION THIS
EVENING. MODELS FORECAST HIGH CLOUDS TO THIN SUNDAY NIGHT WITH CLEAR
SKIES ON MONDAY. OTHERWISE...ABOVE NORMAL TEMPERATURES WILL CONTINUE
INTO EARLY NEXT WEEK. FORECASTS LOOK GOOD. NO UPDATES PLANNED.


.PREVIOUS DISCUSSION...310 PM MST...

REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...VASQUEZ/MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ











000
FXUS65 KPSR 210305
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
805 PM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
CONSIDERABLE HIGH CLOUDS CONTINUED TO STREAM INTO THE REGION THIS
EVENING. MODELS FORECAST HIGH CLOUDS TO THIN SUNDAY NIGHT WITH CLEAR
SKIES ON MONDAY. OTHERWISE...ABOVE NORMAL TEMPERATURES WILL CONTINUE
INTO EARLY NEXT WEEK. FORECASTS LOOK GOOD. NO UPDATES PLANNED.


.PREVIOUS DISCUSSION...310 PM MST...

REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...VASQUEZ/MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ












000
FXUS65 KFGZ 202215
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
315 PM MST SAT DEC 20 2014

.SYNOPSIS...
AREAS OF LOW CLOUDS AND FOG WILL FORM ONCE AGAIN OVER PORTIONS OF
NORTHEAST ARIZONA TONIGHT. OTHERWISE...DRY NORTHWEST FLOW ALOFT WILL
DELIVER FAIR WEATHER...A FEW CLOUDS AND GRADUALLY WARMING
TEMPERATURES THROUGH MONDAY. A DRY COLD FRONT WILL BRING COLDER
TEMPERATURES AND NORTHEASTERLY BREEZES FOR TUESDAY.

&&

.DISCUSSION...THE AREA OF LOW STRATUS AND FOG OVER NE ARIZONA HAS
ERODED QUICKLY THIS AFTERNOON...AND IS CURRENTLY LIMITED TO A FEW
AREAS BELOW 5500FT BETWEEN WINSLOW AND PAGE. OUR PRIMARY FORECAST
CHALLENGE WILL BE WITH REGARD TO THE FORMATION AND EXPANSION OF THE
INVERSION STRATUS AND FOG AGAIN TONIGHT AND EARLY TOMORROW.

SEVERAL FACTORS WILL BE IN PLACE WHICH MAY LIMIT THE AMOUNT OF LOW
CLOUDS AND FOG THAT FORMS OVERNIGHT...BUT IT LOOKS LIKE THE CLOUDS
WILL PREVAIL. A TIGHTENING GRADIENT ALOFT WILL PROMOTE STRONGER
NORTHWEST WINDS. BY DAYBREAK TOMORROW...FORECAST MODELS ARE
INDICATING 10-20KT WINDS JUST A COUPLE THOUSAND FEET OFF THE
SURFACE...WHICH MAY BE ENOUGH TO ERODE THE INVERSION AND SUBSEQUENT
CLOUDS BY MORNING...ESPECIALLY OVER NORTHEASTERN COCONINO COUNTY.
THIS FLOW WILL LIKELY ALSO PUSH THE CLOUDS FURTHER UP THE RIM TO THE
SOUTH OF WINSLOW...AND CREATE AN AREA OF UPSLOPE FOG. HIGH CLOUDS
OVERNIGHT MAY LIMIT THE RADIATIONAL COOLING AT THE SURFACE...BUT
WHERE THE STRATUS IS ALREADY IN PLACE...ITS NOT MUCH OF AN ISSUE.
OUR FORECAST THEREFORE WILL HAVE THE LOW CLOUDS AND FOG REFORMING
LATE THIS EVENING IN GENERALLY THE SAME AREAS AS IT WAS THIS
MORNING...THEN PUSHING FURTHER SOUTH TOWARD DAYBREAK. IN ANY
CASE...WE SHOULD SEE MOST OF THE LOW CLOUDS ACROSS NE ARIZONA
DISSIPATE TOMORROW AFTERNOON...WITH LESS REFORMING ON SUNDAY NIGHT.

OTHERWISE...A STRONG RIDGE OF HIGH PRESSURE BUILDING OVER THE WEST
COAST WILL KEEP NORTHERN ARIZONA UNDER NORTHWEST FLOW...WITH FAIR
AND MILD WEATHER THROUGH MONDAY. A RELATIVELY STRONG...BUT DRY COLD
FRONT WILL MOVE ACROSS THE NORTHLAND ON MONDAY NIGHT...BRINGING
COLDER TEMPERATURES AND BREEZY CONDITIONS. HIGHS ON TUESDAY WILL
COOL ABOUT 10 DEGREES 0N TUESDAY...WITH THE GREATEST IMPACT BEING
OVER THE NORTHEAST PART OF THE STATE. THE CHILL WILL BE SHORT-LIVED
HOWEVER...AS WARMER WESTERLY FLOW ALOFT QUICKLY BRINGS OUR
TEMPERATURES BACK TO NEAR NORMAL ON WEDNESDAY.

THE DETERMINISTIC MODELS AND ENSEMBLE MEMBERS ARE STARTING TO COME
INTO LINE WITH THE TROUGH TO IMPACT ARIZONA ON CHRISTMAS DAY.
CURRENT INDICATIONS ARE THAT THIS SYSTEM WILL HAVE VERY LIMITED
MOISTURE...AND WILL BRING STRONGER WINDS...COOLER TEMPERATURES...AND
ONLY A SLIGHT CHANCE FOR RAIN AND SNOW TO THE NORTHLAND.

&&

.AVIATION...FOR THE 00Z PACKAGE...LOW CLOUDS AND FOG REMAIN WITHIN
THE LITTLE COLORADO RIVER VALLEY GENERALLY TO THE NORTHWEST OF KINW.
THIS REGION OF LOW CLOUDS AND FOG ARE FORECAST TO EXPAND BEGINNING
IN THE EARLY EVENING. IFR TO VLIFR CONDITIONS WILL GENERALLY BE
LIMITED TO AREAS WITHIN THE LITTLE COLORADO RIVER VALLEY. IFR TO
VLIFR CONDITIONS ARE LIKELY OVERNIGHT AT KINW...WITH IFR CONDITIONS
POSSIBLE AT KPGA. VFR CONDITIONS ARE EXPECTED ELSEWHERE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.


&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....BAK/JJ
AVIATION...RICKEY/BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 202215
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
315 PM MST SAT DEC 20 2014

.SYNOPSIS...
AREAS OF LOW CLOUDS AND FOG WILL FORM ONCE AGAIN OVER PORTIONS OF
NORTHEAST ARIZONA TONIGHT. OTHERWISE...DRY NORTHWEST FLOW ALOFT WILL
DELIVER FAIR WEATHER...A FEW CLOUDS AND GRADUALLY WARMING
TEMPERATURES THROUGH MONDAY. A DRY COLD FRONT WILL BRING COLDER
TEMPERATURES AND NORTHEASTERLY BREEZES FOR TUESDAY.

&&

.DISCUSSION...THE AREA OF LOW STRATUS AND FOG OVER NE ARIZONA HAS
ERODED QUICKLY THIS AFTERNOON...AND IS CURRENTLY LIMITED TO A FEW
AREAS BELOW 5500FT BETWEEN WINSLOW AND PAGE. OUR PRIMARY FORECAST
CHALLENGE WILL BE WITH REGARD TO THE FORMATION AND EXPANSION OF THE
INVERSION STRATUS AND FOG AGAIN TONIGHT AND EARLY TOMORROW.

SEVERAL FACTORS WILL BE IN PLACE WHICH MAY LIMIT THE AMOUNT OF LOW
CLOUDS AND FOG THAT FORMS OVERNIGHT...BUT IT LOOKS LIKE THE CLOUDS
WILL PREVAIL. A TIGHTENING GRADIENT ALOFT WILL PROMOTE STRONGER
NORTHWEST WINDS. BY DAYBREAK TOMORROW...FORECAST MODELS ARE
INDICATING 10-20KT WINDS JUST A COUPLE THOUSAND FEET OFF THE
SURFACE...WHICH MAY BE ENOUGH TO ERODE THE INVERSION AND SUBSEQUENT
CLOUDS BY MORNING...ESPECIALLY OVER NORTHEASTERN COCONINO COUNTY.
THIS FLOW WILL LIKELY ALSO PUSH THE CLOUDS FURTHER UP THE RIM TO THE
SOUTH OF WINSLOW...AND CREATE AN AREA OF UPSLOPE FOG. HIGH CLOUDS
OVERNIGHT MAY LIMIT THE RADIATIONAL COOLING AT THE SURFACE...BUT
WHERE THE STRATUS IS ALREADY IN PLACE...ITS NOT MUCH OF AN ISSUE.
OUR FORECAST THEREFORE WILL HAVE THE LOW CLOUDS AND FOG REFORMING
LATE THIS EVENING IN GENERALLY THE SAME AREAS AS IT WAS THIS
MORNING...THEN PUSHING FURTHER SOUTH TOWARD DAYBREAK. IN ANY
CASE...WE SHOULD SEE MOST OF THE LOW CLOUDS ACROSS NE ARIZONA
DISSIPATE TOMORROW AFTERNOON...WITH LESS REFORMING ON SUNDAY NIGHT.

OTHERWISE...A STRONG RIDGE OF HIGH PRESSURE BUILDING OVER THE WEST
COAST WILL KEEP NORTHERN ARIZONA UNDER NORTHWEST FLOW...WITH FAIR
AND MILD WEATHER THROUGH MONDAY. A RELATIVELY STRONG...BUT DRY COLD
FRONT WILL MOVE ACROSS THE NORTHLAND ON MONDAY NIGHT...BRINGING
COLDER TEMPERATURES AND BREEZY CONDITIONS. HIGHS ON TUESDAY WILL
COOL ABOUT 10 DEGREES 0N TUESDAY...WITH THE GREATEST IMPACT BEING
OVER THE NORTHEAST PART OF THE STATE. THE CHILL WILL BE SHORT-LIVED
HOWEVER...AS WARMER WESTERLY FLOW ALOFT QUICKLY BRINGS OUR
TEMPERATURES BACK TO NEAR NORMAL ON WEDNESDAY.

THE DETERMINISTIC MODELS AND ENSEMBLE MEMBERS ARE STARTING TO COME
INTO LINE WITH THE TROUGH TO IMPACT ARIZONA ON CHRISTMAS DAY.
CURRENT INDICATIONS ARE THAT THIS SYSTEM WILL HAVE VERY LIMITED
MOISTURE...AND WILL BRING STRONGER WINDS...COOLER TEMPERATURES...AND
ONLY A SLIGHT CHANCE FOR RAIN AND SNOW TO THE NORTHLAND.

&&

.AVIATION...FOR THE 00Z PACKAGE...LOW CLOUDS AND FOG REMAIN WITHIN
THE LITTLE COLORADO RIVER VALLEY GENERALLY TO THE NORTHWEST OF KINW.
THIS REGION OF LOW CLOUDS AND FOG ARE FORECAST TO EXPAND BEGINNING
IN THE EARLY EVENING. IFR TO VLIFR CONDITIONS WILL GENERALLY BE
LIMITED TO AREAS WITHIN THE LITTLE COLORADO RIVER VALLEY. IFR TO
VLIFR CONDITIONS ARE LIKELY OVERNIGHT AT KINW...WITH IFR CONDITIONS
POSSIBLE AT KPGA. VFR CONDITIONS ARE EXPECTED ELSEWHERE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.


&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....BAK/JJ
AVIATION...RICKEY/BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KPSR 202211 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST SAT DEC 20 2014

.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ









000
FXUS65 KPSR 202211 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST SAT DEC 20 2014

.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ









000
FXUS65 KPSR 202211 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST SAT DEC 20 2014

.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ









000
FXUS65 KPSR 202211 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST SAT DEC 20 2014

.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
EXPECT VARIABLE AMOUNTS OF CIRRUS TONIGHT AND SUNDAY WITH NORTH AND
NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE LIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...WITH SOMEWHAT MORE NOTICEABLE NORTHERLY
WINDS SUNDAY AFTERNOON OVER PORTIONS OF SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH SATURDAY...
A WEATHER SYSTEM MOVING THROUGH THE ROCKIES WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM THE NORTH AND NORTHEAST BEGINNING MONDAY
AFTERNOON OVER SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA...EXPANDING TO SOUTH-CENTRAL ARIZONA BY TUESDAY MORNING.
WINDS AT RIDGETOPS WILL BE QUITE STRONG MONDAY NIGHT INTO TUESDAY.
THE SYSTEM WILL BE DRY ACROSS THE FORECAST AREA AND HUMIDITIES WILL
DROP DRAMATICALLY FROM MONDAY TO TUESDAY. SOME SPOTS MAY FLIRT WITH
CRITICAL WIND AND HUMIDITY THRESHOLDS FOR A BRIEF TIME. THE SYSTEM
WILL BRING SOME MODEST COOLING AS WELL. ANOTHER EPISODE OF ENHANCED
WINDS IS EXPECTED THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM MOVES
THROUGH. IT WILL HAVE LIMITED MOISTURE AND THERE IS ONLY A VERY
SLIGHT CHANCE OF PRECIPITATION FOR THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA ON FRIDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...AJ
FIRE WEATHER...AJ









000
FXUS65 KPSR 202205
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
304 PM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN





000
FXUS65 KPSR 202205
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
304 PM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY THIS COMING THURSDAY...A FAST MOVING STORM SYSTEM
WILL MOVE THROUGH THE FOUR CORNERS REGION...BRINGING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS AFTERNOON REVEALS A LARGE SWATH
OF THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE CLOUD DEVELOPMENT DUE TO AN UPPER LEVEL JET
STREAK OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE
STRENGTHENING EASTERN PACIFIC RIDGE CURRENTLY IN PLACE OFF THE WEST
COAST.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH/JET AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS OF
582-588DM FORECAST TO REMAIN IN PLACE OVER THE PACIFIC THROUGH AT
LEAST WEDNESDAY. THIS WILL RESULT IN A DRY NORTHWESTERLY FLOW OVER
THE REGION...A DIRTY RIDGE PATTERN WITH PERIODS OF HIGH THIN CLOUDS
AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS
CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY...A BIT
WARMER AROUND YUMA AND EL CENTRO...WITH NEAR NORMAL LOWS IN THE MID
40S CWA-WIDE.

ATTENTION TURNS TO CHRISTMAS DAY/THURSDAY AND BEYOND...AS PRIOR RUNS
OF THE ECMWF/GFS WERE SHOWING SOME DIFFERENCES IN STRENGTH/TIMING OF
THE NEXT UPPER LEVEL TROUGH OVER THE INTERMOUNTAIN WEST. HOWEVER...
THE 20.12Z ECMWF NOW ALIGNS BETTER WITH THE OPERATIONAL GFS...
DEPICTING A MORE PROGRESSIVE WAVE/UPPER LEVEL TROUGH THAT SWINGS
THROUGH NORTHERN PORTIONS OF THE GREAT BASIN THURSDAY INTO FRIDAY.
THE GFS IS STILL THE DRIER OF BOTH SOLUTIONS...LACKING MOISTURE AS
IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN STEADY AND INDICATE
THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL BUT NOT WANTING TO
DISCOUNT THE WETTER ECMWF...WILL CONTINUE TO INTRODUCED VERY LOW END
DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX THURSDAY ALONG WITH SLIGHTLY
COOLER TEMPERATURES. IMPACTS LOOK MINIMAL BUT WILL NEED TO KEEP
MONITORING SUBSEQUENT MODEL RUNS TO SEE HOW THEY TREND. STILL...A
RETURN TO NORTHWESTERLY FLOW LOOKS LIKELY LATE NEXT WEEK INTO THE
WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN






000
FXUS65 KTWC 202113 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY ACROSS SOUTHEAST ARIZONA THIS
AFTERNOON AS SOME HIGH CIRROFORM CLOUDINESS MOVES THROUGH THE AREA
UNDER NORTHWESTERLY FLOW ALOFT. AS A LARGE RIDGE OF HIGH PRESSURE
SETS UP ACROSS THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON
THE EASTERN SIDE OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND
GRADUALLY RISING HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT
UPTICK IN DAYTIME TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE
NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE
WILL BE SOME MAINLY THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM
TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

.AVIATION...VALID THRU 22/00Z.
SCT TO LCLY BKN MOSTLY HIGH CLOUDS. SURFACE WIND LESS THAN 10 KTS
WILL PREVAIL THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

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

&&

$$

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

GL








000
FXUS65 KTWC 202113 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY ACROSS SOUTHEAST ARIZONA THIS
AFTERNOON AS SOME HIGH CIRROFORM CLOUDINESS MOVES THROUGH THE AREA
UNDER NORTHWESTERLY FLOW ALOFT. AS A LARGE RIDGE OF HIGH PRESSURE
SETS UP ACROSS THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON
THE EASTERN SIDE OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND
GRADUALLY RISING HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT
UPTICK IN DAYTIME TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE
NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE
WILL BE SOME MAINLY THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM
TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

.AVIATION...VALID THRU 22/00Z.
SCT TO LCLY BKN MOSTLY HIGH CLOUDS. SURFACE WIND LESS THAN 10 KTS
WILL PREVAIL THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

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

&&

$$

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

GL








000
FXUS65 KTWC 202113 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY ACROSS SOUTHEAST ARIZONA THIS
AFTERNOON AS SOME HIGH CIRROFORM CLOUDINESS MOVES THROUGH THE AREA
UNDER NORTHWESTERLY FLOW ALOFT. AS A LARGE RIDGE OF HIGH PRESSURE
SETS UP ACROSS THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON
THE EASTERN SIDE OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND
GRADUALLY RISING HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT
UPTICK IN DAYTIME TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE
NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE
WILL BE SOME MAINLY THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM
TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

.AVIATION...VALID THRU 22/00Z.
SCT TO LCLY BKN MOSTLY HIGH CLOUDS. SURFACE WIND LESS THAN 10 KTS
WILL PREVAIL THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

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

&&

$$

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

GL








000
FXUS65 KTWC 202113 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
213 PM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS WITH TEMPERATURES NEAR NORMAL SUNDAY AND SLIGHTLY
ABOVE NORMAL MONDAY. A WEAK COLD FRONT WILL MOVE THROUGH MONDAY
NIGHT BRINGING SLIGHTLY COOLER TEMPERATURES ESPECIALLY EAST OF
TUCSON TUESDAY AND WEDNESDAY. A STORM SYSTEM WILL STAY MAINLY TO OUR
NORTH FOR THE END OF THE WEEK WITH A SLIGHT CHANCE OF PRECIPITATION
FOR THE WHITE MOUNTAINS. OTHERWISE...SOME BREEZES AND COOLER
TEMPERATURES FOR THE END OF THE WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY ACROSS SOUTHEAST ARIZONA THIS
AFTERNOON AS SOME HIGH CIRROFORM CLOUDINESS MOVES THROUGH THE AREA
UNDER NORTHWESTERLY FLOW ALOFT. AS A LARGE RIDGE OF HIGH PRESSURE
SETS UP ACROSS THE EASTERN PACIFIC...SOUTHEAST ARIZONA WILL BE ON
THE EASTERN SIDE OF THE RIDGE WITH CONTINUED NORTHWESTERLY FLOW AND
GRADUALLY RISING HEIGHTS INTO MONDAY. THIS WILL BRING A SLIGHT
UPTICK IN DAYTIME TEMPERATURES SUNDAY AND MONDAY WITH HIGHS WILL BE
NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE
WILL BE SOME MAINLY THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM
TIME TO TIME.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. AS HIGH PRESSURE STRENGTHENS ACROSS THE SOUTHERN
ROCKIES...A WEAK COLD FRONT FROM THE NORTH WILL MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT INTO TUESDAY MORNING. WE CAN`T RULE
OUT JUST ENOUGH MOISTURE TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE
MOUNTAINS MONDAY NIGHT BUT WILL CONTINUE WITH DRY FORECAST AT THIS
TIME. TEMPERATURES WILL DROP BACK A FEW DEGREES ESPECIALLY FOR THE
VALLEYS EAST OF TUCSON ON TUESDAY WITH A SLIGHT TEMPERATURE
MODERATION WEDNESDAY.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. THE 12Z GLOBAL MODEL GUIDANCE AND ENSEMBLES IS
CONTINUING TO TREND KEEPING THE BULK OF THE DYNAMICS AND MOISTURE TO
OUR NORTH. WITH THAT SAID...EXPECT THE MAIN IMPACTS FOR SOUTHEAST
ARIZONA TO BE SOME INCREASED BREEZES AND COOLER TEMPERATURES MOVING
IN BY ABOUT FRIDAY. HAVE MAINTAINED SLIGHT CHANCE POPS FOR THE
MOUNTAINS FROM TUCSON NORTHEASTWARD AS IT WON`T TAKE MUCH TO SQUEEZE
OUT A LITTLE MOISTURE.

&&

.AVIATION...VALID THRU 22/00Z.
SCT TO LCLY BKN MOSTLY HIGH CLOUDS. SURFACE WIND LESS THAN 10 KTS
WILL PREVAIL THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH WEDNESDAY. 20-FT
WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE MIDDLE
OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR MONDAY
AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING SAFFORD...AS
AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST ACROSS THE
FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE
TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY
AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE FOR VALLEY RAIN
AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN INCREASE IN WINDS ON
THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF TUCSON TOWARD THE
INTERNATIONAL BORDER AS WELL AS THE BORDER WITH NEW MEXICO.

&&

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

&&

$$

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

GL








000
FXUS65 KPSR 201721
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 AM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY NEXT THURSDAY...A FAST MOVING STORM SYSTEM WILL
MOVE THROUGH THE FOUR CORNERS REGION AND WILL BRING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS MORNING REVEALS A LARGE SWATH OF
THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE DEVELOPMENT DUE TO AN UPPER LEVEL JET STREAK
OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE STRENGTHENING
EASTERN PACIFIC RIDGE IN PLACE OFF THE WEST COAST. SURFACE
CONDITIONS ACROSS OUR FORECAST AREA REMAIN PERSISTENT...SHOWING
LITTLE CHANGE OVER THE LAST DAY OR TWO...DIURNAL DEW POINT TEMP
TRENDS MAINLY IN THE 30S-40S ACROSS OUR CWA...WITH FORECAST DAYTIME
MAX TEMPERATURES TODAY TOPPING OUT IN THE 60S ACROSS THE LOWER
DESERT ELEVATIONS.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS
FORECAST TO REMAIN IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL
RESULT IN VARYING AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL
TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS CORRECTED GUIDANCE
SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY /SLIGHTLY WARMER AROUND
YUMA AND EL CENTRO/ WITH NEAR NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN





000
FXUS65 KPSR 201721
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 AM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY NEXT THURSDAY...A FAST MOVING STORM SYSTEM WILL
MOVE THROUGH THE FOUR CORNERS REGION AND WILL BRING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS MORNING REVEALS A LARGE SWATH OF
THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE DEVELOPMENT DUE TO AN UPPER LEVEL JET STREAK
OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE STRENGTHENING
EASTERN PACIFIC RIDGE IN PLACE OFF THE WEST COAST. SURFACE
CONDITIONS ACROSS OUR FORECAST AREA REMAIN PERSISTENT...SHOWING
LITTLE CHANGE OVER THE LAST DAY OR TWO...DIURNAL DEW POINT TEMP
TRENDS MAINLY IN THE 30S-40S ACROSS OUR CWA...WITH FORECAST DAYTIME
MAX TEMPERATURES TODAY TOPPING OUT IN THE 60S ACROSS THE LOWER
DESERT ELEVATIONS.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS
FORECAST TO REMAIN IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL
RESULT IN VARYING AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL
TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS CORRECTED GUIDANCE
SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY /SLIGHTLY WARMER AROUND
YUMA AND EL CENTRO/ WITH NEAR NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN





000
FXUS65 KPSR 201721
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 AM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY NEXT THURSDAY...A FAST MOVING STORM SYSTEM WILL
MOVE THROUGH THE FOUR CORNERS REGION AND WILL BRING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS MORNING REVEALS A LARGE SWATH OF
THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE DEVELOPMENT DUE TO AN UPPER LEVEL JET STREAK
OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE STRENGTHENING
EASTERN PACIFIC RIDGE IN PLACE OFF THE WEST COAST. SURFACE
CONDITIONS ACROSS OUR FORECAST AREA REMAIN PERSISTENT...SHOWING
LITTLE CHANGE OVER THE LAST DAY OR TWO...DIURNAL DEW POINT TEMP
TRENDS MAINLY IN THE 30S-40S ACROSS OUR CWA...WITH FORECAST DAYTIME
MAX TEMPERATURES TODAY TOPPING OUT IN THE 60S ACROSS THE LOWER
DESERT ELEVATIONS.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS
FORECAST TO REMAIN IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL
RESULT IN VARYING AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL
TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS CORRECTED GUIDANCE
SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY /SLIGHTLY WARMER AROUND
YUMA AND EL CENTRO/ WITH NEAR NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN





000
FXUS65 KPSR 201721
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 AM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH THE MIDDLE
OF NEXT WEEK. BY NEXT THURSDAY...A FAST MOVING STORM SYSTEM WILL
MOVE THROUGH THE FOUR CORNERS REGION AND WILL BRING SLIGHTLY COOLER
TEMPERATURES AND INCREASED CLOUDINESS THAT WILL LAST THROUGH FRIDAY.
DRY WEATHER IS EXPECTED NEXT WEEKEND WITH BELOW NORMAL TEMPERATURES.

&&

.DISCUSSION...
REGIONAL IR SATELLITE IMAGERY THIS MORNING REVEALS A LARGE SWATH OF
THICKER UPPER LEVEL CLOUDS OVERSPREADING PORTIONS OF THE WESTERN
UNITED STATES...THE DEVELOPMENT DUE TO AN UPPER LEVEL JET STREAK
OVER NORTHERN CALIFORNIA RIDING OVER THE TOP OF THE STRENGTHENING
EASTERN PACIFIC RIDGE IN PLACE OFF THE WEST COAST. SURFACE
CONDITIONS ACROSS OUR FORECAST AREA REMAIN PERSISTENT...SHOWING
LITTLE CHANGE OVER THE LAST DAY OR TWO...DIURNAL DEW POINT TEMP
TRENDS MAINLY IN THE 30S-40S ACROSS OUR CWA...WITH FORECAST DAYTIME
MAX TEMPERATURES TODAY TOPPING OUT IN THE 60S ACROSS THE LOWER
DESERT ELEVATIONS.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE WEAK TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH
NORTHERN CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE
SOUTHERN CALIFORNIA COAST WITH ANOMALOUSLY HIGH 500MB HEIGHTS
FORECAST TO REMAIN IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL
RESULT IN VARYING AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL
TEMPERATURES. A BLEND OF THE BEST PERFORMING BIAS CORRECTED GUIDANCE
SUGGESTS DAILY HIGHS FROM 65-70 EACH DAY /SLIGHTLY WARMER AROUND
YUMA AND EL CENTRO/ WITH NEAR NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...MEYERS/LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN





000
FXUS65 KFGZ 201643
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
945 AM MST SAT DEC 20 2014

.SYNOPSIS...
AREAS OF LOW CLOUDS AND FOG WILL PERSIST OVER PORTIONS OF NORTHEAST
ARIZONA THIS MORNING...AND REFORM AGAIN TONIGHT. OTHERWISE...DRY
NORTHWEST FLOW ALOFT WILL DELIVER FAIR WEATHER...A FEW CLOUDS AND
GRADUALLY WARMING TEMPERATURES EACH DAY THROUGH MONDAY. A DRY COLD
FRONT WILL BRING COLDER TEMPERATURES AND NORTHEASTERLY BREEZES FOR
TUESDAY.

&&

.DISCUSSION...PRIMARY WEATHER STORY THIS MORNING IS THE LOW STRATUS
AND FOG WHICH FORMED ONCE AGAIN OVER THE LOWER ELEVATIONS OF NE
ARIZONA. WITH THE HEATING OF THE DAY THESE CLOUDS SHOULD DISSIPATE
SIGNIFICANTLY...BUT REFORM ONCE AGAIN OVERNIGHT TONIGHT WITH THE
STRONG DIURNAL FORCING. ONE FACTOR WHICH MAY LIMIT THE EXTENT OF THE
STRATUS AND FOG FORMATION TONIGHT WILL BE THE EXTENSIVE MID AND HIGH
LEVEL CLOUDS WHICH WILL SPREAD ACROSS THE AREA THIS AFTERNOON AND
OVERNIGHT. OTHERWISE...EXPECT FAIR WEATHER ACROSS ARIZONA.  SOME
MINOR UPDATES TO THE FORECAST WILL TO ADJUST FOR THE CURRENT AND
FORECAST EXTENT OF THE STRATUS AND FOG.

&&

.PREV DISCUSSION /410AM MST/...NORTHWESTERLY FLOW ALOFT WILL
CONTINUE THIS WEEKEND...WITH DRY CONDITIONS AND GRADUALLY WARMING
TEMPERATURES. SOME AREAS OF LOW CLOUDS AND PATCHY FOG WILL AFFECT
NORTHEAST AZ VALLEY AREAS THIS MORNING...BUT SHOULD DECREASE BY THIS
AFTERNOON. OTHERWISE...LOOK FOR PERIODS OF HIGH CLOUDS IN THE
NORTHWEST FLOW.

LATE MONDAY INTO TUESDAY...A TROUGH DIVING THROUGH THE CENTRAL
ROCKIES TO THE PLAINS STATES WILL PUSH A COLD FRONT INTO ARIZONA.
HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO THE NORTHEAST CORNER
OF THE STATE MONDAY NIGHT...BUT THE MAIN IMPACT IS LIKELY TO BE
NORTHEAST WINDS AND SEVERAL DEGREES OF COOLING BY TUESDAY.
TEMPERATURES SHOULD MODERATE BY WEDNESDAY AS THE TROUGH SHIFTS EAST.

FOR CHRISTMAS DAY AND FRIDAY...THE ECMWF MODEL STILL INDICATES THE
POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS. THE GFS
ENSEMBLES AND OPERATIONAL RUNS CONTINUE TO BACK OFF ON THE CHANCES
FOR PRECIPITATION...ALONG WITH SOME OTHER MODELS. KEPT LOW CHANCES
FOR PRECIP IN THE FORECAST...BUT CONFIDENCE IS LOW AT THIS TIME...
CHECK BACK FOR UPDATES.

&&

.AVIATION...FOR THE 18Z PACKAGE...WIDESPREAD IFR TO VLIFR CONDITIONS
IN LOW CLOUD AND FOG ARE PRESENT ACROSS LOWER TERRAIN REGIONS OF
NORTHEASTERN ARIZONA THIS MORNING...ESPECIALLY IN THE LITTLE
COLORADO RIVER AND CHINLE VALLEYS. CONDITIONS ARE EXPECTED TO
IMPROVE THROUGH THE DAY TODAY WITH DAYTIME HEATING...BUT WILL LIKELY
RETURN AGAIN OVERNIGHT. VFR CONDITIONS ARE FORECAST ELSEWHERE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.


&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....BAK/JJ
AVIATION...RICKEY/BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF







000
FXUS65 KTWC 201555 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
855 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY SKIES ACROSS SOUTHEAST ARIZONA
THIS MORNING UNDER DRY WEST TO NORTHWESTERLY FLOW ALOFT. 12Z KTWC
SOUNDING DEPICTS A RELATIVELY STEEP INVERSION WHICH WILL MIX OUT AS
THE DAY PROGRESSES TO ABOUT 850MB. EXPECT HIGH TEMPERATURES A FEW
DEGREES WARMER THAN YESTERDAY...TOPPING OUT IN THE LOWER 60S IN THE
TUCSON AREA.

AS A LARGE RIDGE OF HIGH PRESSURE SETS UP ACROSS THE EASTERN
PACIFIC...SOUTHEAST ARIZONA WILL BE ON THE EASTERN SIDE OF THE RIDGE
WITH NORTHWESTERLY FLOW ALOFT AND GRADUALLY RISING HEIGHTS SUNDAY
AND MONDAY. THIS WILL BRING A SLIGHT UPTICK IN DAYTIME
TEMPERATURES SUNDAY AND MONDAY AS HIGHS WILL BE NEAR NORMAL SUNDAY
AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE WILL BE SOME MAINLY
THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM TIME TO TIME ON THE
NORTHWESTERLY FLOW ALOFT.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. EXPECT HIGH PRESSURE TO STRENGTHEN ACROSS THE SOUTHERN
ROCKIES WITH A WEAK COLD FRONT FROM THE NORTH MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT. CAN`T RULE OUT JUST ENOUGH MOISTURE
TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE MOUNTAINS MONDAY NIGHT
BUT WILL LEAVE FORECAST DRY AT THIS TIME. TEMPERATURES WILL DROP
BACK JUST A COUPLE OF DEGREES MAINLY FOR GRAHAM/GREENLEE/COCHISE
TUESDAY WITH LITTLE NOTICEABLE CHANGE FROM TUCSON WESTWARD OTHER
THAN THE WIND SHIFT.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. LATEST TRENDS FAVOR A SOLUTION CLOSE TO THE 00Z ECMWF
AND ENSEMBLE MEANS WHICH WILL KEEP THE BULK OF THE MOISTURE TO THE
NORTH OF OUR AREA AND SOME GUSTY WINDS DUE TO A TIGHTER PRESSURE
GRADIENT. WILL KEEP SLIGHT CHANCE POPS NORTHEAST OF TUCSON AND
REEVALUATE WITH THE 12Z MODEL SUITE.

&&

.AVIATION...VALID THRU 21/18Z.
SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU THIS AFTERNOON. SURFACE WIND
LESS THAN 10 KTS WILL PREVAIL THROUGH THE PERIOD. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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

GL






000
FXUS65 KTWC 201555 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
855 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY SKIES ACROSS SOUTHEAST ARIZONA
THIS MORNING UNDER DRY WEST TO NORTHWESTERLY FLOW ALOFT. 12Z KTWC
SOUNDING DEPICTS A RELATIVELY STEEP INVERSION WHICH WILL MIX OUT AS
THE DAY PROGRESSES TO ABOUT 850MB. EXPECT HIGH TEMPERATURES A FEW
DEGREES WARMER THAN YESTERDAY...TOPPING OUT IN THE LOWER 60S IN THE
TUCSON AREA.

AS A LARGE RIDGE OF HIGH PRESSURE SETS UP ACROSS THE EASTERN
PACIFIC...SOUTHEAST ARIZONA WILL BE ON THE EASTERN SIDE OF THE RIDGE
WITH NORTHWESTERLY FLOW ALOFT AND GRADUALLY RISING HEIGHTS SUNDAY
AND MONDAY. THIS WILL BRING A SLIGHT UPTICK IN DAYTIME
TEMPERATURES SUNDAY AND MONDAY AS HIGHS WILL BE NEAR NORMAL SUNDAY
AND ABOUT 5 DEGREES ABOVE NORMAL MONDAY. THERE WILL BE SOME MAINLY
THIN CIRROFORM CLOUDINESS MOVING THROUGH FROM TIME TO TIME ON THE
NORTHWESTERLY FLOW ALOFT.

TROUGHINESS WILL DEEPEN MAINLY ACROSS THE PLAINS TUESDAY INTO
WEDNESDAY. EXPECT HIGH PRESSURE TO STRENGTHEN ACROSS THE SOUTHERN
ROCKIES WITH A WEAK COLD FRONT FROM THE NORTH MOVING THROUGH
SOUTHEAST ARIZONA MONDAY NIGHT. CAN`T RULE OUT JUST ENOUGH MOISTURE
TO SQUEEZE OUT A FLURRY OR TWO IN THE WHITE MOUNTAINS MONDAY NIGHT
BUT WILL LEAVE FORECAST DRY AT THIS TIME. TEMPERATURES WILL DROP
BACK JUST A COUPLE OF DEGREES MAINLY FOR GRAHAM/GREENLEE/COCHISE
TUESDAY WITH LITTLE NOTICEABLE CHANGE FROM TUCSON WESTWARD OTHER
THAN THE WIND SHIFT.

THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE WESTERN US BY THURSDAY
AND FRIDAY. LATEST TRENDS FAVOR A SOLUTION CLOSE TO THE 00Z ECMWF
AND ENSEMBLE MEANS WHICH WILL KEEP THE BULK OF THE MOISTURE TO THE
NORTH OF OUR AREA AND SOME GUSTY WINDS DUE TO A TIGHTER PRESSURE
GRADIENT. WILL KEEP SLIGHT CHANCE POPS NORTHEAST OF TUCSON AND
REEVALUATE WITH THE 12Z MODEL SUITE.

&&

.AVIATION...VALID THRU 21/18Z.
SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU THIS AFTERNOON. SURFACE WIND
LESS THAN 10 KTS WILL PREVAIL THROUGH THE PERIOD. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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

GL





000
FXUS65 KPSR 201215
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
515 AM MST SAT DEC 20 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH MID WEEK. A
FAST MOVING STORM SYSTEM WILL MOVE THROUGH THE FOUR CORNERS LATER
THIS WEEK BUT SHOULD ONLY RESULT IN SLIGHTLY COOLER TEMPERATURES AND
INCREASED CLOUDINESS. DRY WEATHER IS EXPECTED NEXT WEEKEND WITH
BELOW NORMAL TEMPS.

&&

.DISCUSSION...
ONSHORE FLOW ACROSS NORTHERN CALIFORNIA AND THE ASSOCIATED 300-400MB
JET STREAK HAS RESULTED IN QUITE A BIT OF HIGH CLOUD COVER ACROSS
THE REGION THIS MORNING. INITIAL BAND OF CLOUDS WAS POSITIONED OVER
CENTRAL ARIZONA AS OF 08Z WITH CLEARING ACROSS SOUTHEAST
CALIFORNIA...THEN ADDITIONAL HIGH CLOUDINESS OVER CENTRAL
CALIFORNIA. SO FAR THE HIGH CLOUD COVER HAS HAD A NEGLIGIBLE IMPACT
ON TEMPERATURES AS READINGS AS OF 08Z WERE ON PAR WITH READINGS THE
PAST SEVERAL MORNINGS. MOST DESERT LOCALES WERE IN THE LOW/MID 40S
WITH LIGHT WINDS. MUCH LIKE YESTERDAY...NO FOG HAS SHOWN UP AT ANY
OF THE ASOSS OR ON ANY WEBCAMS QUITE YET BUT WITH ELEVATED
DEWPOINTS AND STEADILY DECREASING DEWPOINT DEPRESSIONS...I WILL
LEAVE A MENTION OF FOG IN THE LOCATIONS THAT SAW IT EARLY FRIDAY
MORNING.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH NORTHERN
CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE SOUTHERN
CALIFORNIA COAST WITH ANOMALOUSLY HIGH H5 HEIGHTS FORECAST TO REMAIN
IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL RESULT IN VARYING
AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE
BEST PERFORMING BIAS CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM
65-70 EACH DAY /SLIGHTLY WARMER AROUND YUMA AND EL CENTRO/ WITH NEAR
NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN








000
FXUS65 KPSR 201215
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
515 AM MST SAT DEC 20 2014

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH MID WEEK. A
FAST MOVING STORM SYSTEM WILL MOVE THROUGH THE FOUR CORNERS LATER
THIS WEEK BUT SHOULD ONLY RESULT IN SLIGHTLY COOLER TEMPERATURES AND
INCREASED CLOUDINESS. DRY WEATHER IS EXPECTED NEXT WEEKEND WITH
BELOW NORMAL TEMPS.

&&

.DISCUSSION...
ONSHORE FLOW ACROSS NORTHERN CALIFORNIA AND THE ASSOCIATED 300-400MB
JET STREAK HAS RESULTED IN QUITE A BIT OF HIGH CLOUD COVER ACROSS
THE REGION THIS MORNING. INITIAL BAND OF CLOUDS WAS POSITIONED OVER
CENTRAL ARIZONA AS OF 08Z WITH CLEARING ACROSS SOUTHEAST
CALIFORNIA...THEN ADDITIONAL HIGH CLOUDINESS OVER CENTRAL
CALIFORNIA. SO FAR THE HIGH CLOUD COVER HAS HAD A NEGLIGIBLE IMPACT
ON TEMPERATURES AS READINGS AS OF 08Z WERE ON PAR WITH READINGS THE
PAST SEVERAL MORNINGS. MOST DESERT LOCALES WERE IN THE LOW/MID 40S
WITH LIGHT WINDS. MUCH LIKE YESTERDAY...NO FOG HAS SHOWN UP AT ANY
OF THE ASOSS OR ON ANY WEBCAMS QUITE YET BUT WITH ELEVATED
DEWPOINTS AND STEADILY DECREASING DEWPOINT DEPRESSIONS...I WILL
LEAVE A MENTION OF FOG IN THE LOCATIONS THAT SAW IT EARLY FRIDAY
MORNING.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH NORTHERN
CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE SOUTHERN
CALIFORNIA COAST WITH ANOMALOUSLY HIGH H5 HEIGHTS FORECAST TO REMAIN
IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL RESULT IN VARYING
AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE
BEST PERFORMING BIAS CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM
65-70 EACH DAY /SLIGHTLY WARMER AROUND YUMA AND EL CENTRO/ WITH NEAR
NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. SFC WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW
TYPICAL DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH A GOOD PORTION...IF NOT
ALL...OF NEXT WEEK WITH ABOVE NORMAL TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD
WITH MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT
FOR THE MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...NOLTE/KUHLMAN
FIRE WEATHER...KUHLMAN









000
FXUS65 KFGZ 201113
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
410 AM MST SAT DEC 20 2014

.SYNOPSIS...
AREAS OF LOW CLOUDS AND PATCHY FOG WILL PERSIST OVER PORTIONS OF
NORTHEAST ARIZONA THIS MORNING. OTHERWISE...DRY NORTHWEST FLOW ALOFT
WILL DELIVER FAIR WEATHER...A FEW CLOUDS AND GRADUALLY WARMING
TEMPERATURES EACH DAY THROUGH MONDAY. A DRY COLD FRONT WILL BRING
COLDER TEMPERATURES AND NORTHEASTERLY BREEZES FOR TUESDAY.
&&

.DISCUSSION...NORTHWESTERLY FLOW ALOFT WILL CONTINUE THIS
WEEKEND...WITH DRY CONDITIONS AND GRADUALLY WARMING TEMPERATURES.
SOME AREAS OF LOW CLOUDS AND PATCHY FOG WILL AFFECT NORTHEAST AZ
VALLEY AREAS THIS MORNING...BUT SHOULD DECREASE BY THIS AFTERNOON.
OTHERWISE...LOOK FOR PERIODS OF HIGH CLOUDS IN THE NORTHWEST FLOW.

LATE MONDAY INTO TUESDAY...A TROUGH DIVING THROUGH THE CENTRAL
ROCKIES TO THE PLAINS STATES WILL PUSH A COLD FRONT INTO ARIZONA.
HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO THE NORTHEAST CORNER
OF THE STATE MONDAY NIGHT...BUT THE MAIN IMPACT IS LIKELY TO BE
NORTHEAST WINDS AND SEVERAL DEGREES OF COOLING BY TUESDAY.
TEMPERATURES SHOULD MODERATE BY WEDNESDAY AS THE TROUGH SHIFTS EAST.

FOR CHRISTMAS DAY AND FRIDAY...THE ECMWF MODEL STILL INDICATES THE
POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS. THE GFS
ENSEMBLES AND OPERATIONAL RUNS CONTINUE TO BACK OFF ON THE CHANCES
FOR PRECIPITATION...ALONG WITH SOME OTHER MODELS. KEPT LOW CHANCES
FOR PRECIP IN THE FORECAST...BUT CONFIDENCE IS LOW AT THIS TIME...
CHECK BACK FOR UPDATES.

&&

.AVIATION...FOR THE 12Z PACKAGE...AREAS OF STRATUS AND FOG ARE
FORECAST ACROSS PORTIONS OF NORTHEASTERN ARIZONA WITH IFR AND MVFR
CONDITIONS EXPECTED. VFR CONDITIONS ARE FORECAST ELSEWHERE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....JJ
AVIATION...BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 201113
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
410 AM MST SAT DEC 20 2014

.SYNOPSIS...
AREAS OF LOW CLOUDS AND PATCHY FOG WILL PERSIST OVER PORTIONS OF
NORTHEAST ARIZONA THIS MORNING. OTHERWISE...DRY NORTHWEST FLOW ALOFT
WILL DELIVER FAIR WEATHER...A FEW CLOUDS AND GRADUALLY WARMING
TEMPERATURES EACH DAY THROUGH MONDAY. A DRY COLD FRONT WILL BRING
COLDER TEMPERATURES AND NORTHEASTERLY BREEZES FOR TUESDAY.
&&

.DISCUSSION...NORTHWESTERLY FLOW ALOFT WILL CONTINUE THIS
WEEKEND...WITH DRY CONDITIONS AND GRADUALLY WARMING TEMPERATURES.
SOME AREAS OF LOW CLOUDS AND PATCHY FOG WILL AFFECT NORTHEAST AZ
VALLEY AREAS THIS MORNING...BUT SHOULD DECREASE BY THIS AFTERNOON.
OTHERWISE...LOOK FOR PERIODS OF HIGH CLOUDS IN THE NORTHWEST FLOW.

LATE MONDAY INTO TUESDAY...A TROUGH DIVING THROUGH THE CENTRAL
ROCKIES TO THE PLAINS STATES WILL PUSH A COLD FRONT INTO ARIZONA.
HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS TO THE NORTHEAST CORNER
OF THE STATE MONDAY NIGHT...BUT THE MAIN IMPACT IS LIKELY TO BE
NORTHEAST WINDS AND SEVERAL DEGREES OF COOLING BY TUESDAY.
TEMPERATURES SHOULD MODERATE BY WEDNESDAY AS THE TROUGH SHIFTS EAST.

FOR CHRISTMAS DAY AND FRIDAY...THE ECMWF MODEL STILL INDICATES THE
POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS. THE GFS
ENSEMBLES AND OPERATIONAL RUNS CONTINUE TO BACK OFF ON THE CHANCES
FOR PRECIPITATION...ALONG WITH SOME OTHER MODELS. KEPT LOW CHANCES
FOR PRECIP IN THE FORECAST...BUT CONFIDENCE IS LOW AT THIS TIME...
CHECK BACK FOR UPDATES.

&&

.AVIATION...FOR THE 12Z PACKAGE...AREAS OF STRATUS AND FOG ARE
FORECAST ACROSS PORTIONS OF NORTHEASTERN ARIZONA WITH IFR AND MVFR
CONDITIONS EXPECTED. VFR CONDITIONS ARE FORECAST ELSEWHERE. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.....JJ
AVIATION...BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KTWC 200923 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...TWO AREAS OF CONCERN FOR THIS FORECAST PERIOD...ONE
VERY SHORT TERM AND THE OTHER LONG TERM.  THE SHORT TERM CONCERN
RELATES TO THE POTENTIAL FOR FOG DEVELOPMENT EARLY THIS MORNING.  AT
THIS TIME A LARGE PORTION OF THE FORECAST AREA EAST OF TUCSON HAS
TEMP/DEWPOINTS WITHIN 3 DEGREES WITH A FEW LOCATIONS NEAR THE NEW
MEXICO BORDER WITH A ZERO SPREAD.  THUS FAR NO FOG IS INDICATED IN
ANY OBS OR SATELLITE PIX AND NOW HAVE A BAND OF RELATIVELY THICK
CIRRUS CLOUDS MOVING ACROSS THE AREA WHICH SHOULD HINDER FOG
DEVELOPMENT.  SO HAVE TWEAKED THE WORDING FROM AREAS OF FOG/FREEZING
FOG TO PATCHY.  WHATEVER FORMS WILL BURN OFF QUICKER THAN
YESTERDAY.  OTHERWISE IT WILL BE A COUPLE OF DEGREES WARMER THIS
AFTERNOON WITH CONTINUED LIGHT WINDS AND A FEW HIGH CLOUDS PASSING
BY AT TIMES.

THEN SUNDAY THROUGH WEDNESDAY THE AREA WILL HAVE A DRY NORTHWEST
FLOW OVERHEAD WITH TEMPERATURES WARMING TO A FEW DEGREES WARMER THAN
NORMAL OVERALL.  THE ONLY ITEM OF INTEREST THROUGH THIS PERIOD IS A
PASSING SHORTWAVE MONDAY NIGHT WHICH WILL TRIM TEMPERATURES BACK A
FEW DEGREES TUESDAY AFTERNOON AND NIGHT.  AT THIS POINT STILL
CARRYING A DRY FORECAST ALTHOUGH THERE COULD BE A FEW
FLURRIES/SPRINKLES ACROSS THE WHITE MOUNTAINS MONDAY NIGHT AS THE
AXIS OF THIS SYSTEM PASSES.

NOW FOR THE SECOND PERIOD OF CONCERN...CHRISTMAS DAY AND FRIDAY.  A
TROUGH IS EXPECTED TO IMPACT THE WEST COAST WEDNESDAY THEN MOVE
SOUTHEAST ACROSS THE REGION THURSDAY INTO FRIDAY.  THE BIG QUESTION
HAS BEEN THE DEPTH OF THE SYSTEM AS IT PASSES.  THIS EVENINGS 00Z
GFS OPERATIONAL RUN IS VERY FLAT WITH THIS FEATURE WITH BASICALLY NO
IMPACT ON THE AREA.  HOWEVER...LOOKING AT A PLOT OF THE 00Z GFS
ENSEMBLE MEMBERS SHOWS THIS SOLUTION TO BE ONE OF THE 5 WARM RUNS
WHILE THE OTHER 15 RUNS MORE CLOSELY RESEMBLE THE 00Z HIGH RES GFS
AND THE 00Z ECMWF WHICH IS SIMILAR TO THE PREVIOUS COUPLE OF ECMWF
RUNS...BEING A DEEPER AND SHARPER TROUGH.

THEREFORE HAVE TOSSED THE 00Z GFS AND LEANED ON THE HIGH RES GFS
WHICH IS SIMILAR TO BUT A BIT WEAKER THAN THE ECMWF.  WHAT THAT
MEANS IS A CHANCE OF A FEW SNOW/RAIN SHOWERS ACROSS THE WHITE
MOUNTAINS AND THE NE SKY ISLANDS CHRISTMAS DAY INTO FRIDAY WITH A
GOOD NORTHWEST BREEZE BOTH DAYS WITH TEMPERATURES COOLING BACK
DOWN TO OR BELOW NORMAL CHRISTMAS DAY INTO SATURDAY.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER THROUGH AROUND 20/17Z. SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU
THIS AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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







000
FXUS65 KTWC 200923 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...TWO AREAS OF CONCERN FOR THIS FORECAST PERIOD...ONE
VERY SHORT TERM AND THE OTHER LONG TERM.  THE SHORT TERM CONCERN
RELATES TO THE POTENTIAL FOR FOG DEVELOPMENT EARLY THIS MORNING.  AT
THIS TIME A LARGE PORTION OF THE FORECAST AREA EAST OF TUCSON HAS
TEMP/DEWPOINTS WITHIN 3 DEGREES WITH A FEW LOCATIONS NEAR THE NEW
MEXICO BORDER WITH A ZERO SPREAD.  THUS FAR NO FOG IS INDICATED IN
ANY OBS OR SATELLITE PIX AND NOW HAVE A BAND OF RELATIVELY THICK
CIRRUS CLOUDS MOVING ACROSS THE AREA WHICH SHOULD HINDER FOG
DEVELOPMENT.  SO HAVE TWEAKED THE WORDING FROM AREAS OF FOG/FREEZING
FOG TO PATCHY.  WHATEVER FORMS WILL BURN OFF QUICKER THAN
YESTERDAY.  OTHERWISE IT WILL BE A COUPLE OF DEGREES WARMER THIS
AFTERNOON WITH CONTINUED LIGHT WINDS AND A FEW HIGH CLOUDS PASSING
BY AT TIMES.

THEN SUNDAY THROUGH WEDNESDAY THE AREA WILL HAVE A DRY NORTHWEST
FLOW OVERHEAD WITH TEMPERATURES WARMING TO A FEW DEGREES WARMER THAN
NORMAL OVERALL.  THE ONLY ITEM OF INTEREST THROUGH THIS PERIOD IS A
PASSING SHORTWAVE MONDAY NIGHT WHICH WILL TRIM TEMPERATURES BACK A
FEW DEGREES TUESDAY AFTERNOON AND NIGHT.  AT THIS POINT STILL
CARRYING A DRY FORECAST ALTHOUGH THERE COULD BE A FEW
FLURRIES/SPRINKLES ACROSS THE WHITE MOUNTAINS MONDAY NIGHT AS THE
AXIS OF THIS SYSTEM PASSES.

NOW FOR THE SECOND PERIOD OF CONCERN...CHRISTMAS DAY AND FRIDAY.  A
TROUGH IS EXPECTED TO IMPACT THE WEST COAST WEDNESDAY THEN MOVE
SOUTHEAST ACROSS THE REGION THURSDAY INTO FRIDAY.  THE BIG QUESTION
HAS BEEN THE DEPTH OF THE SYSTEM AS IT PASSES.  THIS EVENINGS 00Z
GFS OPERATIONAL RUN IS VERY FLAT WITH THIS FEATURE WITH BASICALLY NO
IMPACT ON THE AREA.  HOWEVER...LOOKING AT A PLOT OF THE 00Z GFS
ENSEMBLE MEMBERS SHOWS THIS SOLUTION TO BE ONE OF THE 5 WARM RUNS
WHILE THE OTHER 15 RUNS MORE CLOSELY RESEMBLE THE 00Z HIGH RES GFS
AND THE 00Z ECMWF WHICH IS SIMILAR TO THE PREVIOUS COUPLE OF ECMWF
RUNS...BEING A DEEPER AND SHARPER TROUGH.

THEREFORE HAVE TOSSED THE 00Z GFS AND LEANED ON THE HIGH RES GFS
WHICH IS SIMILAR TO BUT A BIT WEAKER THAN THE ECMWF.  WHAT THAT
MEANS IS A CHANCE OF A FEW SNOW/RAIN SHOWERS ACROSS THE WHITE
MOUNTAINS AND THE NE SKY ISLANDS CHRISTMAS DAY INTO FRIDAY WITH A
GOOD NORTHWEST BREEZE BOTH DAYS WITH TEMPERATURES COOLING BACK
DOWN TO OR BELOW NORMAL CHRISTMAS DAY INTO SATURDAY.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER THROUGH AROUND 20/17Z. SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU
THIS AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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







000
FXUS65 KTWC 200923 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...TWO AREAS OF CONCERN FOR THIS FORECAST PERIOD...ONE
VERY SHORT TERM AND THE OTHER LONG TERM.  THE SHORT TERM CONCERN
RELATES TO THE POTENTIAL FOR FOG DEVELOPMENT EARLY THIS MORNING.  AT
THIS TIME A LARGE PORTION OF THE FORECAST AREA EAST OF TUCSON HAS
TEMP/DEWPOINTS WITHIN 3 DEGREES WITH A FEW LOCATIONS NEAR THE NEW
MEXICO BORDER WITH A ZERO SPREAD.  THUS FAR NO FOG IS INDICATED IN
ANY OBS OR SATELLITE PIX AND NOW HAVE A BAND OF RELATIVELY THICK
CIRRUS CLOUDS MOVING ACROSS THE AREA WHICH SHOULD HINDER FOG
DEVELOPMENT.  SO HAVE TWEAKED THE WORDING FROM AREAS OF FOG/FREEZING
FOG TO PATCHY.  WHATEVER FORMS WILL BURN OFF QUICKER THAN
YESTERDAY.  OTHERWISE IT WILL BE A COUPLE OF DEGREES WARMER THIS
AFTERNOON WITH CONTINUED LIGHT WINDS AND A FEW HIGH CLOUDS PASSING
BY AT TIMES.

THEN SUNDAY THROUGH WEDNESDAY THE AREA WILL HAVE A DRY NORTHWEST
FLOW OVERHEAD WITH TEMPERATURES WARMING TO A FEW DEGREES WARMER THAN
NORMAL OVERALL.  THE ONLY ITEM OF INTEREST THROUGH THIS PERIOD IS A
PASSING SHORTWAVE MONDAY NIGHT WHICH WILL TRIM TEMPERATURES BACK A
FEW DEGREES TUESDAY AFTERNOON AND NIGHT.  AT THIS POINT STILL
CARRYING A DRY FORECAST ALTHOUGH THERE COULD BE A FEW
FLURRIES/SPRINKLES ACROSS THE WHITE MOUNTAINS MONDAY NIGHT AS THE
AXIS OF THIS SYSTEM PASSES.

NOW FOR THE SECOND PERIOD OF CONCERN...CHRISTMAS DAY AND FRIDAY.  A
TROUGH IS EXPECTED TO IMPACT THE WEST COAST WEDNESDAY THEN MOVE
SOUTHEAST ACROSS THE REGION THURSDAY INTO FRIDAY.  THE BIG QUESTION
HAS BEEN THE DEPTH OF THE SYSTEM AS IT PASSES.  THIS EVENINGS 00Z
GFS OPERATIONAL RUN IS VERY FLAT WITH THIS FEATURE WITH BASICALLY NO
IMPACT ON THE AREA.  HOWEVER...LOOKING AT A PLOT OF THE 00Z GFS
ENSEMBLE MEMBERS SHOWS THIS SOLUTION TO BE ONE OF THE 5 WARM RUNS
WHILE THE OTHER 15 RUNS MORE CLOSELY RESEMBLE THE 00Z HIGH RES GFS
AND THE 00Z ECMWF WHICH IS SIMILAR TO THE PREVIOUS COUPLE OF ECMWF
RUNS...BEING A DEEPER AND SHARPER TROUGH.

THEREFORE HAVE TOSSED THE 00Z GFS AND LEANED ON THE HIGH RES GFS
WHICH IS SIMILAR TO BUT A BIT WEAKER THAN THE ECMWF.  WHAT THAT
MEANS IS A CHANCE OF A FEW SNOW/RAIN SHOWERS ACROSS THE WHITE
MOUNTAINS AND THE NE SKY ISLANDS CHRISTMAS DAY INTO FRIDAY WITH A
GOOD NORTHWEST BREEZE BOTH DAYS WITH TEMPERATURES COOLING BACK
DOWN TO OR BELOW NORMAL CHRISTMAS DAY INTO SATURDAY.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER THROUGH AROUND 20/17Z. SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU
THIS AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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







000
FXUS65 KTWC 200923 RRA
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...TWO AREAS OF CONCERN FOR THIS FORECAST PERIOD...ONE
VERY SHORT TERM AND THE OTHER LONG TERM.  THE SHORT TERM CONCERN
RELATES TO THE POTENTIAL FOR FOG DEVELOPMENT EARLY THIS MORNING.  AT
THIS TIME A LARGE PORTION OF THE FORECAST AREA EAST OF TUCSON HAS
TEMP/DEWPOINTS WITHIN 3 DEGREES WITH A FEW LOCATIONS NEAR THE NEW
MEXICO BORDER WITH A ZERO SPREAD.  THUS FAR NO FOG IS INDICATED IN
ANY OBS OR SATELLITE PIX AND NOW HAVE A BAND OF RELATIVELY THICK
CIRRUS CLOUDS MOVING ACROSS THE AREA WHICH SHOULD HINDER FOG
DEVELOPMENT.  SO HAVE TWEAKED THE WORDING FROM AREAS OF FOG/FREEZING
FOG TO PATCHY.  WHATEVER FORMS WILL BURN OFF QUICKER THAN
YESTERDAY.  OTHERWISE IT WILL BE A COUPLE OF DEGREES WARMER THIS
AFTERNOON WITH CONTINUED LIGHT WINDS AND A FEW HIGH CLOUDS PASSING
BY AT TIMES.

THEN SUNDAY THROUGH WEDNESDAY THE AREA WILL HAVE A DRY NORTHWEST
FLOW OVERHEAD WITH TEMPERATURES WARMING TO A FEW DEGREES WARMER THAN
NORMAL OVERALL.  THE ONLY ITEM OF INTEREST THROUGH THIS PERIOD IS A
PASSING SHORTWAVE MONDAY NIGHT WHICH WILL TRIM TEMPERATURES BACK A
FEW DEGREES TUESDAY AFTERNOON AND NIGHT.  AT THIS POINT STILL
CARRYING A DRY FORECAST ALTHOUGH THERE COULD BE A FEW
FLURRIES/SPRINKLES ACROSS THE WHITE MOUNTAINS MONDAY NIGHT AS THE
AXIS OF THIS SYSTEM PASSES.

NOW FOR THE SECOND PERIOD OF CONCERN...CHRISTMAS DAY AND FRIDAY.  A
TROUGH IS EXPECTED TO IMPACT THE WEST COAST WEDNESDAY THEN MOVE
SOUTHEAST ACROSS THE REGION THURSDAY INTO FRIDAY.  THE BIG QUESTION
HAS BEEN THE DEPTH OF THE SYSTEM AS IT PASSES.  THIS EVENINGS 00Z
GFS OPERATIONAL RUN IS VERY FLAT WITH THIS FEATURE WITH BASICALLY NO
IMPACT ON THE AREA.  HOWEVER...LOOKING AT A PLOT OF THE 00Z GFS
ENSEMBLE MEMBERS SHOWS THIS SOLUTION TO BE ONE OF THE 5 WARM RUNS
WHILE THE OTHER 15 RUNS MORE CLOSELY RESEMBLE THE 00Z HIGH RES GFS
AND THE 00Z ECMWF WHICH IS SIMILAR TO THE PREVIOUS COUPLE OF ECMWF
RUNS...BEING A DEEPER AND SHARPER TROUGH.

THEREFORE HAVE TOSSED THE 00Z GFS AND LEANED ON THE HIGH RES GFS
WHICH IS SIMILAR TO BUT A BIT WEAKER THAN THE ECMWF.  WHAT THAT
MEANS IS A CHANCE OF A FEW SNOW/RAIN SHOWERS ACROSS THE WHITE
MOUNTAINS AND THE NE SKY ISLANDS CHRISTMAS DAY INTO FRIDAY WITH A
GOOD NORTHWEST BREEZE BOTH DAYS WITH TEMPERATURES COOLING BACK
DOWN TO OR BELOW NORMAL CHRISTMAS DAY INTO SATURDAY.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER THROUGH AROUND 20/17Z. SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU
THIS AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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







000
FXUS65 KTWC 200923
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
220 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...TWO AREAS OF CONCERN FOR THIS FORECAST PERIOD...ONE
VERY SHORT TERM AND THE OTHER LONG TERM.  THE SHORT TERM CONCERN
RELATES TO THE POTENTIAL FOR FOG DEVELOPMENT EARLY THIS MORNING.  AT
THIS TIME A LARGE PORTION OF THE FORECAST AREA EAST OF TUCSON HAS
TEMP/DEWPOINTS WITHIN 3 DEGREES WITH A FEW LOCATIONS NEAR THE NEW
MEXICO BORDER WITH A ZERO SPREAD.  THUS FAR NO FOG IS INDICATED IN
ANY OBS OR SATELLITE PIX AND NOW HAVE A BAND OF RELATIVELY THICK
CIRRUS CLOUDS MOVING ACROSS THE AREA WHICH SHOULD HINDER FOG
DEVELOPMENT.  SO HAVE TWEAKED THE WORDING FROM AREAS OF FOG/FREEZING
FOG TO PATCHY.  WHATEVER FORMS WILL BURN OFF QUICKER THAN
YESTERDAY.  OTHERWISE IT WILL BE A COUPLE OF DEGREES WARMER THIS
AFTERNOON WITH CONTINUED LIGHT WINDS AND A FEW HIGH CLOUDS PASSING
BY AT TIMES.

THEN SUNDAY THROUGH WEDNESDAY THE AREA WILL HAVE A DRY NORTHWEST
FLOW OVERHEAD WITH TEMPERATURES WARMING TO A FEW DEGREES WARMER THAN
NORMAL OVERALL.  THE ONLY ITEM OF INTEREST THROUGH THIS PERIOD IS A
PASSING SHORTWAVE MONDAY NIGHT WHICH WILL TRIM TEMPERATURES BACK A
FEW DEGREES TUESDAY AFTERNOON AND NIGHT.  AT THIS POINT STILL
CARRYING A DRY FORECAST ALTHOUGH THERE COULD BE A FEW
FLURRIES/SPRINKLES ACROSS THE WHITE MOUNTAINS MONDAY NIGHT AS THE
AXIS OF THIS SYSTEM PASSES.

NOW FOR THE SECOND PERIOD OF CONCERN...CHRISTMAS DAY AND FRIDAY.  A
TROUGH IS EXPECTED TO IMPACT THE WEST COAST WEDNESDAY THEN MOVE
SOUTHEAST ACROSS THE REGION THURSDAY INTO FRIDAY.  THE BIG QUESTION
HAS BEEN THE DEPTH OF THE SYSTEM AS IT PASSES.  THIS EVENINGS 00Z
GFS OPERATIONAL RUN IS VERY FLAT WITH THIS FEATURE WITH BASICALLY NO
IMPACT ON THE AREA.  HOWEVER...LOOKING AT A PLOT OF THE 00Z GFS
ENSEMBLE MEMBERS SHOWS THIS SOLUTION TO BE ONE OF THE 5 WARM RUNS
WHILE THE OTHER 15 RUNS MORE CLOSELY RESEMBLE THE 00Z HIGH RES GFS
AND THE 00Z ECMWF WHICH IS SIMILAR TO THE PREVIOUS COUPLE OF ECMWF
RUNS...BEING A DEEPER AND SHARPER TROUGH.

THEREFORE HAVE TOSSED THE 00Z GFS AND LEANED ON THE HIGH RES GFS
WHICH IS SIMILAR TO BUT A BIT WEAKER THAN THE ECMWF.  WHAT THAT
MEANS IS A CHANCE OF A FEW SNOW/RAIN SHOWERS ACROSS THE WHITE
MOUNTAINS AND THE NE SKY ISLANDS CHRISTMAS DAY INTO FRIDAY WITH A
GOOD NORTHWEST BREEZE BOTH DAYS WITH TEMPERATURES COOLING BACK
DOWN TO OR BELOW NORMAL CHRISTMAS DAY INTO SATURDAY.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER THROUGH AROUND 20/17Z. SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU
THIS AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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






000
FXUS65 KTWC 200923
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
220 AM MST SAT DEC 20 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES
THIS WEEKEND.  A FEW PATCHES OF FOG AND FREEZING FOG ARE EXPECTED
AGAIN EARLY THIS MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND
GRAHAM COUNTY.  FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE
TO ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE.
UNSETTLED AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...TWO AREAS OF CONCERN FOR THIS FORECAST PERIOD...ONE
VERY SHORT TERM AND THE OTHER LONG TERM.  THE SHORT TERM CONCERN
RELATES TO THE POTENTIAL FOR FOG DEVELOPMENT EARLY THIS MORNING.  AT
THIS TIME A LARGE PORTION OF THE FORECAST AREA EAST OF TUCSON HAS
TEMP/DEWPOINTS WITHIN 3 DEGREES WITH A FEW LOCATIONS NEAR THE NEW
MEXICO BORDER WITH A ZERO SPREAD.  THUS FAR NO FOG IS INDICATED IN
ANY OBS OR SATELLITE PIX AND NOW HAVE A BAND OF RELATIVELY THICK
CIRRUS CLOUDS MOVING ACROSS THE AREA WHICH SHOULD HINDER FOG
DEVELOPMENT.  SO HAVE TWEAKED THE WORDING FROM AREAS OF FOG/FREEZING
FOG TO PATCHY.  WHATEVER FORMS WILL BURN OFF QUICKER THAN
YESTERDAY.  OTHERWISE IT WILL BE A COUPLE OF DEGREES WARMER THIS
AFTERNOON WITH CONTINUED LIGHT WINDS AND A FEW HIGH CLOUDS PASSING
BY AT TIMES.

THEN SUNDAY THROUGH WEDNESDAY THE AREA WILL HAVE A DRY NORTHWEST
FLOW OVERHEAD WITH TEMPERATURES WARMING TO A FEW DEGREES WARMER THAN
NORMAL OVERALL.  THE ONLY ITEM OF INTEREST THROUGH THIS PERIOD IS A
PASSING SHORTWAVE MONDAY NIGHT WHICH WILL TRIM TEMPERATURES BACK A
FEW DEGREES TUESDAY AFTERNOON AND NIGHT.  AT THIS POINT STILL
CARRYING A DRY FORECAST ALTHOUGH THERE COULD BE A FEW
FLURRIES/SPRINKLES ACROSS THE WHITE MOUNTAINS MONDAY NIGHT AS THE
AXIS OF THIS SYSTEM PASSES.

NOW FOR THE SECOND PERIOD OF CONCERN...CHRISTMAS DAY AND FRIDAY.  A
TROUGH IS EXPECTED TO IMPACT THE WEST COAST WEDNESDAY THEN MOVE
SOUTHEAST ACROSS THE REGION THURSDAY INTO FRIDAY.  THE BIG QUESTION
HAS BEEN THE DEPTH OF THE SYSTEM AS IT PASSES.  THIS EVENINGS 00Z
GFS OPERATIONAL RUN IS VERY FLAT WITH THIS FEATURE WITH BASICALLY NO
IMPACT ON THE AREA.  HOWEVER...LOOKING AT A PLOT OF THE 00Z GFS
ENSEMBLE MEMBERS SHOWS THIS SOLUTION TO BE ONE OF THE 5 WARM RUNS
WHILE THE OTHER 15 RUNS MORE CLOSELY RESEMBLE THE 00Z HIGH RES GFS
AND THE 00Z ECMWF WHICH IS SIMILAR TO THE PREVIOUS COUPLE OF ECMWF
RUNS...BEING A DEEPER AND SHARPER TROUGH.

THEREFORE HAVE TOSSED THE 00Z GFS AND LEANED ON THE HIGH RES GFS
WHICH IS SIMILAR TO BUT A BIT WEAKER THAN THE ECMWF.  WHAT THAT
MEANS IS A CHANCE OF A FEW SNOW/RAIN SHOWERS ACROSS THE WHITE
MOUNTAINS AND THE NE SKY ISLANDS CHRISTMAS DAY INTO FRIDAY WITH A
GOOD NORTHWEST BREEZE BOTH DAYS WITH TEMPERATURES COOLING BACK
DOWN TO OR BELOW NORMAL CHRISTMAS DAY INTO SATURDAY.  CERNIGLIA

&&

.AVIATION...VALID THRU 21/12Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER THROUGH AROUND 20/17Z. SCT TO LCLY BKN MOSTLY HIGH CLOUDS THRU
THIS AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH
THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD...AS AN UPPER LEVEL DISTURBANCE MOVES NORTHWEST TO SOUTHEAST
ACROSS THE FOUR CORNERS REGION. AT THIS TIME CONFIDENCE IS LOW
CONCERNING THE TIMING AND IMPACTS OF THE NEXT SIGNIFICANT WEATHER
MAKER WHICH MAY AFFECT THE REGION LATE NEXT WEEK. A SLIGHT CHANCE
FOR VALLEY RAIN AND MOUNTAIN SNOW ARE POSSIBLE...ALONG WITH AN
INCREASE IN WINDS ON THURSDAY...MAINLY FOR AREAS SOUTH AND EAST OF
TUCSON TOWARD THE INTERNATIONAL BORDER AS WELL AS THE BORDER WITH
NEW MEXICO.

&&

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

&&

$$

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







000
FXUS65 KPSR 200855
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
154 AM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH MID WEEK. A
FAST MOVING STORM SYSTEM WILL MOVE THROUGH THE FOUR CORNERS LATER
THIS WEEK BUT SHOULD ONLY RESULT IN SLIGHTLY COOLER TEMPERATURES AND
INCREASED CLOUDINESS. DRY WEATHER IS EXPECTED NEXT WEEKEND WITH
BELOW NORMAL TEMPS.

&&

.DISCUSSION...
ONSHORE FLOW ACROSS NORTHERN CALIFORNIA AND THE ASSOCIATED 300-400MB
JET STREAK HAS RESULTED IN QUITE A BIT OF HIGH CLOUD COVER ACROSS
THE REGION THIS MORNING. INITIAL BAND OF CLOUDS WAS POSITIONED OVER
CENTRAL ARIZONA AS OF 08Z WITH CLEARING ACROSS SOUTHEAST
CALIFORNIA...THEN ADDITIONAL HIGH CLOUDINESS OVER CENTRAL
CALIFORNIA. SO FAR THE HIGH CLOUD COVER HAS HAD A NEGLIGIBLE IMPACT
ON TEMPERATURES AS READINGS AS OF 08Z WERE ON PAR WITH READINGS THE
PAST SEVERAL MORNINGS. MOST DESERT LOCALES WERE IN THE LOW/MID 40S
WITH LIGHT WINDS. MUCH LIKE YESTERDAY...NO FOG HAS SHOWN UP AT ANY
OF THE ASOSS OR ON ANY WEBCAMS QUITE YET BUT WITH ELEVATED
DEWPOINTS AND STEADILY DECREASING DEWPOINT DEPRESSIONS...I WILL
LEAVE A MENTION OF FOG IN THE LOCATIONS THAT SAW IT EARLY FRIDAY
MORNING.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH NORTHERN
CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE SOUTHERN
CALIFORNIA COAST WITH ANOMALOUSLY HIGH H5 HEIGHTS FORECAST TO REMAIN
IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL RESULT IN VARYING
AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE
BEST PERFORMING BIAS CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM
65-70 EACH DAY /SLIGHTLY WARMER AROUND YUMA AND EL CENTRO/ WITH NEAR
NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. COULD STILL SEE SOME AREAS OF LIMITED GROUND FOG BY THE EARLY
MORNING...BUT CONFIDENCE NOT HIGH ENOUGH FOR DEVELOPMENT NEAR ANY OF
THE TERMINALS TO WARRANT INCLUSION IN EVENING TAF PACKAGES. SFC
WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW TYPICAL
DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE EARLY PART OF NEXT
WEEK WITH WARMING TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HIGHS WILL WARM TO ABOVE NORMAL STARTING SUNDAY WITH
LOWER DESERT HIGHS IN THE LOW TO MID 70S FOR THE MIDDLE OF NEXT
WEEK. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD WITH
MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT FOR THE
MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN






000
FXUS65 KPSR 200855
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
154 AM MST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE OFF THE WEST COAST WILL RESULT IN NEAR NORMAL
TEMPERATURES WITH VARYING AMOUNTS OF HIGH CLOUDS THROUGH MID WEEK. A
FAST MOVING STORM SYSTEM WILL MOVE THROUGH THE FOUR CORNERS LATER
THIS WEEK BUT SHOULD ONLY RESULT IN SLIGHTLY COOLER TEMPERATURES AND
INCREASED CLOUDINESS. DRY WEATHER IS EXPECTED NEXT WEEKEND WITH
BELOW NORMAL TEMPS.

&&

.DISCUSSION...
ONSHORE FLOW ACROSS NORTHERN CALIFORNIA AND THE ASSOCIATED 300-400MB
JET STREAK HAS RESULTED IN QUITE A BIT OF HIGH CLOUD COVER ACROSS
THE REGION THIS MORNING. INITIAL BAND OF CLOUDS WAS POSITIONED OVER
CENTRAL ARIZONA AS OF 08Z WITH CLEARING ACROSS SOUTHEAST
CALIFORNIA...THEN ADDITIONAL HIGH CLOUDINESS OVER CENTRAL
CALIFORNIA. SO FAR THE HIGH CLOUD COVER HAS HAD A NEGLIGIBLE IMPACT
ON TEMPERATURES AS READINGS AS OF 08Z WERE ON PAR WITH READINGS THE
PAST SEVERAL MORNINGS. MOST DESERT LOCALES WERE IN THE LOW/MID 40S
WITH LIGHT WINDS. MUCH LIKE YESTERDAY...NO FOG HAS SHOWN UP AT ANY
OF THE ASOSS OR ON ANY WEBCAMS QUITE YET BUT WITH ELEVATED
DEWPOINTS AND STEADILY DECREASING DEWPOINT DEPRESSIONS...I WILL
LEAVE A MENTION OF FOG IN THE LOCATIONS THAT SAW IT EARLY FRIDAY
MORNING.

NOT MANY CHANGES TO FORECAST THINKING FOR MUCH OF THE UPCOMING WEEK.
ONCE THE TROUGH AND ASSOCIATED ONSHORE FLOW MOVES THROUGH NORTHERN
CALIFORNIA TONIGHT...RIDGING WILL STRENGTHEN OFF THE SOUTHERN
CALIFORNIA COAST WITH ANOMALOUSLY HIGH H5 HEIGHTS FORECAST TO REMAIN
IN PLACE THROUGH AT LEAST WEDNESDAY. THIS WILL RESULT IN VARYING
AMOUNTS OF HIGH CLOUDS AND ABOVE NORMAL TEMPERATURES. A BLEND OF THE
BEST PERFORMING BIAS CORRECTED GUIDANCE SUGGESTS DAILY HIGHS FROM
65-70 EACH DAY /SLIGHTLY WARMER AROUND YUMA AND EL CENTRO/ WITH NEAR
NORMAL LOWS IN THE MID 40S.

ATTENTION TURNS TO CHRISTMAS DAY AS THERE ARE ONCE AGAIN SOME
DIFFERENCES BETWEEN THE ECMWF AND GFS MODELS. BOTH INDICATE
TROUGHING BUT THE ECMWF HAS ONCE AGAIN RETURNED TO ITS SOLUTION OF A
CLOSED CIRCULATION OVER ARIZONA WITH PRECIP DEVELOPING ACROSS THE
HIGHER TERRAIN NORTH/EAST OF PHOENIX. PARALLEL 13KM GFS IS A BIT
DEEPER WITH THE TROUGH WHEN COMPARED TO THE OPERATIONAL GFS BUT IS
LACKING MOISTURE AS IT MOVES THROUGH THE REGION. ENSEMBLES REMAIN
STEADY AND INDICATE THE OPERATIONAL GFS-TYPE SOLUTION WILL PREVAIL
BUT NOT WANTING TO DISCOUNT THE ECMWF /AND 13KM GFS/ ENTIRELY...I
INTRODUCED VERY LOW END DOUBLE DIGIT POPS NORTH/EAST OF PHOENIX ON
THURSDAY ALONG WITH SLIGHTLY COOLER TEMPERATURES. IMPACTS LOOK
MINIMAL BUT WILL NEED TO KEEP MONITORING SUBSEQUENT MODEL RUNS TO
SEE HOW THEY TREND.  REGARDLESS...A RETURN TO NORTHWESTERLY FLOW
LOOKS LIKELY LATE NEXT WEEK INTO THE WEEKEND.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. COULD STILL SEE SOME AREAS OF LIMITED GROUND FOG BY THE EARLY
MORNING...BUT CONFIDENCE NOT HIGH ENOUGH FOR DEVELOPMENT NEAR ANY OF
THE TERMINALS TO WARRANT INCLUSION IN EVENING TAF PACKAGES. SFC
WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW TYPICAL
DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE EARLY PART OF NEXT
WEEK WITH WARMING TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HIGHS WILL WARM TO ABOVE NORMAL STARTING SUNDAY WITH
LOWER DESERT HIGHS IN THE LOW TO MID 70S FOR THE MIDDLE OF NEXT
WEEK. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD WITH
MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT FOR THE
MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN





000
FXUS65 KTWC 200437
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
935 PM MST FRI DEC 19 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW TEMPERATURES THIS
WEEKEND. SOME AREAS OF FOG AND FREEZING FOG ARE EXPECTED AGAIN EARLY
SATURDAY MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND GRAHAM
COUNTY.   FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE TO
ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE. UNSETTLED
AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...MAIN FORECAST CONCERN TONIGHT IS DEVELOPMENT OF FOG
AGAIN MAINLY E OF TUCSON. COULD SEE AREAS OF DENSE FOG AGAIN BUT AT
THIS TIME DON`T BELIEVE THAT IT WILL BE WIDESPREAD ENOUGH FOR AN
ADVISORY BUT OBS WILL BE MONITORED CLOSELY OVERNIGHT INTO SATURDAY
MORNING. OTHERWISE SATELLITE IMAGERY SHOWED HIGH CLOUDS OVER WRN AZ
MOVING E. PARTLY CLOUDY FORECAST FOR TONIGHT RIGHT ON TRACK. CLOUDS
MAY TAKE AN EDGE OFF LOW TEMPERATURES BUT OVERALL IT WILL STILL BE
CHILLY TO COLD WITH AREAS OF FROST. CHECK PREVIOUS DISCUSSION BELOW
FOR ADDITIONAL FORECAST DETAILS FOR THE WEEKEND INTO NEXT WEEK.

&&

.AVIATION...VALID THRU 21/00Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER 20/09Z THROUGH 20/17Z. SCT TO LCLY BKN HIGH CLOUDS THRU
SATURDAY AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL
THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE TIMING AND
IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY AFFECT THE
REGION LATE NEXT WEEK. GUSTY WINDS AND ANOTHER CHANCE FOR VALLEY
RAIN AND MOUNTAIN SNOW ARE POSSIBLE.

&&

.PREVIOUS DISCUSSION...
IN THE LARGER SCALE...WEAK SHORTWAVE RIDGING ALOFT IS CENTERED JUST
WEST OF US AT THIS TIME WITH SOME THIN CIRROFORM CLOUDS ACROSS
WESTERN ARIZONA AND MORE EXTENSIVE MID AND HIGH LEVEL CLOUDS ACROSS
THE EASTERN PACIFIC PUSHING INTO SOUTHERN CALIFORNIA. CONSIDERING
AMPLE LOW LEVEL MOISTURE REMAINS TONIGHT WE THINK THERE WILL BE SOME
AREAS OF FOG AND FREEZING FOG AGAIN EARLY SATURDAY MORNING ACROSS
THE VALLEYS OF GRAHAM AND COCHISE COUNTY. THE UPPER GILA RIVER
VALLEY WILL AGAIN HAVE THE BEST CHANCE OF SEEING FOG AND FREEZING
FOG. SOME AREAS OF FROST WILL BE POSSIBLE AS WELL FOR SOME OF THE
OUTLYING AREAS OF THE TUCSON METRO. THERE WILL BE SOME THIN
CIRROFORM CLOUDS OVERNIGHT WHICH COULD HELP MITIGATE LOW
TEMPERATURES AND FOG SLIGHTLY BUT CONFIDENCE IS HIGH ENOUGH TO PUT
AREAS OF FOG IN THE FORECAST FOR THE VALLEYS EAST OF TUCSON.

A WEAK SHORTWAVE TROUGH WILL SKIRT ACROSS MAINLY EASTERN SECTIONS OF
THE FORECAST AREA ON SATURDAY WITH LITTLE SENSIBLE WEATHER IMPACT
OTHER THEN SOME MAINLY HIGH LEVEL CLOUDS. TEMPERATURES WILL WARM A
FEW DEGREES ON SATURDAY COMPARED TO TODAY.

THEREAFTER...DRY NORTHWESTERLY FLOW ALOFT IS EXPECTED FROM SUNDAY
THROUGH THE MIDDLE OF NEXT WEEK AS RIDGING ALOFT IS CENTERED ACROSS
THE EASTERN PACIFIC AND TROUGHINESS IS LOCATED OVER THE PLAINS.
TEMPERATURES WILL BE NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE
NORMAL MONDAY. THERE WILL BE A WEAK COLD FRONT MOVING THROUGH FROM
THE NORTH-NORTHEAST EARLY TUESDAY BUT THIS WILL HAVE LITTLE IMPACT
ON TEMPERATURES FROM TUCSON WESTWARD WITH PERHAPS SLIGHT COOLING FOR
EASTERN AREAS TUESDAY INTO WEDNESDAY.

BY LATE NEXT WEEK...THERE REMAINS CONSIDERABLE DIFFERENCES IN THE
GLOBAL MODEL GUIDANCE AS ANOTHER TROUGH MOVES INTO THE WESTERN US.
THE 12Z GFS KEEPS MAINLY ZONAL WESTERLY FLOW THIS FAR SOUTH WITH THE
12Z CANADIAN AND ECMWF MORE AMPLIFIED WITH THE TROUGH LATE NEXT
WEEK. WILL TAKE A MIDDLE OF THE ROAD APPROACH CLOSE TO 12Z GEFS AND
ECMWF ENSEMBLE MEANS. THUS...HAVE ONLY MADE MINOR TWEAKS TO THE
ONGOING FORECAST WITH SLIGHT CHANCE POPS NORTHEAST OF TUCSON AND
ESPECIALLY IN THE WHITE MOUNTAINS THURSDAY AND FRIDAY. TEMPERATURES
WILL DROP BACK DOWN TO NEAR NORMAL VALUES LATE NEXT WEEK.


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

&&

$$

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







000
FXUS65 KTWC 200437
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
935 PM MST FRI DEC 19 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW TEMPERATURES THIS
WEEKEND. SOME AREAS OF FOG AND FREEZING FOG ARE EXPECTED AGAIN EARLY
SATURDAY MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND GRAHAM
COUNTY.   FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE TO
ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE. UNSETTLED
AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...MAIN FORECAST CONCERN TONIGHT IS DEVELOPMENT OF FOG
AGAIN MAINLY E OF TUCSON. COULD SEE AREAS OF DENSE FOG AGAIN BUT AT
THIS TIME DON`T BELIEVE THAT IT WILL BE WIDESPREAD ENOUGH FOR AN
ADVISORY BUT OBS WILL BE MONITORED CLOSELY OVERNIGHT INTO SATURDAY
MORNING. OTHERWISE SATELLITE IMAGERY SHOWED HIGH CLOUDS OVER WRN AZ
MOVING E. PARTLY CLOUDY FORECAST FOR TONIGHT RIGHT ON TRACK. CLOUDS
MAY TAKE AN EDGE OFF LOW TEMPERATURES BUT OVERALL IT WILL STILL BE
CHILLY TO COLD WITH AREAS OF FROST. CHECK PREVIOUS DISCUSSION BELOW
FOR ADDITIONAL FORECAST DETAILS FOR THE WEEKEND INTO NEXT WEEK.

&&

.AVIATION...VALID THRU 21/00Z.
EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR FREEZING FOG
AFTER 20/09Z THROUGH 20/17Z. SCT TO LCLY BKN HIGH CLOUDS THRU
SATURDAY AFTERNOON. SURFACE WIND LESS THAN 10 KTS WILL PREVAIL
THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE TIMING AND
IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY AFFECT THE
REGION LATE NEXT WEEK. GUSTY WINDS AND ANOTHER CHANCE FOR VALLEY
RAIN AND MOUNTAIN SNOW ARE POSSIBLE.

&&

.PREVIOUS DISCUSSION...
IN THE LARGER SCALE...WEAK SHORTWAVE RIDGING ALOFT IS CENTERED JUST
WEST OF US AT THIS TIME WITH SOME THIN CIRROFORM CLOUDS ACROSS
WESTERN ARIZONA AND MORE EXTENSIVE MID AND HIGH LEVEL CLOUDS ACROSS
THE EASTERN PACIFIC PUSHING INTO SOUTHERN CALIFORNIA. CONSIDERING
AMPLE LOW LEVEL MOISTURE REMAINS TONIGHT WE THINK THERE WILL BE SOME
AREAS OF FOG AND FREEZING FOG AGAIN EARLY SATURDAY MORNING ACROSS
THE VALLEYS OF GRAHAM AND COCHISE COUNTY. THE UPPER GILA RIVER
VALLEY WILL AGAIN HAVE THE BEST CHANCE OF SEEING FOG AND FREEZING
FOG. SOME AREAS OF FROST WILL BE POSSIBLE AS WELL FOR SOME OF THE
OUTLYING AREAS OF THE TUCSON METRO. THERE WILL BE SOME THIN
CIRROFORM CLOUDS OVERNIGHT WHICH COULD HELP MITIGATE LOW
TEMPERATURES AND FOG SLIGHTLY BUT CONFIDENCE IS HIGH ENOUGH TO PUT
AREAS OF FOG IN THE FORECAST FOR THE VALLEYS EAST OF TUCSON.

A WEAK SHORTWAVE TROUGH WILL SKIRT ACROSS MAINLY EASTERN SECTIONS OF
THE FORECAST AREA ON SATURDAY WITH LITTLE SENSIBLE WEATHER IMPACT
OTHER THEN SOME MAINLY HIGH LEVEL CLOUDS. TEMPERATURES WILL WARM A
FEW DEGREES ON SATURDAY COMPARED TO TODAY.

THEREAFTER...DRY NORTHWESTERLY FLOW ALOFT IS EXPECTED FROM SUNDAY
THROUGH THE MIDDLE OF NEXT WEEK AS RIDGING ALOFT IS CENTERED ACROSS
THE EASTERN PACIFIC AND TROUGHINESS IS LOCATED OVER THE PLAINS.
TEMPERATURES WILL BE NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE
NORMAL MONDAY. THERE WILL BE A WEAK COLD FRONT MOVING THROUGH FROM
THE NORTH-NORTHEAST EARLY TUESDAY BUT THIS WILL HAVE LITTLE IMPACT
ON TEMPERATURES FROM TUCSON WESTWARD WITH PERHAPS SLIGHT COOLING FOR
EASTERN AREAS TUESDAY INTO WEDNESDAY.

BY LATE NEXT WEEK...THERE REMAINS CONSIDERABLE DIFFERENCES IN THE
GLOBAL MODEL GUIDANCE AS ANOTHER TROUGH MOVES INTO THE WESTERN US.
THE 12Z GFS KEEPS MAINLY ZONAL WESTERLY FLOW THIS FAR SOUTH WITH THE
12Z CANADIAN AND ECMWF MORE AMPLIFIED WITH THE TROUGH LATE NEXT
WEEK. WILL TAKE A MIDDLE OF THE ROAD APPROACH CLOSE TO 12Z GEFS AND
ECMWF ENSEMBLE MEANS. THUS...HAVE ONLY MADE MINOR TWEAKS TO THE
ONGOING FORECAST WITH SLIGHT CHANCE POPS NORTHEAST OF TUCSON AND
ESPECIALLY IN THE WHITE MOUNTAINS THURSDAY AND FRIDAY. TEMPERATURES
WILL DROP BACK DOWN TO NEAR NORMAL VALUES LATE NEXT WEEK.


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

&&

$$

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






000
FXUS65 KPSR 200349
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
848 PM MST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDING IN FROM THE WEST AND A DRY NORTHWESTERLY FLOW
IS EXPECTED TO KEEP SKIES MAINLY CLEAR...WITH JUST SOME HIGH
CLOUDINESS PASSING OVERHEAD FROM TIME TO TIME...AND ALLOW A SLOW
WARMING TREND TO PROGRESS THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
COOLER TEMPERATURES ARE THEN POSSIBLE BY THE END OF NEXT WEEK AS A
RATHER STRONG AND COLD WEATHER SYSTEM BEGINS TO MOVE INLAND FROM THE
GULF OF ALASKA INTO THE WESTERN STATES.

&&

.DISCUSSION...
FAIRLY QUIET WX DAY ACROSS THE REGION WITH PASSING HIGH LEVEL CLOUD
BANDS AND OBSERVED TEMPERATURES JUST A DEGREE ABOVE /OR BELOW/
SEASONAL NORMALS FOR THE PHX AREA. BROAD NORTHWESTERLY FLOW
CONTINUES TO STREAM INTO THE WEST COAST OFF THE PACIFIC...WITH
SEVERAL N-S ORIENTATED BANDS OF CLOUDS NOTED ON EVENING IR/WV
IMAGERY. LATEST BAND INTO OUR FORECAST AREA CURRENTLY AT THE CO
RIVER VALLEY AND WILL CONTINUE TO TRACK ACROSS ARIZONA THROUGH THE
OVERNIGHT HOURS. IF THIS BAND WERE MORE WIDESPREAD OR SLOWER IN IT`S
MOVEMENT...IT COULD PLAY A ROLE ON IN ADDING A FEW DEGREES OF WARMTH
TO OVERNIGHT TEMPS. WHILE OVERNIGHT LOWS SEEM ON THE COOL SIDE
/COMPARED TO MORE MILD READINGS FROM EARLIER IN THE MONTH/ THEY ARE
ON TRACK FOR NEAR NORMAL READINGS...LOW TO MID 40S FOR THE LOWER
DESERTS AND LOW TO MID 30S ACROSS THE FOOTHILL AND HIGHER TERRAIN
LOCATIONS.

ONLY MINOR UPDATES NEEDED IN THE FORM OF ALIGNING SKY FORECASTS WITH
CURRENT TRENDS AND THE ADDITION OF PATCHY FOG MAINLY ACROSS PORTIONS
OF PINAL AND YUMA COUNTIES IN AZ AND IMPERIAL COUNTY IN CA.
DEWPOINTS GENERALLY REMAIN UNCHANGED FROM READINGS OVER THE LAST
COUPLE OF NIGHTS AND SINCE FOG HAS MADE REPEAT PERFORMANCES OVER THE
LAST COUPLE OF MORNINGS...FELT ADDING MENTION WOULD NOT HURT. REST
OF THE DRY WEEKEND AND EARLY NEXT WEEK FORECAST REMAINS ON
TRACK...WHICH IS OUTLINED IN THE PREVIOUS DISCUSSION BELOW.

&&

.PREVIOUS DISCUSSION /ISSUED AT 130 PM MST/1230 PM PST/...
TONIGHT THROUGH WEDNESDAY...
DRY CONDITIONS AND MOSTLY CLEAR SKIES HAVE RETURNED TO OUR CWA TODAY
AS THE LONG-WAVE UPPER TROF THAT BROUGHT US SEVERAL DAYS OF
UNSETTLED WEATHER HAS NOW MOVED OFF WELL TO THE EAST...INTO THE
SOUTHERN PLAINS. HIGH PRESSURE RIDGING THAT IS NOW JUST BEGINNING TO
BECOME ESTABLISHED OVER THE EASTERN PACIFIC HAS NOW PUSHED
LIGHT...AND DRY NORTHWESTERLY FLOW BACK OVER THE REGION.
NORTHWESTERLY FLOW IS EXPECTED TO REMAIN IN PLACE OVER THE DESERT
SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK...WITH 500MB HEIGHTS
RISING FROM THEIR PRESENT LEVEL NEAR 570DM UP INTO THE 576-582DM BY
MONDAY...THEN HOLD AT THESE LEVELS THROUGH AT LEAST WEDNESDAY. THIS
AIRMASS WARMING IS EXPECTED TO ALLOW LOWER DESERT HIGHS TO WARM FROM
TODAY/S LOW TO MID 60S UP INTO THE 70-75F RANGE BY MONDAY...THEN
HOLD AT THOSE LEVELS THROUGH AT LEAST WEDNESDAY. THE DRY
NORTHWESTERLY FLOW ALOFT IS ALSO EXPECTED TO KEEP SKIES MAINLY
CLEAR...EXCEPT FOR SOME PERIODS OF HIGH CLOUDINESS TONIGHT AND
SATURDAY AS A WEAK TROF EMBEDDED IN THIS NORTHWESTERLY FLOW PUSHES A
BIT OF HIGH-LEVEL PACIFIC MOISTURE INLAND OVER THE REGION. A 2ND
SHORTWAVE IS THEN EXPECTED TO PASS WELL TO OUR NORTH AND EAST ON
MONDAY AND MONDAY NIGHT...BUT THE ONLY IMPACT TO OUR CWA FROM THIS
SYSTEM WILL BE TO INCREASE WINDS A BIT ON MONDAY AFTERNOON...AND TO
PUSH EVEN DRIER AIR NEAR THE SFC INTO OUR CWA.

.THURSDAY THROUGH SATURDAY...
ALTHOUGH A CHANGE TOWARD COOLER WEATHER STILL LOOKS LIKELY DURING
THIS PERIOD...CONSIDERABLE MODEL DISAGREEMENT HAS NOW CROPPED BACK
UP ON THE MAGNITUDE OF THIS EXPECTED COOLDOWN...WITH THE EURO AND
GEM GOING BACK TO THE IDEA OF A MUCH DEEPER...AND COLDER TROF MOVING
INTO OUR REGION...WHILE THE OPERATIONAL GFS...AND THE PARALLEL 13KM
GFS KEEPS THE TROF MUCH FURTHER TO OUR NORTH...WITH JUST SOME SLIGHT
COOLING OVER OUR CWA. AT THIS POINT...GIVEN ALL OF THIS MODEL
DISAGREEMENT...WITH LEAVE THE EXTENDED FORECAST ALONE PENDING FUTURE
MODEL RUNS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. COULD STILL SEE SOME AREAS OF LIMITED GROUND FOG BY THE EARLY
MORNING...BUT CONFIDENCE NOT HIGH ENOUGH FOR DEVELOPMENT NEAR ANY OF
THE TERMINALS TO WARRANT INCLUSION IN EVENING TAF PACKAGES. SFC
WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW TYPICAL
DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE EARLY PART OF NEXT
WEEK WITH WARMING TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HIGHS WILL WARM TO ABOVE NORMAL STARTING SUNDAY WITH
LOWER DESERT HIGHS IN THE LOW TO MID 70S FOR THE MIDDLE OF NEXT
WEEK. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD WITH
MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT FOR THE
MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN








000
FXUS65 KPSR 200349
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
848 PM MST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDING IN FROM THE WEST AND A DRY NORTHWESTERLY FLOW
IS EXPECTED TO KEEP SKIES MAINLY CLEAR...WITH JUST SOME HIGH
CLOUDINESS PASSING OVERHEAD FROM TIME TO TIME...AND ALLOW A SLOW
WARMING TREND TO PROGRESS THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
COOLER TEMPERATURES ARE THEN POSSIBLE BY THE END OF NEXT WEEK AS A
RATHER STRONG AND COLD WEATHER SYSTEM BEGINS TO MOVE INLAND FROM THE
GULF OF ALASKA INTO THE WESTERN STATES.

&&

.DISCUSSION...
FAIRLY QUIET WX DAY ACROSS THE REGION WITH PASSING HIGH LEVEL CLOUD
BANDS AND OBSERVED TEMPERATURES JUST A DEGREE ABOVE /OR BELOW/
SEASONAL NORMALS FOR THE PHX AREA. BROAD NORTHWESTERLY FLOW
CONTINUES TO STREAM INTO THE WEST COAST OFF THE PACIFIC...WITH
SEVERAL N-S ORIENTATED BANDS OF CLOUDS NOTED ON EVENING IR/WV
IMAGERY. LATEST BAND INTO OUR FORECAST AREA CURRENTLY AT THE CO
RIVER VALLEY AND WILL CONTINUE TO TRACK ACROSS ARIZONA THROUGH THE
OVERNIGHT HOURS. IF THIS BAND WERE MORE WIDESPREAD OR SLOWER IN IT`S
MOVEMENT...IT COULD PLAY A ROLE ON IN ADDING A FEW DEGREES OF WARMTH
TO OVERNIGHT TEMPS. WHILE OVERNIGHT LOWS SEEM ON THE COOL SIDE
/COMPARED TO MORE MILD READINGS FROM EARLIER IN THE MONTH/ THEY ARE
ON TRACK FOR NEAR NORMAL READINGS...LOW TO MID 40S FOR THE LOWER
DESERTS AND LOW TO MID 30S ACROSS THE FOOTHILL AND HIGHER TERRAIN
LOCATIONS.

ONLY MINOR UPDATES NEEDED IN THE FORM OF ALIGNING SKY FORECASTS WITH
CURRENT TRENDS AND THE ADDITION OF PATCHY FOG MAINLY ACROSS PORTIONS
OF PINAL AND YUMA COUNTIES IN AZ AND IMPERIAL COUNTY IN CA.
DEWPOINTS GENERALLY REMAIN UNCHANGED FROM READINGS OVER THE LAST
COUPLE OF NIGHTS AND SINCE FOG HAS MADE REPEAT PERFORMANCES OVER THE
LAST COUPLE OF MORNINGS...FELT ADDING MENTION WOULD NOT HURT. REST
OF THE DRY WEEKEND AND EARLY NEXT WEEK FORECAST REMAINS ON
TRACK...WHICH IS OUTLINED IN THE PREVIOUS DISCUSSION BELOW.

&&

.PREVIOUS DISCUSSION /ISSUED AT 130 PM MST/1230 PM PST/...
TONIGHT THROUGH WEDNESDAY...
DRY CONDITIONS AND MOSTLY CLEAR SKIES HAVE RETURNED TO OUR CWA TODAY
AS THE LONG-WAVE UPPER TROF THAT BROUGHT US SEVERAL DAYS OF
UNSETTLED WEATHER HAS NOW MOVED OFF WELL TO THE EAST...INTO THE
SOUTHERN PLAINS. HIGH PRESSURE RIDGING THAT IS NOW JUST BEGINNING TO
BECOME ESTABLISHED OVER THE EASTERN PACIFIC HAS NOW PUSHED
LIGHT...AND DRY NORTHWESTERLY FLOW BACK OVER THE REGION.
NORTHWESTERLY FLOW IS EXPECTED TO REMAIN IN PLACE OVER THE DESERT
SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK...WITH 500MB HEIGHTS
RISING FROM THEIR PRESENT LEVEL NEAR 570DM UP INTO THE 576-582DM BY
MONDAY...THEN HOLD AT THESE LEVELS THROUGH AT LEAST WEDNESDAY. THIS
AIRMASS WARMING IS EXPECTED TO ALLOW LOWER DESERT HIGHS TO WARM FROM
TODAY/S LOW TO MID 60S UP INTO THE 70-75F RANGE BY MONDAY...THEN
HOLD AT THOSE LEVELS THROUGH AT LEAST WEDNESDAY. THE DRY
NORTHWESTERLY FLOW ALOFT IS ALSO EXPECTED TO KEEP SKIES MAINLY
CLEAR...EXCEPT FOR SOME PERIODS OF HIGH CLOUDINESS TONIGHT AND
SATURDAY AS A WEAK TROF EMBEDDED IN THIS NORTHWESTERLY FLOW PUSHES A
BIT OF HIGH-LEVEL PACIFIC MOISTURE INLAND OVER THE REGION. A 2ND
SHORTWAVE IS THEN EXPECTED TO PASS WELL TO OUR NORTH AND EAST ON
MONDAY AND MONDAY NIGHT...BUT THE ONLY IMPACT TO OUR CWA FROM THIS
SYSTEM WILL BE TO INCREASE WINDS A BIT ON MONDAY AFTERNOON...AND TO
PUSH EVEN DRIER AIR NEAR THE SFC INTO OUR CWA.

.THURSDAY THROUGH SATURDAY...
ALTHOUGH A CHANGE TOWARD COOLER WEATHER STILL LOOKS LIKELY DURING
THIS PERIOD...CONSIDERABLE MODEL DISAGREEMENT HAS NOW CROPPED BACK
UP ON THE MAGNITUDE OF THIS EXPECTED COOLDOWN...WITH THE EURO AND
GEM GOING BACK TO THE IDEA OF A MUCH DEEPER...AND COLDER TROF MOVING
INTO OUR REGION...WHILE THE OPERATIONAL GFS...AND THE PARALLEL 13KM
GFS KEEPS THE TROF MUCH FURTHER TO OUR NORTH...WITH JUST SOME SLIGHT
COOLING OVER OUR CWA. AT THIS POINT...GIVEN ALL OF THIS MODEL
DISAGREEMENT...WITH LEAVE THE EXTENDED FORECAST ALONE PENDING FUTURE
MODEL RUNS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. COULD STILL SEE SOME AREAS OF LIMITED GROUND FOG BY THE EARLY
MORNING...BUT CONFIDENCE NOT HIGH ENOUGH FOR DEVELOPMENT NEAR ANY OF
THE TERMINALS TO WARRANT INCLUSION IN EVENING TAF PACKAGES. SFC
WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW TYPICAL
DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE EARLY PART OF NEXT
WEEK WITH WARMING TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HIGHS WILL WARM TO ABOVE NORMAL STARTING SUNDAY WITH
LOWER DESERT HIGHS IN THE LOW TO MID 70S FOR THE MIDDLE OF NEXT
WEEK. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD WITH
MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT FOR THE
MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN









000
FXUS65 KPSR 200349
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
848 PM MST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDING IN FROM THE WEST AND A DRY NORTHWESTERLY FLOW
IS EXPECTED TO KEEP SKIES MAINLY CLEAR...WITH JUST SOME HIGH
CLOUDINESS PASSING OVERHEAD FROM TIME TO TIME...AND ALLOW A SLOW
WARMING TREND TO PROGRESS THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
COOLER TEMPERATURES ARE THEN POSSIBLE BY THE END OF NEXT WEEK AS A
RATHER STRONG AND COLD WEATHER SYSTEM BEGINS TO MOVE INLAND FROM THE
GULF OF ALASKA INTO THE WESTERN STATES.

&&

.DISCUSSION...
FAIRLY QUIET WX DAY ACROSS THE REGION WITH PASSING HIGH LEVEL CLOUD
BANDS AND OBSERVED TEMPERATURES JUST A DEGREE ABOVE /OR BELOW/
SEASONAL NORMALS FOR THE PHX AREA. BROAD NORTHWESTERLY FLOW
CONTINUES TO STREAM INTO THE WEST COAST OFF THE PACIFIC...WITH
SEVERAL N-S ORIENTATED BANDS OF CLOUDS NOTED ON EVENING IR/WV
IMAGERY. LATEST BAND INTO OUR FORECAST AREA CURRENTLY AT THE CO
RIVER VALLEY AND WILL CONTINUE TO TRACK ACROSS ARIZONA THROUGH THE
OVERNIGHT HOURS. IF THIS BAND WERE MORE WIDESPREAD OR SLOWER IN IT`S
MOVEMENT...IT COULD PLAY A ROLE ON IN ADDING A FEW DEGREES OF WARMTH
TO OVERNIGHT TEMPS. WHILE OVERNIGHT LOWS SEEM ON THE COOL SIDE
/COMPARED TO MORE MILD READINGS FROM EARLIER IN THE MONTH/ THEY ARE
ON TRACK FOR NEAR NORMAL READINGS...LOW TO MID 40S FOR THE LOWER
DESERTS AND LOW TO MID 30S ACROSS THE FOOTHILL AND HIGHER TERRAIN
LOCATIONS.

ONLY MINOR UPDATES NEEDED IN THE FORM OF ALIGNING SKY FORECASTS WITH
CURRENT TRENDS AND THE ADDITION OF PATCHY FOG MAINLY ACROSS PORTIONS
OF PINAL AND YUMA COUNTIES IN AZ AND IMPERIAL COUNTY IN CA.
DEWPOINTS GENERALLY REMAIN UNCHANGED FROM READINGS OVER THE LAST
COUPLE OF NIGHTS AND SINCE FOG HAS MADE REPEAT PERFORMANCES OVER THE
LAST COUPLE OF MORNINGS...FELT ADDING MENTION WOULD NOT HURT. REST
OF THE DRY WEEKEND AND EARLY NEXT WEEK FORECAST REMAINS ON
TRACK...WHICH IS OUTLINED IN THE PREVIOUS DISCUSSION BELOW.

&&

.PREVIOUS DISCUSSION /ISSUED AT 130 PM MST/1230 PM PST/...
TONIGHT THROUGH WEDNESDAY...
DRY CONDITIONS AND MOSTLY CLEAR SKIES HAVE RETURNED TO OUR CWA TODAY
AS THE LONG-WAVE UPPER TROF THAT BROUGHT US SEVERAL DAYS OF
UNSETTLED WEATHER HAS NOW MOVED OFF WELL TO THE EAST...INTO THE
SOUTHERN PLAINS. HIGH PRESSURE RIDGING THAT IS NOW JUST BEGINNING TO
BECOME ESTABLISHED OVER THE EASTERN PACIFIC HAS NOW PUSHED
LIGHT...AND DRY NORTHWESTERLY FLOW BACK OVER THE REGION.
NORTHWESTERLY FLOW IS EXPECTED TO REMAIN IN PLACE OVER THE DESERT
SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK...WITH 500MB HEIGHTS
RISING FROM THEIR PRESENT LEVEL NEAR 570DM UP INTO THE 576-582DM BY
MONDAY...THEN HOLD AT THESE LEVELS THROUGH AT LEAST WEDNESDAY. THIS
AIRMASS WARMING IS EXPECTED TO ALLOW LOWER DESERT HIGHS TO WARM FROM
TODAY/S LOW TO MID 60S UP INTO THE 70-75F RANGE BY MONDAY...THEN
HOLD AT THOSE LEVELS THROUGH AT LEAST WEDNESDAY. THE DRY
NORTHWESTERLY FLOW ALOFT IS ALSO EXPECTED TO KEEP SKIES MAINLY
CLEAR...EXCEPT FOR SOME PERIODS OF HIGH CLOUDINESS TONIGHT AND
SATURDAY AS A WEAK TROF EMBEDDED IN THIS NORTHWESTERLY FLOW PUSHES A
BIT OF HIGH-LEVEL PACIFIC MOISTURE INLAND OVER THE REGION. A 2ND
SHORTWAVE IS THEN EXPECTED TO PASS WELL TO OUR NORTH AND EAST ON
MONDAY AND MONDAY NIGHT...BUT THE ONLY IMPACT TO OUR CWA FROM THIS
SYSTEM WILL BE TO INCREASE WINDS A BIT ON MONDAY AFTERNOON...AND TO
PUSH EVEN DRIER AIR NEAR THE SFC INTO OUR CWA.

.THURSDAY THROUGH SATURDAY...
ALTHOUGH A CHANGE TOWARD COOLER WEATHER STILL LOOKS LIKELY DURING
THIS PERIOD...CONSIDERABLE MODEL DISAGREEMENT HAS NOW CROPPED BACK
UP ON THE MAGNITUDE OF THIS EXPECTED COOLDOWN...WITH THE EURO AND
GEM GOING BACK TO THE IDEA OF A MUCH DEEPER...AND COLDER TROF MOVING
INTO OUR REGION...WHILE THE OPERATIONAL GFS...AND THE PARALLEL 13KM
GFS KEEPS THE TROF MUCH FURTHER TO OUR NORTH...WITH JUST SOME SLIGHT
COOLING OVER OUR CWA. AT THIS POINT...GIVEN ALL OF THIS MODEL
DISAGREEMENT...WITH LEAVE THE EXTENDED FORECAST ALONE PENDING FUTURE
MODEL RUNS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. COULD STILL SEE SOME AREAS OF LIMITED GROUND FOG BY THE EARLY
MORNING...BUT CONFIDENCE NOT HIGH ENOUGH FOR DEVELOPMENT NEAR ANY OF
THE TERMINALS TO WARRANT INCLUSION IN EVENING TAF PACKAGES. SFC
WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW TYPICAL
DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE EARLY PART OF NEXT
WEEK WITH WARMING TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HIGHS WILL WARM TO ABOVE NORMAL STARTING SUNDAY WITH
LOWER DESERT HIGHS IN THE LOW TO MID 70S FOR THE MIDDLE OF NEXT
WEEK. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD WITH
MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT FOR THE
MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN








000
FXUS65 KPSR 200349
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
848 PM MST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDING IN FROM THE WEST AND A DRY NORTHWESTERLY FLOW
IS EXPECTED TO KEEP SKIES MAINLY CLEAR...WITH JUST SOME HIGH
CLOUDINESS PASSING OVERHEAD FROM TIME TO TIME...AND ALLOW A SLOW
WARMING TREND TO PROGRESS THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
COOLER TEMPERATURES ARE THEN POSSIBLE BY THE END OF NEXT WEEK AS A
RATHER STRONG AND COLD WEATHER SYSTEM BEGINS TO MOVE INLAND FROM THE
GULF OF ALASKA INTO THE WESTERN STATES.

&&

.DISCUSSION...
FAIRLY QUIET WX DAY ACROSS THE REGION WITH PASSING HIGH LEVEL CLOUD
BANDS AND OBSERVED TEMPERATURES JUST A DEGREE ABOVE /OR BELOW/
SEASONAL NORMALS FOR THE PHX AREA. BROAD NORTHWESTERLY FLOW
CONTINUES TO STREAM INTO THE WEST COAST OFF THE PACIFIC...WITH
SEVERAL N-S ORIENTATED BANDS OF CLOUDS NOTED ON EVENING IR/WV
IMAGERY. LATEST BAND INTO OUR FORECAST AREA CURRENTLY AT THE CO
RIVER VALLEY AND WILL CONTINUE TO TRACK ACROSS ARIZONA THROUGH THE
OVERNIGHT HOURS. IF THIS BAND WERE MORE WIDESPREAD OR SLOWER IN IT`S
MOVEMENT...IT COULD PLAY A ROLE ON IN ADDING A FEW DEGREES OF WARMTH
TO OVERNIGHT TEMPS. WHILE OVERNIGHT LOWS SEEM ON THE COOL SIDE
/COMPARED TO MORE MILD READINGS FROM EARLIER IN THE MONTH/ THEY ARE
ON TRACK FOR NEAR NORMAL READINGS...LOW TO MID 40S FOR THE LOWER
DESERTS AND LOW TO MID 30S ACROSS THE FOOTHILL AND HIGHER TERRAIN
LOCATIONS.

ONLY MINOR UPDATES NEEDED IN THE FORM OF ALIGNING SKY FORECASTS WITH
CURRENT TRENDS AND THE ADDITION OF PATCHY FOG MAINLY ACROSS PORTIONS
OF PINAL AND YUMA COUNTIES IN AZ AND IMPERIAL COUNTY IN CA.
DEWPOINTS GENERALLY REMAIN UNCHANGED FROM READINGS OVER THE LAST
COUPLE OF NIGHTS AND SINCE FOG HAS MADE REPEAT PERFORMANCES OVER THE
LAST COUPLE OF MORNINGS...FELT ADDING MENTION WOULD NOT HURT. REST
OF THE DRY WEEKEND AND EARLY NEXT WEEK FORECAST REMAINS ON
TRACK...WHICH IS OUTLINED IN THE PREVIOUS DISCUSSION BELOW.

&&

.PREVIOUS DISCUSSION /ISSUED AT 130 PM MST/1230 PM PST/...
TONIGHT THROUGH WEDNESDAY...
DRY CONDITIONS AND MOSTLY CLEAR SKIES HAVE RETURNED TO OUR CWA TODAY
AS THE LONG-WAVE UPPER TROF THAT BROUGHT US SEVERAL DAYS OF
UNSETTLED WEATHER HAS NOW MOVED OFF WELL TO THE EAST...INTO THE
SOUTHERN PLAINS. HIGH PRESSURE RIDGING THAT IS NOW JUST BEGINNING TO
BECOME ESTABLISHED OVER THE EASTERN PACIFIC HAS NOW PUSHED
LIGHT...AND DRY NORTHWESTERLY FLOW BACK OVER THE REGION.
NORTHWESTERLY FLOW IS EXPECTED TO REMAIN IN PLACE OVER THE DESERT
SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK...WITH 500MB HEIGHTS
RISING FROM THEIR PRESENT LEVEL NEAR 570DM UP INTO THE 576-582DM BY
MONDAY...THEN HOLD AT THESE LEVELS THROUGH AT LEAST WEDNESDAY. THIS
AIRMASS WARMING IS EXPECTED TO ALLOW LOWER DESERT HIGHS TO WARM FROM
TODAY/S LOW TO MID 60S UP INTO THE 70-75F RANGE BY MONDAY...THEN
HOLD AT THOSE LEVELS THROUGH AT LEAST WEDNESDAY. THE DRY
NORTHWESTERLY FLOW ALOFT IS ALSO EXPECTED TO KEEP SKIES MAINLY
CLEAR...EXCEPT FOR SOME PERIODS OF HIGH CLOUDINESS TONIGHT AND
SATURDAY AS A WEAK TROF EMBEDDED IN THIS NORTHWESTERLY FLOW PUSHES A
BIT OF HIGH-LEVEL PACIFIC MOISTURE INLAND OVER THE REGION. A 2ND
SHORTWAVE IS THEN EXPECTED TO PASS WELL TO OUR NORTH AND EAST ON
MONDAY AND MONDAY NIGHT...BUT THE ONLY IMPACT TO OUR CWA FROM THIS
SYSTEM WILL BE TO INCREASE WINDS A BIT ON MONDAY AFTERNOON...AND TO
PUSH EVEN DRIER AIR NEAR THE SFC INTO OUR CWA.

.THURSDAY THROUGH SATURDAY...
ALTHOUGH A CHANGE TOWARD COOLER WEATHER STILL LOOKS LIKELY DURING
THIS PERIOD...CONSIDERABLE MODEL DISAGREEMENT HAS NOW CROPPED BACK
UP ON THE MAGNITUDE OF THIS EXPECTED COOLDOWN...WITH THE EURO AND
GEM GOING BACK TO THE IDEA OF A MUCH DEEPER...AND COLDER TROF MOVING
INTO OUR REGION...WHILE THE OPERATIONAL GFS...AND THE PARALLEL 13KM
GFS KEEPS THE TROF MUCH FURTHER TO OUR NORTH...WITH JUST SOME SLIGHT
COOLING OVER OUR CWA. AT THIS POINT...GIVEN ALL OF THIS MODEL
DISAGREEMENT...WITH LEAVE THE EXTENDED FORECAST ALONE PENDING FUTURE
MODEL RUNS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID TO HIGH LEVEL CLOUDS EXPECTED AT PERIODS THROUGH THE
WEEKEND...GENERATING BKN TO OVC SKIES AND REMAINING MOSTLY ABOVE
20KFT. COULD STILL SEE SOME AREAS OF LIMITED GROUND FOG BY THE EARLY
MORNING...BUT CONFIDENCE NOT HIGH ENOUGH FOR DEVELOPMENT NEAR ANY OF
THE TERMINALS TO WARRANT INCLUSION IN EVENING TAF PACKAGES. SFC
WINDS WILL REMAIN LIGHT...GNLY 8KTS OR LESS...AND FOLLOW TYPICAL
DIURNAL HEADINGS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE EARLY PART OF NEXT
WEEK WITH WARMING TEMPERATURES AND SLIGHTLY DRIER
CONDITIONS. HIGHS WILL WARM TO ABOVE NORMAL STARTING SUNDAY WITH
LOWER DESERT HIGHS IN THE LOW TO MID 70S FOR THE MIDDLE OF NEXT
WEEK. HUMIDITIES WILL REMAIN FAIRLY HIGH THROUGH THE PERIOD WITH
MINIMUM VALUES STAYING ABOVE 25 PERCENT. WINDS WILL BE LIGHT FOR THE
MOST PART THROUGH WEDNESDAY WITH THE EXCEPTION OF OCCASIONAL
AFTERNOON BREEZINESS. A PACIFIC LOW PRESSURE SYSTEM MAY AFFECT THE
REGION LATE NEXT WEEK BRINGING THE POTENTIAL FOR GUSTY
WINDS...COOLER TEMPERATURES...AND SLIGHT CHANCES FOR PRECIPITATION
ACROSS HIGHER TERRAIN AREAS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN









000
FXUS65 KFGZ 192240
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
340 PM MST FRI DEC 19 2014

.SYNOPSIS...
LOOK FOR AREAS OF LOW CLOUD AND PATCHY FOG OVER NORTHEAST ARIZONA
SATURDAY MORNING. OTHERWISE...DRY NORTHWEST FLOW ALOFT WILL DELIVER FAIR
WEATHER...A FEW CLOUDS AND WARMING TEMPERATURES EACH DAY THROUGH
EARLY NEXT WEEK.

&&

.DISCUSSION...
FOR TONIGHT AND TOMORROW MORNING...THE LARGE AREAS OF LOW CLOUD
AND FOG THAT EXISTED ACROSS PORTIONS OF NORTHERN ARIZONA THIS
MORNING HAVE LARGELY BURNED OFF WITH DAYTIME HEATING.
HOWEVER...SOME PATCHES OF LOW CLOUD REMAIN WITHIN THE LITTLE
COLORADO RIVER VALLEY EAST OF WINSLOW. WHILE AN UPPER LEVEL
TROUGH IS FORECAST TO CROSS THE REGION TONIGHT THROUGH TOMORROW
MORNING...THIS FEATURE WILL HAVE LITTLE EFFECT ON BOUNDARY LAYER
CONDITIONS ALLOWING FOR THE RETURN OF LOW CLOUD AND FOG
OVERNIGHT...ESPECIALLY IN THE LITTLE COLORADO RIVER AND CHINLE
VALLEYS. I HAVE GONE A FEW DEGREES ABOVE GUIDANCE FOR TOMORROW
MORNINGS LOWS IN PLACES WHERE LOW CLOUD AND FOG ARE EXPECTED TO
FORM.

TOMORROW THROUGH CHRISTMAS EVE...MODELS CONTINUE TO SHOW HIGH
PRESSURE BUILDING OFF THE CALIFORNIA COAST AND PLACING ARIZONA
UNDER A DRY NORTHWEST FLOW ALOFT. A SERIES OF WEATHER DISTURBANCES
EMBEDDED WITHIN THIS NORTHWEST FLOW WILL BRUSH ARIZONA RESULTING IN
DAY-TO-DAY VARIATIONS IN CLOUD COVER AND WINDS. OTHERWISE, IT LOOKS
LIKE DAYTIME TEMPERATURES WILL WARM INTO MONDAY THEN GRADUALLY
COOL.

FOR CHRISTMAS DAY AND BEYOND...SOME LONG RANGE MODELS STILL
INDICATE THE POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS.
THE GFS ENSEMBLES HAVE BACKED OFF A BIT ON THE CHANCES FOR
PRECIPITATION WHILE THE ECMWF CONTINUES TO FORECAST THE PASSAGE OF
A DEEPER...SLIGHTLY WETTER SYSTEM. CONFIDENCE IS LOW AT THIS TIME
BUT DEFINITELY SOMETHING WORTH CHECKING BACK ON.

&&

.AVIATION...
FOR THE 00Z PACKAGE...STRATUS AND FOG FCST TO EXPAND AGAIN BY EARLY
EVENING WITH INCREASING IFR AND MVFR CONDITIONS. AREAS IMPACTED
OVERNIGHT MAY INCLUDE BUT NOT LIMITED TO PORTIONS OF THE CHINLE
VALLEY...LITTLE COLORADO RIVER VALLEY...PORTION OF THE COCONINO
PLATEAU...AND MARBLE AND GLEN CANYONS INCLUDING THE PAGE AREA.
OUTSIDE OF THE LOW STRATUS AREAS...VFR CONDITIONS AND GENERALLY
LIGHT WINDS THRU THE 24HR TAF PERIOD. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.........RR
AVIATION.......TC

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 192240
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
340 PM MST FRI DEC 19 2014

.SYNOPSIS...
LOOK FOR AREAS OF LOW CLOUD AND PATCHY FOG OVER NORTHEAST ARIZONA
SATURDAY MORNING. OTHERWISE...DRY NORTHWEST FLOW ALOFT WILL DELIVER FAIR
WEATHER...A FEW CLOUDS AND WARMING TEMPERATURES EACH DAY THROUGH
EARLY NEXT WEEK.

&&

.DISCUSSION...
FOR TONIGHT AND TOMORROW MORNING...THE LARGE AREAS OF LOW CLOUD
AND FOG THAT EXISTED ACROSS PORTIONS OF NORTHERN ARIZONA THIS
MORNING HAVE LARGELY BURNED OFF WITH DAYTIME HEATING.
HOWEVER...SOME PATCHES OF LOW CLOUD REMAIN WITHIN THE LITTLE
COLORADO RIVER VALLEY EAST OF WINSLOW. WHILE AN UPPER LEVEL
TROUGH IS FORECAST TO CROSS THE REGION TONIGHT THROUGH TOMORROW
MORNING...THIS FEATURE WILL HAVE LITTLE EFFECT ON BOUNDARY LAYER
CONDITIONS ALLOWING FOR THE RETURN OF LOW CLOUD AND FOG
OVERNIGHT...ESPECIALLY IN THE LITTLE COLORADO RIVER AND CHINLE
VALLEYS. I HAVE GONE A FEW DEGREES ABOVE GUIDANCE FOR TOMORROW
MORNINGS LOWS IN PLACES WHERE LOW CLOUD AND FOG ARE EXPECTED TO
FORM.

TOMORROW THROUGH CHRISTMAS EVE...MODELS CONTINUE TO SHOW HIGH
PRESSURE BUILDING OFF THE CALIFORNIA COAST AND PLACING ARIZONA
UNDER A DRY NORTHWEST FLOW ALOFT. A SERIES OF WEATHER DISTURBANCES
EMBEDDED WITHIN THIS NORTHWEST FLOW WILL BRUSH ARIZONA RESULTING IN
DAY-TO-DAY VARIATIONS IN CLOUD COVER AND WINDS. OTHERWISE, IT LOOKS
LIKE DAYTIME TEMPERATURES WILL WARM INTO MONDAY THEN GRADUALLY
COOL.

FOR CHRISTMAS DAY AND BEYOND...SOME LONG RANGE MODELS STILL
INDICATE THE POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS.
THE GFS ENSEMBLES HAVE BACKED OFF A BIT ON THE CHANCES FOR
PRECIPITATION WHILE THE ECMWF CONTINUES TO FORECAST THE PASSAGE OF
A DEEPER...SLIGHTLY WETTER SYSTEM. CONFIDENCE IS LOW AT THIS TIME
BUT DEFINITELY SOMETHING WORTH CHECKING BACK ON.

&&

.AVIATION...
FOR THE 00Z PACKAGE...STRATUS AND FOG FCST TO EXPAND AGAIN BY EARLY
EVENING WITH INCREASING IFR AND MVFR CONDITIONS. AREAS IMPACTED
OVERNIGHT MAY INCLUDE BUT NOT LIMITED TO PORTIONS OF THE CHINLE
VALLEY...LITTLE COLORADO RIVER VALLEY...PORTION OF THE COCONINO
PLATEAU...AND MARBLE AND GLEN CANYONS INCLUDING THE PAGE AREA.
OUTSIDE OF THE LOW STRATUS AREAS...VFR CONDITIONS AND GENERALLY
LIGHT WINDS THRU THE 24HR TAF PERIOD. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.........RR
AVIATION.......TC

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 192240
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
340 PM MST FRI DEC 19 2014

.SYNOPSIS...
LOOK FOR AREAS OF LOW CLOUD AND PATCHY FOG OVER NORTHEAST ARIZONA
SATURDAY MORNING. OTHERWISE...DRY NORTHWEST FLOW ALOFT WILL DELIVER FAIR
WEATHER...A FEW CLOUDS AND WARMING TEMPERATURES EACH DAY THROUGH
EARLY NEXT WEEK.

&&

.DISCUSSION...
FOR TONIGHT AND TOMORROW MORNING...THE LARGE AREAS OF LOW CLOUD
AND FOG THAT EXISTED ACROSS PORTIONS OF NORTHERN ARIZONA THIS
MORNING HAVE LARGELY BURNED OFF WITH DAYTIME HEATING.
HOWEVER...SOME PATCHES OF LOW CLOUD REMAIN WITHIN THE LITTLE
COLORADO RIVER VALLEY EAST OF WINSLOW. WHILE AN UPPER LEVEL
TROUGH IS FORECAST TO CROSS THE REGION TONIGHT THROUGH TOMORROW
MORNING...THIS FEATURE WILL HAVE LITTLE EFFECT ON BOUNDARY LAYER
CONDITIONS ALLOWING FOR THE RETURN OF LOW CLOUD AND FOG
OVERNIGHT...ESPECIALLY IN THE LITTLE COLORADO RIVER AND CHINLE
VALLEYS. I HAVE GONE A FEW DEGREES ABOVE GUIDANCE FOR TOMORROW
MORNINGS LOWS IN PLACES WHERE LOW CLOUD AND FOG ARE EXPECTED TO
FORM.

TOMORROW THROUGH CHRISTMAS EVE...MODELS CONTINUE TO SHOW HIGH
PRESSURE BUILDING OFF THE CALIFORNIA COAST AND PLACING ARIZONA
UNDER A DRY NORTHWEST FLOW ALOFT. A SERIES OF WEATHER DISTURBANCES
EMBEDDED WITHIN THIS NORTHWEST FLOW WILL BRUSH ARIZONA RESULTING IN
DAY-TO-DAY VARIATIONS IN CLOUD COVER AND WINDS. OTHERWISE, IT LOOKS
LIKE DAYTIME TEMPERATURES WILL WARM INTO MONDAY THEN GRADUALLY
COOL.

FOR CHRISTMAS DAY AND BEYOND...SOME LONG RANGE MODELS STILL
INDICATE THE POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS.
THE GFS ENSEMBLES HAVE BACKED OFF A BIT ON THE CHANCES FOR
PRECIPITATION WHILE THE ECMWF CONTINUES TO FORECAST THE PASSAGE OF
A DEEPER...SLIGHTLY WETTER SYSTEM. CONFIDENCE IS LOW AT THIS TIME
BUT DEFINITELY SOMETHING WORTH CHECKING BACK ON.

&&

.AVIATION...
FOR THE 00Z PACKAGE...STRATUS AND FOG FCST TO EXPAND AGAIN BY EARLY
EVENING WITH INCREASING IFR AND MVFR CONDITIONS. AREAS IMPACTED
OVERNIGHT MAY INCLUDE BUT NOT LIMITED TO PORTIONS OF THE CHINLE
VALLEY...LITTLE COLORADO RIVER VALLEY...PORTION OF THE COCONINO
PLATEAU...AND MARBLE AND GLEN CANYONS INCLUDING THE PAGE AREA.
OUTSIDE OF THE LOW STRATUS AREAS...VFR CONDITIONS AND GENERALLY
LIGHT WINDS THRU THE 24HR TAF PERIOD. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.........RR
AVIATION.......TC

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 192240
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
340 PM MST FRI DEC 19 2014

.SYNOPSIS...
LOOK FOR AREAS OF LOW CLOUD AND PATCHY FOG OVER NORTHEAST ARIZONA
SATURDAY MORNING. OTHERWISE...DRY NORTHWEST FLOW ALOFT WILL DELIVER FAIR
WEATHER...A FEW CLOUDS AND WARMING TEMPERATURES EACH DAY THROUGH
EARLY NEXT WEEK.

&&

.DISCUSSION...
FOR TONIGHT AND TOMORROW MORNING...THE LARGE AREAS OF LOW CLOUD
AND FOG THAT EXISTED ACROSS PORTIONS OF NORTHERN ARIZONA THIS
MORNING HAVE LARGELY BURNED OFF WITH DAYTIME HEATING.
HOWEVER...SOME PATCHES OF LOW CLOUD REMAIN WITHIN THE LITTLE
COLORADO RIVER VALLEY EAST OF WINSLOW. WHILE AN UPPER LEVEL
TROUGH IS FORECAST TO CROSS THE REGION TONIGHT THROUGH TOMORROW
MORNING...THIS FEATURE WILL HAVE LITTLE EFFECT ON BOUNDARY LAYER
CONDITIONS ALLOWING FOR THE RETURN OF LOW CLOUD AND FOG
OVERNIGHT...ESPECIALLY IN THE LITTLE COLORADO RIVER AND CHINLE
VALLEYS. I HAVE GONE A FEW DEGREES ABOVE GUIDANCE FOR TOMORROW
MORNINGS LOWS IN PLACES WHERE LOW CLOUD AND FOG ARE EXPECTED TO
FORM.

TOMORROW THROUGH CHRISTMAS EVE...MODELS CONTINUE TO SHOW HIGH
PRESSURE BUILDING OFF THE CALIFORNIA COAST AND PLACING ARIZONA
UNDER A DRY NORTHWEST FLOW ALOFT. A SERIES OF WEATHER DISTURBANCES
EMBEDDED WITHIN THIS NORTHWEST FLOW WILL BRUSH ARIZONA RESULTING IN
DAY-TO-DAY VARIATIONS IN CLOUD COVER AND WINDS. OTHERWISE, IT LOOKS
LIKE DAYTIME TEMPERATURES WILL WARM INTO MONDAY THEN GRADUALLY
COOL.

FOR CHRISTMAS DAY AND BEYOND...SOME LONG RANGE MODELS STILL
INDICATE THE POSSIBILITY OF COLD...WINDY AND UNSETTLED CONDITIONS.
THE GFS ENSEMBLES HAVE BACKED OFF A BIT ON THE CHANCES FOR
PRECIPITATION WHILE THE ECMWF CONTINUES TO FORECAST THE PASSAGE OF
A DEEPER...SLIGHTLY WETTER SYSTEM. CONFIDENCE IS LOW AT THIS TIME
BUT DEFINITELY SOMETHING WORTH CHECKING BACK ON.

&&

.AVIATION...
FOR THE 00Z PACKAGE...STRATUS AND FOG FCST TO EXPAND AGAIN BY EARLY
EVENING WITH INCREASING IFR AND MVFR CONDITIONS. AREAS IMPACTED
OVERNIGHT MAY INCLUDE BUT NOT LIMITED TO PORTIONS OF THE CHINLE
VALLEY...LITTLE COLORADO RIVER VALLEY...PORTION OF THE COCONINO
PLATEAU...AND MARBLE AND GLEN CANYONS INCLUDING THE PAGE AREA.
OUTSIDE OF THE LOW STRATUS AREAS...VFR CONDITIONS AND GENERALLY
LIGHT WINDS THRU THE 24HR TAF PERIOD. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC.........RR
AVIATION.......TC

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KTWC 192134
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
234 PM MST FRI DEC 19 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW TEMPERATURES THIS
WEEKEND. SOME AREAS OF FOG AND FREEZING FOG ARE EXPECTED AGAIN EARLY
SATURDAY MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND GRAHAM
COUNTY.   FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE TO
ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE. UNSETTLED
AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...SKIES ARE NOW MOSTLY SUNNY THIS AFTERNOON ACROSS
SOUTHEAST ARIZONA WITH BELOW NORMAL TEMPERATURES. A STEEP INVERSION
THIS MORNING WITH EXTENSIVE AREAS OF CLOUDS AND FOG IN THE VALLEYS
FROM TUCSON SOUTH AND EASTWARD HAVE FINALLY DISSIPATED WITH THE LAST
VESTIGES OF CLOUDS CLEARING AROUND 1 PM NEAR SAFFORD. IN THE LARGER
SCALE...WEAK SHORTWAVE RIDGING ALOFT IS CENTERED JUST WEST OF US AT
THIS TIME WITH SOME THIN CIRROFORM CLOUDS ACROSS WESTERN ARIZONA AND
MORE EXTENSIVE MID AND HIGH LEVEL CLOUDS ACROSS THE EASTERN PACIFIC
PUSHING INTO SOUTHERN CALIFORNIA. CONSIDERING AMPLE LOW LEVEL
MOISTURE REMAINS TONIGHT WE THINK THERE WILL BE SOME AREAS OF FOG
AND FREEZING FOG AGAIN EARLY SATURDAY MORNING ACROSS THE VALLEYS OF
GRAHAM AND COCHISE COUNTY. THE UPPER GILA RIVER VALLEY WILL AGAIN
HAVE THE BEST CHANCE OF SEEING FOG AND FREEZING FOG. SOME AREAS OF
FROST WILL BE POSSIBLE AS WELL FOR SOME OF THE OUTLYING AREAS OF THE
TUCSON METRO. THERE WILL BE SOME THIN CIRROFORM CLOUDS OVERNIGHT
WHICH COULD HELP MITIGATE LOW TEMPERATURES AND FOG SLIGHTLY BUT
CONFIDENCE IS HIGH ENOUGH TO PUT AREAS OF FOG IN THE FORECAST FOR
THE VALLEYS EAST OF TUCSON.

A WEAK SHORTWAVE TROUGH WILL SKIRT ACROSS MAINLY EASTERN SECTIONS OF
THE FORECAST AREA ON SATURDAY WITH LITTLE SENSIBLE WEATHER IMPACT
OTHER THEN SOME MAINLY HIGH LEVEL CLOUDS. TEMPERATURES WILL WARM A
FEW DEGREES ON SATURDAY COMPARED TO TODAY.

THEREAFTER...DRY NORTHWESTERLY FLOW ALOFT IS EXPECTED FROM SUNDAY
THROUGH THE MIDDLE OF NEXT WEEK AS RIDGING ALOFT IS CENTERED ACROSS
THE EASTERN PACIFIC AND TROUGHINESS IS LOCATED OVER THE PLAINS.
TEMPERATURES WILL BE NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE
NORMAL MONDAY. THERE WILL BE A WEAK COLD FRONT MOVING THROUGH FROM
THE NORTH-NORTHEAST EARLY TUESDAY BUT THIS WILL HAVE LITTLE IMPACT
ON TEMPERATURES FROM TUCSON WESTWARD WITH PERHAPS SLIGHT COOLING FOR
EASTERN AREAS TUESDAY INTO WEDNESDAY.

BY LATE NEXT WEEK...THERE REMAINS CONSIDERABLE DIFFERENCES IN THE
GLOBAL MODEL GUIDANCE AS ANOTHER TROUGH MOVES INTO THE WESTERN US.
THE 12Z GFS KEEPS MAINLY ZONAL WESTERLY FLOW THIS FAR SOUTH WITH THE
12Z CANADIAN AND ECMWF MORE AMPLIFIED WITH THE TROUGH LATE NEXT
WEEK. WILL TAKE A MIDDLE OF THE ROAD APPROACH CLOSE TO 12Z GEFS AND
ECMWF ENSEMBLE MEANS. THUS...HAVE ONLY MADE MINOR TWEAKS TO THE
ONGOING FORECAST WITH SLIGHT CHANCE POPS NORTHEAST OF TUCSON AND
ESPECIALLY IN THE WHITE MOUNTAINS THURSDAY AND FRIDAY. TEMPERATURES
WILL DROP BACK DOWN TO NEAR NORMAL VALUES LATE NEXT WEEK.


&&

.AVIATION...VALID THRU 21/00Z.
GENERALLY SKC WITH PERIODS OF SCT HIGH CLOUDS MOVING THROUGH EARLY
TONIGHT. EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR
FREEZING FOG AFTER 20/09Z THROUGH 20/17Z. OTHERWISE CLEAR SKIES AND
SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE TIMING AND
IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY AFFECT THE
REGION LATE NEXT WEEK. GUSTY WINDS AND ANOTHER CHANCE FOR VALLEY
RAIN AND MOUNTAIN SNOW ARE POSSIBLE.

&&

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

&&

$$

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

DISCUSSION...GL
AVIATION/FIRE WEATHER...RH











000
FXUS65 KTWC 192134
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
234 PM MST FRI DEC 19 2014

.SYNOPSIS...A DRY NORTHWEST FLOW PATTERN WILL RESULT IN SOME PASSING
HIGH LEVEL CLOUDS AND NEAR TO SLIGHTLY BELOW TEMPERATURES THIS
WEEKEND. SOME AREAS OF FOG AND FREEZING FOG ARE EXPECTED AGAIN EARLY
SATURDAY MORNING MAINLY ACROSS THE VALLEYS OF COCHISE AND GRAHAM
COUNTY.   FOR EARLY TO MID NEXT WEEK...TEMPERATURES WILL RISE TO
ABOVE NORMAL LEVELS DUE TO A PASSING UPPER LEVEL RIDGE. UNSETTLED
AND COOLER WEATHER LOOKS LIKELY FOR THE END OF NEXT WEEK.

&&

.DISCUSSION...SKIES ARE NOW MOSTLY SUNNY THIS AFTERNOON ACROSS
SOUTHEAST ARIZONA WITH BELOW NORMAL TEMPERATURES. A STEEP INVERSION
THIS MORNING WITH EXTENSIVE AREAS OF CLOUDS AND FOG IN THE VALLEYS
FROM TUCSON SOUTH AND EASTWARD HAVE FINALLY DISSIPATED WITH THE LAST
VESTIGES OF CLOUDS CLEARING AROUND 1 PM NEAR SAFFORD. IN THE LARGER
SCALE...WEAK SHORTWAVE RIDGING ALOFT IS CENTERED JUST WEST OF US AT
THIS TIME WITH SOME THIN CIRROFORM CLOUDS ACROSS WESTERN ARIZONA AND
MORE EXTENSIVE MID AND HIGH LEVEL CLOUDS ACROSS THE EASTERN PACIFIC
PUSHING INTO SOUTHERN CALIFORNIA. CONSIDERING AMPLE LOW LEVEL
MOISTURE REMAINS TONIGHT WE THINK THERE WILL BE SOME AREAS OF FOG
AND FREEZING FOG AGAIN EARLY SATURDAY MORNING ACROSS THE VALLEYS OF
GRAHAM AND COCHISE COUNTY. THE UPPER GILA RIVER VALLEY WILL AGAIN
HAVE THE BEST CHANCE OF SEEING FOG AND FREEZING FOG. SOME AREAS OF
FROST WILL BE POSSIBLE AS WELL FOR SOME OF THE OUTLYING AREAS OF THE
TUCSON METRO. THERE WILL BE SOME THIN CIRROFORM CLOUDS OVERNIGHT
WHICH COULD HELP MITIGATE LOW TEMPERATURES AND FOG SLIGHTLY BUT
CONFIDENCE IS HIGH ENOUGH TO PUT AREAS OF FOG IN THE FORECAST FOR
THE VALLEYS EAST OF TUCSON.

A WEAK SHORTWAVE TROUGH WILL SKIRT ACROSS MAINLY EASTERN SECTIONS OF
THE FORECAST AREA ON SATURDAY WITH LITTLE SENSIBLE WEATHER IMPACT
OTHER THEN SOME MAINLY HIGH LEVEL CLOUDS. TEMPERATURES WILL WARM A
FEW DEGREES ON SATURDAY COMPARED TO TODAY.

THEREAFTER...DRY NORTHWESTERLY FLOW ALOFT IS EXPECTED FROM SUNDAY
THROUGH THE MIDDLE OF NEXT WEEK AS RIDGING ALOFT IS CENTERED ACROSS
THE EASTERN PACIFIC AND TROUGHINESS IS LOCATED OVER THE PLAINS.
TEMPERATURES WILL BE NEAR NORMAL SUNDAY AND ABOUT 5 DEGREES ABOVE
NORMAL MONDAY. THERE WILL BE A WEAK COLD FRONT MOVING THROUGH FROM
THE NORTH-NORTHEAST EARLY TUESDAY BUT THIS WILL HAVE LITTLE IMPACT
ON TEMPERATURES FROM TUCSON WESTWARD WITH PERHAPS SLIGHT COOLING FOR
EASTERN AREAS TUESDAY INTO WEDNESDAY.

BY LATE NEXT WEEK...THERE REMAINS CONSIDERABLE DIFFERENCES IN THE
GLOBAL MODEL GUIDANCE AS ANOTHER TROUGH MOVES INTO THE WESTERN US.
THE 12Z GFS KEEPS MAINLY ZONAL WESTERLY FLOW THIS FAR SOUTH WITH THE
12Z CANADIAN AND ECMWF MORE AMPLIFIED WITH THE TROUGH LATE NEXT
WEEK. WILL TAKE A MIDDLE OF THE ROAD APPROACH CLOSE TO 12Z GEFS AND
ECMWF ENSEMBLE MEANS. THUS...HAVE ONLY MADE MINOR TWEAKS TO THE
ONGOING FORECAST WITH SLIGHT CHANCE POPS NORTHEAST OF TUCSON AND
ESPECIALLY IN THE WHITE MOUNTAINS THURSDAY AND FRIDAY. TEMPERATURES
WILL DROP BACK DOWN TO NEAR NORMAL VALUES LATE NEXT WEEK.


&&

.AVIATION...VALID THRU 21/00Z.
GENERALLY SKC WITH PERIODS OF SCT HIGH CLOUDS MOVING THROUGH EARLY
TONIGHT. EASTERN AREAS COULD SEE DEVELOPMENT OF PATCHY FOG OR
FREEZING FOG AFTER 20/09Z THROUGH 20/17Z. OTHERWISE CLEAR SKIES AND
SURFACE WIND LESS THAN 10 KTS WILL PREVAIL THROUGH THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL TODAY THROUGH WEDNESDAY.
20-FT WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THROUGH THE
MIDDLE OF NEXT WEEK. HOWEVER...SOME NORTHWEST BREEZES WILL OCCUR
MONDAY AFTERNOON ACROSS THE UPPER GILA RIVER VALLEY INCLUDING
SAFFORD. AT THIS TIME CONFIDENCE IS LOW CONCERNING THE TIMING AND
IMPACTS OF THE NEXT SIGNIFICANT WEATHER MAKER WHICH MAY AFFECT THE
REGION LATE NEXT WEEK. GUSTY WINDS AND ANOTHER CHANCE FOR VALLEY
RAIN AND MOUNTAIN SNOW ARE POSSIBLE.

&&

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

&&

$$

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

DISCUSSION...GL
AVIATION/FIRE WEATHER...RH












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