[top]
000
FXUS65 KFGZ 251708
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1005 AM MST SAT MAY 25 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL REMAIN OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. A LOW
PRESSURE SYSTEM IS FORECAST TO AFFECT THE SOUTHWEST BY TUESDAY AND
WEDNESDAY OF NEXT WEEK...WITH COOLER TEMPERATURES AND A CHANCE OF
SHOWERS OR THUNDERSTORMS.
&&
.DISCUSSION...THE DRY...WARM...AND BREEZY WEATHER PATTERN WILL
CONTINUE TODAY. OVERALL...WEATHER CONDITIONS WILL BE VERY SIMILAR TO
YESTERDAY. FORECAST TRENDS ARE ON TRACK WITH NO MORNING UPDATES
NEEDED.
&&
.PREVIOUS DISCUSSION (330 AM MST)...A PERSISTENT CLOSED LOW PRESSURE
SYSTEM RESIDING OVER THE NORTHWEST U.S. WILL CONTINUE TO BRING DRY
CONDITIONS AND BREEZY SOUTHWEST WINDS TO NORTHERN ARIZONA THROUGH
MEMORIAL DAY. HIGH TEMPERATURES WILL BE WITHIN A DEGREE OR TWO OF
NORMAL.
TUESDAY INTO WEDNESDAY...THE NORTHWEST U.S. LOW DIGS A TROUGH OF LOW
PRESSURE SOUTHWARD INTO THE SOUTHWEST STATES. THIS WEATHER
DISTURBANCE WILL BRING AN INCREASE IN THE SOUTHWEST FLOW...BELOW
NORMAL HIGH TEMPERATURES...AND AN INCREASE IN MOISTURE AND
INSTABILITY WHICH WILL LEAD TO ISOLATED TO WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS LATE TUESDAY INTO WEDNESDAY. THE ECMWF HAS BEEN
CONSISTENTLY DEEPER WITH MOVING A LOW PRESSURE TROUGH THROUGH
ARIZONA...WITH COLDER TEMPERATURES WINDY CONDITIONS AND GREATER
CHANCES FOR PRECIPITATION. THE GFS HAS BEEN TRENDING CLOSER TO THE
ECMWF SOLUTIONS. FOR NOW THE FORECAST FOR TUESDAY INTO WEDNESDAY
COVER A BLEND BETWEEN BOTH THE GFS AND THE ECMWF.
THURSDAY AND FRIDAY...THE CLOSED LOW IS FORECAST TO MOVE EAST OVER
PORTIONS OF THE GREAT BASIN AND WYOMING. THIS PATTERN WILL CONTINUE
TO BRING A SOUTHWEST TO WESTERLY FLOW WITH BREEZY TO WINDY
CONDITIONS IN THE AFTERNOON. RH VALUES WILL BE FALLING INTO THE
SINGLE DIGITS TO LOWER TEENS BY FRIDAY. THE GFS AND ECMWF ARE VERY
DIFFERENT BY NEXT FRIDAY...THE GFS HAS A BUILDING RIDGE WHERE THE
ECMWF HAS THE STRONG CLOSED LOW OVER THE UPPER HIGH PLAINS STATES.
THE GFS SOLUTION WOULD BRING LIGHTER WINDS AND WARMER
TEMPERATURES...MEANWHILE THE ECMWF WOULD BRING MUCH COOLER
CONDITIONS ON NORTHWEST FLOW.
&&
.AVIATION...FOR THE 18Z PACKAGE...EXPECT VFR CONDITIONS WITH LIGHT
CIRRUS COVER 24 HOUR PERIOD. EXPECT SW SFC WINDS AT 15-30KTS THROUGH
02Z SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...A BROAD LOW PRESSURE SYSTEM WILL REMAIN ANCHORED
OVER THE PACIFIC NORTHWEST...BRINGING MORE BREEZY AND DRY CONDITIONS
TO THE REGION THROUGH SUNDAY. WIND SPEEDS ARE EXPECTED TO APPROACH
BUT NOT EXCEED CRITICAL FIRE WEATHER THRESHOLDS FOR OUR FIRE ZONES.
HOWEVER...A FEW OF THE WINDIER LOCATIONS MAY BRIEFLY EXCEED THESE
CRITICAL THRESHOLDS.
MONDAY THROUGH WEDNESDAY...ON MONDAY...LOW PRESSURE SYSTEM WILL
REMAIN IN PLACE ALONG THE WEST COAST...KEEPING ARIZONA IN A DRY
AND BREEZY WEATHER PATTERN. BY TUESDAY...A COLD FRONT PUSHES EAST
BRINGING STRONGER WINDS AND COOLER TEMPERATURES TO ARIZONA. A GOOD
CHANCE FOR CRITICAL FIRE WEATHER CONDITIONS IS EXPECTED FOR FIRE
ZONES BELOW 5000 FEET ELEVATION...NORTH OF THE MOGOLLON RIM.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........MCS/TC
AVIATION.......PETERSON
FIRE WEATHER...PETERSON
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
[top]
000
FXUS65 KPSR 251659
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
955 AM MST SAT MAY 25 2013
.SYNOPSIS...
DRY AND WARM CONDITIONS WILL PERSIST ACROSS THE REGION THROUGH THE
MEMORIAL DAY HOLIDAY WEEKEND. A QUICK MOVING LOW PRESSURE SYSTEM IS
EXPECTED TO AFFECT THE DESERT SOUTHWEST NEXT TUESDAY AND WEDNESDAY
BRINGING COOLER THAN NORMAL TEMPERATURES AND BREEZY TO WINDY
CONDITIONS. A WARMING TREND WITH CONTINUED DRY AIR IN PLACE SHOULD
MOVE IN FOR LATE NEXT WEEK.
&&
.DISCUSSION...
VIS/IR SATELLITE REVEALS A FEW HIGH CLOUDS DRIFTING ACROSS THE
REGION THIS MORNING. SURFACE CONDITIONS REMAIN WARM AND DRY...DEW
POINT TEMPS IN THE 20S ACROSS THE SOUTHWEST AZ DESERTS...SOMEWHAT
HIGHER INTO THE 30S ACROSS SOUTHEAST CALIFORNIA. THE KTWC SOUNDING
PROFILES OVER THE PAST SEVERAL DAYS DO SHOW A REPEATED SHALLOW
MOISTURE SEEP IN THE 800-700MB LAYER DUE TO A STRONGER NOCTURNAL LOW
LEVEL SOUTHERLY FLOW...BUT OTHER THAN THAT...NOT MUCH IN THE WAY OF
ATMOSPHERIC MOISTURE FOR ANY CLOUD DEVELOPMENT TO MAR THE SUNNY
FORECAST ON TAP FOR OUR AREA. REGIONAL UPPER AIR PLOTS OVER THE PAST
24 HOURS SHOW A 20-30MB INCREASE IN 500MB HEIGHTS...AND WITH THE
DRY CONDITIONS...SUNSHINE AND MIXING POTENTIAL...AFTERNOON TEMPS
SHOULD HEAT UP ONCE AGAIN CLOSE TO THE CENTURY MARK FOR SOME OF OUR
WARMER DESERT SITES. THE INHERITED FORECAST GRIDS CAPTURE THE
CURRENT OBSERVATIONS AND MODEL TRENDS...NO CHANGES NEEDED TO THE
FORECAST AT THIS TIME.
PREVIOUS DISCUSSION...
A FEW MORE DAYS OF THIS BLOCKING WEATHER PATTERN IS EXPECTED AS
SOUTHWESTERLY FLOW ALOFT DOMINATES THE DESERT SOUTHWEST AND
SHORTWAVE ENERGY PINWHEELS AROUND THE LARGE STATIONARY LOW OVER THE
PACIFIC NORTHWEST. THE LAST COUPLE DAYS HAVE BEEN A DEGREE OR TWO
WARMER THAN FORECAST...MOST LIKELY DUE TO SLIGHTLY HIGHER HEIGHTS
ACROSS THE REGION AND EFFICIENT DAYTIME MIXING UNDER THE BREEZY
CONDITIONS. GIVEN THIS TREND...HAVE BUMPED UP HIGHS TODAY A BIT WITH
MOST LOWER DESERT SPOTS NEARING THE CENTURY MARK. THIS SHOULD BE THE
LAST DAY OF ABOVE NORMAL TEMPERATURES THROUGH MID NEXT WEEK AS THE
NEXT WEATHER SYSTEM WILL DIVE MUCH FURTHER SOUTH. A COUPLE MINOR
SHORTWAVE IMPULSES HELP TO BRING DOWN HEIGHTS AND TEMPERATURES
BEGINNING SUNDAY AND MONDAY...ONE TRACKING ACROSS THE GREAT BASIN ON
SUNDAY AND ANOTHER COMING ONSHORE IN SOUTHERN CALIFORNIA ON MONDAY.
THIS SHOULD ALLOW FOR AT LEAST SOME HIGH CLOUDINESS AND HIGHS 2-5
DEGREES COOLER THAN NORMAL WITH THE COOLEST TEMPERATURES ACROSS OUR
WESTERN ZONES.
THE TRACK AND STRENGTH OF THE MAIN WEATHER FEATURE THAT WE HAVE BEEN
FOLLOWING OVER THE PAST COUPLE DAYS IS STILL SOMEWHAT
UNCERTAIN...BUT OVERALL...MODELS ARE STARTING TO COME TO A
CONSENSUS. THE EUROPEAN IS SLIGHTLY STRONGER...FURTHER SOUTH...AND
MORE MOIST THAN THE GFS...BUT AT LEAST THE OPERATIONAL RUN AND EACH
MODEL/S ENSEMBLE MEMBERS SHOW LESS SPREAD THAN THE LAST COUPLE DAYS.
THE CURRENT FORECAST REFLECTS A FAIRLY EVEN BLEND BETWEEN THE TWO
SOLUTIONS WITH THE MAIN SHORTWAVE TROUGH TRACKING THROUGH THE
NORTHERN HALF OF ARIZONA TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS
TRACK WILL DEFINITELY BRING IN COOLER AIR...BUT NOT QUITE AS MUCH AS
MODELS HAD BEEN SHOWING THE PAST SEVERAL RUNS. MOISTURE AVAILABILITY
WILL STILL BE ON THE FAIRLY LOW SIDE AND WITH A TRACK TO OUR
NORTH...ANY PRECIPITATION CHANCES WILL GENERALLY BE CONFINED TO THE
NORTHERN HALF OF THE STATE. FORECAST CONFIDENCE IN THIS SOLUTION IS
MUCH BETTER THAN THE SEVERAL DAYS...BUT THERE IS ALWAYS STILL ROOM
FOR ADJUSTMENTS TO BE MADE. THE SYSTEM WILL ALSO BRING INCREASED
WINDS...BUT CURRENT THINKING IS SPEEDS SHOULD REMAIN WELL BELOW
ADVISORY STRENGTH.
FOR LATE NEXT WEEK...A NORTHWEST TO WESTERLY UPPER FLOW IS LIKELY
ACROSS THE DESERT SOUTHWEST WITH A BROAD TROUGH ACROSS THE CENTRAL
UNITED STATES. THIS SHOULD LEAD TO A MODERATING OF TEMPERATURES FOR
THURSDAY AND FRIDAY WITH HIGHS RETURNING TO AROUND OR SLIGHTLY ABOVE
SEASONAL NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL...ONCE AGAIN...KEEP SKIES CLEAR TO
MOSTLY CLEAR THROUGH THE TAF PERIOD. WINDS ARE EXPECTED TO FOLLOW
THE USUAL DIURNAL TRENDS IN DIRECTION AND SPEED...WITH WESTERLY
BREEZES REDEVELOPING DURING THE AFTERNOON AND EVENING HOURS ON
SATURDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
LOW PRESSURE ALONG THE WEST COAST WILL BEGIN TO PUSH INLAND OVER THE
DESERT SOUTHWEST LATE MONDAY...THEN SLOWLY MOVE EASTWARD ACROSS THE
REGION ON TUESDAY AND WEDNESDAY. AS A RESULT...TEMPERATURES ARE
EXPECTED TO FALL FROM THE MID AND UPPER 90S ON MONDAY INTO THE UPPER
80S AND LOW 90S ON TUESDAY AND WEDNESDAY ACROSS THE LOWER DESERTS.
ALTHOUGH SOME INCREASE IN THE WIND SPEEDS CAN ALSO BE EXPECTED ON
TUESDAY AND WEDNESDAY AFTERNOON...SLIGHTLY HIGHER HUMIDITIES WILL
KEEP FIRE DANGER VALUES FROM REACHING CRITICAL LEVELS. TEMPERATURES
WILL THEN RECOVER TO NEAR-NORMAL VALUES ON THURSDAY AND
FRIDAY...WITH A RETURN TO SINGLE DIGIT DAYTIME HUMIDITIES...AND
LIGHTER WINDS AS A DRY WESTERLY FLOW RETURNS TO THE REGION.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MEYERS/KUHLMAN
AVIATION...PERCHA
FIRE WEATHER...PERCHA
[top]
000
FXUS65 KTWC 251645
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
945 AM MST SAT MAY 25 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW ACROSS SOUTHEAST ARIZONA THROUGH
THIS HOLIDAY WEEKEND. EXPECT SOME INCREASE IN CLOUDS WITH BREEZY
TO LOCALLY WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A
DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY COOLER DAYTIME
TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE MOSTLY SUNNY SKIES ACROSS SE AZ AT THIS TIME...WITH ONLY A
FEW CIRRIFORM CLOUDS MOVING NEWD MAINLY NORTH OF TUCSON. 25/12Z KTWC
SOUNDING SUPPORTS A HIGH TEMP THIS AFTERNOON OF 96 F...WHICH IS
WITHIN A DEGREE OF THE OFFICIAL FORECAST HIGH TEMP FOR KTUS. AT ANY
RATE...ABUNDANT SUNSHINE IS ON TAP TODAY WITH A FEW TO PERHAPS
SCATTERED CIRRIFORM CLOUDS. BASED ON RECEIPT OF THE 25/12Z NAM/GFS...
THERE ARE NO UPDATES PLANNED AT THIS TIME. PLEASE REFER TO THE
PREVIOUS DISCUSSION SECTION BELOW FOR ADDITIONAL DETAIL.
&&
.PREV DISCUSSION /215 AM MST SAT MAY 25 2013/...A DRY SOUTHWESTERLY
FLOW ALOFT WILL CONTINUE AS A LOW PRESSURE TROUGH REMAINS OVER THE
WESTERN STATES. DAYTIME TEMPERATURES WILL DROP A DEGREE OR TWO EACH
DAY THE NEXT FEW DAYS AS HEIGHTS AND THICKNESSES LOWER WITH THE MEAN
TROUGH DEEPENING. THE MAIN FORECAST CHALLENGE WILL BE FOR EARLY TO
MID NEXT WEEK. MODELS CONTINUED TO DIFFER SIGNIFICANTLY ON THE TRACK
AND STRENGTH OF A SHORTWAVE THAT WAS PROGGED TO PASS THROUGH THE
REGION AROUND TUESDAY INTO WEDNESDAY. THE ECMWF SOLUTION DEPICTED AN
UPPER LOW DEVELOPING OVER THE DESERT SOUTHWEST WITH THE POSSIBILITY
OF SHOWERS THIS FAR SOUTH. THE GFS ON THE OTHER HAND SHOWED NO SUCH
FEATURE WITH THE BEST CHANCE OF SHOWERS ACROSS NORTHERN ARIZONA. FOR
NOW...WILL INTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS IN THE WHITE
MOUNTAINS FOR MAINLY WEDNESDAY. ELSEWHERE...WILL JUST CONTINUE THE
GENERAL TREND TOWARD COOLER DAYTIME TEMPERATURES...INCREASING
CLOUDINESS...AND BREEZY TO WINDY CONDITIONS BY THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION...SKC-SCT CLOUDS ABOVE 20K FT AGL THRU SUNDAY MORNING OR
26/18Z. SURFACE WIND THIS AFTERNOON AND EARLY THIS EVENING SLY/SWLY
12-18 KTS WITH GUSTS TO AROUND 25 KTS. OTHERWISE...SURFACE WIND
GENERALLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH OF LOW PRESSURE OVER THE PACIFIC NORTHWEST
WILL RESULT IN A DRY WEATHER PATTERN FOR SOUTHEAST ARIZONA THIS
WEEKEND. EXPECT SOUTHWEST WINDS THE NEXT COUPLE OF DAYS WITH
STRONGER GUSTS DURING THE AFTERNOON AND EARLY EVENING HOURS.
OTHERWISE...THERE WILL BE AN INCREASE IN CLOUDS...ALONG WITH BREEZY
TO LOCALLY WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A
DISTURBANCE MOVES ACROSS THE REGION. COOLER DAYTIME TEMPERATURES
WILL ALSO OCCUR BY THE MIDDLE OF THE UPCOMING WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
BF
000
FXUS65 KFGZ 251030
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST SAT MAY 25 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL REMAIN OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. A LOW
PRESSURE SYSTEM IS FORECAST TO AFFECT THE SOUTHWEST BY TUESDAY AND
WEDNESDAY OF NEXT WEEK...WITH COOLER TEMPERATURES AND A CHANCE OF
SHOWERS OR THUNDERSTORMS.
&&
.DISCUSSION...A PERSISTENT CLOSED LOW PRESSURE SYSTEM RESIDING OVER
THE NORTHWEST U.S. WILL CONTINUE TO BRING DRY CONDITIONS AND BREEZY
SOUTHWEST WINDS TO NORTHERN ARIZONA THROUGH MEMORIAL DAY. HIGH
TEMPERATURES WILL BE WITHIN A DEGREE OR TWO OF NORMAL.
TUESDAY INTO WEDNESDAY...THE NORTHWEST U.S. LOW DIGS A TROUGH OF LOW
PRESSURE SOUTHWARD INTO THE SOUTHWEST STATES. THIS WEATHER
DISTURBANCE WILL BRING AN INCREASE IN THE SOUTHWEST FLOW...BELOW
NORMAL HIGH TEMPERATURES...AND AN INCREASE IN MOISTURE AND
INSTABILITY WHICH WILL LEAD TO ISOLATED TO WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS LATE TUESDAY INTO WEDNESDAY. THE ECMWF HAS BEEN
CONSISTENTLY DEEPER WITH MOVING A LOW PRESSURE TROUGH THROUGH
ARIZONA...WITH COLDER TEMPERATURES WINDY CONDITIONS AND GREATER
CHANCES FOR PRECIPITATION. THE GFS HAS BEEN TRENDING CLOSER TO THE
ECMWF SOLUTIONS. FOR NOW THE FORECAST FOR TUESDAY INTO WEDNESDAY
COVER A BLEND BETWEEN BOTH THE GFS AND THE ECMWF.
THURSDAY AND FRIDAY...THE CLOSED LOW IS FORECAST TO MOVE EAST OVER
PORTIONS OF THE GREAT BASIN AND WYOMING. THIS PATTERN WILL CONTINUE
TO BRING A SOUTHWEST TO WESTERLY FLOW WITH BREEZY TO WINDY
CONDITIONS IF THE AFTERNOON. RH VALUES WILL BE FALLING INTO THE
SINGLE DIGITS TO LOWER TEENS BY FRIDAY. THE GFS AND ECMWF ARE VERY
DIFFERENT BY NEXT FRIDAY...THE GFS HAS A BUILDING RIDGE WHERE THE
ECMWF HAS THE STRONG CLOSED LOW OVER THE UPPER HIGH PLAINS STATES.
THE GFS SOLUTION WOULD BRING LIGHTER WINDS AND WARMER
TEMPERATURES...MEANWHILE THE ECMWF WOULD BRING MUCH COOLER
CONDITIONS ON NORTHWEST FLOW.
&&
.AVIATION...FOR THE 12Z PACKAGE...EXPECT VFR CONDITIONS...BREEZY
WINDS AND OCCASIONAL HIGH CLOUDS THROUGH THE 24 HOUR PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...A BROAD LOW PRESSURE SYSTEM WILL REMAIN ANCHORED
OVER THE PACIFIC NORTHWEST...BRINGING MORE BREEZY AND DRY CONDITIONS
TO THE REGION THROUGH SUNDAY. WIND SPEEDS ARE EXPECTED TO APPROACH
BUT NOT EXCEED CRITICAL FIRE WEATHER THRESHOLDS FOR OUR FIRE ZONES.
HOWEVER...A FEW OF THE WINDIER LOCATIONS MAY BRIEFLY EXCEED THESE
CRITICAL THRESHOLDS.
MONDAY THROUGH WEDNESDAY...ON MONDAY...THE LOW PRESSURE TROUGH WILL
REMAIN IN PLACE ALONG THE WEST COAST KEEPING ARIZONA IN A DRY AND
BREEZY WEATHER PATTERN. BY TUESDAY...A COLD FRONT PUSHES EAST
BRINGING STRONGER WINDS AND COOLER TEMPERATURES TO ARIZONA WITH A
GOOD CHANCE FOR WARNING CONDITIONS FOR FIRE ZONES BELOW 5000 FEET
ELEVATION NORTH OF THE MOGOLLON RIM.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........TC
AVIATION.......BOHLIN
FIRE WEATHER...BOHLIN
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KPSR 250950
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 AM MST SAT MAY 25 2013
.SYNOPSIS...
DRY AND WARM CONDITIONS WILL PERSIST ACROSS THE REGION THROUGH THE
MEMORIAL DAY HOLIDAY WEEKEND. A QUICK MOVING LOW PRESSURE SYSTEM IS
EXPECTED TO AFFECT THE DESERT SOUTHWEST NEXT TUESDAY AND WEDNESDAY
BRINGING COOLER THAN NORMAL TEMPERATURES AND BREEZY TO WINDY
CONDITIONS. A WARMING TREND WITH CONTINUED DRY AIR IN PLACE SHOULD
MOVE IN FOR LATE NEXT WEEK.
&&
.DISCUSSION...
A FEW MORE DAYS OF THIS BLOCKING WEATHER PATTERN IS EXPECTED AS
SOUTHWESTERLY FLOW ALOFT DOMINATES THE DESERT SOUTHWEST AND
SHORTWAVE ENERGY PINWHEELS AROUND THE LARGE STATIONARY LOW OVER THE
PACIFIC NORTHWEST. THE LAST COUPLE DAYS HAVE BEEN A DEGREE OR TWO
WARMER THAN FORECAST...MOST LIKELY DUE TO SLIGHTLY HIGHER HEIGHTS
ACROSS THE REGION AND EFFICIENT DAYTIME MIXING UNDER THE BREEZY
CONDITIONS. GIVEN THIS TREND...HAVE BUMPED UP HIGHS TODAY A BIT WITH
MOST LOWER DESERT SPOTS NEARING THE CENTURY MARK. THIS SHOULD BE THE
LAST DAY OF ABOVE NORMAL TEMPERATURES THROUGH MID NEXT WEEK AS THE
NEXT WEATHER SYSTEM WILL DIVE MUCH FURTHER SOUTH. A COUPLE MINOR
SHORTWAVE IMPULSES HELP TO BRING DOWN HEIGHTS AND TEMPERATURES
BEGINNING SUNDAY AND MONDAY...ONE TRACKING ACROSS THE GREAT BASIN ON
SUNDAY AND ANOTHER COMING ONSHORE IN SOUTHERN CALIFORNIA ON MONDAY.
THIS SHOULD ALLOW FOR AT LEAST SOME HIGH CLOUDINESS AND HIGHS 2-5
DEGREES COOLER THAN NORMAL WITH THE COOLEST TEMPERATURES ACROSS OUR
WESTERN ZONES.
THE TRACK AND STRENGTH OF THE MAIN WEATHER FEATURE THAT WE HAVE BEEN
FOLLOWING OVER THE PAST COUPLE DAYS IS STILL SOMEWHAT
UNCERTAIN...BUT OVERALL...MODELS ARE STARTING TO COME TO A
CONSENSUS. THE EUROPEAN IS SLIGHTLY STRONGER...FURTHER SOUTH...AND
MORE MOIST THAN THE GFS...BUT AT LEAST THE OPERATIONAL RUN AND EACH
MODEL/S ENSEMBLE MEMBERS SHOW LESS SPREAD THAN THE LAST COUPLE DAYS.
THE CURRENT FORECAST REFLECTS A FAIRLY EVEN BLEND BETWEEN THE TWO
SOLUTIONS WITH THE MAIN SHORTWAVE TROUGH TRACKING THROUGH THE
NORTHERN HALF OF ARIZONA TUESDAY NIGHT INTO WEDNESDAY MORNING. THIS
TRACK WILL DEFINITELY BRING IN COOLER AIR...BUT NOT QUITE AS MUCH AS
MODELS HAD BEEN SHOWING THE PAST SEVERAL RUNS. MOISTURE AVAILABILITY
WILL STILL BE ON THE FAIRLY LOW SIDE AND WITH A TRACK TO OUR
NORTH...ANY PRECIPITATION CHANCES WILL GENERALLY BE CONFINED TO THE
NORTHERN HALF OF THE STATE. FORECAST CONFIDENCE IN THIS SOLUTION IS
MUCH BETTER THAN THE SEVERAL DAYS...BUT THERE IS ALWAYS STILL ROOM
FOR ADJUSTMENTS TO BE MADE. THE SYSTEM WILL ALSO BRING INCREASED
WINDS...BUT CURRENT THINKING IS SPEEDS SHOULD REMAIN WELL BELOW
ADVISORY STRENGTH.
FOR LATE NEXT WEEK...A NORTHWEST TO WESTERLY UPPER FLOW IS LIKELY
ACROSS THE DESERT SOUTHWEST WITH A BROAD TROUGH ACROSS THE CENTRAL
UNITED STATES. THIS SHOULD LEAD TO A MODERATING OF TEMPERATURES FOR
THURSDAY AND FRIDAY WITH HIGHS RETURNING TO AROUND OR SLIGHTLY ABOVE
SEASONAL NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL...ONCE AGAIN...KEEP SKIES CLEAR TO
MOSTLY CLEAR THROUGH THE TAF PERIOD. WINDS ARE EXPECTED TO FOLLOW
THE USUAL DIURNAL TRENDS IN DIRECTION AND SPEED...WITH WESTERLY
BREEZES REDEVELOPING DURING THE AFTERNOON AND EVENING HOURS ON
SATURDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
LOW PRESSURE ALONG THE WEST COAST WILL BEGIN TO PUSH INLAND OVER THE
DESERT SOUTHWEST LATE MONDAY...THEN SLOWLY MOVE EASTWARD ACROSS THE
REGION ON TUESDAY AND WEDNESDAY. AS A RESULT...TEMPERATURES ARE
EXPECTED TO FALL FROM THE MID AND UPPER 90S ON MONDAY INTO THE UPPER
80S AND LOW 90S ON TUESDAY AND WEDNESDAY ACROSS THE LOWER DESERTS.
ALTHOUGH SOME INCREASE IN THE WIND SPEEDS CAN ALSO BE EXPECTED ON
TUESDAY AND WEDNESDAY AFTERNOON...SLIGHTLY HIGHER HUMIDITIES WILL
KEEP FIRE DANGER VALUES FROM REACHING CRITICAL LEVELS. TEMPERATURES
WILL THEN RECOVER TO NEAR-NORMAL VALUES ON THURSDAY AND
FRIDAY...WITH A RETURN TO SINGLE DIGIT DAYTIME HUMIDITIES...AND
LIGHTER WINDS AS A DRY WESTERLY FLOW RETURNS TO THE REGION.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
AVIATION...PERCHA
FIRE WEATHER...PERCHA
000
FXUS65 KTWC 250915
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
215 AM MST SAT MAY 25 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW ACROSS SOUTHEAST ARIZONA THROUGH
THE HOLIDAY WEEKEND. EXPECT SOME INCREASE IN CLOUDS WITH BREEZY
TO LOCALLY WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A
DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY COOLER DAYTIME
TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...A DRY SOUTHWESTERLY FLOW ALOFT WILL CONTINUE AS A LOW
PRESSURE TROUGH REMAINS OVER THE WESTERN STATES. DAYTIME
TEMPERATURES WILL DROP A DEGREE OR TWO EACH DAY THE NEXT FEW DAYS AS
HEIGHTS AND THICKNESSES LOWER WITH THE MEAN TROUGH DEEPENING. THE
MAIN FORECAST CHALLENGE WILL BE FOR EARLY TO MID NEXT WEEK. MODELS
CONTINUED TO DIFFER SIGNIFICANTLY ON THE TRACK AND STRENGTH OF A
SHORTWAVE THAT WAS PROGGED TO PASS THROUGH THE REGION AROUND TUESDAY
INTO WEDNESDAY. THE ECMWF SOLUTION DEPICTED AN UPPER LOW DEVELOPING
OVER THE DESERT SOUTHWEST WITH THE POSSIBILITY OF SHOWERS THIS FAR
SOUTH. THE GFS ON THE OTHER HAND SHOWED NO SUCH FEATURE WITH THE
BEST CHANCE OF SHOWERS ACROSS NORTHERN ARIZONA. FOR NOW...WILL
INTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS IN THE WHITE MOUNTAINS
FOR MAINLY WEDNESDAY. ELSEWHERE...WILL JUST CONTINUE THE GENERAL
TREND TOWARD COOLER DAYTIME TEMPERATURES...INCREASING
CLOUDINESS...AND BREEZY TO WINDY CONDITIONS BY THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION...SKC CONDITIONS EXPECTED THRU SUNDAY MORNING OR 26/14Z.
SURFACE WIND LESS THAN 10 KTS THRU 25/15Z...THEN INCREASING SURFACE
WIND WITH SLY/SWLY AT 13-18 KTS WITH GUSTS TO NEAR 30 KTS BETWEEN
25/18Z AND 26/02Z. SURFACE WIND GENERALLY LESS THAN 10 KTS AFT
26/04Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH OF LOW PRESSURE OVER THE PACIFIC NORTHWEST
WILL RESULT IN A DRY WEATHER PATTERN FOR SOUTHEAST ARIZONA INTO
EARLY NEXT WEEK. EXPECT SOUTHWEST WINDS THE NEXT COUPLE OF DAYS WITH
STRONGER GUSTS DURING THE AFTERNOON AND EARLY EVENING HOURS.
OTHERWISE...THERE WILL BE AN INCREASE IN CLOUDS...ALONG WITH BREEZY
TO LOCALLY WINDY CONDITIONS MONDAY THROUGH WEDNESDAY OF NEXT WEEK AS
A DISTURBANCE MOVES ACROSS THE REGION. COOLER DAYTIME TEMPERATURES
WILL ALSO OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
000
FXUS65 KPSR 250459
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1000 PM MST FRI MAY 24 2013
.SYNOPSIS...
LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY
CONDITIONS AT TIMES INTO NEXT WEEK. ANTICIPATE LITTLE CHANGE IN
TEMPERATURES THROUGH SUNDAY. THEREAFTER...A TROUGH ALONG THE
WEST COAST IS ANTICIPATED TO DEEPEN WHICH WILL LEAD TO SOME MODEST
COOLING MONDAY WITH SOME MORE NOTICEABLE COOLING TUESDAY AND
WEDNESDAY.
&&
.DISCUSSION...
DOMINANT SOUTHWEST FLOW CONTINUES TO SPREAD MOSTLY DRY AREA ACROSS
THE REGION WITH LINGERING EVENING BREEZINESS. PAC NW LOW HAS
EXPANDED NORTHWARD INTO CANADA...WITH LONGWAVE TROUGHING EXPANDING
DOWN INTO THE INTERMOUNTAIN WEST. PERSISTENCE WILL REIGN OVER THE
FORECAST...WITH CONTINUED AFTERNOON BREEZINESS AND MILD LATE MAY
TEMPERATURES THROUGH THE HOLIDAY WEEKEND. NO MAJOR UPDATES PLANNED
TO THE FORECAST GRIDS TONIGHT...JUST MINOR TWEAKS TO TREND THE GRIDS
CLOSER TO EVENING OBSERVATIONS.
&&
.PREVIOUS DISCUSSION /ISSUED 150 PM MST/PDT/...
FOR THE NEXT FEW DAYS...NO SIGNIFICANT CHANGES TO THE WEATHER
PATTERN ARE EXPECTED...AT LEAST NONE THAT WILL CHANGE OUR SENSIBLE
WEATHER VERY MUCH. A SERIES OF PV ANOMALIES/VORT MAXES ROTATE AROUND
THE MAIN UPPER LOW AND INTO THE PAC NW...KEEPING PERSISTENT SWLY
FLOW ALOFT IN PLACE ACROSS ARIZONA THRU THE WEEKEND AND INTO EARLY
NEXT WEEK. H5 HEIGHTS/THICKNESSES CHANGE LITTLE OVER THIS TIME AND
AS SUCH HIGH TEMPS WILL REMAIN IN THE MID 90S TO AROUND 100 SATURDAY
INTO NEXT MONDAY. PROGS INDICATE THAT THERE WILL BE AN INCREASE IN
HIGH CLOUDS MONDAY FOR PARTLY SUNNY SKIES...BUT UNTIL THEN EXPECT
MOSTLY SUNNY OR SUNNY DAYS AND CLEAR NIGHTS. AFTERNOON AND EARLY
EVENING BREEZES WILL BE ON TAP TONIGHT INTO MONDAY AS WELL AS MID
LEVEL GRADIENTS REMAIN SOMEWHAT TIGHT.
PROGS AGREE THAT A LARGE AND RATHER PROGRESSIVE UPPER TROF WILL
DEVELOP ALONG THE PAC NW COAST...THEN SLIDE SOUTHEASTWARD AND INTO
OUR REGION BY NEXT TUESDAY. MODEL DIFFERENCES ARE STILL PROBLEMATIC
WITH THE OPERATIONAL EUROPEAN LIKELY ON THE OVERLY STRONG AND WET
SIDE OF THE SPECTRUM AND THE GEM ON THE OPPOSITE SIDE OF THE
SPECTRUM WITH THE MAIN SHORTWAVE ENDING UP ACROSS THE PACIFIC
NORTHWEST. THE EUROPEAN AND GFS ENSEMBLE MEANS ARE FAIRLY CLOSE TO
EACH OTHER IN SPEED AND STRENGTH WITH MORE SPREAD SEEN WITHIN THE
EUROPEAN ENSEMBLE MEMBERS. GIVEN THIS...HAVE TRENDED THE CURRENT
FORECAST TOWARD THE GFS...GFS ENSEMBLE MEAN...AND EUROPEAN ENSEMBLE
MEAN. THIS STILL RESULTS IN A MODEST COOLDOWN OF 5-10 DEGREES FOR
THE MIDDLE OF NEXT WEEK...AND ESPECIALLY TUESDAY AND WEDNESDAY WITH
THE POTENTIAL FOR DECENT MID AND HIGH LEVEL MOISTURE AND RESULTING
CLOUD COVER. PRECIPITATION CHANCES STILL LOOK FAIRLY LOW GIVEN
OVERALL FAIRLY DRY AIRMASS...WHICH WOULD BE LIKELY GIVEN THE TIME OF
YEAR AND VERY LOW POPS EXPECTED BY CLIMO. HAVE ELECTED TO MOSTLY
IGNORE THE OPERATIONAL EUROPEAN QPF FORECAST FOR THE REGION GIVEN
IT/S OVERLY STRONG SOLUTION...BUT HAVE AT LEAST INCLUDED SLIGHTLY
HIGHER THAN CLIMO POPS FOR TUESDAY INTO WEDNESDAY. IF OTHER MODEL
SOLUTIONS START TRENDING TOWARD THE STRONGER EUROPEAN...HIGHER POPS
WILL BE NEEDED.
DRY WESTERLY FLOW ALOFT WILL FOLLOW ON THURSDAY FOR MOSTLY SUNNY
SKIES...ALONG WITH WARMING TEMPERATURES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL CONTINUE MOSTLY CLEAR SKIES AND
ELEVATED EVENING BREEZINESS THROUGH THE LATE EVENING. WINDS FOR THE
PHX TERMINALS WILL GRADUALLY DECREASE TO VRB BEFORE PICKING UP
TYPICAL EASTERLY DRAINAGES WHILE KIPL AND KBLH WILL CONTINUE
SOUTHWEST-WEST HEADINGS WITH PERIODIC GUSTS UP TO 20KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
LARGE AREA OF ALMOST STATIONARY LOW PRESSURE ACROSS THE NORTHWEST
U.S. WILL BEGIN TO OPEN UP INTO A MORE NOTICEABLE TROUGHING PATTERN
BY MONDAY. A SERIES OF DRY WEATHER SYSTEMS WILL MOVE THROUGH THE
PREDOMINATELY SOUTHWEST FLOW...PERSISTING AFTERNOON AND EARLY
EVENING WINDS WHILE ALSO INTRODUCING A MILD COOLING TREND. WITH
CURRENT FORECAST MODEL GUIDANCE...WINDS LOOK TO BE THEIR STRONGEST
LATE TUESDAY INTO WEDNESDAY...HOWEVER AT THIS TIME REMAINING BELOW
CRITICAL FIRE WEATHER THRESHOLDS. HUMIDITIES WILL SEE A SLIGHT
INCREASE MIDWEEK WITH THE COOLER TEMPERATURES AND POTENTIAL FOR SOME
WEAK LOW LEVEL MOISTURE ADVECTION...AHEAD OF THE MOST PROMISING
WEATHER SYSTEM ATTM. OVERALL...CONDITIONS FOR THE SOUTHWEST FIRE
DISTRICTS WILL REMAIN DRY AS DRY WESTERLY FLOW RETURNS TO THE REGION
LATE WEEK. NEAR NORMAL TEMPERATURES WITH A RETURN TO SINGLE DIGIT
DAYTIME HUMIDITIES ARE EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
PREVIOUS DISCUSSION...CB/KUHLMAN
AVIATION...NOLTE
FIRE WEATHER...NOLTE
000
FXUS65 KFGZ 250408
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
905 PM MST FRI MAY 24 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL REMAIN OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. A LOW
PRESSURE SYSTEM IS FORECAST TO AFFECT THE SOUTHWEST BY TUESDAY AND
WEDNESDAY OF NEXT WEEK...WITH COOLER TEMPERATURES AND A CHANCE OF
SHOWERS OR THUNDERSTORMS.
&&
.DISCUSSION...DRY CONDITIONS WITH LOCAL SOUTHWEST BREEZES CAN BE
EXPECTED OVERNIGHT. NO UPDATES TO THE FORECAST PLANNED FOR THE
OVERNIGHT TIME PERIOD TONIGHT.
&&
.PREVIOUS DISCUSSION /330 PM MST/...A LARGE UPPER LEVEL CLOSED LOW
OVER THE NORTHWEST U.S. AND RIDGING ACROSS THE CENTRAL PART OF THE
COUNTRY WILL KEEP AZ IN A VERY PERSISTENT DRY AND BREEZY WEATHER
PATTERN THROUGH THE UPCOMING HOLIDAY WEEKEND. SOUTHWEST FLOW WILL
PREVAIL WITH SURFACE WIND SPEEDS EACH AFTERNOON GENERALLY RANGING
FROM 15-25 MPH WITH GUSTS IN THE 30-35 MPH RANGE. NEAR TO SLIGHTLY
ABOVE AVERAGE TEMPERATURES AND LOW AFTERNOON HUMIDITY ARE EXPECTED.
OTHER THAN PERIODIC HIGH CLOUDS...SKIES LOOK TO REMAIN MOSTLY CLEAR
THROUGH SUNDAY. A MORE SUBSTANTIAL INCREASE IN HIGH CLOUDS LOOKS
LIKELY ON MONDAY.
TUESDAY ONWARD...CONFIDENCE DECREASES IN THE LONG TERM PORTION OF
THE FORECAST AS A RESULT OF DECREASED MODEL CONSISTENCY. THE 24/12Z
RUN OF THE ECMWF CONTINUES TO SHOW A CLOSED LOW DROPPING INTO THE
SOUTHWEST U.S. TUESDAY NIGHT AND ACROSS NORTHERN AZ ON WEDNESDAY.
HOWEVER..THE 24/12Z RUN OF THE GFS SHOWS A MORE OPEN WAVE TROUGH
MOVING THROUGH THE ROCKY MOUNTAIN REGION. IN ADDITION...THE
ENSEMBLES OF BOTH MODELS STILL SHOW CONSIDERABLE SPREAD IN
SOLUTIONS. WE WILL CONTINUE WITH A BLEND BETWEEN THE GFS/ECMWF
SOLUTIONS UNTIL CONSISTENCY IMPROVES. THIS FEATURES A TREND TOWARD
COOLER TEMPERATURES BY THE MIDDLE OF NEXT WEEK AND A CHANCE FOR
SHOWERS/THUNDERSTORMS MAINLY TUESDAY NIGHT THROUGH WEDNESDAY.
&&
.AVIATION...FOR THE 06Z PACKAGE...EXPECT VFR CONDITIONS UNDER
OCCASIONAL HIGH CLOUDS THROUGH THE 24 HOUR PERIOD. SFC WINDS WILL
RANGE FROM 15-30KTS FROM THE SW AFT 17Z SATURDAY AND BECOME LIGHT
AND VARIABLE WINDS BETWEEN 01-03Z SUNDAY. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...A DEEP LOW PRESSURE SYSTEM WILL REMAIN OVER THE
PACIFIC NORTHWEST...BRINGING MORE BREEZY AND DRY CONDITIONS TO THE
REGION SATURDAY AND SUNDAY. ALTHOUGH CONDITIONS ARE NOT EXPECTED TO
EXCEED CRITICAL FIRE WEATHER THRESHOLDS OVER A LARGE AREA OR A
PERSISTENT AMOUNT OF TIME...SOME LOCATIONS MAY EXPERIENCE BRIEF
PERIODS CRITICAL FIRE WEATHER CONDITIONS. DAYTIME RELATIVE HUMIDITY
VALUES WILL REMAIN BELOW 10 TO 15 PERCENT...WITH ONLY MODERATE
OVERNIGHT RECOVERY.
MONDAY THROUGH WEDNESDAY...LOW PRESSURE WILL REMAIN IN PLACE ACROSS
THE WESTERN UNITED STATES AND WILL ALLOW BREEZY SOUTHWEST WINDS AND
DRY CONDITIONS TO CONTINUE ON MONDAY. THE TROUGH WILL MOVE EAST AND
APPROACH ARIZONA ON TUESDAY...BRINGING COOLER TEMPERATURES AND A
CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........TC/MCS
AVIATION.......TC/PETERSON
FIRE WEATHER...PETERSON
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KTWC 250405
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
905 PM MST FRI MAY 24 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW ACROSS SOUTHEAST ARIZONA THROUGH
THE HOLIDAY WEEKEND. EXPECT SOME INCREASE IN CLOUDS WITH BREEZY
TO LOCALLY WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A
DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY COOLER DAYTIME
TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...IR SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATED A FEW-TO-SCATTERED CIRRIFORM CLOUDS FROM THE TUCSON METRO
AREA EWD TO THE NEW MEXICO BORDER AT THIS TIME. CLEAR SKIES
PREVAILED ACROSS WRN/CENTRAL PIMA COUNTY AND SOUTH-CENTRAL PINAL
COUNTY. SURFACE WINDS HAD DIMINISHED TO GENERALLY LESS THAN 10 MPH
ACROSS MUCH OF SE AZ.
HAVE MAINTAINED MOSTLY CLEAR SKIES FOR THE REST OF TONIGHT GENERALLY
FROM TUCSON EWD/SWD WITH CLEAR SKIES ACROSS WRN SECTIONS. MOSTLY
SUNNY SKIES TO THEN OCCUR SATURDAY WITH SOME CIRRIFORM CLOUDS TO
MOVE ACROSS THE AREA. HIGH TEMPS SATURDAY WILL AVERAGE WITHIN A FEW
DEGREES OF NORMAL. PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION
BELOW FOR ADDITIONAL DETAIL.
&&
.PREV DISCUSSION /210 PM MST FRI MAY 24 2013/...PERSISTENT PATTERN
CONTINUES THROUGH THE HOLIDAY WEEKEND WITH SOUTHWEST FLOW ALOFT
BRINGING AFTERNOON BREEZES AND NEAR NORMAL HIGH TEMPERATURES. AFTER
THAT THE MAIN FORECAST CHALLENGE CONCERNS THE AMOUNT OF ENERGY THAT
WILL DIVE SOUTHWARD TOWARD ARIZONA DURING THE MIDDLE OF NEXT WEEK.
COMPARISON OF 00Z AND 12Z GFS MODEL RUNS SHOWS DECENT CONSISTENCY
WITH THE LATITUDE OF THE OPEN TROUGH CROSSING IN THE INTERMOUNTAIN
WEST. MEANWHILE THE ECMWF CONTINUES TRACKING A CLOSED LOW ACROSS
ARIZONA. THE GFS ENSEMBLE MEMBERS WERE FAIRLY CONSISTENT WITH A HIGH
RELATIVE MEASURE OF PROBABILITY VALUE SHOWING UP FOR THE 00Z
SOLUTION AT 12Z WED.
WITH THE ABOVE IN MIND...NOT DEVIATING FROM THE MORE
CLIMATOLOGICALLY REPRESENTATIVE GFS SOLUTION OF AN OPEN TROUGH
PASSING ACROSS ARIZONA NEXT WEEK ALTHOUGH WOULD NOT BE SURPRISED IF
LATER GFS VERSIONS DEEPEN SLIGHTLY. IN ANY EVENT...THE TROUGH SHOULD
ENHANCE WINDS MON-WED. SOME COOLING ALSO EXPECTED WITH HIGH
TEMPERATURES AROUND FIVE DEGREES BELOW NORMAL BY WEDNESDAY. WHETHER
IT IS ANY COOLER THAN THAT WILL DEPEND ON THE AMOUNT OF CLOUD COVER
PRESENT OR IF LOW/TROUGH DROPS FARTHER SOUTH. IT WOULD NOT BE OUT OF
THE QUESTION TO SEE LIGHT RAIN OR SPRINKLES AS THIS TROUGH
PASSES...AND PERHAPS EVEN THUNDERSTORMS. AT THIS TIME THE CHANCES
FOR MEASURABLE PRECIPITATION STILL TOO LOW TO INTRODUCE INTO THE
FORECAST THOUGH.
&&
.AVIATION...SKC-SCT CLOUDS ABOVE 20K FT AGL THRU SATURDAY EVENING OR
26/06Z. SURFACE WIND LATE SATURDAY MORNING INTO EARLY SATURDAY
EVENING SWLY 12-18 KTS WITH GUSTS TO AROUND 25 KTS. OTHERWISE...
SURFACE WIND MAINLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH OF LOW PRESSURE OVER THE PACIFIC NORTHWEST
WILL RESULT IN A DRY WEATHER PATTERN FOR SOUTHEAST ARIZONA INTO
EARLY NEXT WEEK. EXPECT SOUTHWEST WINDS WITH A FEW STRONGER GUSTS
DURING THE AFTERNOON AND EARLY EVENING HOURS THIS WEEKEND.
OTHERWISE...EXPECT SOME INCREASE IN CLOUDS WITH BREEZY TO LOCALLY
WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A DISTURBANCE MOVES
ACROSS THE REGION. SLIGHTLY COOLER DAYTIME TEMPERATURES WILL OCCUR
BY THE MIDDLE OF NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...BF
PREVIOUS DISCUSSION...KD
AVIATION/FIRE WEATHER...CR
000
FXUS65 KFGZ 242233
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 PM MST FRI MAY 24 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL REMAIN OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. A LOW
PRESSURE SYSTEM IS FORECAST TO AFFECT THE SOUTHWEST BY TUESDAY AND
WEDNESDAY OF NEXT WEEK...WITH COOLER TEMPERATURES AND A CHANCE OF
SHOWERS OR THUNDERSTORMS.
&&
.DISCUSSION...A LARGE UPPER LEVEL CLOSED LOW OVER THE NORTHWEST U.S.
AND RIDGING ACROSS THE CENTRAL PART OF THE COUNTRY WILL KEEP AZ IN A
VERY PERSISTENT DRY AND BREEZY WEATHER PATTERN THROUGH THE UPCOMING
HOLIDAY WEEKEND. SOUTHWEST FLOW WILL PREVAIL WITH SURFACE WIND
SPEEDS EACH AFTERNOON GENERALLY RANGING FROM 15-25 MPH WITH GUSTS IN
THE 30-35 MPH RANGE. NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES AND
LOW AFTERNOON HUMIDITY ARE EXPECTED. OTHER THAN PERIODIC HIGH
CLOUDS...SKIES LOOK TO REMAIN MOSTLY CLEAR THROUGH SUNDAY. A MORE
SUBSTANTIAL INCREASE IN HIGH CLOUDS LOOKS LIKELY ON MONDAY.
TUESDAY ONWARD...CONFIDENCE DECREASES IN THE LONG TERM PORTION OF
THE FORECAST AS A RESULT OF DECREASED MODEL CONSISTENCY. THE 24/12Z
RUN OF THE ECMWF CONTINUES TO SHOW A CLOSED LOW DROPPING INTO THE
SOUTHWEST U.S. TUESDAY NIGHT AND ACROSS NORTHERN AZ ON WEDNESDAY.
HOWEVER..THE 24/12Z RUN OF THE GFS SHOWS A MORE OPEN WAVE TROUGH
MOVING THROUGH THE ROCKY MOUNTAIN REGION. IN ADDITION...THE
ENSEMBLES OF BOTH MODELS STILL SHOW CONSIDERABLE SPREAD IN
SOLUTIONS. WE WILL CONTINUE WITH A BLEND BETWEEN THE GFS/ECMWF
SOLUTIONS UNTIL CONSISTENCY IMPROVES. THIS FEATURES A TREND TOWARD
COOLER TEMPERATURES BY THE MIDDLE OF NEXT WEEK AND A CHANCE FOR
SHOWERS/THUNDERSTORMS MAINLY TUESDAY NIGHT THROUGH WEDNESDAY.
&&
.AVIATION...FOR THE 00Z PACKAGE...EXPECT VFR CONDITIONS UNDER
OCCASIONAL HIGH CLOUDS THROUGH THE 24 HOUR PERIOD. SFC WINDS WILL
RANGE FROM 15-30KTS FROM THE SW THROUGH 02Z AND WILL RESUME AFT 17Z
AGAIN ON SATURDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...A DEEP LOW PRESSURE SYSTEM WILL REMAIN OVER THE
PACIFIC NORTHWEST...BRINGING MORE BREEZY AND DRY CONDITIONS TO THE
REGION SATURDAY AND SUNDAY. ALTHOUGH CONDITIONS ARE NOT EXPECTED TO
EXCEED CRITICAL FIRE WEATHER THRESHOLDS OVER A LARGE AREA OR A
PERSISTENT AMOUNT OF TIME...SOME LOCATIONS MAY EXPERIENCE BRIEF
PERIODS CRITICAL FIRE WEATHER CONDITIONS. DAYTIME RELATIVE HUMIDITY
VALUES WILL REMAIN BELOW 10 TO 15 PERCENT...WITH ONLY MODERATE
OVERNIGHT RECOVERY.
MONDAY THROUGH WEDNESDAY...LOW PRESSURE WILL REMAIN IN PLACE ACROSS
THE WESTERN UNITED STATES AND WILL ALLOW BREEZY SOUTHWEST WINDS AND
DRY CONDITIONS TO CONTINUE ON MONDAY. THE TROUGH WILL MOVE EAST AND
APPROACH ARIZONA ON TUESDAY...BRINGING COOLER TEMPERATURES AND A
CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........MCS
AVIATION.......PETERSON
FIRE WEATHER...PETERSON
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KPSR 242132
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
230 PM MST FRI MAY 24 2013
...UPDATE TO AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY
CONDITIONS AT TIMES INTO NEXT WEEK. ANTICIPATE LITTLE CHANGE IN
TEMPERATURES THROUGH SUNDAY. THEREAFTER...A TROUGH ALONG THE
WEST COAST IS ANTICIPATED TO DEEPEN WHICH WILL LEAD TO SOME MODEST
COOLING MONDAY WITH SOME MORE NOTICEABLE COOLING TUESDAY AND
WEDNESDAY.
&&
.DISCUSSION...
A LARGE AREA OF LOW PRESSURE REMAINS ANCHORED ALONG THE WEST COAST
THIS AFTERNOON WITH THE MAIN UPPER LOW CENTERED IN THE VICINITY OF
THE PAC NW COAST. ARIZONA REMAINS UNDER PERSISTENT SOUTHWEST FLOW
ALOFT...KEEPING SKIES MOSTLY CLEAR AND ALLOWING FOR AFTERNOON
BREEZINESS. H5 HEIGHTS REMAIN SOMEWHAT ELEVATED...NEAR 580DM ACROSS
SRN AZ...AND AS SUCH HIGH TEMPS REMAIN NEAR OR SLIGHTLY ABOVE
SEASONAL NORMALS WITH WARMEST DESERTS APPROACHING 100 DEGREES.
FOR THE NEXT FEW DAYS...NO SIGNIFICANT CHANGES TO THE WEATHER
PATTERN ARE EXPECTED...AT LEAST NONE THAT WILL CHANGE OUR SENSIBLE
WEATHER VERY MUCH. A SERIES OF PV ANOMALIES/VORT MAXES ROTATE AROUND
THE MAIN UPPER LOW AND INTO THE PAC NW...KEEPING PERSISTENT SWLY
FLOW ALOFT IN PLACE ACROSS ARIZONA THRU THE WEEKEND AND INTO EARLY
NEXT WEEK. H5 HEIGHTS/THICKNESSES CHANGE LITTLE OVER THIS TIME AND
AS SUCH HIGH TEMPS WILL REMAIN IN THE MID 90S TO AROUND 100 SATURDAY
INTO NEXT MONDAY. PROGS INDICATE THAT THERE WILL BE AN INCREASE IN
HIGH CLOUDS MONDAY FOR PARTLY SUNNY SKIES...BUT UNTIL THEN EXPECT
MOSTLY SUNNY OR SUNNY DAYS AND CLEAR NIGHTS. AFTERNOON AND EARLY
EVENING BREEZES WILL BE ON TAP TONIGHT INTO MONDAY AS WELL AS MID
LEVEL GRADIENTS REMAIN SOMEWHAT TIGHT.
PROGS AGREE THAT A LARGE AND RATHER PROGRESSIVE UPPER TROF WILL
DEVELOP ALONG THE PAC NW COAST...THEN SLIDE SOUTHEASTWARD AND INTO
OUR REGION BY NEXT TUESDAY. MODEL DIFFERENCES ARE STILL PROBLEMATIC
WITH THE OPERATIONAL EUROPEAN LIKELY ON THE OVERLY STRONG AND WET
SIDE OF THE SPECTRUM AND THE GEM ON THE OPPOSITE SIDE OF THE
SPECTRUM WITH THE MAIN SHORTWAVE ENDING UP ACROSS THE PACIFIC
NORTHWEST. THE EUROPEAN AND GFS ENSEMBLE MEANS ARE FAIRLY CLOSE TO
EACH OTHER IN SPEED AND STRENGTH WITH MORE SPREAD SEEN WITHIN THE
EUROPEAN ENSEMBLE MEMBERS. GIVEN THIS...HAVE TRENDED THE CURRENT
FORECAST TOWARD THE GFS...GFS ENSEMBLE MEAN...AND EUROPEAN ENSEMBLE
MEAN. THIS STILL RESULTS IN A MODEST COOLDOWN OF 5-10 DEGREES FOR
THE MIDDLE OF NEXT WEEK...AND ESPECIALLY TUESDAY AND WEDNESDAY WITH
THE POTENTIAL FOR DECENT MID AND HIGH LEVEL MOISTURE AND RESULTING
CLOUD COVER. PRECIPITATION CHANCES STILL LOOK FAIRLY LOW GIVEN
OVERALL FAIRLY DRY AIRMASS...WHICH WOULD BE LIKELY GIVEN THE TIME OF
YEAR AND VERY LOW POPS EXPECTED BY CLIMO. HAVE ELECTED TO MOSTLY
IGNORE THE OPERATIONAL EUROPEAN QPF FORECAST FOR THE REGION GIVEN
IT/S OVERLY STRONG SOLUTION...BUT HAVE AT LEAST INCLUDED SLIGHTLY
HIGHER THAN CLIMO POPS FOR TUESDAY INTO WEDNESDAY. IF OTHER MODEL
SOLUTIONS START TRENDING TOWARD THE STRONGER EUROPEAN...HIGHER POPS
WILL BE NEEDED.
DRY WESTERLY FLOW ALOFT WILL FOLLOW ON THURSDAY FOR MOSTLY SUNNY
SKIES...ALONG WITH WARMING TEMPERATURES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
MOSTLY CLEAR SKIES AND BREEZY WINDS WILL PERSIST FOR THE TERMINALS
THROUGH THE EVENING HOURS. KIPL AND KBLH WINDS WILL GRADUALLY
TRANSITION FROM SOUTHERLY TO SWSTRLY HEADINGS CLOSER TO SUNSET WHILE
THE PHX TERMINALS CAN EXPECTED SOUTHWESTERLY BREEZES. SUSTAINED
WINDS EXPECT GENLY 15 KTS OR LESS WITH GUSTS OF 20 TO 25KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
LARGE AREA OF ALMOST STATIONARY LOW PRESSURE ACROSS THE NORTHWEST
U.S. WILL BEGIN TO OPEN UP INTO A MORE NOTICEABLE TROUGHING PATTERN
BY MONDAY. A SERIES OF DRY WEATHER SYSTEMS WILL MOVE THROUGH THE
PREDOMINATELY SOUTHWEST FLOW...PERSISTING AFTERNOON AND EARLY
EVENING WINDS WHILE ALSO INTRODUCING A MILD COOLING TREND. WITH
CURRENT FORECAST MODEL GUIDANCE...WINDS LOOK TO BE THEIR STRONGEST
LATE TUESDAY INTO WEDNESDAY...HOWEVER AT THIS TIME REMAINING BELOW
CRITICAL FIRE WEATHER THRESHOLDS. HUMIDITIES WILL SEE A SLIGHT
INCREASE MIDWEEK WITH THE COOLER TEMPERATURES AND POTENTIAL FOR SOME
WEAK LOW LEVEL MOISTURE ADVECTION...AHEAD OF THE MOST PROMISING
WEATHER SYSTEM ATTM. OVERALL...CONDITIONS FOR THE SOUTHWEST FIRE
DISTRICTS WILL REMAIN DRY AS DRY WESTERLY FLOW RETURNS TO THE REGION
LATE WEEK. NEAR NORMAL TEMPERATURES WITH A RETURN TO SINGLE DIGIT
DAYTIME HUMIDITIES ARE EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB/KUHLMAN
AVIATION...NOLTE
FIRE WEATHER...NOLTE
000
FXUS65 KTWC 242110
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
210 PM MST FRI MAY 24 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW ACROSS SOUTHEAST ARIZONA THROUGH
THE HOLIDAY WEEKEND. EXPECT SOME INCREASE IN CLOUDS WITH BREEZY
TO LOCALLY WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A
DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY COOLER DAYTIME
TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...PERSISTENT PATTERN CONTINUES THROUGH THE HOLIDAY
WEEKEND WITH SOUTHWEST FLOW ALOFT BRINGING AFTERNOON BREEZES AND
NEAR NORMAL HIGH TEMPERATURES. AFTER THAT THE MAIN FORECAST
CHALLENGE CONCERNS THE AMOUNT OF ENERGY THAT WILL DIVE SOUTHWARD
TOWARD ARIZONA DURING THE MIDDLE OF NEXT WEEK.
COMPARISON OF 00Z AND 12Z GFS MODEL RUNS SHOWS DECENT CONSISTENCY
WITH THE LATITUDE OF THE OPEN TROUGH CROSSING IN THE INTERMOUNTAIN
WEST. MEANWHILE THE ECMWF CONTINUES TRACKING A CLOSED LOW ACROSS
ARIZONA. THE GFS ENSEMBLE MEMBERS WERE FAIRLY CONSISTENT WITH A
HIGH RELATIVE MEASURE OF PROBABILITY VALUE SHOWING UP FOR THE 00Z
SOLUTION AT 12Z WED.
WITH THE ABOVE IN MIND...NOT DEVIATING FROM THE MORE
CLIMATOLOGICALLY REPRESENTATIVE GFS SOLUTION OF AN OPEN TROUGH
PASSING ACROSS ARIZONA NEXT WEEK ALTHOUGH WOULD NOT BE SURPRISED IF
LATER GFS VERSIONS DEEPEN SLIGHTLY. IN ANY EVENT...THE TROUGH SHOULD
ENHANCE WINDS MON-WED. SOME COOLING ALSO EXPECTED WITH HIGH
TEMPERATURES AROUND FIVE DEGREES BELOW NORMAL BY WEDNESDAY. WHETHER
IT IS ANY COOLER THAN THAT WILL DEPEND ON THE AMOUNT OF CLOUD COVER
PRESENT OR IF LOW/TROUGH DROPS FARTHER SOUTH. IT WOULD NOT BE OUT
OF THE QUESTION TO SEE LIGHT RAIN OR SPRINKLES AS THIS TROUGH
PASSES...AND PERHAPS EVEN THUNDERSTORMS. AT THIS TIME THE CHANCES
FOR MEASURABLE PRECIPITATION STILL TOO LOW TO INTRODUCE INTO THE
FORECAST THOUGH...KD
&&
.AVIATION...SKC-FEW CLOUDS ABOVE 20K FT AGL THRU SATURDAY AFTERNOON
OR 26/00Z. SURFACE WIND LATE SATURDAY MORNING INTO EARLY SATURDAY
EVENING SWLY 12-18 KTS WITH GUSTS TO AROUND 25 KTS.
OTHERWISE...SURFACE WIND MAINLY LESS THAN 10 KTS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH OF LOW PRESSURE OVER THE PACIFIC NORTHWEST
WILL RESULT IN A DRY WEATHER PATTERN FOR SOUTHEAST ARIZONA INTO
EARLY NEXT WEEK. EXPECT SOUTHWEST WINDS WITH A FEW STRONGER GUSTS
DURING THE AFTERNOON AND EARLY EVENING HOURS THIS WEEKEND.
OTHERWISE...EXPECT SOME INCREASE IN CLOUDS WITH BREEZY TO LOCALLY
WINDY CONDITIONS MONDAY THROUGH WEDNESDAY AS A DISTURBANCE MOVES
ACROSS THE REGION. SLIGHTLY COOLER DAYTIME TEMPERATURES WILL OCCUR
BY THE MIDDLE OF NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
000
FXUS65 KPSR 242050
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
150 PM MST FRI MAY 24 2013
.SYNOPSIS...
LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY
CONDITIONS AT TIMES INTO NEXT WEEK. ANTICIPATE LITTLE CHANGE IN
TEMPERATURES THROUGH SUNDAY. THEREAFTER...A TROUGH ALONG THE
WEST COAST IS ANTICIPATED TO DEEPEN WHICH WILL LEAD TO SOME MODEST
COOLING MONDAY WITH SOME MORE NOTICEABLE COOLING TUESDAY AND
WEDNESDAY.
&&
.DISCUSSION...
A LARGE AREA OF LOW PRESSURE REMAINS ANCHORED ALONG THE WEST COAST
THIS AFTERNOON WITH THE MAIN UPPER LOW CENTERED IN THE VICINITY OF
THE PAC NW COAST. ARIZONA REMAINS UNDER PERSISTENT SOUTHWEST FLOW
ALOFT...KEEPING SKIES MOSTLY CLEAR AND ALLOWING FOR AFTERNOON
BREEZINESS. H5 HEIGHTS REMAIN SOMEWHAT ELEVATED...NEAR 580DM ACROSS
SRN AZ...AND AS SUCH HIGH TEMPS REMAIN NEAR OR SLIGHTLY ABOVE
SEASONAL NORMALS WITH WARMEST DESERTS APPROACHING 100 DEGREES.
FOR THE NEXT FEW DAYS...NO SIGNIFICANT CHANGES TO THE WEATHER
PATTERN ARE EXPECTED...AT LEAST NONE THAT WILL CHANGE OUR SENSIBLE
WEATHER VERY MUCH. A SERIES OF PV ANOMALIES/VORT MAXES ROTATE AROUND
THE MAIN UPPER LOW AND INTO THE PAC NW...KEEPING PERSISTENT SWLY
FLOW ALOFT IN PLACE ACROSS ARIZONA THRU THE WEEKEND AND INTO EARLY
NEXT WEEK. H5 HEIGHTS/THICKNESSES CHANGE LITTLE OVER THIS TIME AND
AS SUCH HIGH TEMPS WILL REMAIN IN THE MID 90S TO AROUND 100 SATURDAY
INTO NEXT MONDAY. PROGS INDICATE THAT THERE WILL BE AN INCREASE IN
HIGH CLOUDS MONDAY FOR PARTLY SUNNY SKIES...BUT UNTIL THEN EXPECT
MOSTLY SUNNY OR SUNNY DAYS AND CLEAR NIGHTS. AFTERNOON AND EARLY
EVENING BREEZES WILL BE ON TAP TONIGHT INTO MONDAY AS WELL AS MID
LEVEL GRADIENTS REMAIN SOMEWHAT TIGHT.
PROGS AGREE THAT A LARGE AND RATHER PROGRESSIVE UPPER TROF WILL
DEVELOP ALONG THE PAC NW COAST...THEN SLIDE SOUTHEASTWARD AND INTO
OUR REGION BY NEXT TUESDAY. MODEL DIFFERENCES ARE STILL PROBLEMATIC
WITH THE OPERATIONAL EUROPEAN LIKELY ON THE OVERLY STRONG AND WET
SIDE OF THE SPECTRUM AND THE GEM ON THE OPPOSITE SIDE OF THE
SPECTRUM WITH THE MAIN SHORTWAVE ENDING UP ACROSS THE PACIFIC
NORTHWEST. THE EUROPEAN AND GFS ENSEMBLE MEANS ARE FAIRLY CLOSE TO
EACH OTHER IN SPEED AND STRENGTH WITH MORE SPREAD SEEN WITHIN THE
EUROPEAN ENSEMBLE MEMBERS. GIVEN THIS...HAVE TRENDED THE CURRENT
FORECAST TOWARD THE GFS...GFS ENSEMBLE MEAN...AND EUROPEAN ENSEMBLE
MEAN. THIS STILL RESULTS IN A MODEST COOLDOWN OF 5-10 DEGREES FOR
THE MIDDLE OF NEXT WEEK...AND ESPECIALLY TUESDAY AND WEDNESDAY WITH
THE POTENTIAL FOR DECENT MID AND HIGH LEVEL MOISTURE AND RESULTING
CLOUD COVER. PRECIPITATION CHANCES STILL LOOK FAIRLY LOW GIVEN
OVERALL FAIRLY DRY AIRMASS...WHICH WOULD BE LIKELY GIVEN THE TIME OF
YEAR AND VERY LOW POPS EXPECTED BY CLIMO. HAVE ELECTED TO MOSTLY
IGNORE THE OPERATIONAL EUROPEAN QPF FORECAST FOR THE REGION GIVEN
IT/S OVERLY STRONG SOLUTION...BUT HAVE AT LEAST INCLUDED SLIGHTLY
HIGHER THAN CLIMO POPS FOR TUESDAY INTO WEDNESDAY. IF OTHER MODEL
SOLUTIONS START TRENDING TOWARD THE STRONGER EUROPEAN...HIGHER POPS
WILL BE NEEDED.
DRY WESTERLY FLOW ALOFT WILL FOLLOW ON THURSDAY FOR MOSTLY SUNNY
SKIES...ALONG WITH WARMING TEMPERATURES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL KEEP SKIES CLEAR TO MOSTLY CLEAR
THROUGH THE TAF PERIOD. WINDS ARE EXPECTED TO FOLLOW THE USUAL
DIURNAL TRENDS IN DIRECTION AND SPEED...WITH WESTERLY BREEZES
DEVELOPING DURING THE AFTERNOON AND EVENING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
LOW PRESSURE THAT IS EXPECTED TO REMAIN ALONG THE WEST COAST ON
SUNDAY AND MONDAY IS FORECAST TO MOVE INLAND OVER THE DESERT
SOUTHWEST ON TUESDAY AND WEDNESDAY...THEN OFF TO THE EAST INTO THE
CENTRAL PLAINS ON THURSDAY. DRY SOUTHWEST TO WEST FLOW AHEAD OF THIS
LOW CENTER WILL KEEP SKIES MOSTLY CLEAR AND TEMPERATURES NEAR NORMAL
ON SUNDAY AND MONDAY...WITH COOLER TEMPERATURES...AN INCREASE IN
CLOUDINESS...AND GUSTY WINDS LIKELY ON TUESDAY AND WEDNESDAY...AS
THE LOW PASSES THROUGH THE REGION. WARMER TEMPERATURES ARE THEN
EXPECTED ON THURSDAY AS RIDGING BEGINS TO BUILD IN FROM THE WEST.
SINGLE DIGIT MINIMUM HUMIDITIES ARE EXPECTED ON SUNDAY AND
MONDAY...WITH SOMEWHAT HIGHER VALUES ON TUESDAY AND WEDNESDAY...THEN
FALLING BACK INTO THE SINGLE NUMBERS AND LOW TEENS ON THURSDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB/KUHLMAN
AVIATION...PERCHA
FIRE WEATHER...PERCHA
000
FXUS65 KFGZ 241659
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
955 AM MST FRI MAY 24 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL SETTLE OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. A WEAK
LOW PRESSURE SYSTEM IS FORECAST TO AFFECT THE SOUTHWEST BY TUESDAY
AND WEDNESDAY...WITH COOLER TEMPERATURES AND A CHANCE OF SHOWERS OR
THUNDERSTORMS.
&&
.DISCUSSION...A CLOSED UPPER LEVEL LOW PRESSURE SYSTEM SPINNING OVER
THE PACIFIC NORTHWEST AND RIDGING ACROSS THE CENTRAL U.S. IS KEEPING
AZ IN A DRY SOUTHWESTERLY FLOW PATTERN. THIS WILL CONTINUE RIGHT ON
THROUGH THE HOLIDAY WEEKEND WITH SEASONABLE TEMPERATURES AND BREEZY
AFTERNOON WINDS. CURRENT FORECAST IS IN GREAT SHAPE WITH NO MORNING
UPDATES NEEDED.
&&
.PREVIOUS DISCUSSION (330 AM MST)...A LARGE CLOSED LOW WILL CONTINUE
TO SIT OVER THE NORTHWEST U.S THROUGH MEMORIAL DAY...WITH VERY
LITTLE CHANGE IN WEATHER FOR NORTHERN ARIZONA THROUGH THIS PERIOD.
THIS PATTERN WILL PRODUCE A BREEZY SOUTHWEST FLOW AND LOW HUMIDITIES
IN THE AFTERNOON AND EARLY EVENING. HIGH TEMPERATURES EACH DAY WILL
BE VERY NEAR SEASONAL AVERAGES FOR LATE MAY. MOSTLY CLEAR SKIES ARE
EXPECTED OVER THE WEEKEND...WITH INCREASING CLOUDS FOR MEMORIAL DAY
AHEAD OF A DEVELOPING TROUGH.
TUESDAY AND WEDNESDAY...MEDIUM RANGE GUIDANCE CONTINUES TO TREND
TOWARD A TROUGH DIGGING SOUTHEASTWARD TOWARD THE REGION FOR TUESDAY
INTO WEDNESDAY. STILL SOME UNCERTAINTY WITH THE DEPTH/TIMING OF THE
SYSTEM...BUT THERE IS ENOUGH CONFIDENCE IN THIS SCENARIO TO INCLUDE
AT LEAST A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FOR MOST AREAS
TUE/WED. FORECAST HIGH TEMPERATURES FOR THOSE DAYS ARE NEAR 10
DEGREES BELOW SEASONAL AVERAGES.
&&
.AVIATION...FOR THE 18Z PACKAGE...EXPECT VFR CONDITIONS UNDER
OCCASIONAL HIGH CLOUDS THROUGH THE 24 HOUR PERIOD. SFC WINDS WILL
RANGE FROM 15-30KTS FROM THE SW FROM 17Z-02Z. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...A DEEP LOW PRESSURE SYSTEM WILL REMAIN OVER THE
PACIFIC NORTHWEST...BRINGING MORE BREEZY AND DRY CONDITIONS TODAY
AND SATURDAY. CONDITIONS ARE NOT EXPECTED TO EXCEED CRITICAL FIRE
WEATHER THRESHOLDS OVER A LARGE AREA OR A PERSISTENT AMOUNT OF TIME.
HOWEVER...SOME LOCATIONS MAY EXPERIENCE BRIEF PERIODS OF CRITICAL
FIRE WEATHER CONDITIONS. DAYTIME RELATIVE HUMIDITY VALUES WILL
REMAIN BELOW 10 PERCENT...WITH ONLY MODERATE OVERNIGHT RECOVERY.
SUNDAY THROUGH TUESDAY...LOW PRESSURE WILL REMAIN IN PLACE ACROSS
THE WESTERN UNITED STATES AND WILL ALLOW BREEZY SOUTHWEST WINDS AND
DRY CONDITIONS TO CONTINUE THROUGH MONDAY. THE TROUGH WILL MOVE EAST
AND APPROACH ARIZONA ON TUESDAY...BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........MCS/JJ
AVIATION.......PETERSON
FIRE WEATHER...PETERSON
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KTWC 241551
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
851 AM MST FRI MAY 24 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW INTO NEXT WEEK. EXPECT SOME
INCREASE IN CLOUDS WITH BREEZY TO LOCALLY WINDY CONDITIONS MONDAY
THROUGH WEDNESDAY AS A DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY
COOLER DAYTIME TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...NEW 12Z MODEL GUIDANCE FROM NAM/MET SIMILAR TO 00Z RUN
FOR HIGH TEMPERATURES TODAY. AFTERNOON BREEZES FIGURE TO BE A TICK
LESS THAN LAST COUPLE OF DAYS. OTHERWISE...PREVIOUS FORECAST ON
TRACK. WILL VIEW LATEST LONGER RANGE MODELS DEPICTION OF TROUGH
AFFECTING SW US NEXT WEEK AS THEY COME IN LATER THIS MORNING AND
DISCUSS IN NEXT ISSUANCE...KD
&&
.PREV DISCUSSION...A LOW PRESSURE TROUGH OVER THE WESTERN ONE-THIRD
OF THE UNITED STATES WILL MAINTAIN A DRY SOUTHWESTERLY FLOW ALOFT
FOR THE NEXT SEVERAL DAYS. HIGH TEMPERATURES WILL REMAIN ABOUT THE
SAME TODAY AND SATURDAY...BUT WILL GRADUALLY LOWER A DEGREE OR TWO
EACH DAY STARTING AROUND SUNDAY. THIS COOLING TREND WILL BE IN
RESPONSE TO A COUPLE OF SHORTWAVES ENTERING THE MEAN TROUGH AND
AMPLIFYING IT FARTHER SOUTH. LATEST MODELS CONTINUED TO DIFFER
SIGNIFICANTLY ON THE TRACK AND STRENGTH OF A SHORTWAVE THAT WAS
PROGGED TO PASS THROUGH THE REGION AROUND TUESDAY INTO WEDNESDAY.
THE ECMWF SOLUTION DEPICTED AN UPPER LOW DEVELOPING OVER THE DESERT
SOUTHWEST WITH THE POSSIBILITY OF SHOWERS THIS FAR SOUTH. THE GFS ON
THE OTHER HAND SHOWED NO SUCH FEATURE WITH THE BEST CHANCE OF
SHOWERS ACROSS NORTHERN ARIZONA. THAT SAID...WILL JUST CONTINUE THE
GENERAL TREND TOWARD COOLER DAYTIME TEMPERATURES...INCREASING
CLOUDINESS...AND BREEZY TO WINDY CONDITIONS BY THE MIDDLE OF NEXT
WEEK.
&&
.AVIATION...SKC-FEW CLOUDS ABOVE 20K FT AGL THRU SATURDAY MORNING OR
25/15Z. SURFACE WIND INCREASING FROM SWLY/WLY AT 12-17 KTS WITH
GUSTS TO AROUND 25 KTS BETWEEN 24/18Z AND 25/02Z. SURFACE WIND
GENERALLY LESS THAN 10 KTS AFT 25/04Z. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH WILL GRADUALLY BUILD DOWN THE WEST COAST
INTO NEXT WEEK. THIS WILL RESULT IN CONTINUED DRY CONDITIONS AND A
VERY GRADUAL COOLING TREND THROUGH THE MIDDLE OF NEXT WEEK...WHEN
DAYTIME TEMPERATURES ARE EXPECTED TO BE BELOW SEASONAL NORMALS.
GUSTY WINDS CAN ALSO BE EXPECTED AT TIMES...ESPECIALLY DURING THE
AFTERNOON AND EARLY EVENING HOURS. CRITICAL FIRE WEATHER CONDITIONS
ARE NOT EXPECTED TO OCCUR THROUGH SUNDAY BUT WILL MONITOR LATEST
MODEL TRENDS FOR MONDAY AND TUESDAY CONDITIONS WHICH WILL BE
DEPENDENT ON POSITION OF TROUGH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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000
FXUS65 KPSR 241541
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
840 AM MST FRI MAY 24 2013
.SYNOPSIS...
LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY
CONDITIONS AT TIMES INTO NEXT WEEK. ANTICIPATE LITTLE CHANGE IN
TEMPERATURES THROUGH SATURDAY. THEREAFTER...A TROUGH ALONG THE
WEST COAST IS ANTICIPATED TO DEEPEN WHICH WILL LEAD TO SOME MODEST
COOLING SUNDAY AND MONDAY WITH SOME MORE NOTICEABLE COOLING TUESDAY
AND WEDNESDAY.
&&
.DISCUSSION...
NOT MUCH CHANGE IN THE WEATHER PATTERN FOR OUR AREA THIS
MORNING...AS DRY SOUTHWEST FLOW ALOFT PERSISTS ACROSS THE
AREA...AHEAD OF AN UPPER TROF PARKED ALONG THE WEST COAST. IR
IMAGERY AT 8 AM SHOWED SUNNY SKIES AROUND ARIZONA AND SERN
CALIFORNIA...AND AREA RAOBS CONTINUED TO SHOW SWLY FLOW THRU MOST OF
THE COLUMN. LOW/MID LEVEL GRADIENTS REMAIN SUFFICIENTLY TIGHT TO
GIVE ANOTHER DAY OF BREEZY CONDITIONS DURING THE AFTERNOON AND
EVENING HOURS. FLG/TUS 12Z SOUNDINGS SHOWED 15-20KT BELOW 700MB AND
THIS WILL MIX TO THE SURFACE LATER TODAY UNDER NEARLY FULL SUNSHINE.
WITH 500MB HEIGHTS REMAINING HIGH...NEAR 580DM OVER THE SRN
DESERTS...HIGH TEMPS TODAY WILL STAY SLIGHTLY ABOVE SEASONAL NORMALS
AND THE WARMEST DESERTS SHOULD REACH TO 100 DEGREES...OR AT LEAST
INTO THE UPPER 90S. THE CURRENT HIGH OF 100 AT PHOENIX TODAY MAY BE
REACHED BUT IT IS POSSIBLE THAT IT WILL COME UP A DEGREE OR TWO
SHORT...GIVEN THAT BOTH TUS AND FLG SHOWED A COUPLE DEGREES OF
COOLING OVER THE PAST 24 HOURS BELOW 700MB...AND CENTRAL DESERTS ARE
CURRENTLY RUNNING A FEW DEGREES COOLER THAN YESTERDAY. OVERALL
FORECASTS ARE IN FINE SHAPE AND NO UPDATES ARE NEEDED.
.PREVIOUS DISCUSSION...
AREAWIDE WEATHER HAS BEEN ON THE QUIET SIDE THIS WEEK AND SLIGHTLY
WARMER THAN EXPECTED THE PAST COUPLE DAYS. THE DEEP UPPER LOW OVER
THE PACIFIC NORTHWEST IS NOT QUITE HAVING AS MUCH OF A COOLING
EFFECT OVER THE DESERT SOUTHWEST AS ANTICIPATED.
HOWEVER...TEMPERATURES HAVE COOLED NOTICEABLY ACROSS OUR WESTERN
ZONES AND SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH
THE WEEKEND THERE. FARTHER AWAY FROM THE COOLER
AIRMASS...SOUTH-CENTRAL ARIZONA REMAINS ABOVE NORMAL WITH METRO
PHOENIX READINGS AROUND 100 THE PAST COUPLE DAYS. NOT EXPECTING ANY
NOTICEABLE CHANGE IN TEMPERATURES ACROSS SOUTH-CENTRAL ARIZONA TODAY
OR EVEN INTO SATURDAY.
BY SUNDAY...THE PERSISTENT UPPER LOW OVER THE PACIFIC NORTHWEST
FINALLY WEAKENS AND BECOMES MORE OF AN OPEN TROUGH. A SHORTWAVE DOES
PEEL OFF THE MAIN LOW AND DIVES SOUTHWARD INTO THE GREAT
BASIN...THUS LOWERING HEIGHTS ACROSS THE DESERT SOUTHWEST. THIS IS
EXPECTED TO HAVE A SLIGHT COOLING EFFECT ACROSS THE REGION...BUT THE
MORE SIGNIFICANT COOLING WON/T OCCUR UNTIL THE MIDDLE OF NEXT WEEK.
THROUGH MONDAY...DRY SOUTHWESTERLY FLOW MAINTAINS IT/S HOLD ACROSS
THE REGION...BUT CHANGES IN THE FLOW STARTING TUESDAY.
A FAIRLY STRONG SHORTWAVE TROUGH IS FORECAST TO SLIDE SOUTHEASTWARD
FROM THE NORTH PACIFIC SUNDAY INTO MONDAY COMING ONSHORE IN
CALIFORNIA MONDAY NIGHT. THE LARGE SCALE TROUGHING PATTERN ACROSS
THE WESTERN UNITED STATES AND A 120KT UPPER JET WILL AID IN THE
QUICK PROGRESSION OF THIS SHORTWAVE INTO OUR REGION BY TUESDAY.
MODEL DIFFERENCES ARE STILL PROBLEMATIC WITH THE OPERATIONAL
EUROPEAN LIKELY ON THE OVERLY STRONG SIDE OF THE SPECTRUM AND THE
GEM ON THE OPPOSITE SIDE OF THE SPECTRUM WITH THE MAIN SHORTWAVE
ENDING UP ACROSS THE PACIFIC NORTHWEST. THE EUROPEAN AND GFS
ENSEMBLE MEANS ARE FAIRLY CLOSE TO EACH OTHER IN SPEED AND STRENGTH
WITH MORE SPREAD SEEN WITHIN THE EUROPEAN ENSEMBLE MEMBERS. GIVEN
THIS...HAVE TRENDED THE CURRENT FORECAST TOWARD THE GFS...GFS
ENSEMBLE MEAN...AND EUROPEAN ENSEMBLE MEAN. THIS STILL RESULTS IN A
MODEST COOLDOWN OF 5-10 DEGREES FOR THE MIDDLE OF NEXT WEEK...AND
ESPECIALLY TUESDAY AND WEDNESDAY WITH THE POTENTIAL FOR DECENT MID
AND HIGH LEVEL MOISTURE AND RESULTING CLOUD COVER. PRECIPITATION
CHANCES STILL LOOK FAIRLY LOW GIVEN OVERALL FAIRLY DRY AIRMASS. HAVE
ELECTED TO MOSTLY IGNORE THE OPERATIONAL EUROPEAN QPF FORECAST FOR
THE REGION GIVEN IT/S OVERLY STRONG SOLUTION...BUT HAVE AT LEAST
INCLUDED SLIGHTLY HIGHER THAN CLIMO POPS FOR TUESDAY INTO WEDNESDAY.
IF OTHER MODEL SOLUTIONS START TRENDING TOWARD THE STRONGER
EUROPEAN...HIGHER POPS WILL BE NEEDED.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL KEEP SKIES CLEAR TO MOSTLY CLEAR
THROUGH THE TAF PERIOD. WINDS ARE EXPECTED TO FOLLOW THE USUAL
DIURNAL TRENDS IN DIRECTION AND SPEED...WITH WESTERLY BREEZES
DEVELOPING DURING THE AFTERNOON AND EVENING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
LOW PRESSURE THAT IS EXPECTED TO REMAIN ALONG THE WEST COAST ON
SUNDAY AND MONDAY IS FORECAST TO MOVE INLAND OVER THE DESERT
SOUTHWEST ON TUESDAY AND WEDNESDAY...THEN OFF TO THE EAST INTO THE
CENTRAL PLAINS ON THURSDAY. DRY SOUTHWEST TO WEST FLOW AHEAD OF THIS
LOW CENTER WILL KEEP SKIES MOSTLY CLEAR AND TEMPERATURES NEAR NORMAL
ON SUNDAY AND MONDAY...WITH COOLER TEMPERATURES...AN INCREASE IN
CLOUDINESS...AND GUSTY WINDS LIKELY ON TUESDAY AND WEDNESDAY...AS
THE LOW PASSES THROUGH THE REGION. WARMER TEMPERATURES ARE THEN
EXPECTED ON THURSDAY AS RIDGING BEGINS TO BUILD IN FROM THE WEST.
SINGLE DIGIT MINIMUM HUMIDITIES ARE EXPECTED ON SUNDAY AND
MONDAY...WITH SOMEWHAT HIGHER VALUES ON TUESDAY AND WEDNESDAY...THEN
FALLING BACK INTO THE SINGLE NUMBERS AND LOW TEENS ON THURSDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...CB
PREVIOUS DISCUSSION...KUHLMAN
AVIATION...PERCHA
FIRE WEATHER...PERCHA
000
FXUS65 KFGZ 241040
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST FRI MAY 24 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL SETTLE OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. A WEAK
LOW PRESSURE SYSTEM IS FORECAST TO AFFECT THE SOUTHWEST BY TUESDAY
AND WEDNESDAY...WITH COOLER TEMPERATURES AND A CHANCE OF SHOWERS OR
THUNDERSTORMS.
&&
.DISCUSSION...A LARGE CLOSED LOW WILL CONTINUE TO SIT OVER THE
NORTHWEST U.S THROUGH MEMORIAL DAY...WITH VERY LITTLE CHANGE IN
WEATHER FOR NORTHERN ARIZONA THROUGH THIS PERIOD. THIS PATTERN WILL
PRODUCE A BREEZY SOUTHWEST FLOW AND LOW HUMIDITIES IN THE AFTERNOON
AND EARLY EVENING. HIGH TEMPERATURES EACH DAY WILL BE VERY NEAR
SEASONAL AVERAGES FOR LATE MAY. MOSTLY CLEAR SKIES ARE EXPECTED OVER
THE WEEKEND...WITH INCREASING CLOUDS FOR MEMORIAL DAY AHEAD OF A
DEVELOPING TROUGH.
TUESDAY AND WEDNESDAY...MEDIUM RANGE GUIDANCE CONTINUES TO TREND
TOWARD A TROUGH DIGGING SOUTHEASTWARD TOWARD THE REGION FOR TUESDAY
INTO WEDNESDAY. STILL SOME UNCERTAINTY WITH THE DEPTH/TIMING OF THE
SYSTEM...BUT THERE IS ENOUGH CONFIDENCE IN THIS SCENARIO TO INCLUDE
AT LEAST A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FOR MOST AREAS
TUE/WED. FORECAST HIGH TEMPERATURES FOR THOSE DAYS ARE NEAR 10
DEGREES BELOW SEASONAL AVERAGES.
&&
.AVIATION...FOR THE 12Z PACKAGE...BREEZY SW WINDS 15 TO 25 MPH WITH
GUSTS FROM 30 TO 35 MPH WILL DEVELOP 16Z-18Z AND CONTINUE TO 01-03Z
SATURDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...A BROAD TROUGH OF LOW PRESSURE WILL REMAIN ACROSS
THE WESTERN STATES BRINGING A CONTINUATION OF BREEZY SOUTHWEST WINDS
AND DRY CONDITIONS TODAY AND SATURDAY. CONDITIONS ARE NOT EXPECTED
TO EXCEED CRITICAL FIRE WEATHER THRESHOLDS. MINIMUM RELATIVE
HUMIDITY WILL REMAIN BELOW 10 PERCENT WITH ONLY MODERATE OVERNIGHT
RECOVERY.
SUNDAY AND MONDAY...THE TROUGH WILL REMAIN IN PLACE ACROSS
THE WESTERN STATES AND ALLOW BREEZY SOUTHWEST WINDS TO CONTINUE
ALONG WITH VERY LOW MINIMUM RELATIVE HUMIDITY. WINDS MAY APPROACH
BUT ARE NOT EXPECTED TO EXCEED CRITICAL FIRE WEATHER CONDITIONS ON
SUNDAY AND MONDAY.
THE TROUGH FINALLY MOVES EAST AND APPROACHES ARIZONA ON TUESDAY
WITH A CHANCE OF THUNDERSTORMS AND LIGHTNING.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........JJ
AVIATION.......MAS
FIRE WEATHER...MAS
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KPSR 240950
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 AM MST FRI MAY 24 2013
.SYNOPSIS...
LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY
CONDITIONS AT TIMES INTO NEXT WEEK. ANTICIPATE LITTLE CHANGE IN
TEMPERATURES THROUGH SATURDAY. THEREAFTER...A TROUGH ALONG THE
WEST COAST IS ANTICIPATED TO DEEPEN WHICH WILL LEAD TO SOME MODEST
COOLING SUNDAY AND MONDAY WITH SOME MORE NOTICEABLE COOLING TUESDAY
AND WEDNESDAY.
&&
.DISCUSSION...
AREAWIDE WEATHER HAS BEEN ON THE QUIET SIDE THIS WEEK AND SLIGHTLY
WARMER THAN EXPECTED THE PAST COUPLE DAYS. THE DEEP UPPER LOW OVER
THE PACIFIC NORTHWEST IS NOT QUITE HAVING AS MUCH OF A COOLING
EFFECT OVER THE DESERT SOUTHWEST AS ANTICIPATED.
HOWEVER...TEMPERATURES HAVE COOLED NOTICEABLY ACROSS OUR WESTERN
ZONES AND SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH
THE WEEKEND THERE. FARTHER AWAY FROM THE COOLER
AIRMASS...SOUTH-CENTRAL ARIZONA REMAINS ABOVE NORMAL WITH METRO
PHOENIX READINGS AROUND 100 THE PAST COUPLE DAYS. NOT EXPECTING ANY
NOTICEABLE CHANGE IN TEMPERATURES ACROSS SOUTH-CENTRAL ARIZONA TODAY
OR EVEN INTO SATURDAY.
BY SUNDAY...THE PERSISTENT UPPER LOW OVER THE PACIFIC NORTHWEST
FINALLY WEAKENS AND BECOMES MORE OF AN OPEN TROUGH. A SHORTWAVE DOES
PEEL OFF THE MAIN LOW AND DIVES SOUTHWARD INTO THE GREAT
BASIN...THUS LOWERING HEIGHTS ACROSS THE DESERT SOUTHWEST. THIS IS
EXPECTED TO HAVE A SLIGHT COOLING EFFECT ACROSS THE REGION...BUT THE
MORE SIGNIFICANT COOLING WON/T OCCUR UNTIL THE MIDDLE OF NEXT WEEK.
THROUGH MONDAY...DRY SOUTHWESTERLY FLOW MAINTAINS IT/S HOLD ACROSS
THE REGION...BUT CHANGES IN THE FLOW STARTING TUESDAY.
A FAIRLY STRONG SHORTWAVE TROUGH IS FORECAST TO SLIDE SOUTHEASTWARD
FROM THE NORTH PACIFIC SUNDAY INTO MONDAY COMING ONSHORE IN
CALIFORNIA MONDAY NIGHT. THE LARGE SCALE TROUGHING PATTERN ACROSS
THE WESTERN UNITED STATES AND A 120KT UPPER JET WILL AID IN THE
QUICK PROGRESSION OF THIS SHORTWAVE INTO OUR REGION BY TUESDAY.
MODEL DIFFERENCES ARE STILL PROBLEMATIC WITH THE OPERATIONAL
EUROPEAN LIKELY ON THE OVERLY STRONG SIDE OF THE SPECTRUM AND THE
GEM ON THE OPPOSITE SIDE OF THE SPECTRUM WITH THE MAIN SHORTWAVE
ENDING UP ACROSS THE PACIFIC NORTHWEST. THE EUROPEAN AND GFS
ENSEMBLE MEANS ARE FAIRLY CLOSE TO EACH OTHER IN SPEED AND STRENGTH
WITH MORE SPREAD SEEN WITHIN THE EUROPEAN ENSEMBLE MEMBERS. GIVEN
THIS...HAVE TRENDED THE CURRENT FORECAST TOWARD THE GFS...GFS
ENSEMBLE MEAN...AND EUROPEAN ENSEMBLE MEAN. THIS STILL RESULTS IN A
MODEST COOLDOWN OF 5-10 DEGREES FOR THE MIDDLE OF NEXT WEEK...AND
ESPECIALLY TUESDAY AND WEDNESDAY WITH THE POTENTIAL FOR DECENT MID
AND HIGH LEVEL MOISTURE AND RESULTING CLOUD COVER. PRECIPITATION
CHANCES STILL LOOK FAIRLY LOW GIVEN OVERALL FAIRLY DRY AIRMASS. HAVE
ELECTED TO MOSTLY IGNORE THE OPERATIONAL EUROPEAN QPF FORECAST FOR
THE REGION GIVEN IT/S OVERLY STRONG SOLUTION...BUT HAVE AT LEAST
INCLUDED SLIGHTLY HIGHER THAN CLIMO POPS FOR TUESDAY INTO WEDNESDAY.
IF OTHER MODEL SOLUTIONS START TRENDING TOWARD THE STRONGER
EUROPEAN...HIGHER POPS WILL BE NEEDED.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL KEEP SKIES CLEAR TO MOSTLY CLEAR
THROUGH THE TAF PERIOD. WINDS ARE EXPECTED TO FOLLOW THE USUAL
DIURNAL TRENDS IN DIRECTION AND SPEED...WITH WESTERLY BREEZES
DEVELOPING DURING THE AFTERNOON AND EVENING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
LOW PRESSURE THAT IS EXPECTED TO REMAIN ALONG THE WEST COAST ON
SUNDAY AND MONDAY IS FORECAST TO MOVE INLAND OVER THE DESERT
SOUTHWEST ON TUESDAY AND WEDNESDAY...THEN OFF TO THE EAST INTO THE
CENTRAL PLAINS ON THURSDAY. DRY SOUTHWEST TO WEST FLOW AHEAD OF THIS
LOW CENTER WILL KEEP SKIES MOSTLY CLEAR AND TEMPERATURES NEAR NORMAL
ON SUNDAY AND MONDAY...WITH COOLER TEMPERATURES...AN INCREASE IN
CLOUDINESS...AND GUSTY WINDS LIKELY ON TUESDAY AND WEDNESDAY...AS
THE LOW PASSES THROUGH THE REGION. WARMER TEMPERATURES ARE THEN
EXPECTED ON THURSDAY AS RIDGING BEGINS TO BUILD IN FROM THE WEST.
SINGLE DIGIT MINIMUM HUMIDITIES ARE EXPECTED ON SUNDAY AND
MONDAY...WITH SOMEWHAT HIGHER VALUES ON TUESDAY AND WEDNESDAY...THEN
FALLING BACK INTO THE SINGLE NUMBERS AND LOW TEENS ON THURSDAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
AVIATION...PERCHA
FIRE WEATHER...PERCHA
000
FXUS65 KTWC 240941
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 AM MST FRI MAY 24 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW INTO NEXT WEEK. EXPECT SOME
INCREASE IN CLOUDS WITH BREEZY TO LOCALLY WINDY CONDITIONS MONDAY
THROUGH WEDNESDAY AS A DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY
COOLER DAYTIME TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...A LOW PRESSURE TROUGH OVER THE WESTERN ONE-THIRD OF
THE UNITED STATES WILL MAINTAIN A DRY SOUTHWESTERLY FLOW ALOFT FOR
THE NEXT SEVERAL DAYS. HIGH TEMPERATURES WILL REMAIN ABOUT THE SAME
TODAY AND SATURDAY...BUT WILL GRADUALLY LOWER A DEGREE OR TWO EACH
DAY STARTING AROUND SUNDAY. THIS COOLING TREND WILL BE IN RESPONSE
TO A COUPLE OF SHORTWAVES ENTERING THE MEAN TROUGH AND AMPLIFYING IT
FARTHER SOUTH. LATEST MODELS CONTINUED TO DIFFER SIGNIFICANTLY ON
THE TRACK AND STRENGTH OF A SHORTWAVE THAT WAS PROGGED TO PASS
THROUGH THE REGION AROUND TUESDAY INTO WEDNESDAY. THE ECMWF SOLUTION
DEPICTED AN UPPER LOW DEVELOPING OVER THE DESERT SOUTHWEST WITH THE
POSSIBILITY OF SHOWERS THIS FAR SOUTH. THE GFS ON THE OTHER HAND
SHOWED NO SUCH FEATURE WITH THE BEST CHANCE OF SHOWERS ACROSS
NORTHERN ARIZONA. THAT SAID...WILL JUST CONTINUE THE GENERAL TREND
TOWARD COOLER DAYTIME TEMPERATURES...INCREASING CLOUDINESS...AND
BREEZY TO WINDY CONDITIONS BY THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...SKC-FEW CLOUDS ABOVE 20K FT AGL THRU SATURDAY MORNING OR
25/12Z. SURFACE WIND LESS THAN 10 KTS THRU 24/15Z...THEN INCREASING
SURFACE WIND WITH SWLY/WLY AT 12-17 KTS WITH GUSTS TO AROUND 25 KTS
BETWEEN 24/18Z AND 25/02Z. SURFACE WIND GENERALLY LESS THAN 10 KTS
AFT 25/04Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH WILL GRADUALLY BUILD DOWN THE WEST COAST
INTO NEXT WEEK. THIS WILL RESULT IN CONTINUED DRY CONDITIONS AND A
VERY GRADUAL COOLING TREND THROUGH THE MIDDLE OF NEXT WEEK...WHEN
DAYTIME TEMPERATURES ARE EXPECTED TO BE BELOW SEASONAL NORMALS.
GUSTY WINDS CAN ALSO BE EXPECTED AT TIMES...ESPECIALLY DURING THE
AFTERNOON AND EARLY EVENING HOURS. HOWEVER...CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED TO OCCUR.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
000
FXUS65 KTWC 240423
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
923 PM MST THU MAY 23 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW INTO NEXT WEEK. EXPECT SOME
INCREASE IN CLOUDS WITH BREEZY TO LOCALLY WINDY CONDITIONS MONDAY
THROUGH WEDNESDAY AS A DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY
COOLER DAYTIME TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...IR SATELLITE IMAGERY INDICATED CLEAR SKIES ACROSS SE
AZ AT THIS TIME. SURFACE WINDS HAD DIMINISHED TO GENERALLY LESS THAN
10 MPH ACROSS MUCH OF SE AZ. HOWEVER...SWLY WINDS WITH GUSTS TO 26
MPH WERE OBSERVED AT KFHU AT 855 PM MST. CLEAR SKIES WILL PREVAIL
THE REST OF TONIGHT. ABUNDANT SUNSHINE IS THEN ON TAP FRIDAY WITH
PERHAPS A FEW CIRRIFORM CLOUDS TO MOVE ACROSS THE AREA. HIGH TEMPS
FRIDAY WILL AVERAGE WITHIN A FEW DEGREES OF NORMAL. PLEASE REFER TO
THE PREVIOUS DISCUSSION SECTION BELOW FOR ADDITIONAL DETAIL.
&&
.PREV DISCUSSION...LONG WAVE TROUGH ALONG THE WEST COAST WILL REMAIN
IN PLACE THROUGH THE WEEKEND AND INTO NEXT WEEK. THIS TROUGH WILL
MODERATE OUR HIGH TEMPERATURES TO NEAR AVERAGE LEVELS. THE SOUTHWEST
FLOW OVER ARIZONA WILL CAUSE GUSTY AFTERNOON WINDS AT MOST LOCATIONS
THROUGH MEMORIAL DAY.
ON TUESDAY A SHORT WAVE SYSTEM DROPS INTO THIS TROUGH AND AMPLIFIES
IT FURTHER SOUTH. THE LATEST 12Z RUNS OF THE ECMWF AND GFS HAVE
SLIGHTLY DIFFERENT SOLUTIONS ON THE TRACK FOR THIS LOW. THE ECMWF
HAS THE LOW CENTER IN NORTHERN ARIZONA ON WEDNESDAY AT 18Z...WHEREAS
THE GFS HAS THE LOW INTO NORTHERN NEW MEXICO. THIS VARIATION
DECREASES THE CONFIDENT OF THE EXTENDED FORECASTS AT DAYS 6 AND 7.
IF THE ECMWF VERIFIES...A SLIGHT CHANCE OF SHOWERS WOULD OCCUR THE
MIDDLE OF NEXT WEEK. IF THE GFS VERIFIES...MOST OF THE LIGHT SHOWER
ACTIVITY WOULD BE IN NORTHERN ARIZONA. DUE TO THESE VARIATIONS...
INCREASED THE POPS AND SKY COVER SLIGHTLY AT THE HIGHER ELEVATIONS.
HOWEVER AT THIS TIME THE DRY FORECAST CONTINUES THROUGH SEVEN DAYS.
&&
.AVIATION...SKC-FEW CLOUDS ABOVE 20K FT AGL THRU FRIDAY EVENING OR
25/06Z. SURFACE WIND LATE FRIDAY MORNING INTO EARLY FRIDAY EVENING
SWLY 12-18 KTS WITH GUSTS TO AROUND 25 KTS. OTHERWISE...SURFACE WIND
MAINLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS WILL CONTINUE INTO NEXT WEEK. DAYTIME
MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE DIGITS
WITH FAIR TO POOR OVERNIGHT RECOVERIES. SOME BREEZES WILL OCCUR
DURING THE AFTERNOON HOURS. HOWEVER...CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED TO OCCUR. AN UPPER LEVEL DISTURBANCE IS
FORECAST TO MOVE ACROSS THE AREA TUESDAY THROUGH WEDNESDAY. AT THIS
TIME APPEARS THAT THE MAIN IMPACT WILL BE BREEZY TO LOCALLY WINDY
CONDITIONS AND SLIGHTLY COOLER TEMPERATURES. HOWEVER...FIELD CREWS
ARE ENCOURAGED TO MONITOR SUBSEQUENT FORECASTS FOR THE POTENTIAL OF
DRY LIGHTNING...ESPECIALLY NEAR THE MOUNTAINS. EXPECT DRY CONDITIONS
NEXT THURSDAY AS THE SYSTEM MOVES EAST OF THE AREA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
BF
PREVIOUS DISCUSSION...GWS
000
FXUS65 KTWC 240411
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
910 PM MST THU MAY 23 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
MAINTAIN A DRY SOUTHWESTERLY FLOW INTO NEXT WEEK. EXPECT SOME
INCREASE IN CLOUDS WITH BREEZY TO LOCALLY WINDY CONDITIONS TUESDAY
THROUGH WEDNESDAY AS A DISTURBANCE MOVES ACROSS THE AREA. SLIGHTLY
COOLER DAYTIME TEMPERATURES WILL OCCUR BY THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...IR SATELLITE IMAGERY INDICATED CLEAR SKIES ACROSS SE
AZ AT THIS TIME. SURFACE WINDS HAD DIMINISHED TO GENERALLY LESS THAN
10 MPH ACROSS MUCH OF SE AZ. HOWEVER...SWLY WINDS WITH GUSTS TO 26
MPH WERE OBSERVED AT KFHU AT 855 PM MST. CLEAR SKIES WILL PREVAIL
THE REST OF TONIGHT. ABUNDANT SUNSHINE IS THEN ON TAP FRIDAY WITH
PERHAPS A FEW CIRRIFORM CLOUDS TO MOVE ACROSS THE AREA. HIGH TEMPS
FRIDAY WILL AVERAGE WITHIN A FEW DEGREES OF NORMAL. PLEASE REFER TO
THE PREVIOUS DISCUSSION SECTION BELOW FOR ADDITIONAL DETAIL.
&&
.PREV DISCUSSION...LONG WAVE TROUGH ALONG THE WEST COAST WILL REMAIN
IN PLACE THROUGH THE WEEKEND AND INTO NEXT WEEK. THIS TROUGH WILL
MODERATE OUR HIGH TEMPERATURES TO NEAR AVERAGE LEVELS. THE SOUTHWEST
FLOW OVER ARIZONA WILL CAUSE GUSTY AFTERNOON WINDS AT MOST LOCATIONS
THROUGH MEMORIAL DAY.
ON TUESDAY A SHORT WAVE SYSTEM DROPS INTO THIS TROUGH AND AMPLIFIES
IT FURTHER SOUTH. THE LATEST 12Z RUNS OF THE ECMWF AND GFS HAVE
SLIGHTLY DIFFERENT SOLUTIONS ON THE TRACK FOR THIS LOW. THE ECMWF
HAS THE LOW CENTER IN NORTHERN ARIZONA ON WEDNESDAY AT 18Z...WHEREAS
THE GFS HAS THE LOW INTO NORTHERN NEW MEXICO. THIS VARIATION
DECREASES THE CONFIDENT OF THE EXTENDED FORECASTS AT DAYS 6 AND 7.
IF THE ECMWF VERIFIES...A SLIGHT CHANCE OF SHOWERS WOULD OCCUR THE
MIDDLE OF NEXT WEEK. IF THE GFS VERIFIES...MOST OF THE LIGHT SHOWER
ACTIVITY WOULD BE IN NORTHERN ARIZONA. DUE TO THESE VARIATIONS...
INCREASED THE POPS AND SKY COVER SLIGHTLY AT THE HIGHER ELEVATIONS.
HOWEVER AT THIS TIME THE DRY FORECAST CONTINUES THROUGH SEVEN DAYS.
&&
.AVIATION...SKC-FEW CLOUDS ABOVE 20K FT AGL THRU FRIDAY EVENING OR
25/06Z. SURFACE WIND LATE FRIDAY MORNING INTO EARLY FRIDAY EVENING
SWLY 12-18 KTS WITH GUSTS TO AROUND 25 KTS. OTHERWISE...SURFACE WIND
MAINLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS WILL CONTINUE INTO NEXT WEEK. DAYTIME
MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE DIGITS
WITH FAIR TO POOR OVERNIGHT RECOVERIES. SOME BREEZES WILL OCCUR
DURING THE AFTERNOON HOURS. HOWEVER...CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED TO OCCUR. AN UPPER LEVEL DISTURBANCE IS
FORECAST TO MOVE ACROSS THE AREA TUESDAY THROUGH WEDNESDAY. AT THIS
TIME APPEARS THAT THE MAIN IMPACT WILL BE BREEZY TO LOCALLY WINDY
CONDITIONS AND SLIGHTLY COOLER TEMPERATURES. HOWEVER...FIELD CREWS
ARE ENCOURAGED TO MONITOR SUBSEQUENT FORECASTS FOR THE POTENTIAL OF
DRY LIGHTNING...ESPECIALLY NEAR THE MOUNTAINS. EXPECT DRY CONDITIONS
NEXT THURSDAY AS THE SYSTEM MOVES EAST OF THE AREA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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BF
PREVIOUS DISCUSSION...GWS
000
FXUS65 KPSR 240401
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
900 PM MST THU MAY 23 2013
.SYNOPSIS...
LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY TO WINDY
CONDITIONS AT TIMES THE REST OF THIS WEEK AND INTO NEXT WEEK.
ANTICIPATE LITTLE CHANGE IN TEMPERATURES THROUGH SATURDAY. NEXT
WEEK...THE TROUGH ALONG THE WEST COAST IS ANTICIPATED TO DEEPEN
WHICH WILL LEAD TO SOME MODEST COOLING SUNDAY AND MONDAY WITH SOME
MORE NOTICEABLE COOLING TUESDAY AND WEDNESDAY.
&&
.DISCUSSION...
UNDER MOSTLY CLEAR SKIES TODAY...THE SOUTHWEST DESERTS AGAIN WARMED
INTO THE UPPER 90S TO LOW 100S. 8 PM MST OBSERVATIONS FROM AROUND
THE AREA ARE SIMILAR TO READINGS FROM LAST NIGHT...WITH UPPER 80 TO
LOW 90 DEGREE TEMPERATURES AND PERSISTENTLY ELEVATED WEST TO
SOUTHWEST BREEZINESS. LARGE UPPER LOW AND TROUGHING CONTINUES TO
EXPAND AND SETTLE ACROSS THE PACIFIC NW AND DOWN INTO THE GREAT
BASIN. MOSTLY DRY SOUTHWEST FLOW ALOFT REMAINS OVER THE DESERTS. AS
THIS LOW FEATURE REMAINS SOMEWHAT STATIONARY...WITH INDIVIDUAL
SHORTWAVES EMBEDDED THROUGH THE FLOW...AFTERNOON BREEZES WILL
CONTINUE WHILE TEMPERATURES WILL BEGIN A SLIGHT COOL DOWN THROUGH
MEMORIAL DAY HOLIDAY WEEKEND. FOR TONIGHT...EXPECT CONTINUED CLEAR
SKIES WITH ELEVATED WEST-SOUTHWEST WINDS PERSISTING ACROSS SOUTHEAST
CALIFORNIA. BACK INTO THE SOUTH CENTRAL DESERTS...WINDS WILL SLOWLY
RELAX BECOMING MORE VARIABLE IN NATURE OVERNIGHT BEFORE PICKING UP
TYPICAL EAST DRAINAGE FLOW BY SUNRISE. NO UPDATES PLANNED FOR THE
GRID PACKAGE THIS EVENING.
&&
.PREVIOUS DISCUSSION /ISSUED AT 250 PM MST/PDT/...
REST OF TODAY THROUGH MEMORIAL DAY...
TEMPERATURES EARLY THIS AFTERNOON ARE RUNNING A BIT COOLER THAN 24
HOURS AGO...ESPECIALLY OVER SOUTHEAST CALIFORNIA WHICH IS CLOSER TO
AXIS OF THE UPPER TROUGH CENTERED ALONG THE WEST COAST. THE ENHANCED
SOUTHWESTERLY FLOW ALOFT COMBINED WITH GOOD MIXING DUE TO SURFACE
HEATING WILL KEEP AFTERNOONS AND EARLY EVENINGS BREEZY THROUGH THE
WEEKEND. THERE WILL BE DAY TO DAY FLUCTUATIONS IN THE STRENGTH OF
THE BREEZINESS AS VORT MAXES MOVE THROUGH THE TROUGH...PASSING
MAINLY TO THE NORTH OF OUR FORECAST AREA. THERE WILL BE MINOR
FLUCTUATIONS IN HIGH TEMPERATURES THROUGH SATURDAY WITH READINGS ON
THE LOW DESERTS IN THE MID 90S TO NEAR 100. BEGINNING SUNDAY...THE
MODELS SHOW THE SOUTHERN END OF THE TROUGH DEEPENING IN RESPONSE TO
UPSTREAM LOW PRESSURE SYSTEMS OVER THE PACIFIC. IN ESSENCE...THERE
WILL BE A SERIES OF SHORT WAVES THAT WILL LEAD TO SOME MODEST
COOLING. SKIES WILL BE CLEAR EXCEPT FOR THICKER HIGH CLOUDINESS ON
MONDAY.
TUESDAY THROUGH THURSDAY...
THE GFS/ECMWF/GEM ALL SHOW A SPLIT IN THE FLOW ON THE UPSTREAM SIDE
OF THE TROUGH WHICH LEADS TO A SIZABLE SHORT WAVE IN THE SOUTHERN
BRANCH THAT MOVES THROUGH THE DESERT SOUTHWEST IN THE LATE MONDAY
THROUGH WEDNESDAY TIME FRAME. HOWEVER...THERE ARE CONSIDERABLE
DIFFERENCES IN TIMING AND DEPTH OF THE FEATURE. THE ECMWF IS DEEPEST
AND SLOWEST. THE GEM IS WEAKEST AND FASTEST. THE GFS IS IN BETWEEN
BUT CLOSER TO THE GEM SOLUTION. THE GEFS MEAN SUPPORTS THE GFS
PRETTY WELL. THE ECMWF ENSEMBLE OUTPUT SUGGESTS THAT THE OPERATIONAL
RUN IS TOO DEEP AND A BIT SLOW. HOWEVER...THERE IS CONSIDERABLE
SPREAD AMONGST THE INDIVIDUAL ENSEMBLE MEMBERS. MADE SOME SUBTLE
DOWNWARD ADJUSTMENTS TO TEMPS BUT NOT AS AGGRESSIVE AS WHAT ECMWF
WOULD SUGGEST. KEEPING THINGS DRY FOR NOW AS THERE WILL NOT BE MUCH
MOISTURE AVAILABLE WITH THE SYSTEM PLUS THE TIME OF YEAR INDICATES
LOW PROBABILITY FOR PRECIP. BEHIND THE SYSTEM...TEMPS START TO WARM
UP. THE STRENGTH AND TIMING OF THE SYSTEM WILL ALSO INFLUENCE THE
STRENGTH OF THE SURFACE WINDS. ANTICIPATE AT LEAST BREEZY CONDITIONS
AT TIMES WITH THE PASSAGE OF THE SYSTEM.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
THE TERMINAL FORECASTS WILL FAVOR PERSISTENCE THE NEXT FEW DAYS AS
DRY SOUTHWEST FLOW ALOFT REMAINS OVER THE SOUTHWEST. THIS WILL
CONTINUE MOSTLY CLEAR SKIES AND PERIODS OF ELEVATED WINDS. FOR KIPL
AND KBLH...WEST-SOUTHWEST BREEZES WILL PERSIST BEFORE BECOMING MORE
VARIABLE AT AND AFTER SUNRISE. THE PHX METRO TERMINALS WILL ALSO SEE
A DECREASE IN WESTERLY BREEZES BEFORE VRBING OUT AND GOING EAST
BEFORE SUNRISE. AFTN/EVE BREEZES WILL REDEVELOP FRIDAY...BEGINNING
TYPICALLY BY EARLY/MID AFTERNOON AND CONTINUING THRU MID EVENING.
GUSTS IN EXCESS OF 20KT ARE LIKELY AT ALL AIRFIELDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
LOW PRESSURE IS EXPECTED TO REMAIN ALONG THE WEST COAST FROM SUNDAY
INTO MONDAY...THEN MOVE INLAND ON TUESDAY AND WEDNESDAY...KEEPING
ARIZONA AND SOUTHEAST CALIFORNIA UNDER A DRY SOUTHWEST TO WEST FLOW
ALOFT THROUGH THE PERIOD. BREEZY TO WINDY CONDITIONS WILL DEVELOP
DURING THE AFTERNOON AND EVENING HOURS EACH DAY...WITH PEAK WIND
GUSTS IN EXCESS OF 25 MPH POSSIBLE. SINGLE DIGIT MINIMUM HUMIDITIES
WILL CONTINUE THROUGH MONDAY...WITH SLIGHTLY HIGHER VALUES TUESDAY
INTO THURSDAY. OVERNIGHT RECOVERY WILL BE POOR OVER SOUTH-CENTRAL
ARIZONA AND POOR TO FAIR OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA. HIGH TEMPERATURES WILL REMAIN NEAR OR A BIT BELOW
SEASONAL NORMALS THROUGH MONDAY...WITH COOLER TEMPERATURES POSSIBLE
ON TUESDAY AND WEDNESDAY AS THE LOW PRESSURE MOVES INLAND INTO THE
DESERT SOUTHWEST. DRY WESTERLY FLOW ALOFT WILL FOLLOW THURSDAY ALONG
WITH SLIGHTLY WARMER HIGH TEMPERATURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ
AVIATION...NOLTE
FIRE WEATHER...CB/PERCHA
000
FXUS65 KFGZ 240355
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
840 PM MST THU MAY 23 2013
.SYNOPSIS...A BROAD LOW PRESSURE SYSTEM WILL SETTLE OVER THE PACIFIC
NORTHWEST THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA.
&&
.DISCUSSION...THE WEATHER DISTURBANCE THAT HELPED INCREASE THE WINDS
TODAY CONTINUES TO MOVE NORTHEAST THROUGH THE CENTRAL AND NORTHERN
ROCK MOUNTAINS AWAY FROM ARIZONA. THE WINDS HAVE BEEN STEADILY
DROPPING THIS EVENING WITH MOST LOCATIONS NOW INDICATING SOUTHWEST
WINDS FROM 5 TO 15 MPH WITH GUSTS FROM 15 MPH TO 25 MPH.
A LARGE CLOSED LOW WILL CONTINUE TO SIT OVER THE NORTHWEST U.S
THROUGH THE WEEKEND. THIS PATTERN WILL CONTINUE TO HELP PRODUCE A
BREEZY SOUTHWEST FLOW AND LOW HUMIDITIES IN THE AFTERNOON AND EARLY
EVENING. HIGH TEMPERATURES ARE FORECAST TO RUN NEAR SEASONAL VALUES
DURING THIS TIME PERIOD.
SEE PREVIOUS DISCUSSION FOR ADDITIONAL DETAILS ABOUT THIS WEEKEND
AND NEXT WEEKS WEATHER.
&&
.PREVIOUS DISCUSSION /329 PM MST/...
GUSTY WINDS ARE TAKING PLACE ACROSS MUCH OF THE NORTHLAND THIS
AFTERNOON...WITH OBSERVED GUSTS BEING COMMONLY REPORTED IN THE 35
TO 45 MPH RANGE. THIS IS ALL OCCURRING AS LOW PRESSURE MEANDERS
ACROSS THE PACIFIC NORTHWEST INTO THE COMING HOLIDAY WEEKEND.
WINDS...THOUGH DEFINITELY REMAINING BREEZY...ARE LIKELY TO WEAKEN
A NOTCH FOR FRIDAY AND THE WEEKEND AS PRESSURE GRADIENTS LOOSEN A
SKOSH. DRY CONDITIONS AND DAYTIME TEMPS NEAR SEASONAL NORMS WILL
ACCOMPANY THE BREEZY WEATHER INTO EARLY NEXT WEEK. BY THE MIDDLE
OF NEXT WEEK...EXTENDED RANGES OF THE ECMWF AND GFS SUGGEST A
POTENTIAL LOW PRESSURE SYSTEM MOVING ACROSS THE STATE. OUR
FORECAST FOR THIS SCENARIO INCLUDES COOLER DAYTIME TEMPS AND
CHANCES FOR PRECIP.
&&
.AVIATION...EXPECT VFR CONDITIONS FOR THE NEXT 24 HOURS. BREEZY SW
WINDS 15 TO 25 MPH WITH GUSTS FROM 30 TO 35 MPH WILL DEVELOP AND
CONTINUE FROM AROUND 16Z FRIDAY TO AROUND 04Z SATURDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...
A BROAD TROUGH OF LOW PRESSURE WILL REMAIN ACROSS THE WESTERN
STATES THROUGH EARLY NEXT WEEK BRINGING A CONTINUATION OF BREEZY
SOUTHWEST WINDS AND DRY CONDITIONS.
FOR FRIDAY AND SATURDAY...BREEZY SOUTHWEST WINDS WILL CONTINUE BUT
ARE NOT EXPECTED TO EXCEED CRITICAL FIRE WEATHER THRESHOLDS.
MINIMUM RELATIVE HUMIDITIES WILL REMAIN BELOW 10 PERCENT WITH ONLY
MODERATE OVERNIGHT RECOVERY.
SUNDAY THROUGH TUESDAY...THE TROUGH WILL REMAIN IN PLACE ACROSS
THE WESTERN STATES AND ALLOW BREEZY SOUTHWEST WINDS TO CONTINUE
ALONG WITH VERY LOW MINIMUM RELATIVE HUMIDITIES. WINDS MAY
APPROACH BUT ARE NOT EXPECTED TO EXCEED CRITICAL FIRE WEATHER
CONDITIONS ON SUNDAY AND MONDAY.
AS THE TROUGH FINALLY PUSHES TO THE EAST THERE WILL BE A CHANCE OF
THUNDERSTORMS AND LIGHTNING ON TUESDAY.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........TC/KD
AVIATION.......TC
FIRE WEATHER...DB
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KTWC 232348 CCA
AFDTWC
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE TUCSON AZ
448 PM MST THU MAY 23 2013
CORRECTED ISSUANCE TIME
.SYNOPSIS...AN UPPER LEVEL TROUGH IN THE PACIFIC NORTHWEST WILL
DEEPEN ALONG THE WEST COAST AND PERSIST INTO EARLY NEXT WEEK. THIS
TROUGH WILL CAUSE A PROLONGED PERIOD OF DRY SOUTHWEST FLOW ACROSS
SOUTHERN ARIZONA WITH NEAR AVERAGE AFTERNOON TEMPERATURES AND GUSTY
WINDS AT TIMES. AN INCREASE IN CLOUDS ON TUESDAY AND WEDNESDAY AS
THE TROUGH DEEPENS DURING THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...LONG WAVE TROUGH ALONG THE WEST COAST WILL REMAIN IN
PLACE THROUGH THE WEEKEND AND INTO NEXT WEEK. THIS TROUGH WILL
MODERATE OUR HIGH TEMPERATURES TO NEAR AVERAGE LEVELS. THE SOUTHWEST
FLOW OVER ARIZONA WILL CAUSE GUSTY AFTERNOON WINDS AT MOST LOCATIONS
THROUGH MEMORIAL DAY.
ON TUESDAY A SHORT WAVE SYSTEM DROPS INTO THIS TROUGH AND AMPLIFIES
IT FURTHER SOUTH. THE LATEST 12Z RUNS OF THE ECMWF AND GFS HAVE
SLIGHTLY DIFFERENT SOLUTIONS ON THE TRACK FOR THIS LOW. THE ECMWF
HAS THE LOW CENTER IN NORTHERN ARIZONA ON WEDNESDAY AT 18Z...WHEREAS
THE GFS HAS THE LOW INTO NORTHERN NEW MEXICO. THIS VARIATION
DECREASES THE CONFIDENT OF THE EXTENDED FORECASTS AT DAYS 6 AND 7.
IF THE ECMWF VERIFIES...A SLIGHT CHANCE OF SHOWERS WOULD OCCUR THE
MIDDLE OF NEXT WEEK. IF THE GFS VERIFIES...MOST OF THE LIGHT SHOWER
ACTIVITY WOULD BE IN NORTHERN ARIZONA. DUE TO THESE VARIATIONS...
INCREASED THE POPS AND SKY COVER SLIGHTLY AT THE HIGHER ELEVATIONS.
HOWEVER AT THIS TIME THE DRY FORECAST CONTINUES THROUGH SEVEN DAYS.
&&
.AVIATION...SURFACE WIND SLY/SWLY AT 15-20 KTS WITH GUSTS AROUND 30
KTS THRU 24/03Z...THEN DIMINISHING TO GENERALLY LESS THAN 10 KTS
AGAIN AFT 24/05Z. SKIES GENERALLY CLEAR WITH A FEW HIGH THIN CLOUDS
AT TIMES. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH WILL GRADUALLY BUILD DOWN THE WEST COAST
AND THEN SHIFT EAST ACROSS THE INTERMOUNTAIN WEST THROUGH THE
UPCOMING WEEKEND. THIS WILL RESULT IN CONTINUED DRY CONDITIONS AND A
VERY GRADUAL COOLING TREND...WITH TEMPERATURES APPROACHING AVERAGE
VALUES BY LATE THIS WEEKEND. OTHERWISE...GUSTY WINDS CAN BE EXPECTED
AT TIMES. CRITICAL FIRE WEATHER THRESHOLDS MAY BE EXCEEDED THIS
AFTERNOON IN THE MOUNTAINS OF NORTHERN GREENLEE COUNTY (THE ALPINE
DISTRICT) WHERE A RED FLAG WARNING REMAINS IN EFFECT FROM NOON UNTIL
8 PM MST.
&&
.CLIMATE...WITH TUCSON JUST MISSING THE FIRST 100 OF THE YEAR BY AN
EYELASH...LOOKS LIKE THE NEXT ATTEMPT HAVE TO WAIT UNTIL EARLY JUNE.
ALTHOUGH THE FIRST 100 HAS OCCURRED IN JUNE ONLY TWICE SINCE
1990...HISTORICALLY 1/3RD OF THE OCCURRENCES HAVE BEEN IN JUNE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MST THIS EVENING FOR NORTHERN
FIRE WEATHER ZONE 146 INCLUDING THE ALPINE DISTRICT.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
PUBLIC...GWS
AVIATION/FIRE WEATHER...LADER
000
FXUS65 KFGZ 232229
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
329 PM MST THU MAY 23 2013
.SYNOPSIS...
A BROAD LOW PRESSURE SYSTEM WILL SETTLE OVER THE PACIFIC NORTHWEST
THROUGH MEMORIAL DAY. THIS WILL PRODUCE PERIODS OF GUSTY
SOUTHWEST WINDS AND DRY CONDITIONS ACROSS NORTHERN ARIZONA. THE
STRONGEST WINDS ARE EXPECTED INTO THIS EVENING WITH GUSTS OF 40
MPH OVER MUCH OF THE NORTHLAND.
&&
.DISCUSSION...
GUSTY WINDS ARE TAKING PLACE ACROSS MUCH OF THE NORTHLAND THIS
AFTERNOON...WITH OBSERVED GUSTS BEING COMMONLY REPORTED IN THE 35
TO 45 MPH RANGE. THIS IS ALL OCCURRING AS LOW PRESSURE MEANDERS
ACROSS THE PACIFIC NORTHWEST INTO THE COMING HOLIDAY WEEKEND.
WINDS...THOUGH DEFINITELY REMAINING BREEZY...ARE LIKELY TO WEAKEN
A NOTCH FOR FRIDAY AND THE WEEKEND AS PRESSURE GRADIENTS LOOSEN A
SKOSH. DRY CONDITIONS AND DAYTIME TEMPS NEAR SEASONAL NORMS WILL
ACCOMPANY THE BREEZY WEATHER INTO EARLY NEXT WEEK. BY THE MIDDLE
OF NEXT WEEK...EXTENDED RANGES OF THE ECMWF AND GFS SUGGEST A
POTENTIAL LOW PRESSURE SYSTEM MOVING ACROSS THE STATE. OUR
FORECAST FOR THIS SCENARIO INCLUDES COOLER DAYTIME TEMPS AND
CHANCES FOR PRECIP.
&&
.AVIATION...
FOR THE 00Z PACKAGE...WINDS SW15-30G40KTS. BLDU PSBL ACROSS NERN
AZ THRU 02Z. WINDS DECREASING BELOW 15KTS AFT 03-04Z. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...
A BROAD TROUGH OF LOW PRESSURE WILL REMAIN ACROSS THE WESTERN
STATES THROUGH EARLY NEXT WEEK BRINGING A CONTINUATION OF BREEZY
SOUTHWEST WINDS AND DRY CONDITIONS.
FOR FRIDAY AND SATURDAY...BREEZY SOUTHWEST WINDS WILL CONTINUE BUT
ARE NOT EXPECTED TO EXCEED CRITICAL FIRE WEATHER THRESHOLDS.
MINIMUM RELATIVE HUMIDITIES WILL REMAIN BELOW 10 PERCENT WITH ONLY
MODERATE OVERNIGHT RECOVERY.
SUNDAY THROUGH TUESDAY...THE TROUGH WILL REMAIN IN PLACE ACROSS
THE WESTERN STATES AND ALLOW BREEZY SOUTHWEST WINDS TO CONTINUE
ALONG WITH VERY LOW MINIMUM RELATIVE HUMIDITIES. WINDS MAY
APPROACH BUT ARE NOT EXPECTED TO EXCEED CRITICAL FIRE WEATHER
CONDITIONS ON SUNDAY AND MONDAY.
AS THE TROUGH FINALLY PUSHES TO THE EAST THERE WILL BE A CHANCE OF
THUNDERSTORMS AND LIGHTNING ON TUESDAY.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ104>117-
137>140.
WIND ADVISORY UNTIL 8 PM MST THIS EVENING FOR AZZ004>017-
038>040.
&&
$$
PUBLIC.........KD
AVIATION.......DB
FIRE WEATHER...DB
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
000
FXUS65 KPSR 232207 AAA
AFDPSR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
305 PM MST THU MAY 23 2013
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
A LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY TO WINDY
CONDITIONS AT TIMES THE REST OF THIS WEEK AND INTO NEXT WEEK.
ANTICIPATE LITTLE CHANGE IN TEMPERATURES THROUGH SATURDAY. NEXT
WEEK...THE TROUGH ALONG THE WEST COAST IS ANTICIPATED TO DEEPEN
WHICH WILL LEAD TO SOME MODEST COOLING SUNDAY AND MONDAY WITH SOME
MORE NOTICEABLE COOLING TUESDAY AND WEDNESDAY.
&&
.DISCUSSION...
REST OF TODAY THROUGH MEMORIAL DAY...
TEMPERATURES EARLY THIS AFTERNOON ARE RUNNING A BIT COOLER THAN 24
HOURS AGO...ESPECIALLY OVER SOUTHEAST CALIFORNIA WHICH IS CLOSER TO
AXIS OF THE UPPER TROUGH CENTERED ALONG THE WEST COAST. THE ENHANCED
SOUTHWESTERLY FLOW ALOFT COMBINED WITH GOOD MIXING DUE TO SURFACE
HEATING WILL KEEP AFTERNOONS AND EARLY EVENINGS BREEZY THROUGH THE
WEEKEND. THERE WILL BE DAY TO DAY FLUCTUATIONS IN THE STRENGTH OF
THE BREEZINESS AS VORT MAXES MOVE THROUGH THE TROUGH...PASSING
MAINLY TO THE NORTH OF OUR FORECAST AREA. THERE WILL BE MINOR
FLUCTUATIONS IN HIGH TEMPERATURES THROUGH SATURDAY WITH READINGS ON
THE LOW DESERTS IN THE MID 90S TO NEAR 100. BEGINNING SUNDAY...THE
MODELS SHOW THE SOUTHERN END OF THE TROUGH DEEPENING IN RESPONSE TO
UPSTREAM LOW PRESSURE SYSTEMS OVER THE PACIFIC. IN ESSENCE...THERE
WILL BE A SERIES OF SHORT WAVES THAT WILL LEAD TO SOME MODEST
COOLING. SKIES WILL BE CLEAR EXCEPT FOR THICKER HIGH CLOUDINESS ON
MONDAY.
TUESDAY THROUGH THURSDAY...
THE GFS/ECMWF/GEM ALL SHOW A SPLIT IN THE FLOW ON THE UPSTREAM SIDE
OF THE TROUGH WHICH LEADS TO A SIZABLE SHORT WAVE IN THE SOUTHERN
BRANCH THAT MOVES THROUGH THE DESERT SOUTHWEST IN THE LATE MONDAY
THROUGH WEDNESDAY TIME FRAME. HOWEVER...THERE ARE CONSIDERABLE
DIFFERENCES IN TIMING AND DEPTH OF THE FEATURE. THE ECMWF IS DEEPEST
AND SLOWEST. THE GEM IS WEAKEST AND FASTEST. THE GFS IS IN BETWEEN
BUT CLOSER TO THE GEM SOLUTION. THE GEFS MEAN SUPPORTS THE GFS
PRETTY WELL. THE ECMWF ENSEMBLE OUTPUT SUGGESTS THAT THE OPERATIONAL
RUN IS TOO DEEP AND A BIT SLOW. HOWEVER...THERE IS CONSIDERABLE
SPREAD AMONGST THE INDIVIDUAL ENSEMBLE MEMBERS. MADE SOME SUBTLE
DOWNWARD ADJUSTMENTS TO TEMPS BUT NOT AS AGGRESSIVE AS WHAT ECMWF
WOULD SUGGEST. KEEPING THINGS DRY FOR NOW AS THERE WILL NOT BE MUCH
MOISTURE AVAILABLE WITH THE SYSTEM PLUS THE TIME OF YEAR INDICATES
LOW PROBABILITY FOR PRECIP. BEHIND THE SYSTEM...TEMPS START TO WARM
UP. THE STRENGTH AND TIMING OF THE SYSTEM WILL ALSO INFLUENCE THE
STRENGTH OF THE SURFACE WINDS. ANTICIPATE AT LEAST BREEZY CONDITIONS
AT TIMES WITH THE PASSAGE OF THE SYSTEM.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
LITTLE CHANGE IN WEATHER PATTERN EXPECTED THIS EVENING THROUGH AT
LEAST SATURDAY...AS DRY SOUTHWEST FLOW ALOFT REMAINS IN PLACE ACROSS
THE AREA. THIS WILL LEAD TO PERSISTENT AFTN/EVE BREEZES AT MOST
AIRFIELDS...BEGINNING TYPICALLY BY EARLY/MID AFTERNOON AND
CONTINUING THRU MID EVENING. GUSTS IN EXCESS OF 20KT ARE LIKELY AT
ALL AIRFIELDS. WINDS TO FAVOR SOUTHWEST DURING AFTN/EVE HOURS...AND
WILL RETURN TO SOUTHEAST ACROSS THE SOUTH CENTRAL AZ DESERTS AFTER
MIDNIGHT EACH NIGHT. SKIES TO BE GENLY CLEAR THRU MIDDAY FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
LOW PRESSURE IS EXPECTED TO REMAIN ALONG THE WEST COAST FROM SUNDAY
INTO MONDAY...THEN MOVE INLAND ON TUESDAY AND WEDNESDAY...KEEPING
ARIZONA AND SOUTHEAST CALIFORNIA UNDER A DRY SOUTHWEST TO WEST FLOW
ALOFT THROUGH THE PERIOD. BREEZY TO WINDY CONDITIONS WILL DEVELOP
DURING THE AFTERNOON AND EVENING HOURS EACH DAY...WITH PEAK WIND
GUSTS IN EXCESS OF 25 MPH POSSIBLE. SINGLE DIGIT MINIMUM HUMIDITIES
WILL CONTINUE THROUGH MONDAY...WITH SLIGHTLY HIGHER VALUES TUESDAY
INTO THURSDAY. OVERNIGHT RECOVERY WILL BE POOR OVER SOUTH-CENTRAL
ARIZONA AND POOR TO FAIR OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA. HIGH TEMPERATURES WILL REMAIN NEAR OR A BIT BELOW
SEASONAL NORMALS THROUGH MONDAY...WITH COOLER TEMPERATURES POSSIBLE
ON TUESDAY AND WEDNESDAY AS THE LOW PRESSURE MOVES INLAND INTO THE
DESERT SOUTHWEST. DRY WESTERLY FLOW ALOFT WILL FOLLOW THURSDAY ALONG
WITH SLIGHTLY WARMER HIGH TEMPERATURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...CB
FIRE WEATHER...CB/PERCHA
000
FXUS65 KPSR 232151
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 PM MST THU MAY 23 2013
.SYNOPSIS...
A LOW PRESSURE CENTER OVER THE PACIFIC NORTHWEST IS EXPECTED TO KEEP
THE REGION UNDER DRY SOUTHWESTERLY FLOW ALOFT...WITH BREEZY TO WINDY
CONDITIONS AT TIMES THE REST OF THIS WEEK AND INTO NEXT WEEK.
ANTICIPATE LITTLE CHANGE IN TEMPERATURES THROUGH SATURDAY. NEXT
WEEK...THE TROUGH ALONG THE WEST COAST IS ANTICIPATED TO DEEPEN
WHICH WILL LEAD TO SOME MODEST COOLING SUNDAY AND MONDAY WITH SOME
MORE NOTICEABLE COOLING TUESDAY AND WEDNESDAY.
&&
.DISCUSSION...
REST OF TODAY THROUGH MEMORIAL DAY...
TEMPERATURES EARLY THIS AFTERNOON ARE RUNNING A BIT COOLER THAN 24
HOURS AGO...ESPECIALLY OVER SOUTHEAST CALIFORNIA WHICH IS CLOSER TO
AXIS OF THE UPPER TROUGH CENTERED ALONG THE WEST COAST. THE ENHANCED
SOUTHWESTERLY FLOW ALOFT COMBINED WITH GOOD MIXING DUE TO SURFACE
HEATING WILL KEEP AFTERNOONS AND EARLY EVENINGS BREEZY THROUGH THE
WEEKEND. THERE WILL BE DAY TO DAY FLUCTUATIONS IN THE STRENGTH OF
THE BREEZINESS AS VORT MAXES MOVE THROUGH THE TROUGH...PASSING
MAINLY TO THE NORTH OF OUR FORECAST AREA. THERE WILL BE MINOR
FLUCTUATIONS IN HIGH TEMPERATURES THROUGH SATURDAY WITH READINGS ON
THE LOW DESERTS IN THE MID 90S TO NEAR 100. BEGINNING SUNDAY...THE
MODELS SHOW THE SOUTHERN END OF THE TROUGH DEEPENING IN RESPONSE TO
UPSTREAM LOW PRESSURE SYSTEMS OVER THE PACIFIC. IN ESSENCE...THERE
WILL BE A SERIES OF SHORT WAVES THAT WILL LEAD TO SOME MODEST
COOLING. SKIES WILL BE CLEAR EXCEPT FOR THICKER HIGH CLOUDINESS ON
MONDAY.
TUESDAY THROUGH THURSDAY...
THE GFS/ECMWF/GEM ALL SHOW A SPLIT IN THE FLOW ON THE UPSTREAM SIDE
OF THE TROUGH WHICH LEADS TO A SIZABLE SHORT WAVE IN THE SOUTHERN
BRANCH THAT MOVES THROUGH THE DESERT SOUTHWEST IN THE LATE MONDAY
THROUGH WEDNESDAY TIME FRAME. HOWEVER...THERE ARE CONSIDERABLE
DIFFERENCES IN TIMING AND DEPTH OF THE FEATURE. THE ECMWF IS DEEPEST
AND SLOWEST. THE GEM IS WEAKEST AND FASTEST. THE GFS IS IN BETWEEN
BUT CLOSER TO THE GEM SOLUTION. THE GEFS MEAN SUPPORTS THE GFS
PRETTY WELL. THE ECMWF ENSEMBLE OUTPUT SUGGESTS THAT THE OPERATIONAL
RUN IS TOO DEEP AND A BIT SLOW. HOWEVER...THERE IS CONSIDERABLE
SPREAD AMONGST THE INDIVIDUAL ENSEMBLE MEMBERS. MADE SOME SUBTLE
DOWNWARD ADJUSTMENTS TO TEMPS BUT NOT AS AGGRESSIVE AS WHAT ECMWF
WOULD SUGGEST. KEEPING THINGS DRY FOR NOW AS THERE WILL NOT BE MUCH
MOISTURE AVAILABLE WITH THE SYSTEM PLUS THE TIME OF YEAR INDICATES
LOW PROBABILITY FOR PRECIP. BEHIND THE SYSTEM...TEMPS START TO WARM
UP. THE STRENGTH AND TIMING OF THE SYSTEM WILL ALSO INFLUENCE THE
STRENGTH OF THE SURFACE WINDS. ANTICIPATE AT LEAST BREEZY CONDITIONS
AT TIMES WITH THE PASSAGE OF THE SYSTEM.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
DRY SOUTHWEST FLOW ALOFT WILL KEEP SKIES CLEAR TO MOSTLY CLEAR
THROUGH THE TAF PERIOD. GUSTY WINDS ARE EXPECTED TO REDEVELOP AT THE
TERMINALS THIS AFTERNOON...BUT WITH SPEEDS REMAINING LIGHTER THAN
WHAT WE SAW YESTERDAY. WINDS WILL THEN DIMINISH LATER THIS
EVENING...AND REVERT BACK TO THE USUAL DIURNAL TRENDS IN DIRECTION
AT THE PHX AREA TERMINALS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
LOW PRESSURE IS EXPECTED TO REMAIN ALONG THE WEST COAST FROM
SATURDAY ONWARD INTO MONDAY...THEN MOVE INLAND ON TUESDAY AND
WEDNESDAY...KEEPING ARIZONA AND SOUTHEAST CALIFORNIA UNDER A DRY
SOUTHWEST TO WEST FLOW ALOFT THROUGH THE PERIOD. BREEZY TO WINDY
CONDITIONS WILL DEVELOP DURING THE AFTERNOON AND EVENING HOURS EACH
DAY...WITH PEAK WIND GUSTS IN EXCESS OF 25 MPH POSSIBLE. SINGLE
DIGIT MINIMUM HUMIDITIES WILL CONTINUE THROUGH MONDAY...WITH
SLIGHTLY HIGHER VALUES ON TUESDAY AND WEDNESDAY. OVERNIGHT RECOVERY
WILL BE POOR OVER SOUTH-CENTRAL ARIZONA AND POOR TO FAIR OVER
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. HIGH TEMPERATURES WILL
REMAIN NEAR OR A BIT BELOW SEASONAL NORMALS FROM SATURDAY ONWARD
INTO MONDAY...WITH SOMEWHAT COOLER TEMPERATURES POSSIBLE ON TUESDAY
AND WEDNESDAY AS THE LOW PRESSURE MOVES INLAND INTO THE DESERT
SOUTHWEST.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...PERCHA
FIRE WEATHER...PERCHA
000
FXUS65 KTWC 232129
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
229 AM MST THU MAY 23 2013
.SYNOPSIS...AN UPPER LEVEL TROUGH IN THE PACIFIC NORTHWEST WILL
DEEPEN ALONG THE WEST COAST AND PERSIST INTO EARLY NEXT WEEK. THIS
TROUGH WILL CAUSE A PROLONGED PERIOD OF DRY SOUTHWEST FLOW ACROSS
SOUTHERN ARIZONA WITH NEAR AVERAGE AFTERNOON TEMPERATURES AND GUSTY
WINDS AT TIMES. AN INCREASE IN CLOUDS ON TUESDAY AND WEDNESDAY AS
THE TROUGH DEEPENS DURING THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...LONG WAVE TROUGH ALONG THE WEST COAST WILL REMAIN IN
PLACE THROUGH THE WEEKEND AND INTO NEXT WEEK. THIS TROUGH WILL
MODERATE OUR HIGH TEMPERATURES TO NEAR AVERAGE LEVELS. THE SOUTHWEST
FLOW OVER ARIZONA WILL CAUSE GUSTY AFTERNOON WINDS AT MOST LOCATIONS
THROUGH MEMORIAL DAY.
ON TUESDAY A SHORT WAVE SYSTEM DROPS INTO THIS TROUGH AND AMPLIFIES
IT FURTHER SOUTH. THE LATEST 12Z RUNS OF THE ECMWF AND GFS HAVE
SLIGHTLY DIFFERENT SOLUTIONS ON THE TRACK FOR THIS LOW. THE ECMWF
HAS THE LOW CENTER IN NORTHERN ARIZONA ON WEDNESDAY AT 18Z...WHEREAS
THE GFS HAS THE LOW INTO NORTHERN NEW MEXICO. THIS VARIATION
DECREASES THE CONFIDENT OF THE EXTENDED FORECASTS AT DAYS 6 AND 7.
IF THE ECMWF VERIFIES...A SLIGHT CHANCE OF SHOWERS WOULD OCCUR THE
MIDDLE OF NEXT WEEK. IF THE GFS VERIFIES...MOST OF THE LIGHT SHOWER
ACTIVITY WOULD BE IN NORTHERN ARIZONA. DUE TO THESE
VARIATIONS...INCREASED THE POPS AND SKY COVER SLIGHTLY AT THE HIGHER
ELEVATIONS. HOWEVER AT THIS TIME THE DRY FORECAST CONTINUES THROUGH
SEVEN DAYS.
&&
.AVIATION...SURFACE WIND SLY/SWLY AT 15-20 KTS WITH GUSTS AROUND 30
KTS THRU 24/03Z...THEN DIMINISHING TO GENERALLY LESS THAN 10 KTS
AGAIN AFT 24/05Z. SKIES GENERALLY CLEAR WITH A FEW HIGH THIN CLOUDS
AT TIMES. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A TROUGH WILL GRADUALLY BUILD DOWN THE WEST COAST
AND THEN SHIFT EAST ACROSS THE INTERMOUNTAIN WEST THROUGH THE
UPCOMING WEEKEND. THIS WILL RESULT IN CONTINUED DRY CONDITIONS AND A
VERY GRADUAL COOLING TREND...WITH TEMPERATURES APPROACHING AVERAGE
VALUES BY LATE THIS WEEKEND. OTHERWISE...GUSTY WINDS CAN BE EXPECTED
AT TIMES. CRITICAL FIRE WEATHER THRESHOLDS MAY BE EXCEEDED THIS
AFTERNOON IN THE MOUNTAINS OF NORTHERN GREENLEE COUNTY (THE ALPINE
DISTRICT) WHERE A RED FLAG WARNING REMAINS IN EFFECT FROM NOON UNTIL
8 PM MST.
&&
.CLIMATE...WITH TUCSON JUST MISSING THE FIRST 100 OF THE YEAR BY AN
EYELASH...LOOKS LIKE THE NEXT ATTEMPT HAVE TO WAIT UNTIL EARLY JUNE.
ALTHOUGH THE FIRST 100 HAS OCCURRED IN JUNE ONLY TWICE SINCE
1990...HISTORICALLY 1/3RD OF THE OCCURRENCES HAVE BEEN IN JUNE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING TODAY FROM 12 NOON UNTIL 8 PM FOR NORTHERN
FIRE WEATHER ZONE 146 INCLUDING THE ALPINE DISTRICT.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
PUBLIC...GWS
AVIATION/FIRE WEATHER...LADER
| 
