Area Forecast Discussion
Issued by NWS Phoenix, AZ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KPSR 011603
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
900 AM MST WED OCT 1 2014

.SYNOPSIS...
A WEATHER SYSTEM PASSING TO OUR NORTH WILL GENERATE NORTH TO
NORTHEASTERLY BREEZES TODAY WITH A PERSISTENT TEMPERATURE FORECAST
TODAY. HIGH PRESSURE RIDGE BUILDING INTO THE REGION WILL LEAD TO A
WARMING TREND FOR THE REST OF THE WEEK WITH ABOVE NORMAL TEMPERATURES
PEAKING ON SATURDAY. THERE WILL BE LITTLE CHANGE IN TEMPERATURES OVER
THE WEEKEND ALONG WITH LIGHT WINDS. HIGH PRESSURE WEAKENS NEXT WEEK
RESULTING IN A VERY SLOW COOLING TREND.

&&

.DISCUSSION...
A COMPACT SHORTWAVE PROGRESSING THROUGH CNTRL/NRN UTAH WAS FORCING A
SOUTHWARD MOVING COLD FRONT INTO FAR NWRN ARIZONA THIS
MORNING...THOUGH PREFRONTAL MOISTURE HAS BEEN SUBSTANTIALLY LACKING.
OBJECTIVE ANALYSIS INDICATES STRONG SFC PRESSURE RISES OVER SRN
NEVADA WHILE SATELLITE WV IMAGERY SHOWS SIGNIFICANT POST FRONTAL
DRYING AND SUBSIDENCE APPROACHING THE FORECAST AREA. THIS SCENARIO
WILL ALLOW NEUTRAL TO SLIGHTLY NEGATIVE HEIGHT FALLS/THERMAL
ADVECTION THROUGH THIS EVENING...ARGUING FOR A NEAR PERSISTENCE
FORECAST. ONLY VERY MINOR HOURLY ADJUSTMENTS WERE NECESSARY THIS
MORNING...WITH NO CHANGE TO THE OVERALL FORECAST THEME.

&&

.PREVIOUS DISCUSSION...
/325 AM MST WED OCT 1 2014/
LONGWAVE TROUGHING LINGERS OVER THE WESTERN CONUS...WITH PERSISTENTLY
DRY WEST FLOW ACROSS SOUTHERN CA AND AZ. CLOUDLESS SKIES WITH LIGHT
WINDS AND MILD MORNING TEMPERATURES WERE OBSERVED ACROSS THE FORECAST
AREA. LATEST SHORTWAVE DISTURBANCE CURRENTLY PASSING THROUGH NORTHERN
CA AND THE SIERRA WILL BRUSH THROUGH NORTHERN AZ TODAY WITH ONLY
MINOR INFLUENCES ON THE FORECAST FOR THE SOUTH-CENTRAL AZ AND
SOUTHEAST CA DESERTS. 850/700MB TEMPERATURE PLOTS AND MSLP ANALYSIS
DEPICT THE ASSOCIATED FRONT WITH THIS SYSTEM TO DRAPE ACROSS NORTHERN
AZ/MOGOLLON LATER TONIGHT AND INTO THURSDAY. VERY LITTLE CHANGE
EXPECTED IN THE THERMAL PROFILE OVER THE LOWER DESERTS...WITH
TEMPERATURES TODAY AND THURSDAY TO REMAIN RATHER PERSISTENT IN THE
LOW TO MID 90S ACROSS THE AZ DESERT ELEVATIONS AND AROUND 100F FOR
THE WESTERN FORECAST AREA.

WITH THE PASSING SHORTWAVE FEATURE AND SURFACE HIGH PRESSURE
EXPANDING ACROSS MUCH OF THE GREAT BASIN...PRESSURE GRADIENT
ORIENTATION WILL RESULT MORE NOTICEABLE NORTH TO NORTHEASTERLY
WINDS...PARTICULARLY DOWN THE COLORADO RIVER VALLEY AND THE
MARICOPA/GILA HIGHER TERRAIN/FOOTHILLS. WINDS 10-15 MPH ARE POSSIBLE
WITH ISOLATED GUSTINESS THROUGH THE LATE WEEK. OVERNIGHT WINDS MAY
KEEP LOWS EVEN MORE MILD THAN THEY HAVE BEEN THE PAST FEW
NIGHTS...BUT STILL PLEASANTLY COOL FOR EARLY OCTOBER.

BEGINNING LATE THURSDAY INTO FRIDAY PACIFIC RIDGING WILL BUILD OVER
THE WEST...WARMING THE ATMOSPHERE AND SUPPORTING CONTINUED CLEAR
SKIES. TEMPERATURES ARE EXPECTED TO PEAK ON SATURDAY WHERE WE CANNOT
RULE OUT SOME SOUTH-CENTRAL DESERT LOCALES...INCLUDING
PHOENIX...HITTING THE CENTURY MARK ALONG WITH THE ALREADY WARM
WESTERN AZ/SOUTHEAST CA DESERTS. THE AVERAGE LAST DAY WE`VE SEEN 100F
OVER THE LAST NORMAL PERIOD OF 1981-2010 IN PHOENIX HAS BEEN OCT
3RD...AND OCT 5TH FOR YUMA. BY EARLY NEXT WEEK...HIGH PRESSURE OVER
THE WEST WILL BEGIN WEAKEN AND RIDGE HEIGHTS WILL GRADUALLY LOWER AS
ANOTHER WEATHER DISTURBANCE DEVELOPS DOWN THE WEST COAST. THE
COMBINATION OF LOWER HEIGHTS...SOME PASSING HIGH LEVEL CLOUDS AND A
SUBTLE RETURN OF SOME ELEVATED HUMIDITIES WILL SUPPORT A SLOW COOLING
TREND OF AFTERNOON TEMPERATURES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LIGHT DIURNAL WINDS AND CLEAR SKIES WILL PREDOMINATE AT THE TAF
SITES THROUGH WEDNESDAY. NO AVIATION WEATHER IMPACTS ANTICIPATED.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
WINDS WILL ACQUIRE A NORTHERLY COMPONENT THIS AFTERNOON AS A LOW
PRESSURE SYSTEM SLIDES BY ACROSS THE FOUR CORNERS. AT KBLH...WINDS
WILL GENERALLY REMAIN NEAR 10 KT AFTER 00Z THURSDAY...THOUGH A BRIEF
GUST TO 20 KT IS POSSIBLE...PARTICULARLY IN THE 00Z-03Z PERIOD.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
A RIDGE OF HIGH PRESSURE WILL BE THE PREDOMINANT WEATHER FEATURE
ACROSS THE DESERT SOUTHWEST THROUGH EARLY NEXT WEEK. DRIER THAN
NORMAL CONDITIONS WILL PREVAIL AND NO PRECIPITATION IS EXPECTED.
TEMPERATURES WILL BE ABOVE AVERAGE THROUGH SUNDAY...FOLLOWED BY A
COOLING TREND EARLY NEXT WEEK AS HIGH PRESSURE WEAKENS AND MOISTURE
RETURNS TO THE AREA. MINIMUM HUMIDITIES WILL BE QUITE LOW FRIDAY
THROUGH SUNDAY BEFORE TRENDING UP MONDAY AND TUESDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...MO/NOLTE
AVIATION...HIRSCH
FIRE WEATHER...HIRSCH







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