Your Weather

To update your location please enter your ZIP code, city, state, airport code or country in the field below. Weather by E-mail: Forecast storm alerts. Weather E-Mail Alert Sign Up »

Next 12 Hours

Forecast data from the National Digital Forecast Database.

5 Day Forecast

• Friday
• 
• High: 99 °
• Low: 72 °
• Partly Cloudy

• Saturday
• 
• High: 99 °
• Low: 70 °
• Clear

• Sunday
• 
• High: 97 °
• Low: 72 °
• Clear

• Monday
• 
• High: 95 °
• Low: 72 °
• Partly Cloudy

• Tuesday
• 
• High: 90 °
• Low: 64 °
• Partly Cloudy

Area forecast discussion 
National Weather Service Phoenix Arizona 
900 PM MST Thursday 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 northwest 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 vorticity 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 middle 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 European model (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 European model (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 temperatures but not as aggressive as what European model (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 precipitation. Behind the system...temperatures 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 metropolitan terminals will also see 
a decrease in westerly breezes before vrbing out and going east 
before sunrise. Afternoon/evening breezes will redevelop Friday...beginning 
typically by early/middle afternoon and continuing through middle 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 miles per hour 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... 


Arizona...none. 


California...none. 


&& 


$$ 


Visit US on facebook...twitter...and at weather.Gov/Phoenix 


Discussion...Nolte 
previous discussion...aj 
aviation...Nolte 
fire weather...cb/percha