448 
FXUS65 KPSR 121800
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1100 AM MST Sat Feb 12 2022

.UPDATE...
Updated Aviation

&&

.SYNOPSIS...
High pressure will persist over the region the next several days 
resulting in continued dry weather and temperatures at least 10 
degrees above normal. Next Tuesday and Wednesday, a weather system 
will move through the area bringing locally breezy conditions and 
chances for light precipitation. Temperatures will also retreat back 
to near normal levels during the latter half of the week. 

&&

.DISCUSSION...
The unseasonably strong high pressure ridge remains in place along
the entire West Coast with our region still on the eastern fringes
of the ridge. A weak shortwave trough is also currently tracking 
south southeastward through the Central Rockies with a strong 
surface high building in behind the trough. This high is 
strengthening the pressure gradient over Arizona early this morning 
with breezy conditions already starting over the high terrain. 
Models indicate the gradient should be at its peak late this morning 
when many areas can expect winds occasionally gusting to between 20-
30 mph, locally higher across the high terrain. Winds will begin to 
diminish already by this afternoon, but some gustiness should remain 
through the rest of the daylight hours.

Warm temperatures will continue this weekend through Monday with 
afternoon highs each day from the upper 70s and lower 80s across the 
south-central Arizona deserts to around 85 degrees in Yuma and El 
Centro. Yuma was only one degree shy of tying a daily record 
yesterday hitting 86 degrees and could come close again today, but 
the NBM probability of tying its record of 87 degrees today is 
currently at 14%. El Centro's daily record also is 87 degrees for 
today, but the probability of tying is lower at 4%. Phoenix's daily 
records of 87 and 88 degrees this weekend are well out of reach. As 
the ridge begins to weaken Sunday night, temperatures will begin to 
fall starting Monday, but highs around 80 degrees will still be 
common. 

Model ensembles continue to show excellent agreement with a fast 
moving upper level trough diving south southeastward along the West 
Coast late Monday into Tuesday. Model trends are showing a slight 
shift to the east with the low track which in turn has led to a 
decrease in precipitation chances late Tuesday into Wednesday. 
Latest NBM PoPs are less than 10% across southeast California and 
southwest Arizona to around 20% in the Phoenix area and 30% over the 
high terrain. An increase in winds and potential for blowing dust is 
the main forecast concern for Tuesday afternoon and evening with 
good potential for widespread wind gusts of 30-40 mph, possibly 
higher for a brief period along the eastward advancing cold front. 
Tuesday's highs should still be fairly warm, mostly in the mid to 
upper 70s, but colder air will be quickly filtering in behind the 
cold front later in the day. 

For Wednesday, the low center should quickly exit into New Mexico
with daytime highs from the mid 60s in the Phoenix area to around 70 
degrees across the western deserts. Breezy conditions are still 
likely to continue through Wednesday, but with gusts generally in a 
20-25 mph. Model ensembles become increasingly divergent after 
Wednesday with a subset of members showing a follow-on shortwave 
trough diving southward into our region on Thursday, possibly 
providing a reinforcing shot of cooler air. The rest of the ensemble 
members show another strong ridge building into our region from the 
west which would allow for a faster increase in temperatures. The 
latest NBM temperature guidance shows a gradual warm up late in the 
week into next weekend, but with highs most likely remaining below 
80 degrees during the period.

&&

.AVIATION...Updated at 1755Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: 
A strong surface high across the southern Rockies is again resulting 
in breezy conditions across the Valley. As the lower levels mix out 
through the early afternoon, a few easterly gusts up to 20 kt will 
be possible, particularly at KPHX and KSDL. Winds will then subside 
later this afternoon, though the easterly flow will persist through 
the evening and overnight.

Latest guidance indicates the pressure gradient will not be nearly 
as strong Sunday morning and breezy conditions are not anticipated. 
Weaker flow Sunday afternoon will also promote a diurnal switch to 
westerly winds at KPHX during the mid-late afternoon.


Southeast California/Southwest Arizona including KIPL and KBLH: 
Winds will generally retain a northerly and easterly component this 
afternoon with high pressure positioned in the southern Rockies. An 
occasional gust up to 20 kt will be possible at KBLH, while winds 
will be weaker at KIPL. Winds will subside this afternoon before 
becoming light and diurnal tonight and Sunday. Otherwise, mostly 
clear skies will prevail.

&&

.FIRE WEATHER...
Monday through Friday:
High pressure will weaken on Monday followed by a weather system
expected to pass through the region on Tuesday and Wednesday. The
system will be fairly dry with overall chances for wetting rains
less than 30% and mainly over the Arizona high terrain. Winds are 
likely to be the main impact with the system with locally windy 
conditions on Tuesday and possibly Wednesday. Much cooler 
temperatures are also expected by mid next week. Humidity levels 
will remain quite low for much of the period with Min RHs starting 
out between 7-15% on Monday, rising to 20-30% on Wednesday, before 
dropping back into a 10-15% by Friday.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.

&&

$$

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DISCUSSION...Kuhlman
AVIATION...Hirsch
FIRE WEATHER...Kuhlman