Area Forecast Discussion
Issued by NWS Phoenix, AZ
FXUS65 KPSR 260956
Area Forecast Discussion
National Weather Service Phoenix AZ
300 AM MST Sun Mar 26 2017
A fast moving high pressure system will build into the region today
ahead of another Pacific cold front expected Monday afternoon.
Although light winds are expected area-wide today, gusty winds ahead
and after Mondays cold front are expected. The threat of showers
Monday night and Tuesday will be confined to central and eastern
Arizona. High pressure will redevelop Wednesday and most of
Thursday, ahead of another stronger and colder weather system
expected Friday and Saturday.
Today and Tonight...
A transitory upper level ridge will build over the region today and
tonight resulting in mostly clear skies, light surface wind, and
afternoon temperatures near of slightly above normal.
Monday through Tuesday Night...
Another in a series of Pacific weather systems is forecast to move
into the region Monday afternoon and night. This is a deeper and
colder system, and still a bit moisture starved. The cold front is
expected to move through the Colorado River Valley around 1 pm
Monday, then through Phoenix around 5 pm. Gusty pre and post frontal
surface winds are expected area-wide Monday afternoon and evening,
followed by strong north to northwest winds Tuesday. The strongest
wind gusts however are forecast for southeast CA and Colorado River
Since this system is rather moisture starve, any shower activity
will be associated with the coldest mid level temperatures, near the
system center, and relegated to areas from Phoenix north through
east, especially Tuesday afternoon. Any precip should be on the
light side, with perhaps an isolated mountain thunderstorm as well.
The Tuesday weather system will exit east into New Mexico Tuesday
Wednesday, Wednesday Night, and most of Thursday...
It now appears these incoming weather systems will be a little more
progressive than earlier thought, therefore another transitory upper
level ridge will move through the region Wednesday through most of
Thursday. And except for a few high clouds, mostly clear skies,
light wind, and slightly above normal afternoon temperatures are
forecast. The only caveat Thursday will gusty afternoon evening
west winds over southeast CA and Colorado River with another
approaching cold front for Friday.
Friday and Saturday...
All models are in general agreement in developing yet another
Pacific trof over AZ this period. Models however are still
conflicted in the eventual track of this system, which has potential
to be the strongest, coldest, and wettest system in the series.
However big disparities still exist between the models, which are
flip flopping with the storm track through AZ. Forecast confidence
is very low this far out, so precip probabilities will be shaded
toward slight chances across south central AZ, with better potential
in the mountains of southern Gila County zone 24.
The upper level trof over AZ Saturday could possibly move east into
New Mexico Sunday, however confidence is low at this point. We will
keep it dry across the forecast area this period.
South-Central Arizona including KPHX, KIWA, and KSDL:
Weather system continues to push off to the east and following
sunset skies have cleared nicely. Expect genly clear skies into
Sunday morning with some high cirrus moving in during the day
tomorrow. Winds will remain from the west past midnight but should
eventually turn east after 08z and remain there into the early
afternoon on Monday. Since the gustiness has pretty much ended we do
not expect any aviation concerns for the next 24 hours at least.
Southeast California/Southwest Arizona including KIPL and KBLH:
Weather system continues to push off well to the east and gradients
have relaxed, as such winds have tapered off and the gustiness at
KIPL has subsided. Expect west winds to continue into mid morning
Monday but stay mostly below 15kt. Winds have been less at KBLH and
should continue to favor the northwest through north into Monday
morning with speeds less than 12kt. Skies to be clear for the most
part with possibly some thin high clouds moving into the area during
the day on Monday. Now that the winds have died off there are no
aviation concerns for the next 24 hours at least.
Aviation discussion not updated for amended TAFs.
Monday through Friday...
Active storm pattern will remain over the Intermountain West at
least through the end of the month and possibly into early April
as a series of Pacific storms pass through. Breezy weather will
remain a common feature of most afternoons/early evenings for the
districts with daytime humidity levels ranging 10-25 percent at
their driest. Most of the Pacific storms will travel through the
Great Basin before sweeping into Arizona, allowing for above
normal chances of precipitation for the Arizona districts but near
to below normal chances for precip along and west of the Colorado
River Valley. With an active storm track over the area,
temperatures will trend more towards seasonal averages. Periods of
stronger winds may lead to a locally elevated fire danger at
times that may turn into critical fire weather conditions for some
locales. A fair bit of uncertainty remains with the track of the
next few systems to move through the region in the far extended
period that may ramp up or back off concerns for
elevated/critical fire danger.
.SPOTTER INFORMATION STATEMENT...
Spotter reports will not be needed through the weekend.
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