FXUS65 KPSR 240330

Area Forecast Discussion
National Weather Service Phoenix AZ
830 PM MST Thu Mar 23 2017

A strong low pressure system will continue to move through the
region today, exiting Arizona later tonight. Shower activity today
will develop mainly from Phoenix eastward. High pressure will build
back into the region Friday, however another Pacific disturbance
will move into the region Saturday. The Saturday system will remain
dry, but a larger and colder weather system next Tuesday and
Wednesday may bring another period of showers.



Skies are rapidly clearing this evening over the Phoenix metro as
an upper level trough continues to move eastward. As expected,
most of the shower and thunderstorm activity today was mainly to
the north and east of Phoenix with the strongest thunderstorm
forming near Roosevelt Lake. However, a few showers did manage to
form in the northern and southeast portions of the Phoenix metro

The last bit of shower activity with the trough is currently
confined to northern and eastern portions of Arizona but will be
moving out of the state later tonight. Additionally, winds are
tapering off this evening with the more typical diurnal winds
forecast to return late tonight/early tomorrow morning. For
Friday, a transient ridge builds in which should push most
locations into the upper 70s while the warmest desert locations
will likely see highs in the lower 80s. This is right around
normal for this time of year. Clear skies and light winds will be
the story across our CWA tomorrow; however, some changes will
come Saturday as our next Pacific trough moves onshore. Details
are outlined in the previous discussion below.



A second low-amplitude shortwave trough is forecast to glance
the region late Saturday and Sunday, with the highest
precipitation chances expected to remain north of the region. Some
increase in westerly surface winds will also occur once again,
with the strongest winds across southeast California, but the
current forecast suggests speeds should remain shy of advisory

Yet another storm system, potentially more significant, is
forecast to deepen over the Southwest by Monday. Deterministic
model guidance has come more in line developing a cut off low
early next week. However, precipitation chances will still remain
sensitive to the availability of rich moisture and the exact
track of the low, so will only maintain slight chance PoPs Monday
and Tuesday. The higher confidence impact remains the the
potential for gusty winds on Monday.


South-Central Arizona Including KPHX, KIWA, and KSDL:

Showers have mostly left the terminal area although there may be a
lingering shower or two. Most of the rain and thunderstorms over the
higher terrain north and east of Phoenix. The winds will remain
westerly through the afternoon with occasional gusts upwards of 20
to 30 kts. The winds should follow their diurnal The ceilings
generally should not be a problem although there may be some
temporary passing broken decks between 3 to 5k feet. The lowest
ceilings will impact the areas north and east of Phoenix to possibly
include SDL.

Southeast California/Southwest Arizona Including KIPL and KBLH:

The major aviation weather concern through this afternoon and
evening will be stronger westerly winds. Wind speeds will generally
stay around 15 kts although there may be some stronger gusts.
Otherwise, skies will be generally clear with no other major weather

Aviation discussion not updated for amended TAFs.


Saturday through Wednesday...
Temperatures will moderate back towards the seasonal normal over
the weekend as high pressure and dry weather build back into the
region. Breezy weather will be common through most of the
districts, especially Saturday and Monday afternoon. Despite the
stronger winds and drying trend, humidity levels will be
manageable only falling into a 15-30 percent range. Overnight
recovery will be good to excellent. Periods of stronger winds may
lead to a locally elevated fire danger at times, but critical
conditions should not be breached. An active storm pattern will
remain over the Southwest states, leading to periods of cooler and
windy weather through the end of the month.


Spotter reports will not be needed through the weekend.




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