000
FXUS65 KPSR 312005
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
105 PM MST Tue Mar 31 2020


.SYNOPSIS...
Beginning today, temperatures will warm to above normal readings
under continued dry conditions. Increased high level cloudiness will
continue through the first part of Wednesday before clear to mostly
clear skies then dominate through the weekend. Another dry weather
disturbance will approach the region early next week allowing for a
gradual cooling trend and a return to slightly below normal
temperatures beginning next Monday or Tuesday.

&&

.DISCUSSION...
Weak upper level ridging over the region will bring additional
warming today as highs top out mostly in the 82-85 degree range. To
the southwest, a weak open trough is evident on satellite imagery
well west of Baja, which will track northeastward today. Associated
with this trough is a modest 90 kt 300 mb jet streak. This jet
streak will allow for some weak upper level divergence over Arizona,
leading to high cloud cover this afternoon, and lasting through the
first part of Wednesday.

While the upper atmosphere will cool somewhat on Wednesday as the
weak ridge currently overhead moves east, further warming in the
lower atmosphere and clearing skies is expected to allow daytime
highs reaching into upper 80s across a good portion of the lower
deserts. For Thursday through Saturday, zonal to slightly cyclonic
flow aloft will continue to bring dry conditions and near to
slightly above normal temperatures to the region. Meanwhile, further
west, stronger westerly flow behind the shortwave trough will bring
gusty westerly wind to southeast California on Wednesday and
Thursday.

Broad troughing over the western and central U.S. has been a regular
feature as of late, wedged between persistent high pressure areas in
the Gulf of Alaska and near Hudson Bay Canada. This general pattern
is expected to continue, with an expansion of the trough into
Arizona more likely early next week as shortwave troughs dipping
into the base of the trough push the overall large scale trough
further to the south. Models agree a more significant shortwave
diving down the back side of the large scale trough is likely Sunday
into Monday. However, models disagree on how far south the shortwave
will reach and how well it will hold together as it brushes the
area. Even with the model differences, rain chances across our
region should be fairly low, especially across the lower deserts. As
far as temperatures, there will most likely be a decent cooling
trend during the first half of next week with highs potentially
lowering into the middle 70s.

&&

.AVIATION...Updated at 1740Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:

Minimal aviation concerns anticipated through the TAF period. Winds
will favor typical diurnal directions, with speeds remaining below 8
kts through the next 24 hours. Expect winds to become light and
variable between transition periods. Otherwise, SCT-BKN high clouds
around 20 kft this afternoon will gradually fall to around 16 kft
later this evening.

Southeast California/Southwest Arizona including KIPL and KBLH:

Minimal aviation concerns expected through the next 24 hours. Winds
at KIPL are expected to remain light and variable through much of
today before taking on a light westerly component tonight. At KBLH,
winds will mostly remain light and variable through the TAF period,
though winds may favor a light southerly component at times during
the overnight hours. Expect SCT-BKN high clouds around 20 kft to
continue through the period with SCT decks developing around 16 kft
this evening.

&&

.FIRE WEATHER...
Thursday through Monday:
The region will remain under a dry pattern through the period with
temperatures running around five degrees above seasonal normals
through Saturday before a gradual cool down begins. Multiple weak
upper level disturbances are expected to pass by the region
bringing periods of breezy conditions, but no chances for
precipitation. Minimum RHs will generally drop into the teens each
afternoon.

&&

.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.

&&

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

$$

DISCUSSION...Hodges/Kuhlman
AVIATION...Smith
FIRE WEATHER...Kuhlman

NWS PSR Office Area Forecast Discussion