634
FXUS65 KPSR 272328
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
425 PM MST Sat Apr 27 2024

.UPDATE...
Updated Aviation

&&

.SYNOPSIS...
A departing weather system will result in residual breeziness and
some showers across the higher terrain areas of northern and eastern
AZ today. Higher pressure will follow the departing system and
persist through much of next week, resulting in benign weather
pattern. Lower desert temperatures will warm back into the nineties
by Monday and likely persist in the nineties each day through the
week. No rain is in the forecast following today and winds will be
lighter.

&&

.DISCUSSION...
The upper low circulation which brought yesterday`s windy conditions
and evening thunderstorms in now pushing into Colorado early this
afternoon. This potent low and strong upper level jet around its
southern half is helping drive a Plains severe weather outbreak.
Back here in the southern deserts, the low is still close enough to
create some breezy conditions today. Not nearly as strong as
yesterday, but still with some peak gusts up to 20-30 mph this
afternoon. There is also still sufficient moisture and minimal but
high enough instability for surface-based convection to develop this
afternoon through this evening. Activity should remain confined to
the northern AZ high terrain, but with the northwest flow a few
showers and maybe a storm could drift into parts of NE Maricopa and
S Gila counties. Impacts from the convection, should any make it
into Maricopa and S. Gila counties will likely be limited, few
hundredths of an inch of rain, gusty winds, and small hail.

The height field will rise Sunday into Monday as troffing is
replaced by quasi-zonal flow. This will result in warming
temperatures, with highs going from low to mid 80s today, back to
near normal Sunday, and then back into the low to mid 90s Monday.
The temperatures and overall weather through all of next week will
be mostly steady-state, with very little day-to-day changes.
Lower desert highs are forecast to continue to reach the low to
mid 90s each day, with overnight/morning lows in the 60s. These
temperatures will lead to daily widespread minor HeatRisk. No
rain is in the forecast and skies will be mostly clear. Winds
will also be lighter most days, with typical afternoon 15-20 mph
gusts. Beyond Wednesday however, global ensembles show a lot of
uncertainty regarding a deeper trough pattern in the west. There
is at least strong agreement that the core of the trough pattern
will remain well to the north, mainly through the Great Basin,
but uncertainty in the amplitude of the longwave trough pattern
and uncertainty in timing of potential shortwaves will affect
potential for some gustier conditions mid to late week and could
have a slight impact on temperatures.

&&

.AVIATION...Updated at 2325Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major weather concerns will exist through Sunday afternoon as SCT
decks clear during the evening. Forecast confidence is excellent
that frequent W/SW gusts around 20kt will relax after sunset, then
revert to an easterly component after midnight. The switch back to a
westerly direction should occur slightly earlier than usual Sunday
late morning/early afternoon with only modest late afternoon
gustiness.


Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather issues will exist through Sunday afternoon under
clear skies. Winds across the region will favor a W/NW component
through the period with little in the way of gustiness.

&&

.FIRE WEATHER...
Residual breeziness from a departing weather system can be expected
for today with afternoon and early evening gusts ranging between 20-
30 mph. Some showers may affect the far eastern districts later
today, but with minimal impacts. MinRHs will range between 15-20%
across the lower deserts to 30-40% across the far eastern districts.
A significant warming trend takes place Sunday through early next
week with little change in temperatures expected by the middle to
latter of next week. With the warming temperatures, MinRHs will
generally range between 7-15%. Winds beginning Sunday and continuing
through most of next week will be lighter with typical afternoon
upslope breeziness expected. There is potential for some increased
breeziness toward the latter half of next week with a system(s)
passing well to the north, but confidence is still low at this time.


&&

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

&&

$$

DISCUSSION...Benedict
AVIATION...18
FIRE WEATHER...Benedict/Lojero