200
FXUS65 KPSR 070518
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1015 PM MST Mon May 6 2024

.UPDATE...
Updated Aviation

&&

.SYNOPSIS...
Dry weather will continue through the next week with an increase in
gusty winds expected in some areas Tuesday and Wednesday.
Temperatures will remain near to slightly below normal through
midweek before rising above normal by the end of the week. By the
weekend and into the beginning of next week, afternoon highs are
expected to climb to around 100 degrees across parts of the lower
deserts.

&&

.DISCUSSION...
The upper low responsible for bringing strong winds to the Southwest
over the weekend is now seen ejecting northeast into the Northern
Plains this afternoon. Much lighter winds have prevailed locally,
though temperatures will remain below seasonal normals for today.
Afternoon highs will top out in the mid 80s across the lower deserts
before returning to near normal readings tomorrow. Mostly clear
skies will continue as dry northwesterly flow aloft persists.

Going forward, ensemble and deterministic guidance favor a troughing
pattern persisting over the Desert Southwest through much of the
week. Guidance suggest that shortwave energy pushing into the
Pacific Northwest will dig southward into the Great Basin Tuesday.
As this occurs, a piece of energy from the upper low currently
moving into the Northern Plains will split off and retrograde toward
the Desert Southwest before phasing with the aforementioned
shortwave energy during the middle part of the week. The other piece
of energy associated with the upper low will continue eastward. The
local response to this will be a tightening gradient heading into
the middle part of the week. Increasing gusts will begin Tuesday
afternoon as the strongest gusts favor higher terrain areas across
Arizona with some gusts up to 25-30 mph possible across southern
Gila County. Tuesday night into Wednesday morning, strong low-level
northerly winds will increase down the Lower Colorado River Valley,
though the timing of this isn`t ideal for better momentum transfer
to the surface. Nonetheless, gusty winds in excess of 30 mph will be
possible (>40%) with the strongest winds favoring ridgetop locations
along/near the Lower Colorado River Valley. Additionally, the strong
northerly wind component will promote CAA into southeast California
and southwest Arizona where highs are forecast to cool into the
mid/upper 80s to around 90 degrees Wednesday.

As we head into the end of the week, the upper level circulation
over the Southwest will gradually weaken with heights gradually
rising over the region. Temperatures will respond accordingly,
rising into the mid to upper 90s by the weekend and potentially to
around 100 degrees in some lower desert locales by Sunday/Monday.
Otherwise, dry conditions will persist through the next week.

&&

.AVIATION...Updated at 0515Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No significant weather issues will exist through Tuesday night under
clear skies. Confidence is very good that winds will continue to
weaken overnight switching to the traditional easterly direction by
or shortly after midnight. A westerly component should return
somewhat earlier than usual late Tuesday morning/early afternoon
afternoon with more frequent late afternoon gustiness around 20-25
kt.


Southeast California/Southwest Arizona including KIPL and KBLH:
No weather issues will exist through Tuesday night under clear
skies. Extended periods of light and variable winds will be common,
however in general, W/SW directions will be preferred during the
evening and overnight, with S/SE more common during the afternoon.

&&

.FIRE WEATHER...
Dry conditions and overall light winds outside of afternoon
breeziness will continue through the rest of today. The weather
pattern into the middle of the week will lead to another round of
breezy conditions starting Tuesday with afternoon gusts commonly
reaching to around 20 mph to as high as 25-30 mph in some locations.
Strong gusts in excess of 30 mph are possible (>40%) overnight
Tuesday night into Wednesday morning for areas along the Lower
Colorado River Valley with the strongest winds favoring ridgetops.
Temperatures will warm back to around seasonal normals going into
the middle part of the week with highs as warm as the lower 90s
across the lower deserts. MinRHs will be in the 5-10% range through
at least mid week across the lower deserts to around 10-15% over
higher terrain areas, with overnight recoveries between 20-40%.
Winds during the latter half of the week will return to more typical
seasonal trends with daily afternoon gusts up to around 20 mph.

&&

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

&&

$$

DISCUSSION...Smith
AVIATION...18
FIRE WEATHER...Smith/Kuhlman