Fountain Hills, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

439
FXUS65 KPSR 292050
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
150 PM MST Wed Jan 29 2025

.SYNOPSIS...
Showers and high elevation snowfall chances will begin to diminish
today as a stubborn area of low pressure begins to exit the region.
Behind this system, high pressure will slowly build over the
southwestern United States resulting in a warming trend through the
end of the week. Highs are likely to reach into the lower and
middle 80s by the end of the weekend and into the start of next
week, a good 10 to 15 degrees above normal for this time of year.

&&

.DISCUSSION...
An area of low pressure continues to sit over Arizona which helped
spark more shower and high elevation snowfall this morning,
primarily from Maricopa County eastward. Accumulations that were
observed were generally around a few hundredths to around a tenth
of an inch in a few locations. The good news is, Phoenix Sky
Harbor recorded 0.01 inches of rainfall with this round of
showers, which broke the 159 day streak of no measurable rainfall
that started back on August 22nd 2024. This is now the second
longest dry streak on record, falling one day short of the longest
of 160 days set back in 1972. Our forecast area is not completely
finished with precipitation chances just yet as hi-res model
guidance points towards more activity this afternoon and evening,
primarily for the foothills and high terrain areas of eastern
Maricopa, Pinal, and southern Gila Counties. Any further
accumulations will be very light, upwards of only a few hundredths
of an inch. At elevations greater than 4500 ft, snowfall will be
possible with perhaps additional accumulations of a few inches
above 5000 ft. With the low overhead, temperatures this afternoon
will only reach into the upper 50s to middle 60s for the lower
deserts.

As we head into the latter portion of the week, the stubborn area of
low pressure will migrate eastward toward the Central Plains,
allowing for ridging over the Desert Southwest to build in its wake.
The next few days will be transition days between these two
weather regimes, with heights increasing aloft, but cool
northerly/northwesterly flow continuing to funnel in over the
region. Highs Thursday afternoon across the lower deserts will be
slightly warmer than today but will only reach into the lower and
middle 60s, with perhaps a few areas out in SE California touching
70 degrees due to the presence of higher heights aloft compared
to central Arizona. For many areas, these temperatures will still
be a good 5 or so degrees below normal for this time of year. As
atmospheric thickness continue to increase into the weekend ,
temperatures will follow suit, with most lower desert locations
reaching the lower to middle 70s by Saturday, which will be around
5 degrees above normal.

Model agreement is excellent regarding the continuation of upper-
level ridging into next week, with only subtle differences in the
strength of the high pressure. H5 heights by Sunday will increase to
the order of 582-585dm, translating to afternoon high temperatures
approaching the lower to middle 80s for the majority over lower
elevation communities. Current NBM temperature forecasts call for a
high of 84 degrees at Phoenix Sky Harbor on both Monday and Tuesday,
which would be 15 degrees above normal for the beginning of
February. Since there is very little spread in the NBM temperature
forecast during this timeframe, there is a high likelihood that a 20-
25 degree temperature swing over the next 5-7 days.

&&

.AVIATION...Updated at 1814Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The primary aviation weather concern during the forecast period
will be continued low CIGs through the remainder of this morning
and into the afternoon as light showers continue to push through
the Phoenix area. Places that see these light showers may see
temporary lowered CIGs down to around 4-5 kft and potentially some
SCT to briefly BKN bases down to around 3-4 kft in a few areas.
Expect VCSH and some -SHRA to continue into the afternoon with
chances for TS less than 10%. Chances for showers will gradually
diminish going through the afternoon with CIGs improving. By early
this evening, expect FEW-SCT decks aoa 6-7 kft. Light and variable
winds are favored to continue through the rest of this morning
with moderate confidence in a westerly switch this afternoon.
Could still see some variability in directions this afternoon,
especially with any lingering showers in the area. Confidence is
high that winds will switch back to an easterly component this
evening.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns are expected through the next 24
hours. Winds at KIPL will favor a W-NW component, while directions
at KBLH favor the W before becoming southerly this evening. Speeds
through the period will mostly remain below 8 kts. FEW-SCT mid
level clouds aoa 15 kft will continue to scatter out with mostly
clear skies prevailing by this afternoon.

&&

.FIRE WEATHER...
The weather system currently over the region will continue to
bring chances for isolated showers through this afternoon across
south-central and eastern Arizona. Also can`t rule out some
isolated lightning mainly south of Phoenix late this morning into
early afternoon. Drying conditions will then prevail beginning
Thursday, but MinRHs will continue to mostly stay above 25% before
dropping closer to 15% starting this weekend as high pressure
takes over across the region. Expect overall light winds through
the period. As high pressure spreads over the region into the
weekend, expect temperatures to quickly rise to above normal.

&&

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

$$

DISCUSSION...RW
AVIATION...Smith
FIRE WEATHER...Kuhlman