FXUS65 KTWC 260915
Area Forecast Discussion
National Weather Service Tucson AZ
215 AM MST Tue Mar 26 2019
.SYNOPSIS...Warm late March day with highs approaching the 90
degree mark from Tucson west into the western deserts. A gradual
cooling trend begins Wednesday with highs returning closer to
seasonal normals this weekend. Dry conditions to persist through
Saturday, then a few showers on Sunday near the White Mountains.
.DISCUSSION...Early morning satellite imagery showed upper ridge
axis extending from western Wyoming south across the Great Basin
and eastern Arizona. The southern end of this ridge is rather
dirty and is expected to dirty up some more as the day progresses
as the ridge axis continues to move east. Even with the high cloud
cover, which will be thick at times today, still looking at the
warmest high temperatures for 2019 so far across most of the
area. Lower desert locals, including Tucson, will be right around
90 degrees. A few places will be near record highs for March 26th.
Continued dry conditions through Friday as southwest flow aloft
on Wednesday becomes westerly Thursday night into Friday as a
weather system moves through the Great Basin.
Follow-up system will become a closed low near the four corners
region on Sunday, bringing with it a slight chance of rain and
snow showers to the White Mountains. As this system pushes east
Sunday night, a colder air mass will be over the area with the
coldest eastern valleys potentially seeing near freezing low
temperatures next Monday morning. No foolin`.
After the well above normal high temperatures of today, a very
gradual daily cooling trend for the remainder of the work week
into the weekend.
.AVIATION...Valid through 27/12Z.
BKN-OVC cirrus clouds AOA 25k ft AGL thru the forecast period. SFC
wind will generally be less than 12 kts, although ELY/SELY SFC wind
could be gusty at times thru mid morning in the Gila River Valley
near KSAD. Aviation discussion not updated for TAF amendments.
.FIRE WEATHER...Dry conditions will continue through Saturday.
There will then be a slight chance of showers in the White Mountains
Sunday, with dry conditions elsewhere. 20-foot winds will remain
light through Wednesday. Breezy westerly winds of 10-20 mph are
expected Thursday through Sunday, especially east of Tucson. Above
normal daytime temperatures persist through Thursday, followed by
near normal readings into this weekend. Daytime relative humidity
minimums through early next week of 8 to 15 percent will occur in
the valleys with values of 17 to 27 percent in the mountains.
Moderate overnight recoveries are expected over this period.
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