Area Forecast Discussion
Issued by NWS Tucson, AZ

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FXUS65 KTWC 221821

Area Forecast Discussion
National Weather Service Tucson AZ
Issued by National Weather Service Phoenix AZ
1120 AM MST Tue May 22 2018

Dry conditions through the upcoming holiday weekend. Gusty winds
will occur today and should return again this weekend as a couple of
low pressure systems move north of the area. High temperatures will
warm above seasonal normals later this week and continue into the


An upper level low centered over southern Nevada this morning is
currently bringing clouds and showers to the Great Basin along
with isolated thunderstorms. Just to the south, the Desert SW
sits under very dry southwesterly flow where mostly clear skies
are being observed. In response to this low pressure system,
breezy southwesterly winds will again develop over our CWA this
afternoon as daytime heating mixes higher momentum air down to the
surface. Gusts are forecast to be of similar magnitude to what
was observed on Monday, albeit slightly weaker, ranging from 20 to
30 mph in and around Tucson today. Given the dry and breezy
conditions across our CWA, a Red Flag Warning remains in effect
from noon to 7 PM MST today for the White Mountains.

In addition to the winds, modest cooling from Monday`s
temperatures is expected this afternoon as cooler air from the
aforementioned low pressure system works its way into our area.
Looking at the latest 12Z sounding, 850 mb temperatures have
cooled roughly 2 F over 24 hours ago while surface temperatures
are reporting similar to slightly cooler conditions. Everything
considered, the forecast looks on track and no changes have been


.AVIATION...Valid through 23/18Z.
Under clear skies, gusty SSW winds will be the main aviation
concern. Gusts nearing 25-30kt will prevail through sunset, then
weaken later this evening. Directional headings this afternoon will
be somewhat more due south than is typical. The usual light and
variable drainage wind will settle in overnight. Aviation discussion
not updated for TAF amendments.


.FIRE WEATHER...A Red Flag Warning is in effect from noon to 7 PM
MST today for the northern portions of Fire Weather Zone 153; or,
more specifically for the Alpine District. The combination of strong
and gusty south to southwest winds, low relative humidity, and a
very high fire danger will create critical fire conditions.

Otherwise, dry conditions will continue into early next week.
Although gusty southwest winds will occur this afternoon elsewhere
across southeast Arizona, wind speeds are not expected to meet Red
Flag criteria. 20-foot winds will generally be less than 15 mph
Wednesday through Friday. Gusty afternoon winds should return this
weekend into early next week as another low pressure system moves
north of the area.


Red Flag Warning from noon today to 7 PM MST this evening for



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