Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 212222
Area Forecast Discussion
National Weather Service Tucson AZ
322 PM MST Tue Mar 21 2017
.SYNOPSIS...Remaining dry with unseasonably warm daytime
temperatures through tomorrow. A storm system will then bring a
chance of showers Wednesday night into Thursday. This system will
also bring gusty winds Wednesday afternoon and Wednesday night
followed by much cooler temperatures Thursday. Dry conditions with
warmer temperatures will prevail across much of the area Friday
into early next week.
.DISCUSSION...We`ll see increasing patches of high cloud tonight as
our southwesterly flow increases ahead of the strong Eastern
Pacific trough. Temperatures today similar to yesterday.
As far as the upcoming system we`ve been monitoring, it`s
becoming increasingly clear that the majority of our precip
chances this far south will be directly associated with the
frontal passage (Wednesday night into Thursday morning). A bit of
residual moisture and instability behind the front Thursday
afternoon, mainly east of Tucson by then. Nothing to write home
about with any totals under 1/4 of an inch in valleys. 2 or 3
inches of snow possible in the White Mountain areas of northern
Graham and Greenlee counties.
Surface winds will get busy Wednesday afternoon and Wednesday
evening, but not quite strong enough for an advisory (other than
a few wind prone locations in southern Cochise county). Strong
enough for some Fire Weather concerns as outlined below.
Temperatures still on the warm side ahead of the front Wednesday,
but cool air will drop temperatures to below average Thursday;
down around 25-30 degrees from recent record values.
A shortwave ridge to end the week with temperatures jumping back
above average, but well short of what we`ve been seeing. The next
system this weekend will be a more traditional transition season
system, with wind the main concern and enough cool air to push
temperatures back down a few degrees.
.AVIATION...Valid through 23/00Z.
FEW-BKN clouds above 20k ft AGL thru fcst pd. Sfc wind vrbl in
direction less than 10 kts this morning, then becoming sly/swly
5-15 kts with gusts of 20-25 kts this afternoon. Wind diminishing
after 22/03z. Aviation discussion not updated for TAF amendments.
.FIRE WEATHER...Expect dry conditions into Wednesday. A Pacific
storm system will then bring a chance of showers Wednesday night
followed by a chance of showers mainly northeast of Tucson
Thursday. A few snow showers may occur across the White Mountains
northeast of Safford Thursday night. Dry conditions will then
prevail Friday into Sunday. There is a slight chance of showers
across the White Mountains next Monday.
The Pacific storm system will also bring gusty mainly southwest
winds Wednesday afternoon into Wednesday night. The combination of
strong and gusty southwest winds and low relative humidity may
create critical fire weather conditions Wednesday afternoon across
the southern one-third of Fire Zone 152. At this point however, it
looks borderline with limited coverage and duration, so a Red Flag
Warning has not yet been issued. This will be monitored closely.
There will be some gusty west to northwest winds Thursday, then less
wind Friday into Saturday. Some gusty afternoon west winds are
forecast to return Sunday and next Monday.
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