Area Forecast Discussion
Issued by NWS Tucson, AZ

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FXUS65 KTWC 212057

Area Forecast Discussion
National Weather Service Tucson AZ
157 PM MST Sun Jan 21 2018

.SYNOPSIS...Much cooler temperatures continue, with a
widespread freeze Monday morning. Dry conditions with warmer
temperatures most of the week, before a trough brings cooler air and
gusty winds late in the week.


.DISCUSSION...A very chilly afternoon with temperatures now
struggling to get in the upper 40`s to lower 50`s across most valley
locations with breezy conditions especially east of Tucson. Clear
skies currently under NW flow aloft on the backside of the upper low
exiting to our northeast. Still some residual lower level clouds
over the White Mountains but these will dissipate this afternoon.
With a cold air mass in place, this will set the stage for the
coldest overnight/early morning we`ve had in some time with a freeze
for just about all of our forecast area and an easy hard freeze for
locales south and east of Tucson. The only fly in the ointment is
some increasing cirroform clouds tonight, of which the leading edge
is already working into western portions of the forecast area. These
clouds could prevent temperatures from reaching their lowest

A warming trend will commence Monday, though high temperatures will
still remain about 5 degrees below normal. As a weak disturbance
aloft skirts through, considerable cirroform cloudiness will
continue on Monday as well. Weak ridging is expected Tuesday and
Wednesday with continued warming daytime temperatures before a
trough swings by to our north for the end of the work week. This
trough will result in perhaps a few increased breezes and drop our
temperatures back to near normal levels on Friday. Ridging then
builds back in next weekend with no precipitation again in sight for
at least the next 7 days.


.AVIATION...Valid thru 23/00Z.
Mostly clear skies through about 22/00Z then SCT-BKN cirrus mainly
above 20k ft AGL return this evening from west to east and continue
Monday. Wly/nwly sfc winds this afternoon at 12-20 kts, especially E
of KTUS. A few gusts to around 30 kts will continue to occur near
KSAD. Less wind will occur this evening and through Monday
remaining at 10 kts or less. Aviation discussion not updated for
TAF amendments.


.FIRE WEATHER...Dry conditions will prevail over the next
week. Gusty northwest winds at 15-20 mph will favor the Upper Gila
River Valley including Safford this afternoon, with east winds
returning for Tuesday and Wednesday. A few westerly breezes may
return late in the work week.



Freeze Warning from 1 AM to 9 AM MST Monday for AZZ502-504-505.




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