Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 182200
Area Forecast Discussion
National Weather Service Tucson AZ
300 PM MST WED MAY 18 2016
.SYNOPSIS...A low pressure system over Arizona this afternoon will
move slowly across the area through early Thursday. This will result
in cooler temperatures and a chance of showers and thunderstorms
mainly north and east of Tucson. Dry and warmer conditions will
return for the latter part of the weak, then another upper level
system will impact the region this weekend into early next week with
another round of windy conditions.
.DISCUSSION...Very pleasant day with highs running 8-10 degrees below
normal. Bulk of showers and a few thunderstorms this afternoon have
been confined from eastern Pinal east across Graham and Greenlee
counties. Some of these storm have produced rainfall totals up to a
quarter of an inch. All of this is associated with a weakening upper
level low that is currently move eastern Arizona. Highest PoPs this
evening will be NE of Tucson. Dust issues haven`t cropped up yet this
afternoon but still a concern into the early evening hours. Most of
the activity this evening will be done by 10 pm`ish.
Upper level trof axis will be over eastern New Mexico tomorrow
afternoon. Enough residual moisture over the east-central mountains
will combine with afternoon heating for a good chance of showers and
thunderstorms. The rest of the area will be dry with highs several
degrees warmer than today but still below normal.
Another upper level trof will start to impact the area Friday and
especially this weekend for another round of breezy to windy
conditions. At this time looks like both Saturday and Sunday will
see fire weather issues. See fire weather section below for more
details. Highs Friday will be near normal then be several degrees
below normal over the weekend.
Below normal temperatures and breezy to locally windy conditions
early next week.
.AVIATION...VALID THRU 19/23Z.
Widely scattered showers and isolated thunderstorms mainly north and
east of KTUS thru 19/04z. Surface winds 5 to 15 knots. Gusty and
variable winds are expected near any showers and thunderstorms. Cloud
coverage will generally be scattered to broken at 6-10k ft agl
through this evening with a bit of clearing overnight. Aviation
discussion not updated for TAF ammendments.
.FIRE WEATHER...Widely scattered showers and isolated thunderstorms
into the evening hours then decreasing overnight. Another chance of
afternoon showers and thunderstorms in the White Mountains Thursday.
Gusty and erratic winds are expected near showers and thunderstorms
through early this evening. Dry conditions will then prevail area-
wide Friday into early next week.
A few afternoon gusts on Thursday due to daytime heating, otherwise
fairly light winds. Breezy to locally windy conditions will return
Friday and continue through this weekend into early next week as a
low pressure system deepens northwest of the area. Wind speeds may
approach critical levels for portions of the area as early as
Friday, then continuing through the weekend into early next week.
The best potential for critical fire weather thresholds being met
looks to be both Saturday and Sunday for eastern areas.
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