Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 210939
Area Forecast Discussion
National Weather Service Tucson AZ
238 AM MST SAT MAY 21 2016
.SYNOPSIS...Breezy to locally windy conditions this weekend into next
week. Cooler this weekend with below normal temperatures persisting
through most of next week. No rain in sight.
.DISCUSSION...Mostly clear skies across Southeast arizona this
morning under southwesterly flow aloft with an upper low centered
across far NW Nevada. As the associated trough pushes to the east
across the Great Basin this weekend, we`ll be on the dry southern
side of the system with southwesterly flow and a somewhat tight
pressure gradient. The pattern of southwesterly flow aloft will more
or less continue through the middle of next week as another trough
moves into the west coast early next week and then slowly pushes
east to move through Arizona by about Thursday. Dry weather through
the forecast period with breezy to windy conditions each afternoon
due to deep mixing and enhanced gradient. Some blowing dust is
possible today along I-10 in Pinal County and near San Simon with a
blowing dust threat continuing near San Simon into the middle of
next week. Otherwise, temperatures will be below normal through the
end of next week with highs staying in the 80`s across the lower
elevations. No 100 degree temperatures in sight.
.AVIATION...VALID THRU 22/12Z.
Expect mainly clear skies this morning followed by scattered to
perhaps broken clouds above 20k ft agl this afternoon into Sunday
morning. The bulk of these clouds should be south of KTUS. Surface
wind from around 16Z today into this evening will be south to
southwest at 12-20 kts with gusts to near 30 kts. Surface wind will
be variable in direction generally less than 10 kts at other times.
Aviation discussion not updated for TAF ammendments.
.FIRE WEATHER...Dry conditions will prevail through next Friday.
Daytime minimum relative humidity this weekend will range from 10-15
percent in the lower elevations, and 20-25 percent across the
mountains. Daytime minimum relative humidity Monday through Friday
will mostly range from the upper single digits to mid teens.
Expect gusty generally southwest winds during the afternoon and
early evening hours. These wind speeds are anticipated to remain
below critical fire weather thresholds through next Friday.
However, the combination of gusty southwest winds, low relative
humidity and a very high fire danger rating may briefly produce
critical fire weather conditions this afternoon across portions of
Fire Weather Zone 150 west of Tucson. Thereafter, the combination of
gusty southwest winds and low relative humidity may again produce
critical fire weather conditions Wednesday afternoon across portions
of Fire Weather Zones 151 and 152 southeast of Tucson.
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