Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 210358
Area Forecast Discussion
National Weather Service Tucson AZ
858 PM MST FRI MAY 20 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...Water vapor imagery shows that the synoptic scale is
defined by a ridge axis to our east over western Texas and eastern
New Mexico, with a low pressure system over northern California and
southern Oregon. IR satellite imagery shows a band of extensive
cloudiness associated with this low that covers much of the western
states, with the southern fringes of these clouds across extreme
northwest Arizona. Closer to home, skies across southeast Arizona
are mostly clear.
As of 03Z (8 PM MST), temperatures ranged from the lower 70s to the
mid 80s with the Tucson Intl airport reporting a temp of 84 degs,
after reaching an afternoon high of 94 degs which was 1 deg above
normal for this date. The current temps readings seem to be on track
with the inherited overnight low temps, but will continue to monitor
surface observations and will make changes if needed. Otherwise,
the forecast for the remainder of tonight is in good shape.
.AVIATION...VALID THRU 22/06Z.
Mostly clear skies thru Saturday morning. Increasing high clouds aoa
20k ft agl expected aft 21/20z. Surface wind becoming generally less
than 12 kts between 21/04z and 21/14Z. Increasing surface wind aft
21/14Z...with sly/swly surface wind at 15-23 kts and gusts to 30-35
kts by 21/18Z. Aviation discussion not updated for TAF ammendments.
.FIRE WEATHER...Gusty afternoon/early evening south-southwest winds
will occur through the end of next week. Daytime minimum relative
humidity values through Sunday will range from 10-15 percent in the
lower elevations, to 20-25 percent in the mountains. Somewhat lower
relative humidity values are then expected next week.
Although gusty winds and low daytime relative humidities are
expected through Monday, these values are expected to stay below
critical fire weather thresholds. An increase in wind speeds mid to
late next week will result in the possibility of exceeding critical
fire weather thresholds across portions of the forecast area in the
Tuesday through Thursday time frame.
.CLIMATE...Daily rainfall and low high temperature records were set
in Tucson seven years ago tomorrow, May 21st. The airport recorded a
high of 68 degrees and rainfall was 0.53". Both of these records
stand as the coldest high and wettest May day of the 21st century so
far for Tucson.
On the first 100 degree day in 2016 watch for Tucson, the 12Z GEFS
indicating that the next best threat will be on the 30th or 31st.
Dating back to 1895, the 1st 100 degree date for Tucson has yet to
occur on May 31st. Interesting.
.PREV DISCUSSION...Breezy to locally windy conditions will be
around each afternoon this weekend as low pressure moves through the
Great Basin. Patchy blowing dust possible each day in the normal
trouble spots along I-10 in Pinal County and near San Simon in
Cochise County. The weekend will also see cooler daytime highs.
Gusty winds to continue for most of next week with daytime highs
remaining below normal. Outside of the wind, can`t complain going
into the last part of May.
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