Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 252200
Area Forecast Discussion
National Weather Service Tucson AZ
300 PM MST THU AUG 25 2016
.SYNOPSIS...Increasing moisture will help create better
thunderstorm coverage by Friday and Saturday. Watch for strong
storms with possible areas of blowing dust.
.DISCUSSION...No surprises so far this afternoon as we go through
a transition day. We have lost the strong northwesterly to
northerly flow below 500mb and starting to pick up a little more
moisture. Very slow storm movement this afternoon with poor
structure for valley storms. A couple of modest outflows noted, so
we`ll see a few more storms this afternoon and evening as
development continues. Little organization however.
Still on track for a strong upswing in thunderstorm coverage and
probably intensity as well Friday and Saturday. Our storm level
flow will have finished veering around to gain an increasing
southerly component Friday with precipitable water values jumping
to around 1.5 inches or a little higher by late Friday. More
favorable conditions for storm structure along with a less stable
atmospheric column should combine with the moisture for a strong
thunderstorm day Friday. Strong organized outflows from the south
possible generating areas of blowing dust and heavy rain.
For Saturday, a weakness in the flow digging in from the
northwest may help to kick off another decent thunderstorm day but
our flow will temporarily become a little less favorable. Moisture
will still be sufficient for our needs.
For Sunday our focus will be from Tucson eastward as western areas
try to regain a modest northerly flow in between major features.
Most of the rest of next week a weak favorable flow should allow
us to keep enough moisture around for a chance of thunderstorms,
with the best days looking like Tuesday and Wednesday.
.AVIATION...VALID THRU 27/00Z.
Isold -TSRA/-SHRA through the evening hours with partial clearing
after 26/05z. Increasing thunderstorms Friday, mainly after
26/19z. Brief MVFR conditions possible with storms. Surface wind
generally less than 12 kts with normal diurnal trends, except for
strong erratic outflows with storms. Aviation discussion not
updated for TAF amendments.
.FIRE WEATHER...Isolated thunderstorms will occur mainly near
mountains today. Increasing storm coverage with a moisture
increase Friday through early next week. 20-foot winds through
the upcoming weekend will be terrain driven and less than 15 mph
in most locations. Expect the potential for strong and gusty winds
near any thunderstorms that do develop.
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson