Scientific Forecaster Discussion
fxus65 ktwc 240421
Area forecast discussion
National Weather Service Tucson Arizona
920 PM MST Thu Mar 23 2017
Synopsis...a few lingering snow showers across the White
Mountains the rest of tonight. Dry conditions with milder
temperatures and gusty winds at times will prevail into early next
week. Expect another chance of showers and cooler temperatures by
the middle of next week.
Discussion...mostly cloudy skies prevail at this time northeast of
Tucson with clear skies or mostly clear skies elsewhere across
Southeast Arizona. A deep low pressure system aloft was centered
near The Four Corners region, and this upper low is progged to move
eastward across northern New Mexico and into the Oklahoma Panhandle
by daybreak Friday. There appears to be enough moisture to maintain
a slight chance of snow showers across the White Mountains the rest
of tonight. Otherwise, clear skies or mostly clear skies will
prevail across the area with generally light winds. Low temps later
tonight will average about 2-5 degrees below seasonal normals.
There are no updates warranted at this time. Please refer to the
additional sections for further detail.
Aviation...valid through 25/06z.
Isolated -shsn White Mountains NE of ksad thru 24/12z. Otherwise,
decreasing Clouds Rest of tonight then sky clear or a few clouds above 20k
ft above ground level Friday into Friday evening. Surface wind mainly less than 12
kts except nwly 12-20 kts with gusts to 30 kts Friday afternoon east
of ktus and particularly near ksad. Aviation discussion not updated
for taf amendments.
Fire weather...a few snow showers across the White Mountains the
rest of tonight. Dry conditions with gusty winds at times will
prevail into early next week. A more potent storm system will bring
a chance of showers and cooler temperatures around the middle of
Previous discussion /153 PM MST/...shortwave ridging will build in for
Friday with mostly sunny skies and temperatures warming back up to
seasonable levels. Heading into the weekend and early next week, we
will see a fairly progressive pattern take shape. The next system
will remain to our north on Saturday/Saturday night but the gradient
will tighten again for some afternoon breezes. High temperatures
will rebound back into the lower 80's on Saturday for Tucson.
Another shortwave ridge for Sunday before another system starts
digging into the southwest by late Monday. The models are in
agreement with regard to a more amplified trough evolving into a
cutoff low by Tuesday and Wednesday. Still some uncertainty
regarding the specifics in terms of timing and placement, but
confidence is certainly high regarding a more active pattern by the
middle of next week. We have gone ahead and introduced slight chance
to low end chance pops for much of the area Tuesday into Wednesday
as a starting point. Will also see some increased winds and cooler
temperatures by Tuesday and Wednesday. Thereafter, perhaps a brief
break on Thursday before another potentially strong system moves
into the region by next Friday.