Area Forecast Discussion
Issued by NWS Tucson, AZ

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FXUS65 KTWC 272109
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
210 PM MST Tue Jun 27 2017

.SYNOPSIS...Dry conditions through Friday except for a few
thunderstorms this afternoon southeast of Tucson. Isolated to
scattered thunderstorms will then return mainly east to south of
Tucson by early next week. Seasonably hot daytime temperatures
will prevail into this weekend.

&&

.DISCUSSION...
Dry air continues to overspread the area this afternoon as the sharp
drying noted on all 3 GOES-16 water vapor channels is steadily
marching eastward. Deep BL mixing has allowed surface dewpoints to
fall from the 40s and 50s this morning into the upper 20s and lower
30s across a good portion of the forecast area. Outside of a lone
storm that formed shortly before noon over the Chiricahua mtns,
skies have remained precip free through 21Z. That being said, there
has been some cu development over the mountains of Santa Cruz County
where dewpoints remain slightly elevated.

The forecast remains on track for the rest of the afternoon/evening
hours with the continued advection of dry air into the area. Any
storms that develop from mid afternoon onward should be short lived
and dissipate shortly before sunset with the loss of daytime
heating. I will maintain the slight chance mention in the mountains
of far eastern Arizona until 03Z, but even these locations may end
up dry for the rest of the day.

The story for much of the next 5-6 days will be one of unfavorably
positioned high pressure aloft with the ridge axis located off the
California coast. The resultant westerly flow across the area is
obviously far from ideal for afternoon convection and it won`t be
until late this weekend or early next week before we see the high
center shift and position itself over New Mexico. In the meantime, a
few afternoon cu in the mountains are just about all that one can
hope for in terms of sensible weather. There is a generalized
consensus that moisture will return early next week once the high
sets up to our east and only at that point should we see a return to
more typical monsoon weather.

As for temperatures, above normal values both during the day and at
night will be the rule although nothing anywhere near as hot as what
was seen last week. Upper level heights and temperatures do not
support a return of those types of values at any point during the
next week.

&&

.AVIATION...Valid thru 29/00Z.
SKC west of KTUS with FEW-SCT clouds at 8-12k ft AGL east and south
of KTUS thru the forecast period. Isolated SHRA/TSRA this afternoon
near the International Border including KDUG and KOLS. SFC wind thru
this evening 12-16 kts with gusts of 20-25 kts possible, especially
at KTUS/KSAD, becoming variable at less than 12 kts tonight and
Wednesday morning. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...Isolated thunderstorms across the southern portion
of Fire Weather Zone 152 through early this evening. Thereafter, dry
conditions are then expected area-wide through Friday. Isolated to
scattered thunderstorms returning this weekend into early next week,
mainly near the International Border. Breezy west to northwest 20-ft
winds of 15 to 20 mph are likely during the afternoon hours through
Thursday, especially in the upper Gila River Valley. Speeds will
then generally remain less than 15 mph into early next week.
However, periods of erratic gustiness may occur due to strong
daytime heating and/or thunderstorm outflows.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

Leins/Davis

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