Area Forecast Discussion
Issued by NWS Tucson, AZ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
000
FXUS65 KTWC 262202
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
302 PM MST Mon Jul 26 2021

.SYNOPSIS...After record rainfall across much of the area over the
past few days, we`ll see fewer storms to start the work week.
Conditions look favorable for another increase in storm coverage
later in the week. Temperatures will climb back into the 90s for
most locations.

&&

.DISCUSSION...A modest southerly flow is back in place across
southeast Arizona, in between a low pushing into the Pacific and
high pressure to our northeast and east. We`ll largely rely on
recirculating our moisture over the next couple of days with only
direct outflow from thunderstorm complexes south of the border to
reinforce moisture fields for now. Lower deserts to our west are
continuing to see a bit deeper lower level moisture transport to
help counter a mid level dry slot wrapping around the low from the
south. That means we will tend to steadily lose moisture as daily
convection draws fuel from boundary layer remnants. PW was around
1.5 inches on the morning sounding, but has likely dropped below
1.2 inches this afternoon. Surface dew points are generally in
the 50s, down 4 to 8 degrees over the past 24 hours. As such we
are struggling with storm coverage today as expected.

Tomorrow afternoon was looking similar, however conditions are
favorable for a large thunderstorm complex near the
Sonora/Chihuahua border just southeast of Douglas later this
afternoon. We`ll have to watch for any subsequent outflows
tonight helping things along for us tomorrow. We pushed the
forecast back into the climo range for afternoon thunderstorms
Tuesday.

Another strong easterly wave currently visible on satellite is
setting up to push over from the northern Gulf of Mexico. Ensemble
means are still bringing this one across northern to central
Mexico and through southern Chihuahua and Sonora by Thursday.
Expect deep surge activity the second half of the week and
enhanced storm coverage as the impulse rotates up from the south
on the western flank of the high. Friday through Sunday are
looking interesting again, but not as much of a forecast slam dunk
as the last storm. If the ridge ends up a little further west than
currently planned, it might make it more of a Yuma/Phoenix thing
with only a 12 hour period or so where dynamics associated with
the system help organize SE AZ storms.

&&

.AVIATION...Valid through 28/00Z.
FEW-SCT clouds at 7k-11k ft MSL (locally BKN), with ISOLD -SHRA/-
TSRA thru 27/04Z. Slowly clearing skies overnight. FEW-SCT clouds at
7k-11k ft MSL developing aft 27/17Z and ISOLD-SCT -SHRA/-TSRA
between 27/19Z and 28/00Z. SFC wind less than 12 kts, except near
TSRA where wind gusts to near 35 kts will be possible. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Isolated to scattered showers and thunderstorms will
be possible each afternoon and evening through Wednesday.
Precipitation chances then increase going into the upcoming weekend.
Gusty, erratic winds and locally heavy rainfall will accompany any
storms that do develop. High temperatures will be near normal to
slightly below normal through Friday, lowering to below normal
levels this weekend. 20-foot winds will generally be less than 15
mph when not influenced by thunderstorms.

&&

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

$$

Public...Meyer
Aviation...Zell
Fire Weather....Zell

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.