Area Forecast Discussion
Issued by NWS Tucson, AZ

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
FXUS65 KTWC 041003

Area Forecast Discussion
National Weather Service Tucson AZ
303 AM MST Tue Oct 4 2022

.SYNOPSIS...A low pressure system dropping down from the north will
bring increasing storm chances today. This system will linger over
northwest Mexico and southern Arizona with a chance of showers and
thunderstorms through the coming weekend. Temperatures will fall
to near or below average for early October.


.DISCUSSION...The low dropping down from the north on the trailing
southern portion of the mid level trough is wound up a little
tighter than expected as it pushes through central Arizona this
morning. A convective band is redeveloping southwest of the low
across southern Pinal / northeast Pima counties into Graham and
Greenlee this morning. Mid level cooling associated with the low will
make for more efficient convective processes today. Precipitable
water values between .8 and 1.1 inches will be sufficient for
solid storm development today. The upper level diffluent pattern
across eastern Pima, Santa Cruz and Cochise counties will be a
strong focus for persistent storm development into the evening
hours as these areas also see the best insolation today.

The rest of the week, we have a strong ridge over much of the
west, however the weakness in the flow sagging back over southern
Arizona and northwest Mexico will keep heights and thicknesses in
check as it slowly fills over the next several days. We`ll also
keep a daily chance of storms going as it brings additional
moisture in from the southeast. This will help compensate for any
decreasing storm chances as the low fills and weakens the
associated mid level cold pool.

Ultimately, we should have another strong focus for storms as it
shears into the front side of any kicker system that comes along,
which could happen late in the weekend and/or early next week.


.AVIATION...Valid through 05/12Z.
FEW-SCT clouds (locally BKN) at 7k-12k ft AGL. ISOLD- SCT
TSRA/SHRA. Brief MFR conditions possible with the TSRA and wind
gusts to 40+ kts. Outside of thunderstorm outflows, SFC wind
generally less than 12 kts, with higher gusts during the afternoon
hours. SFC wind will favor a WLY/NWLY direction in the afternoon
and early evening hours hours and will be variable in direction at
other times. Aviation discussion not updated for TAF amendments.


.FIRE WEATHER...Isolated to scattered afternoon and evening showers
and thunderstorms are expected into the upcoming weekend. The
main threats will be strong and gusty outflow winds, isolated
areas of heavy rainfall and dangerous lightning. Outside of
thunderstorm outflow winds, 20-foot winds will remain less than 15
mph through Wednesday. There is the potential for some elevated
east/southeast winds Thursday and Friday.





Visit us on Facebook...Twitter...YouTube...and at is the U.S. government's official web portal to all federal, state and local government web resources and services.