Area Forecast Discussion
Issued by NWS Tucson, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 25 26 27 28 29 30

FXUS65 KTWC 172328

Area Forecast Discussion
National Weather Service Tucson AZ
428 PM MST Mon Jul 17 2017

.SYNOPSIS...Expect widespread showers and thunderstorms into
Tuesday. Heavy rainfall will occur with the stronger thunderstorms.
We`ll keep a chance of showers and thunderstorms into next week.


.DISCUSSION...A busy afternoon with just about any thunderstorm of
substance dropping flash-flood level rains. Deep moisture remains
in place across the area with precipitable water values 1.5 to
1.7 inches and surface dew points in the mid to upper 60s. Each
day we continue to fight through convective inhibition left over
from overnight activity, and each day the flow is enough, in
combination with the influence of our persistent inverted trough,
to reset the atmosphere relatively quickly. The afternoon is
going about as expected with initial development in the partially
clear areas well away from the morning MCV over southwest
Arizona. Several areas of flash flooding this afternoon with
rainfall amounts between 1 and 3 inches over large areas.

With a little less activity expected upstream in New Mexico, we
might actually have an overnight period without many storms,
however with this much moisture in the atmosphere we extended the
Flash Flood Watch until 5 AM just in case.

We can`t sustain this much monsoon activity forever. As long as we
don`t get clobbered tonight, tomorrow should be above average as
well. We will keep a favorable easterly to southerly flow with
high pressure shifting into the central plains, but our long fetch
of deep moisture may slow a little with less focus. Inverted
trough trying to set up again through Sonora later in the week
into next weekend. That, and we will remain open to any easterly
impulse that comes along.


.AVIATION...Valid thru 19/04Z.
Widespread TSRA/SHRA continuing through the late evening hours
tonight, then slowly diminishing overnight. Isolated to scattered
-TSRA/-SHRA developing mainly east-to-south of KTUS Tuesday morning,
with widespread TSRA/SHRA expected areawide Tuesday afternoon and
evening. Otherwise, VFR conditions with cloud decks generally 5k-10k
ft AGL and surface wind variable in direction mainly less than 12
kts. Aviation discussion not updated for TAF amendments.


.FIRE WEATHER...Widespread showers and thunderstorms will prevail
through Tuesday. Thereafter, the greatest daily coverage of
thunderstorms Wednesday into this upcoming weekend is expected to
generally occur east to south of Tucson. Enough moisture will remain
for isolated coverage of thunderstorms west of Tucson. Below normal
daytime temperatures will also continue into the weekend.


Flash Flood Watch through late tonight for AZZ501>515.




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.