263
FXUS65 KTWC 011624
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
924 AM MST Mon Jul 1 2024


.SYNOPSIS...Daily chances of showers and thunderstorms during the
first half of this week will gradually diminish during the second
half of the week. Some storms will generate strong winds and
locally heavy rainfall.

&&

.UPDATE...Visible satellite shows a debris cloud field eroding
aways over the central part of the region and into the upper
Arizona state. A few cumulus clouds have popped up on some of the
Sky Islands due to the weak upslope forcing. The 12Z sounding has
PWATs of 1.75 inches with a little shear of 21 knots and MUCAPE of
986 J/kg. These values are better than yesterday`s morning, but
there is a little subsidence inversion. This likely will erode
aways as the cloud field clears for better insolation and allowing the
low and mid level lapse rates above 7.5 and possibly close to 10
degrees. There is very small area of diffluence aloft that can aid
in the storm development, but the lower levels will need to the
heavy lifting (i.e. better CAPE, steep lapse rates, etc.) The
latest 12Z HREF run highlights the best areas for scattered
thunderstorms will generally be the ling along the I-19 corridor
to the east. Mountains will be the first areas to get storms due
to the upslope winds. Theses multicelluar storms can rise and
fall quickly this afternoon to produce gusty erratic winds and
brief localized heavy rainfall. A few storms may be Severe Storm
worthy in the late afternoon if the CAPE values are high, better
inflow, shear, and cooler air in the midlevels (breaking the
subsidence inversion). If the cumulus clouds start to form around
12-1pm, it will be a good sign that the atmosphere is in better
shape for thunderstorm development. Otherwise, it can be delayed
in the late afternoon and the coverage will be confined a little
more. Keep an eye on the cumulus clouds for the rest of the
morning.


&&

.PREV DISCUSSION... /issued 239 AM MST Mon Jul 1 2024/

Plenty of debris cloud cover over the area this morning with
water vapor showing a weak disturbance moving west across the
area. At 2 am, radar was showing isolated showers developing west-
northwest of Tucson. For today through Wednesday expect scattered
showers and thunderstorms each day with a few storms being strong
and producing locally heavy rain. The second half of the week,
which includes the 4th of July holiday, will see a reduction of
storm coverage as drier air moves in from the north as high
pressure builds in from the northwest. High temperatures near or
slightly above normal first half of week then heating up to close
out the week. Next weekend could see an uptick in storms,
especially east of Tucson.

&&

.AVIATION...Valid through 02/12Z.
SCT-BKN clouds at 9-12k ft AGL thru the fcst pd. Isold -SHRA/-TSRA
this morning becoming SCTD after 01/18z. Expect brief MVFR conds
nr storms. SFC winds 10 kts or less with the occasional afternoon
gusts, except stronger due to gusty outflows from storms. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Relatively deep moisture will stick around through
the forecast period with daily chances of afternoon and evening
showers and thunderstorms. Strong and erratic gusty winds of 40
mph or higher can be expected with any storm development, along
with locally brief heavy rainfall. Outside of thunderstorm winds,
20-foot winds will generally be 15 mph or less each afternoon with
the occasional gust of 20 mph. Min RHs will generally be around
20% in the valleys and 30s in the mountains with good overnight
recoveries.

&&

.CLIMATE...June 2024 goes into the record books as the 4th hottest
and 10th wettest on record for Tucson.

&&

&&

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

$$

Update...Strongman

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