Severe Thunderstorm Warning 105, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
212 PM MST Wed Aug 3 2022

.SYNOPSIS...As we move through the heart of the monsoon season,
expect daily thunderstorm chances with the potential for a few strong
storms at times. Later in the week the pattern shifts toward even
better thunderstorm coverage

&&

.DISCUSSION...

Rest of today...Satellite shows a clear skies over
eastern part of the forecast area with some cumulus cloud build
ups over higher terrain. The increase amount of sunshine will
continue to help build those clouds up into mainly isolated
thunderstorms. The better instability and lift for thunderstorms
can start to occur in the evening from an inverted shortwave
trough. This wave has started to manifest over Mexico when
looking at the water vapor satellite. The deterministic models has
a better grasp on the feature than the previous model runs with a
projected time of starting in the late evening for our forecast
area. This feature can lead into a nocturnal MCS from Mexico as it
moves northwesterly and bringing scatter thunderstorms and
showers through the early morning. Plus, 20Z SPC mesoanalysis
shows bulk shear increasing in coverage and speed, which can
support more organization in the storms and a increase potential
for severe thunderstorm warnings to be issue throughout the
night. In terms of storm evolution, the CAMS all have different
ideas of the evolution of the storms. Some reduce the coverage
size and others showing different durations and timing of the
impacts. Overall, once storms get going, the storm motion will be
generally west-northwesterly and Tucson can receive a little
midnight wake up from a storm.

Tomorrow and the weekend...The upper level flow will continue a
east to southeasterly flow to bring daily chances of thunderstorms.
There can be several minor shortwave troughs around the high
pressure center that can enhance some stronger thunderstorms. PWAT
values will generally remain above 1.40 inches for Tucson and
westward which makes sense for our forecast area to be under a
slight risk from the WPC's Excessive Rainfall Outlook starting
tomorrow through at least Sunday. Not to mention, many parts of
the region is very saturated from the previous week's of rain. It
wouldn't take much to get ponding and flooding from a good storm.
It is the heart of the monsoon.

&&

.AVIATION...Valid through 05/00Z.
Remnant SHRA/TSRA from this morning now exiting the area, allowing
for clearing skies aside from FEW-SCT clouds at 8k-12k ft AGL near
mountain ranges. SHRA/TSRA start to redevelop after 04/21Z,
expanding in coverage this evening and continuing overnight. CIGS
may briefly lower to 4k-6k ft AGL with the TSRA, along with mountain
obscurations and wind gusts to 40+ kts. Light SFC winds otherwise
favor a WLY/NWLY direction during the afternoon hours and variable
in direction at other times. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...The active monsoonal period is expected to continue
through much of the forecast, with daily rounds of scattered showers
and thunderstorms. The typical threats of strong gusty winds and
heavy rainfall remain, as well as the potential for precipitation
outside the normal afternoon/evening cycles. Wind trends are
otherwise light following a diurnal pattern.

&&

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

Public...Strongman
Aviation...Howlett
Fire Weather....Howlett

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