256
FXUS65 KTWC 211548
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
848 AM MST Fri Jun 21 2024

.SYNOPSIS...A strong increase in moisture will bring a chance of
thunderstorms to the area into next week. Some storms will
generate strong outflow winds with locally heavy rain possible.
This will also knock several degrees off of the heat. We may see
temperatures climb back up a bit as high pressure settles
overhead next week.

&&

.UPDATE...The 12Z KTWC sounding came in with 1.27" of PWAT and
additional moisture continues to advect in from the east to
southeast today. HREF/CAMs are showing a similar setup to yesterday
with a north-south axis of showers and thunderstorms developing
early this afternoon across central portions of the forecast area.
Within this axis, SBCAPE values are as high as 1000-1500 J/KG, with
the highest values in northern sections of our forecast area across
eastern Pinal/western Graham Counties. DCAPE values are also around
1500-2000 J/KG which will result in gusty outflow winds. HREF isn`t
as robust with winds today so while we did add areas of blowing dust
into the forecast for susceptible areas of Pinal County, we`re not
going to issue a longer lead Blowing Dust Advisory with this update.
Otherwise, storm motions today will be to the north around 10 to 15
mph and given the deeper moisture profiles, the stronger storms have
the potential to produce locally heavy rainfall in addition to the
wind threat from the storms. No other changes/updates this morning.
See previous discussion below for additional information.

&&

.DISCUSSION...A broad and strong easterly wave across central
Mexico has pushed much deeper moisture toward our area, with
moisture continuing to increase over the next 24 hours. Initial
precipitable waters in the 1.2 to 1.5 inch range will see
additional moisture pushed up from the south as the wave pushes
across the entrance to the Gulf of CA. We may flirt with near
record PW for June. There isn`t much chance for that remnant wave
to get organized as it pushes into much cooler water near and west
of southern Baja, however a southerly surge should be no problem.
With high pressure centered east of the area over the weekend, we
suddenly see a deeper monsoon type forecast jump start the season
for SE AZ. Atypically for June, locally heavy rain a concern
along with SREF CAPE values supporting a few stronger storms.
Deeper moisture probably not pushing into western areas until
tomorrow night. Marginal risks from both SPC (for thunderstorm
winds) and WPC (for excessive rainfall) look reasonable.

Ensemble means spread the ridge further west with the high center
reconsolidating overhead the first half of next week. Warmer mid
levels and weaker moisture support should start to tamp storm
coverage down a bit, but additional surface heating will counter
that somewhat. The bottom line is we keep a chance of
thunderstorms going well into next week, however we should start
to rely more on recirculated boundary layer moisture with the
overall trend down. It remains to be seen if we will keep enough
moisture around to avoid more excessive heat headlines, but my
guess is we will. There`s even a hint that we may see some
moisture reinforcement from newly awakened Sinaloa and Sonora
later next week. An unusual June as we typically see sputtering
starts before deeper moisture sets up immediately upstream in
July.

&&

.AVIATION...Valid through 22/12Z.
SCT-BKN clouds 10-14k ft AGL. SCT -TSRA will develop after 21/19Z,
with TSRA and BKN CIGS around 6k ft AGL possible between 21/21Z
and 22/03Z. East to southeast winds 10-20 mph, diminishing after
22/03Z. Stronger and erratic outflows possible with storms.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Gusty east to southeast winds this morning will
diminish through the day. A strong increase in moisture will bring
better RH values along with a chance of thunderstorms into at
least early next week. Some storms will generate strong and
erratic outflow winds. Moisture is expected to be deep enough for
some storms to generate locally heavy rain.

Temperatures may heat back up by mid week as high pressure builds
nearly overhead, however we should keep some storm chances around.

&&

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

&&

$$

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