733
FXUS65 KTWC 241718
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
1018 AM MST Mon Jun 24 2024

.SYNOPSIS...
Ample moisture will bring daily chances for thunderstorms to the
area into next week. Locally heavy rain will be likely with any
thunderstorm that develops, along with an isolated chance for
strong wind gusts. Temperatures will heat up a few degrees as high
pressure builds overhead.

&&

.UPDATE...
Another moist day with the 12Z sounding at KTWC observing 1.84
inches of PWAT. The pattern observed over the weekend persists
today with continued southerly flow keeping moisture in the area
with afternoon/ evening hour PWATS forecast to be around 2 inches.
Higher PWATs of 2 to 2.1 inches will be focused in western Pima
county and decrease moving east across SE AZ with PWATS around 1.1
to 1.2 inches in Cochise county. Looking at NEAFS, PWATs are
anomalously high pushing into the 99th percentile to maximum
climatological values for this time of year. A thick cloud deck
this morning is situated over eastern Pima county, Santa Cruz
county, eastern Cochise county, and Graham and Greenlee counties.
The clouds seem to begin clearing out, though time will tell how
well the clouds are able to dissipate. How well clouds clear this
morning will increase confidence on how widespread convection will
be this afternoon.

Instability today will be largely dependent on how well clouds
are able to dissipate. If clouds clear, greatest instability
appears to be focused in Santa Cruz county with CAPE around
2000-2500 J/kg and more widespread CAPE of 1000-1500 J/kg for the
rest of southeastern AZ. DCAPE is fairly weak today with values
around 500-1000 J/kg. Isolated to scattered storms are forecast to
begin developing around 2 to 3 PM MST, focused to start in and
around Santa Cruz county and become more widespread into Pima and
Cochise county around 3 to 4 PM MST. This is highly dependent on
how well clouds clear and allow for storms to develop. Based on
how high atmospheric moisture is and the speed of mean wind aloft,
the main concern associated with thunderstorm development is
heavy rain with the potential for flash flood conditions and a
strong gusty wind or two.

&&

.DISCUSSION...Unseasonably deep moisture for late June remains in
place over SE AZ, with surface dewpoints in the 60s and
precipitable water values between 1.5 inches east and 1.9 inches
west. Another morning with convection hanging on through the
overnight hours. Main focus for storms continues to be locally
heavy rainfall with localized flooding issues.

For today, the deepest moisture axis continues through Santa Cruz
county and the T.O. Nation as modest mid level drying tries to
mix into eastern areas. We`ll once again have plenty of debris
cloud to sort through early with slower insolation in most
locations. WPC has us up to a slight risk in the excessive
rainfall outlook today, and looks warranted as we continue to
manage solid convective potential across most of the area today.
Wet microbursts again the main concern, possibly over more of the
area than yesterday.

High pressure will strengthen over the desert southwest with a new
high center consolidating nearly overhead over the next 36 hours.
With the depth of the moisture in place we`ll probably only manage
2 to 5 degrees of heating with this. Mid level warming will tend
to suppress convection, but we should keep a chance of
thunderstorms going even as we slowly mix out some of the moisture
over the next few days.

Another (weaker) easterly wave will push from Mexico into the
Pacific around Wednesday or so. A little further south, but still
in a position to push a fresh but likely weaker surge of moisture
toward the area later in the week.

&&

.AVIATION...Valid through 25/12Z.
SCT-BKN 080-120ft AGL with scattered SHRA and isolated TSRA this
morning. Brief MFR conditions possible with storms. Showers will
diminish after 24/13Z before chances increase between 24/20Z to
25/03Z. Overall winds generally remain under 12 kts with
occasional gusts to 20 kts in the afternoon, while strong gusty
outflow winds are possible around any thunderstorms. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...
Relatively deep moisture will keep RH values on the higher side
into next week, along with daily chances for thunderstorms.
Moisture is expected to be deep enough for some storms to generate
locally heavy rain.

&&

&&

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

$$

Update...Malarkey

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