FXUS65 KTWC 241709

Area Forecast Discussion
National Weather Service Tucson AZ
1009 AM MST Sat Sep 24 2022

.SYNOPSIS...Mainly isolated thunderstorm activity this weekend with
a slight uptick in storms area wide Tuesday and Wednesday next week.
High temperatures will be above normal for the next 7 days.


.DISCUSSION...Latest hires convective allowing model solutions
continue to show the same theme highlighted in the previous
discussion. Air mass over the area slower to dry out versus the model
world which happens more often then not, as the morning Tucson
sounding recorded a 1.42" PW value. That along with the given
synoptic pattern will be good for allowing for the development of
convection later this afternoon into the evening hours. For the most
part storm development will be south and east of Tucson with a chance
that the Catalina and Rincon mountains could get into the action
again. Storms will likely also affect parts of the International
border area west of Nogales later today. High temp forecast also
looks good with highs running 3-4 degrees warmer than average today.

No need for any forecast updates at this time.


.AVIATION...Valid through 25/12z.
FEW-SCT clouds at or above 12k feet this morning, increasing in
coverage this afternoon and evening. Isolated to widely scattered
thunderstorms expected again today, but with generally less coverage
than yesterday and mainly south and east of KTUS. Light winds this
morning will become northwest less than 12 kts this afternoon.
Aviation discussion not updated for TAF amendments.


.FIRE WEATHER...Isolated to scattered showers and thunderstorms this
weekend, mainly east and south of Tucson. Early next week storm
coverage will be confined mainly to the White Mountains. 20 foot
winds will remain less than 15 kts favoring the west to northwest
each afternoon through the weekend. Above normal temperatures are
expected into next week.


.PREV DISCUSSION... /issued 246 AM MST Sat Sep 24 2022/
Weak southwest flow aloft over the area this morning with upper high
centered over central Texas. Precipitable water (PW) values ranged
from just under 1" over the White mountains and far SE Cochise county
to around 1.7" over far western Pima county.

For today, gradual decrease in PW across the area will lead to
less thunderstorm coverage today versus previous days with main
focus of storms being over the higher terrain south and east of
Tucson, where localized heavy rain is possible.

Sunday: PW values continue to erode with most of the area below
1". The exception will be south of Tucson across Santa Cruz and SW
Cochise county where isolated storms are possible.

Sunday night into Monday: Surface high pressure along the front
range will bring a stronger low level easterly gradient across the
area for an increase in easterly breezes. This will also bring a
gradual increase in low moisture from New Mexico resulting in a
chance of storms across the White mountains.

Tuesday into Wednesday: With the upper high near the 4-corners the
resultant easterly mid-level flow will bring an increase in
moisture across the area for an uptick in showers and
thunderstorms both days. Nothing major, basically isolated to
scattered coverage of storms each day as we close out the 2022

High temperature for most of the next 7 days will run 2-6 degrees
above normal with the hottest days being Sunday and Monday.




Fire Weather....Cerniglia

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NWS TWC Office Area Forecast Discussion