FXUS65 KTWC 131010
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
310 AM MST Sun Oct 13 2024

.SYNOPSIS...Unseasonably hot conditions will continue today and
Monday then cooling trend for the rest of the week into next
weekend.

&&

.DISCUSSION...The 13/00z upper air plots placed 500 mb high along
the Intl border. This feature will continue to slide to the south
today but still looking at another day of record highs. Likely the
last in this two week plus stretch and likely the last triple
digit high for Tucson in 2024.

The upper low that was off the Oregon coast Sat am was over SW ID
this am. This feature will gradually drift to the SE over the
next several days and be in NW AZ by Tue am. This system is
moisture starved for SE AZ. However it should be noted that the
EPS is wetter than the GEFS in pulling moisture from the south
across the far eastern areas, or along the AZ/NM border, Tuesday
night into Wednesday. There is a handle of EPS members producing
measurable precip on Wednesday east of a Safford-Douglas line with
NBM showing high end single digit to 11% PoPs in this area. Likely
will see cloud buildups with little chance in measurable precip.
Highs temperatures will be cooling but remaining above normal.

This low opens up on Wednesday before a progressive upper level
trof moves through the Great Basin. on Thursday. The trof will
continue the cooling trend with highs by Friday a few degrees
above normal.

Lots of uncertainty next weekend with respects to the next
Pacific trof to move into the western CONUS. Does this system
become a cut-off low, per GEFS/GEPS, or be progressive, per EPS.
There is definitely a large spread in high temperatures with this
trof along with the uncertainty of precipitation with very slight
chance of the first snow of the season for the White mountains.
Confidence low.

&&

.AVIATION...Valid through 14/12Z.
SKC to few clouds AOA 20k ft AGL thru fcst pd. SFC winds diurnally
and terrain driven less than 12 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Dry conditions will prevail through the middle of
next week. Winds will be diurnally driven through early next week with
speeds less than 15 mph. Winds speeds increase starting the middle
of next week as a weather system moves through. This will also
cool temperatures to around normal by late next week. Minimum RH
values will be 5-15 percent for lower elevations and in the low to
mid 20s for higher elevations through early next week. RH values
improve late next week increasing to 15-25 percent for lower
elevations.

&&

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

&&

$$

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson