525 

FXUS65 KTWC 310835

AFDTWC



Area Forecast Discussion

National Weather Service Tucson AZ

135 AM MST Wed Dec 31 2025



.SYNOPSIS...A storm system will bring chances for precipitation

late this morning through New Years Day and lingering into Friday

morning. Dry conditions return Friday afternoon through the 

weekend. Above normal high temperatures continue for most of the 

upcoming week.



&&



.DISCUSSION...



Happy New Years Eve and final day of 2025! Another day with 

overcast skies and now a chance for precipitation starting this 

afternoon. The upper level pattern today is driven by a trough 

currently off the coast of northern Baja that will gradually shift

to the northeast becoming a weak open wave that will move onshore

into central California Thursday afternoon. The wave will then 

push through southern Utah Friday afternoon. This will lead to a 

few rounds of rain showers the first being late this morning 

through tomorrow morning then again tomorrow afternoon through 

Friday morning.



Precipitation chances today will start from the southwest late 

this morning gradually extending northeast encompassing the area 

by the early evening hours. Rainfall for this time period will be

fairly light ranging from 0.05" to 0.15" for most areas with up 

to 0.25" to 0.50" for the mountains. The heavier rainfall will be 

focused to areas Tucson northward and especially in the mountains.

Snow levels will remain above mountain tops during this time. 



Around midnight tonight temperatures will be in the mid 50s to 

low 60s with a 40-60% chance for rain. Those celebrating New Years

Eve outdoors are encouraged to wear cool temperature, rain 

weather clothing and carry an umbrella. Take caution when driving 

as roads may be slick and some ponding may occur. 



Thursday afternoon into Friday morning, precipitation will be 

focused to areas Tucson northward as well as in the mountains and 

be more convective in nature with even some thunder embedded in 

the heavier precipitation. Given the precipitation will be more 

convective, rainfall amounts will be more variable ranging between

0.01" to 0.05" with locally up to 0.25" in the mountains. Total 

event precipitation from Wednesday into Friday will range from 

about 0.1" to 0.5" (lowest SE Cochise County and highest north of

Tucson), with 0.5" to 1" in the mountains (Catalinas/Rincons 

northeastward) due to orographic lift. 



Friday, the weak trough that brought rain showers to us will fade

into a shortwave ridge diminishing chances for precipitation and 

raise temperatures back into the 70s by Saturday. The ridge will 

shift eastward Sunday replaced by southwest flow influenced by a 

building trough off the coast of California. The trough will 

remain offshore through at least Tuesday, then there is 

considerable differences by the models where and how strong this 

trough will be as it moves onshore. By all indications we'll have 

another system by the middle of next week bringing the possibility

for mountain snow.



&&



.AVIATION...Valid through 01/12Z. 



BKN-OVC clouds AOA 15-20k ft AGL through 31/12Z, then becoming 

BKN-OVC with cloud bases lowering to 6-12k ft AGL through the end

of the valid period. SCT -SHRA expected to develop and spread 

from southwest to northeast, with increasing -SHRA chances for 

KTUS/KOLS aft 31/19Z and KDUG aft 31/23Z. SFC winds easterly to 

southeasterly 5-10 kts gusting 15-20 kts thru 31/18Z. SFC winds 

weaken east of KTUS to light and variable and shift to be south to

southeasterly at 5-10 kts from KTUS westward aft 31/18Z through 

to the end of the forecast period. Aviation discussion not updated

for TAF amendments.



&&



.FIRE WEATHER...Gusty east winds continue early this morning

diminishing to mainly less than 15 mph by this afternoon into 

early next week. A weather system will bring periods of rain 

showers this afternoon afternoon into Friday morning. Any snow 

will be at or above mountain tops. Minimum relative humidity 

values will remain elevated through the upcoming week, ranging 

from 35-55 percent in the valleys and 50-80 percent in the 

mountains. RH's peak Thursday and Friday. Temperatures will mostly

be above normal levels this week.



&&



&&



.TWC WATCHES/WARNINGS/ADVISORIES...

None.

&&



$$



Malarkey



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