FXUS65 KREV 120830

AFDREV



Area Forecast Discussion

National Weather Service Reno NV

1230 AM PST Fri Dec 12 2025



.KEY MESSAGES...



* Dry weather, light winds, and unseasonably warm temperatures 

  continue through this weekend. 



* Hazy skies and minor reductions in air quality possible each 

  morning across lower urban valleys. 



* A pattern change is expected mid-next week, bringing increased

  winds and slight chances for precipitation primarily to the 

  Sierra and northeast California.



&&



.DISCUSSION...



Freezing fog and in some areas a low stratus deck are socked in over 

Lake Tahoe and the surrounding Sierra valleys this morning. Daytime 

heating this morning may be enough to mix out the fog, however there 

may still be low stratus that linger just above the surface this 

afternoon. Light winds this afternoon may not be enough to fully mix 

out the low clouds. Other than that, from now through the middle of 

next week we're going to be under a ridge that will keep us dry and 

relatively warm for December. 



However, next Tuesday and Wednesday we'll likely see a little 

precipitation across the region. Long range models and ensembles 

show NE CA and the Sierra getting clipped by the southern tip of 

an atmospheric river as it moves into the Pacific NW. As of right 

now the QPF and especially the snow amounts don't seem too 

impressive. Blended guidance has a 40% chance of the 24 hour QPF 

exceeding 0.7" along the Sierra crest and up to a 30% chance of at

least 1" of snow. The snow levels look to hover around 9000-9500'

during this storm, so just the highest peaks have the greatest 

chance (30%) to see any snow. 



It seems like this storm next week tries to open the storm door for 

our CWA. Wednesday through at least Saturday, the 300mb jet becomes 

almost purely zonal, only with the jet max situated over 

Oregon/Washington. This basically means that we'll be right on the 

southern periphery of future storms late next week, while staying 

relatively warm each afternoon. 700mb temperatures stay above 

freezing for the most part, even during that brush by system next 

week. For snow down to lake level in Tahoe, ideally we'd like to see 

700mb temps around -6C, so we have some waiting to do still. 

Speaking of which, instead of a ridge over the Pacific NW like we 

have now, EC, Canadian, and GFS ensemble clusters are showing a 

trough setting up off the west coast towards the end of the month 

with slightly cooler upper level temperatures. That's an encouraging 

sign for those who want a white Christmas in the Sierra. We'll 

monitor that as time gets closer.



-Justin



&&



.AVIATION...



FZFG is prevalent this morning for KTRK and KTVL and should burn off 

just after sunrise, otherwise light sfc winds and VFR conditions 

continue through Saturday. Slantwise VIS restriction is also a 

concern for western NV terminals due to haze from morning valley 

inversions.



-Justin



&&



.REV Watches/Warnings/Advisories...

NV...None.

CA...None.

&&



$$