919 
FXUS65 KREV 160922
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
222 AM PDT Thu May 16 2024

.SYNOPSIS...

Unseasonably warm temperatures will persist today with afternoon  
breezes through the weekend. Other than a slight chance of 
showers and thunderstorms in the eastern Sierra south of Highway 
50 on Saturday, conditions will stay dry. Low pressure will bring 
more seasonal temperatures next week with a low potential for 
showers for midweek.

&&

.DISCUSSION...

This afternoon will be our warmest this week, with clear skies and 
breezy afternoon winds. Temperatures will again flirt with the 90 
degree mark, with a less than 10% chance to achieve 90 degrees at 
the Reno-Tahoe Intl Airport. Westerly gusts this afternoon could 
reach 20-25 mph for leeside valleys, while Sierra ridges could see 
gusts of 30+ mph. This could result in some choppy lakes and impacts 
to recreation in wind prone areas. 

The ridge that was holding strong over the Pacific coast will begin 
to retrograde from the coast for Friday as a trough enters the 
picture. The base of the trough will be just to our northwest, so 
while we won't see much in the way of precipitation, temperatures 
will back off slightly for Friday. Afternoon breezes will shift out 
of the north, drawing down some of the cooler northerly breezes. 

As we transition into our weekend, the base of the trough drops in a 
bit further, as chances for showers and storms in Mono County 
increase to 20-25% for Saturday. This activity will be rather short-
lived, since we will again be dry for Sunday. Some clouds will 
appear to our east as the trough exits the region, but along the 
Sierra, there will be fewer clouds. What will be present along the 
Sierra, will be gusty ridges. Westerly gusts return, up to 40-45 mph 
along the Sierra crest. Western Nevada valleys could see gusts up to 
30 mph, as temperatures settle back toward seasonal averages for 
next week. 

Showers chances appear again for Tuesday, with limited confidence 
due to a meandering low that will move inland as an open wave 
somewhere along the SoCal coast. This feature could provide just 
enough instability, moisture and lift to pop showers along the far 
southern Sierra in Mono County. 

Into the midweek, another trough appears to drape across the Pacific 
NW into the Intermountain West. This could serve up some showers and 
storms along the Oregon border. Confidence here again is on the 
lower end until we see better ensemble agreement in the trough 
progression. 

HRICH

&&

.AVIATION...

* VFR flight conditions today, with early morning northerly winds 
  becoming westerly after 21Z. Gusts will also increase around 21Z, 
  to around 20-25 kts. 

* An unsettled pattern will emerge this weekend, with showers and 
  storms for KMMH (20-25% chance) Saturday. Sunday will be breezy, 
  with westerly gusts to 40-45 kts for Sierra terminals, up to 30 
  kts for leeside valley terminals. Chances for showers and storms 
  reappear for midweek as a trough settles across the Pacific 
  Northwest. 
  

HRICH

&&

.HYDROLOGY...

Unseasonably warm daytime temperatures and mild nights, combined  
with higher solar angles, longer days, and limited cloud cover, 
will continue to increase snowmelt rates late week. Even the 
higher elevation deeper snow areas have begun to melt in earnest.  

This rapid melt will lead to elevated flows with rivers and 
streams running cold and fast, most notably in areas draining 
significant terrain over ~7500 feet from Lake Tahoe south through  
Mono County. Rivers and streams in this area will remain high 
through the weekend, with the highest flows likely Thursday into 
Saturday. Cooler temperatures and a depleting snow-covered 
contributing area will help reduce flows somewhat Sunday into 
early next week.

While these high and cold flows can be hazardous to 
recreationalists, flooding is very unlikely. Remember the highest  
flows are significantly lagged from the heat of the day and can 
often occur at night. 

More steady high flows will also continue along the Lower 
Humboldt, with additional rises likely in very late May or early 
June.

Please use extra caution around local rivers and streams which
will be running fast and cold and can be very hazardous.

TB

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$