017
FXUS65 KREV 091900
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
1200 PM PDT Sat May 9 2026

.KEY MESSAGES...

* A warming trend continues with near record high temperatures
  most likely from Sunday through Tuesday.

* Dry conditions are expected through early next week with typical
  afternoon west breezes most days.

* Some cooling returns by mid-late next week with isolated shower
  chances and periods of breezy winds.

&&

.DISCUSSION...

Building upper level ridge over southern CA with a north-south
axis near the Sierra crest today will shift east into the
southwest US/Four Corners region from Sunday through Tuesday.
With this pattern, very warm conditions will spread across the
region, with highs Sunday-Tuesday around 15-20 degrees above
seasonal normals (upper 80s-lower 90s in NE CA and W NV valleys,
and upper 70s-lower 80s for Sierra communities). Record highs
will be within reach--see the Climate section below for a list of
the current temperature records at our two climate sites. The
latest NWS HeatRisk forecast continues to show warmer valleys of
western NV in the Moderate category, with the remainder of the
region in the Minor category. Please take the time now to prepare
for this heat especially if you have outdoor plans in the
afternoon and are sensitive to heat. Also, use extra caution near
rivers which remain cold and could be flowing fast, presenting a
risk of hypothermia.

This ridge pattern will also allow for dry conditions to prevail
through early next week. Increased daytime heating could allow
for a few brief afternoon pop-up showers near the Sierra and
south of US-50 in western NV, but chances look to be less than
10%. Light winds are expected today, then typical zephyr-type SW-W
breezes (gusts around 25 mph) return each afternoon on Sunday
through Tuesday. These winds may edge upward on Tuesday depending
on the eventual ridge location in relation to an upstream
trough/upper low off the CA coast, but confidence is lower on
this wind trend.

The pattern is still on track to change Wednesday-Thursday as the
upper level ridge moves east into Texas while the offshore low
makes landfall in CA and eventually pushes across western NV.
There continues to be variable scenarios with this low`s track and
timing, which would affect when and where the best chances of
showers and thunderstorms occur. Currently, we`re keeping our eyes
on Wednesday through Thursday having the best potential for
active weather. It may end up being more of a showery outcome with
limited lightning coverage, especially if the best forcing moves
through during the overnight/morning hours. Periods of increased
winds (gusts 30-40 mph) are also in the mix for the Wednesday-
Thursday time frame, either due to outflow gusts near
showers/t-storms or increasing 700 mb flow over the Sierra with
tighter pressure and temperature gradients.

We have more confidence in the near-record warmth ending from
Wednesday onward, although highs should remain above mid-May
averages through the end of next week, easing back to the mid
70s-near 80 for lower elevations and mid 60s-near 70 for Sierra
communities. However, there`s a 20-30% chance for additional
cooling on Wednesday or Thursday if the upper low passes directly
overhead with thicker cloud cover and showers. Overall precip
potential decreases by late next week and through the May 16-17
weekend, although stray rain showers can`t be fully ruled out as
minor shortwave disturbances in a zonal flow pattern over the
western US could brush across parts of eastern CA/western NV. MJD

&&

.AVIATION...

Generally light NE-E winds through this evening, then typical
SW-W breezes (gusts around 20 kt) return Sun-Tue, mainly between
20-04Z. VFR conditions are expected through early next week. Only
possible exception is at KTRK where there`s a 20% chance for
patchy shallow fog developing between 10-15Z Sunday morning,
which could cause intermittent sub-VFR conditions.

While dry conditions prevail, the warmest days Sunday-Tuesday
could potentially bring density altitude concerns each afternoon,
especially for the western NV terminals. MJD

&&

.CLIMATE...

Current record high temperatures for Reno, NV that have potential
to be broken or tied (Sunday-Tuesday):

May 10: 88 F, set in 1934.
May 11: 90 F, set in 2001 and 2013.
May 12: 89 F, set in 1959 and 2013.

Current record high temperatures for South Lake Tahoe, CA that
have potential to be broken or tied (Sunday-Tuesday):

May 10: 75 F, set in 2025.
May 11: 78 F, set in 2013.
May 12: 79 F, set in 1988 and 1996.

MJD

&&

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

$$