Mammoth Lakes, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

746
FXUS65 KREV 050852
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
152 AM PDT Fri Jun 5 2026

.KEY MESSAGES...

* Warm and dry conditions continue today, with highs 10 to 15
  degrees above normal and areas of Moderate HeatRisk across lower
  valleys.

* West breezes increase today with brief elevated fire concerns.
  Stronger winds and higher fire risk is expected Saturday.

* Some cooling returns this weekend, with temperatures near or
  slightly below early June averages Sunday through much of next
  week. Gusty winds and shower chances may also return next week.

&&

.DISCUSSION...

Enhanced zephyr breezes are expected this afternoon across the
region with widespread gusts of 20-30 mph and isolated pockets of
up to 35 mph in western NV. Conditions will be marginal for lake
wind advisories today, however lakes out in western NV may become
choppy in the afternoon. Today will also hold the warmest
temperatures for at least the next 6 days, before a cooling trend
commences this weekend. High temps in west central NV will
approach 95-97 degrees, and 90-93 degrees in northeast CA and
along the Sierra Front. Sierra valleys are expected to see
temperatures into the low 80s, and those near Chalfant Valley will
be approaching 100 degrees again today. Pockets of Moderate
HeatRisk and widespread Minor HeatRisk will also be prevalent
across western NV valleys today. With the gusty winds and
widespread RH less than 15% this afternoon, there will be a few
hours of isolated elevated-locally critical fire weather
conditions in western NV and northeast CA.

A large upper level trough located over the Pacific Northwest and
its accompanied slow-moving cold front are what will increase
winds further on Saturday. Tight pre-frontal pressure gradients in
far western NV are driving wind gusts up to 45 mph, though
northeast CA and western NV are more likely to see 35-40 mph. As
such, we have opted to issue Lake Wind Advisories for western NV
and Mono County Saturday morning through evening. More widespread
critical fire weather conditions are expected Saturday for the
aforementioned areas, as up to 9-10 hours of Red Flag conditions
are very possible.

Temperatures start to cool off Saturday, then continue to cool
off through mid-week as a deeper low pushes farther south.
Temperatures bottom out close to average for this time of year, if
not a few degrees below average next week. Highs across western
NV valleys will be in the mid 70s, and low 60s in the Sierra. Some
variation in the models exists as to how far south the low will
move, leading to conflicting potential for rain early next week.
As it stands this morning, precip chances of 20-40% begin Monday
and continue through Tuesday, then decrease to 10-15% by
Wednesday. There will also be an uptick in the winds early next
week as well when this low drops in, though because of the higher
RH, there is less of a concern for critical fire conditions.
Models are hinting at a rather robust ridge moving in at the end
of next week, bringing temperatures back up to above average for
next weekend.

-Justin

&&

.AVIATION...

VFR conditions prevail today and Saturday with no chances for
precipitation. Main concern will be increasing SW-W winds each
afternoon, with gusts 20-25 kt today and near 30 kt Saturday.
FL100 winds out of the west at 30-35 kt may cause areas of
turbulence and crosswinds over the Sierra and Sierra Front on
Saturday.

-Justin

&&

.FIRE WEATHER...

Elevated to brief periods of near critical conditions are
expected today, where westerly gusts of 25-35 mph overlap
receptive grasses and brush over western NV and portions of
eastern Lassen/Plumas counties.

Saturday remains the primary concern as the strongest winds
arrive after several days of drying. Westerly gusts over 35 mph
are likely across much of western NV and portions of eastern CA,
with minimum RH generally 9-16% in lower valleys. Longer critical
wind/RH overlap supports up to 9-10 hours of Red Flag conditions
across western NV and into eastern Lassen County. A fire weather
watch remains in effect for Saturday from 11 AM to 11 PM.

-HC/Justin

&&

.REV Watches/Warnings/Advisories...
NV...Fire Weather Watch from Saturday morning through Saturday
     evening NVZ420-423-429-458.

     Lake Wind Advisory from 11 AM to 11 PM PDT Saturday NVZ001-004.

     Lake Wind Advisory from 8 AM to 11 PM PDT Saturday NVZ003.

CA...Fire Weather Watch from Saturday morning through Saturday
     evening CAZ278.

     Lake Wind Advisory from 11 AM to 11 PM PDT Saturday CAZ073.

&&

$$