085
FXUS65 KREV 032149
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
249 PM PDT Wed Jul 3 2024

.SYNOPSIS...

* High pressure brings a prolonged heatwave starting tomorrow and
  lasting through the middle of next week.

* Afternoon highs will be 10-20 degrees above average by the weekend
  resulting in a moderate to major HeatRisk, a Heat Advisory for the
  California portions of the region, and an Excessive Heat Warning
  for the western Nevada portions.

* It will remain very dry with typical afternoon breezes, and a very
  low chance, less than 5%, for precipitation in the weekend.

.DISCUSSION...

The latest RAP upper air analysis shows high pressure over the
Pacific Ocean allowing for the CWA to have a northwesterly flow
aloft being underneath the forward portion of an upper air ridge.
Current surface observations along with satellite imagery show sunny
skies this afternoon with generally light and variable winds though
eastern portions of the CWA are reporting the occasional gust up
to around 20 mph. Going forward through the rest of the week and
into next week, forecast guidance projects the upper air ridge
dominating the upper air pattern over the western CONUS through at
least Tuesday night when it may start finally advancing eastward
on next Wednesday. With this pattern potentially staying in place,
the region looks to see temperatures within the region increase
with triple digits possible in some portions for multiple days.

While dry conditions are mostly expected to prevail, the main hazard
for the upcoming days will be the above normal temperatures and
heat. According to the latest run of the NBM, portions of western NV
now see a 20-60% probability of reaching 100F or greater on
Independence Day. By Friday, these NBM probabilities increase to 50-
80% with portions of northeastern CA starting to enter into the area
of coverage. By Saturday and lasting through the following days
through Wednesday, NBM probabilities increase even more to around 60-
95% percent within the CWA. As a result of these probabilities
showing multiple days of triple digit temperatures as well as the
latest HeatRisk guidance being moderate to high in the region, the
Excessive Heat Watch for western NV has been upgraded to an
Excessive Heat Warning beginning on Saturday and lasting through
Wednesday at this time. Also, a Heat Advisory has been issued for
the eastern CA counties of the CWA with daytime high temperatures
ranging between 90-100F with some locations possibly exceeding the
century mark. Please see these heat products for more details on
this upcoming heat hazard. It is recommended to take precautions
during this time such as limiting outdoor activity, taking breaks
in a cool area, staying hydrated, and checking in on neighbors and
relatives that may be more susceptible to heat related illness.
For more heat safety tips, please visit weather.gov/safety/heat.
It is also worth noting that the Reno Area has not had more than
two consecutive days of 105F high temperatures in climate history
with the last time of this occurring being in mid July of 2023.
There could be a chance that this consecutive day record is broken
along with daily high temperature records with the upcoming heat.

Winds through the period are still are expected to be generally
light or typical for this time of the year. However, some models are
hinting at a slight uptick with wind gusts up to around 40 mph in
mountain areas especially on Sunday. This would bring some
concerns for fire weather after a period of hot and dry
conditions. Models are also still showing some hints of
precipitation on each day beginning Sunday and going into the
middle. However, the chances for showers and thunderstorms still
remain at or below 5% at this time. Will continue to monitor this
in case these chances increase. -078

.AVIATION...

VFR conditions expect to persist at all REV TAF sites today and
going into tomorrow. Models show clear skies over the region with
the exception of a few clouds over western NV tonight during the
overnight hours. Winds look to be generally 10 kts or less at
most sites with the exception of KMMH seeing gusts up to around 20
kts out of the west between 21Z-03Z. Temperatures continue to
rise through the weekend resulting in density altitude concerns
across the whole area. -078


.FIRE WEATHER...

No major changes from the previous fire weather forecast package
with above normal temperatures and dry conditions prevailing for the
rest of the week and into next week. However, winds generally look
generally light and unsupportive of critical weather at least
through the remainder of this week. However, models are hinting at
some gusts near or above 30 mph starting on Sunday, especially over
mountain areas. So, will continue to monitor these conditions over
the next few days as this could lead to periods of near critical
conditions for those localized areas. There are also some very
slight chances for showers and thunderstorms starting on Sunday
afternoon. However, these chances remain at or below 5%. -078

&&

.REV Watches/Warnings/Advisories...
NV...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday NVZ002.

     Excessive Heat Warning from 10 AM Saturday to 10 AM PDT
     Wednesday NVZ001-003>005.

CA...Heat Advisory from 10 AM Saturday to 10 AM PDT Wednesday
     CAZ070>073.

&&

$$