000
FXUS65 KREV 122105
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
205 PM PDT Sun Jul 12 2020

.SYNOPSIS...

Gusty afternoon winds combined with critically dry conditions are
taking place this afternoon with Red Flag Warnings in effect
through this evening. The hot and dry conditions continue through
Tuesday followed by a return of possible showers and isolated
thunderstorms for the latter half of this week.

&&

.DISCUSSION...

Today`s expected southwest winds have started to increase early
this afternoon in the Sierra and across the Sierra Front region.
Anticipate winds to increase a bit more in intensity and become
more widespread as mixing improves with a shortwave trough passing
just towards the north. Gusts of 20-35 mph are still forecast for
most locations with the strongest for areas north of US-50.

With winds increasing, humidity is decreasing across much of the
region with RH values dipping below 15%, thanks to a dry slot
pushing through at all levels... no clouds today. Red Flag
Warnings are in effect through later this evening due to the windy
and dry conditions. For more details, please see the Fire Weather
Discussion below.

As for the rest of this week... expect the hot and dry conditions
to persist with breezy, zephyr afternoon winds through Tuesday.
High temperatures during this time are forecast to be in the 90s
across western Nevada with the lower valleys reaching into the low
100s (i.e. Lovelock, Fallon, Yerington, and Mina). Relatively cooler
temperatures are anticipated for northeast California and the
Sierra naturally, but still warm nonetheless. The pattern begins
to change on Wednesday as the jet stream shifts north. This would
allow for some moisture advection to take place, transported from
the south, thanks to the strengthening high pressure over the US-
Southwest. Model soundings suggest some instability by the
afternoon as the mid to upper-levels moisten up. This combined
with the continued daytime heat should lead to some cumulus
build-ups and even some isolated thunderstorms over the usual
locations...the eastern Sierra and the Lassen Convergence Zone.
Chances look even better for Thursday and Friday afternoons as
model guidance indicates more moisture and instability available.
Have added slight chances for the eastern Sierra on Saturday as
well, but confidence is lower compared to Thursday and Friday at
this time.

It is important to note that the best chances for more dry
thunderstorm activity, resulting in heightened fire concerns,
would be on Wednesday as of now, since these conditions are
typically experienced on the first day of a pattern change like
this. Something to keep in mind, especially after how dry we have
been lately. -LaGuardia

&&

.AVIATION...

VFR conditions through mid week. Gusty southwest winds today with
peak gusts 25-30 kts for area terminals through 03-04Z. Lighter
winds Monday with peak gusts around 20 kts, then light winds for
Tuesday and Wednesday. Isolated thunderstorms may start Wednesday in
the eastern Sierra with some northward push into next weekend
possible. X

&&

.FIRE WEATHER...

...Red Flag Warning in effect for northwest Nevada and the Surprise
Valley until 9 PM Today...

Winds have been picking up early this afternoon with some gusts
around 30 mph in the warned area. Other areas have started gusting
to 25 mph. Expect the winds to peak around 5 PM today with low end
warning criteria likely for the warned area. RH remains low today
with values from 5-15%. Winds to be lighter Monday more of the
typical afternoon speeds, with light winds for Tuesday and
Wednesday. Only exception to this will be some gusty northeast winds
overnight Monday through Wednesday nights for Pershing and northern
Washoe County. Late week, there may be a return to a light zephyr.

Concerns late in the week will not involve winds as much as
thunderstorm potential. Isolated thunderstorms may start as early as
Wednesday in the eastern Sierra. Into the weekend, favored areas for
the eastern Sierra, southern Sierra Front and Lassen convergence
zone will have the best chances. They still look isolated as there
is no significant increase in moisture or trigger. Still, with fuels
drying fire starts will be possible with any lightning. Gusty
outflow winds would also occur with any storms that do form. X

&&

.REV Watches/Warnings/Advisories...
NV...Red Flag Warning until 9 PM PDT this evening NVZ420-458.

CA...Red Flag Warning until 9 PM PDT this evening CAZ270.

&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno