656
FXUS65 KREV 160304
AFDREV
Area Forecast Discussion
National Weather Service Reno NV
804 PM PDT Sun Jul 15 2018
.UPDATE...
Convection has decrease considerably over the eastern...southern
and far northern parts of the forecast area this evening. But
weak forcing remains over the far north of the far east which may
allow a few thunderstorms to continue into the late evening.
Otherwise...dry air aloft is noted moving into the forecast area.
This will limit any convection the next few days.
Smoke from the Ferguson Fire outside Yosemite is moving into the
forecast area this evening. We will include more smoke in the
forecast tonight and early tomorrow to account for this.
&&
.PREVIOUS DISCUSSION... /Issued 243 PM PDT Sun Jul 15 2018/
SYNOPSIS...
Isolated thunderstorms will continue this evening with drier
weather for Monday and Tuesday. High pressure will build overhead
and bring very hot conditions to Western Nevada Tuesday through
Wednesday and warm conditions to the mountains. The high will
begin to move east on Thursday with thunderstorm chances
increasing along with gradually cooling temperatures.
SHORT TERM...
The heat will be the main concern into midweek as high pressure
builds over the Sierra into Nevada. Hot temperatures are expected
with triple digits for western Nevada and 90s for the Sierra. As
for this evening, isolated to scattered thunderstorms will
continue with the best coverage over Mineral County and along the
Oregon border. Despite the abundant moisture, west flow aloft will
continue to limit mountain top convergence and therefore
thunderstorm initiation.
For Monday, the high begins to build over the central Sierra and
present a nice mid-level cap. West flow aloft will also contribute
some drying. A slight chance will remain over southern Mono and
Mineral Counties, however. The same will be true for Tuesday.
Tuesday-Wednesday the high will be centered just to our south with
temps aloft warming even more. 700 mb temps are forecast to reach
17-19C across the area. This will boost highs to near 105 along
the Highway 95 corridor and 100-105 for the rest of the lower
valleys in western Nevada. The Sierra valley will get into the
90s. Also, it will remain mild overnight with lows 65-75 in
western Nevada, but the Sierra will see a break in the heat as
lows drop to near 50. Will issue a Heat Advisory for western
Nevada with the anomalously warm temperatures that may set a
couple records. The heat will continue into Thursday for some
areas before moisture invades from the south.
LONG TERM...Thursday through next weekend...
The upper level ridge axis will shift eastward over the Four Corners
region late this coming week, which will allow moisture to move
northward into the Great Basin and parts of western NV and eastern
CA. Temperatures will cool and thunderstorms coverage will increase
due to these large scale changes.
Daytime highs will slightly cool in response to the relocation of
the ridge over the Four Corners. However, temperatures will be in
the upper 90s to low 100s for the lower valleys of western NV and
mid to upper 80s for Sierra valley locations. Overnight lows will
remain mild in the upper 60s and low 70s for western NV valleys and
50s for Sierra valleys.
Thunderstorm coverage will increase Thursday afternoon and into next
weekend as moisture advects northward into the region. Strong storms
with heavy rain will be possible as PWATs increase close to 1.00".
The ECMWF brings an easterly wave around the southwest portion of
the ridge. If this impulse moves overhead, the combination of
synoptic cooling/lift and high PWATs could lead to a very active day
Friday. -Johnston
AVIATION...
Storm coverage will continue to increase this afternoon and evening,
with locations over Mono-Mineral Counties as well as northeast CA
and northwest NV being most favored for thunderstorm development.
With stronger westerly flow aloft, storms will likely not affect
terminals within the Tahoe Basin (KTVL/KTRK). A few buildups may
develop within the vicinity of KRNO and KCXP. Isolated storms are
likely over the Basin and Range of western NV from 00-09Z Monday.
Drier southwest flow will hinder thunderstorm development north of
Mono-Mineral County on Monday.
-Johnston
&&
.REV Watches/Warnings/Advisories...
NV...Heat Advisory from noon Tuesday to 9 PM PDT Thursday NVZ003-004.
Heat Advisory from noon Wednesday to 9 PM PDT Thursday NVZ005.
Heat Advisory from noon Tuesday to 9 PM PDT Wednesday NVZ001.
CA...Heat Advisory from noon Wednesday to 9 PM PDT Thursday CAZ070.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno
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