Flash Flood Watch 4, NWS Reno, NV

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WGUS65 KREV 250245
FFAREV

Flood Watch
National Weather Service Reno NV
745 PM PDT Tue Jul 24 2018

CAZ072-073-NVZ001>004-250345-
/O.EXP.KREV.FF.A.0004.000000T0000Z-180725T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Greater Lake Tahoe Area-Mono County-
Mineral and Southern Lyon Counties-Greater Reno-Carson City-
Minden Area-Western Nevada Basin and Range including Pyramid Lake-
Including the cities of Bridgeport, Mammoth Lakes, Hawthorne, 
Yerington, Smith Valley, Sparks, Gardnerville, Virginia City, 
Fernley, Fallon, Lovelock, and Silver Springs
745 PM PDT Tue Jul 24 2018

...FLASH FLOOD WATCH WILL EXPIRE AT 8 PM PDT THIS EVENING...

The Flash Flood Watch for portions of east central California and
Nevada will expire at 8 PM PDT this evening. Thunderstorms are
decreasing in coverage and intensity over western Nevada and
eastern California this evening. The threat for flooding has
diminished, therefore the Flash Flood Watch will be allowed to 
expire.

$$

Area Forecast Discussion
National Weather Service Reno NV
242 AM PDT Tue Jul 24 2018

.SYNOPSIS...

Showers and thunderstorms will continue the next several days
although coverage will gradually shift south and be mostly across
Mono and Mineral Counties Wednesday and Thursday. A few storms
will be strong and capable of very heavy rain. Otherwise expect
temperatures to warm back up to triple digit heat for lower
valleys as high pressure builds into the area.

&&

.SHORT TERM...

The upper high is still forecast to move west across the Desert
Southwest this week which will bring a decrease in storms and
increase daytime temperatures for the Sierra and western NV.
There is a little more flow aloft and it is a bit more southwest
today which will have a tendency to push storms off the northern
Sierra. Best coverage will be from Mono County northward into the
Pine Nuts where convergence will be maximized. Model soundings
continue to indicate sufficient moisture and instability for a few
strong storms today which will be capable of very heavy rainfall
and localized flash flooding as well as hail to 1" in diameter.
Any storms that move out over the lower valleys will also be
capable of strong outflow wind gusts to 50 mph. Isolated
thunderstorms are also possible along the Lassen convergence zone
in northeast CA and far northwest NV late in the afternoon and
early evening.

For Wed-Thu, convection is suppressed a bit farther southward and
will be confined mainly to Mono-Mineral Counties. While coverage
is decreasing, intense heating and sufficient moisture suggests a
few strong storms once again although more isolated than today.
The flow turns a bit more northwesterly across northeast CA and
northwest NV Wednesday which will limit convection to mainly a few
buildups there. Smoke from the northern CA and OR wildfires may
get advected into this area however and we have begun to introduce
the possibility Wednesday afternoon. Between this smoke and the
the smoke from the Ferguson Wildfire, we spread haze throughout
the region with smoke from Susanville/Gerlach northward to the
Oregon border based on latest HRRR smoke guidance.

Temperatures will be up a few more degrees today rising to over
100 degrees for lower valleys and 85-90 in the Sierra valleys Wed-
Thu. Outside of storm outflows, winds are going to generally be
light with a general west-northwest flow late each afternoon and
evening and variable terrain winds late nights and mornings.
Hohmann

.LONG TERM...Friday into next week...

Model suite is a bit different this morning in showing a more east-
west oriented ridge than previous runs. This is followed by a bit of
a stronger trough moving into the Pacific Northwest next week. The
EC still shows a bit more rounded ridge for Sun-Mon and given the
changes and uncertainty, I made few changes.

It still looks dry Friday followed by a small threat of
thunderstorms over Mono and western Mineral Counties for the
weekend. For Monday/Tuesday, I kept the location about the same due
to the lack of consensus. Temperatures will remain above average and
continue to flirt with the century mark in western Nevada with 90s
for northeast California and 80s for the Sierra. It does look to
cool sometime next week, but whether it is from an increase in
monsoon moisture or the trough remains to be seen. X

&&

.AVIATION...

TSRA will continue to be the main threat today with a peak from 22-
03Z. 30-40% chance for KMMH and KMEV, but only about a 20% chance
for the other terminals. Heavy rain, small hail and wind gusts to 45
kts remain the threats. A decrease in thunderstorms is expected
Wednesday with most if not all storms expected to remain south of
highway 50.

Other concerns involve the threat of FG this morning until 15Z at
KTRK and KTVL due to yesterday's rainfall. It is expected to be
shallow, and is not expected to last more than 2-3 hours. Then,
there will be smoke from the fires in CA and OR to deal with.
Looking more like haze with greater reduction in slantwise
visibility vs. surface visibility. Greatest impacts south of Highway
50 from the Ferguson fire, then north of KSVE from the SW Oregon
fires. X

&&

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

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