Damaging Wind in Nevada, August 2, 2018

Area Forecast Discussion
National Weather Service Las Vegas NV
955 AM PDT Thu Aug 2 2018

.SYNOPSIS...
Isolated to scattered showers and thunderstorms are in store today
before moisture is pushed away to the east Friday and into the
weekend. Temperatures will drop a few degrees relative to the last
several days with a drier pattern expected through at least early
next week.
&&

.UPDATE...
Made some adjustments to Sky/PoP/Wx grids to accounts for morning
cloud cover over the valley and expected increase in cloud cover
this afternoon and evening. Also added haze mention for northern
Inyo and Esmeralda Counties as Bishop webcams are showing reduced
visibility and close inspection of VIS satellite confirms this.

&&

.SHORT TERM...today through Friday night.

Indications are that today should be the last favorable day for
isolated to scattered thunderstorms across the forecast area...and
coverage should be greater than Wednesday...especially near central
Nevada and southern Clark and Mohave counties. A feature to watch
today is a circulation currently near the southern California/Baja
border that is forecast to rotate up across southern Clark County
this afternoon and evening. In addition...effects from a shortwave
moving through the Pacific Northwest will combined with the the
SoCal circulation and enhance the upper level jet near central
Nevada and provide mid level convergence.  The latest HRRR and other
high res convective models indicate the aforementioned areas should
see scattered thunderstorms from early afternoon through early
evening then may convection may continue especially over Lincoln and
northern Mohave counties into the night.

Dry and more stable air off the West Coast will spread inland with
increasing westerly flow aloft late tonight and Friday as the
disturbance exits over northern Arizona. Meanwhile...the high
currently centered over Arizona is pushed toward the east. This
spell then end of thunderstorms Friday except possibly over eastern
Mohave County where a slight chance will exist through Friday
afternoon and early evening.
&&

.LONG TERM...Saturday through Thursday.

Zonal flow will set up through the weekend as a closed Pacific low
flattens out the persistent upper level ridging over the western US.
This will bring a period of dry weather to the entire area.
Dewpoints and PWATs will drop back for Saturday and Sunday, so
increased temperatures a bit to reflect the drier air mass. All in
all, the weekend with be quiet weather-wise.

For next week, models continue to show high pressure building back
westward and shoving the upper level trough offshore back to sea.
Latest runs actually bring the high pressure further west, with the
center of the high sitting over the desert Southwest. This set up
would not be as favorable for the return of monsoon moisture,
locking it in to our south. Long range models are slow to increase
PWATs, with mainly soother Mohave and the Colorado River Valley
showing any kind of response in the moisture fields. Given the
latest trends of the westward building ridge as well as drier model
output, decreased precipitation chances for next week. Some eastward
moving waves could enhance precipitation chances at times, and
details will need to be fine tuned as we head into next week.

With high pressure overhead and anchored in place, this would
instead suggest a dry and hot scenario. Used the warmed model
guidance for temperatures for next week, which increased
temperatures, especially midweek onward. Some temperature guidance
does show a return of extreme heat but too early to put any
confidence in those numbers as of yet.

&&

.AVIATION...For McCarran...In general, light diurnal winds are
expected to become south at 10 to 20 knots this afternoon.
Thunderstorms are possible today, mainly south of the airspace, but
could drift into the area. Gusty outflows from these storms are also
possible, however confidence in thunderstorm activity and therefore
outflow strength/direction is low. Once thunderstorms dissipate this
evening, diurnal winds will return overnight. A drying pattern will
limit thunderstorm activity Friday through the weekend. South winds
to 20 knots are possible again Friday afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...Thunderstorm chances today will be limited to mainly
central Nevada, northwest Arizona, and the Sierra, with e the best
chance of thunderstorm activity and erratic gusty winds over the
Sierra, including BIH. Elsewhere, dry conditions with gusty
southerly winds much like yesterday are expected.

&&

SHORT TERM...Adair
LONG TERM/AVIATION...Wolf
UPDATE...Boucher

&&

For more forecast information...see us on our webpage:

http://weather.gov/lasvegas or follow us on Facebook and Twitter

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE LAS VEGAS NV
934 AM PDT THU AUG 2 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0306 PM     FLASH FLOOD      11 WSW DEEP SPRINGS     37.30N 118.16W
08/01/2018                   INYO               CA   LAW ENFORCEMENT

            FLOODING WAS REPORTED ON HWY 168 JUST WEST
            OF WESTGARD PASS BY CHP. THEY REPORTED THE
            ROAD TO BE IMPASSABLE.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
121 PM PDT THU AUG 2 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1245 PM     TSTM WND GST     2 NW HOOVER DAM         36.03N 114.76W
08/02/2018  M52 MPH          CLARK              NV   MESONET

            BOULDER ISLAND HADS SITE REPORTED GUSTS TO
            52MPH.

&&

JV