Area Forecast Discussion
Issued by NWS Las Vegas, NV
FXUS65 KVEF 301652
Area Forecast Discussion
National Weather Service Las Vegas NV
952 AM PDT SAT JUL 30 2016
.SYNOPSIS...The weekend and next week will bring relief from the
very hot temperatures experienced the past several days although
increasing humidity could make it feel a bit sticky at times. Expect
isolated to scattered thunderstorm activity across parts of the area
through the next week.
.Update...A moist and unstable air mass is in place today over most
of the forecast area and a few light showers were lingering from the
overnight convection. There appears to be a lack of a forcing
mechanism to get new convection going today and it may depend on
orographics initially, then outflow boundaries should help generate
more convection in the lower elevations. With the increased moisture
in the air today combined with dust which blew in from near Phoenix
last night partially blocking the sun, temperatures will likely not
reach the previously forecasted highs in many areas. I updated the
forecast for today to make some minor adjustments to cloud cover and
to lower the high temperature forecast a bit in some locations.
.AVIATION...For McCarran...Dust blown in from AZ storms last night
continues to cause lowered visibility at the terminal. With S winds
10-20 kts and gusts to 25 kts expected this afternoon, visibility
may be slow to improve. Models consistently develop convection on
the Spring Mountains by early afternoon moving E/SE into the I-15
corridor through early evening. Slight chance of direct impacts to
the airport, with better chances of impacts in flight corridors and
from outflow winds. Chances of storms continue tonight and Sunday.
For the rest of southern Nevada...northwest Arizona...and southeast
California...Residual dust from AZ storms last night will continue
to lower visibility in southern portions of the region this morning.
Storms expected to develop this afternoon in the high terrain and in
Clark/Mohave Counties with gusty/erratic outflow winds, locally
lowered CIGs, and lightning all threats. Outside of storms, S/SW
winds 10-20 kts with gusts to 30 kts likely through tonight with
strongest speeds this afternoon/evening. Chances of storms continue
220 AM PDT SAT JUL 30 2016
.SHORT TERM...through Monday night.
It`s been an active night across our area as numerous outflow
boundary interactions have sustained convection well into the night.
The strongest of these boundaries was generated from a large
thunderstorm complex in the Phoenix area that pushed northward into
our area and is now beginning to approach the Las Vegas Valley. Wind
gusts in the 30-40 mph range have been common with this feature,
though earlier they produced 50 mph or greater gusts closer to
Laughlin and Lake Havasu. Meanwhile, strong thunderstorms are
ongoing at this hour near the Kingman area where widespread heavy
rain has raised flash flooding concerns.
Atmosphere will remain fairly moist and unstable again Saturday and
Sunday which means storms will stick around through the weekend. In
fact, the large thunderstorm complex that impacted Arizona today has
worked to reinforce the moisture in our area for today. Storms this
afternoon will be capable of strong winds and very heavy rainfall.
Best chances today look to occur in areas not shrouded in morning
cloud cover and in the eastern two-thirds of our forecast area.
.LONG TERM...Tuesday through Friday (From Previous Discussion).
The upper level pattern next week will be characterized by broad,
but low amplitude troughing across the Pacific Northwest and a slow
decrease in the strength of high pressure across the southwest US.
This will result in temperatures near or even slightly below normal.
It will also leave the door open for monsoon moisture and diurnal
convection to continue to impact the region through next week. At
this time, there is little unanimous support for any focusing
features or major pushes that jump out in model guidance. Therefore,
the latest extended forecast has broad-brushed precipitation chances
with the best chances over Mohave County, decreasing to the west.
.FIRE WEATHER...More typical midsummer monsoon pattern expected for
the region with daily chances for thunderstorms and seasonably warm
temperatures. Cloud cover can be expected at times along with a
marked increase in regional humidity values. Thunderstorm chances
will continue next week.
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
significant weather according to standard operating procedures.
Short Term/Fire Weather...Outler
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