439
FXUS65 KVEF 150823
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
123 AM PDT Wed May 15 2024


.SYNOPSIS...An upper low morning from southern California into
Arizona today will keep limited moisture and instability over our
region, leading to isolated light showers or sprinkles along with
a few thunderstorms through Wednesday. An eastern Pacific ridge
nosing inland will bring even warmer weather by Friday with highs
climbing around 10 degrees above normal. A slight cooling trend
with increasing southwest winds develops late this weekend into
early next week.
&&

.SHORT TERM...through Thursday Night.

The area will remain in a sandwich area between the ridge building
to the northwest and an area of low pressure sliding through
southeast California into Arizona today. This afternoon`s weather
set up with be similar to yesterday just everything shifted
southeast. Expecting dry conditions through the morning before
scattered showers and isolated thunderstorms develop this afternoon
in response to decent lift in a convergence zone linking up with low
end moisture and instability. Showers and thunderstorms should
favor the terrain in areas southeast of the I-15 this afternoon
which may or may not blow off into the surrounding valley late in
the afternoon or the evening. There is a consistent signal across hi-
res short term models for precipitation to congeal into southern
Mohave County and eastern San Bernardino after 5PM. Impacts from
precipitation will remain low as instability and moisture are low,
however the very dry low levels will bring the chance for sudden
gusty outflow winds from showers and thunderstorms. DCAPE over
1000J/KG and inverted-v type soundings support this potential, with
sudden winds gusting 40 to 50 MPH possible at times.

Precipitation will slowly diminish after sunset, with things ending
by midnight at the latest.High pressure will build in tonight and
Thursday behind the low pressure as it exits to the east. Once
precipitation ends tonight, dry conditions are expected for the rest
of the week. Temperatures will slowly warm today and Thursday with
above normal temperatures expected for most locations. Moderate heat
risk is expected by Thursday in many valley locations of southeast
California into the lower Colorado River Valley due to persistent
warm temperatures including overnight. Anyone with outdoor plans
should be prepared for the heat with extra water, especially if you
plan on being outdoors with no way to escape the heat for a
prolonged time.

.LONG TERM...Friday through next Wednesday.

A growing ridge over the eastern Pacific will continue to grow over
the western United States late-week into the weekend. Temperatures
will remain 10 to 12 degrees above seasonal averages, with desert
valleys increasing to "Moderate" HeatRisk. Chances of Las Vegas
measuring its first 100F of the year continue to waffle on Friday
and Saturday, with a current NBM4.1 percentage of 30% on Friday and
10% chance on Saturday.

ECMWF ensemble means and GFS ensemble means are in fairly good
agreement regarding a pattern shift over the weekend into the start
of next week. The ridge over the eastern Pacific will start to
deteriorate as a longwave trough over the north-central United
States starts to sag. Meanwhile, a weak closed low will meander
eastward into the northern Baja Coast this weekend, with both sets
of ensemble means indicating that this low will open up and phase
with the longwave trough. As such, expect breezy afternoon winds
each day through the weekend into the start of next week. Details
regarding precipitation and temperature will come more clear as we
move through the work week.
&&

.AVIATION...For Harry Reid...Light, generally southwest winds
are expected for the remainder of the overnight hours. Winds are
expected to shift to a northeast direction after 17z with speeds
generally between 6-10 knots with only a 10-15% chance of sustained
winds reaching over 10 knots. We are expected to see some isolated
convection develop late morning and afternoon with cloud bases AOA
12k feet. There is a slight chance of showers/thunderstorms reaching
the valley along with any associated outflow. If any outflow winds
do occur, we could see winds between 25-35 knots. Convection will
diminish after sunset.

For the rest of southern Nevada, northwest Arizona and southeast
California...Most areas will see winds less than 10 knots through
this afternoon with the exception of KDAG where west winds will be
between 10-15 knots. Expect to see isolated showers and
thunderstorms over portions San Bernardino, Clark, and Mohave
Counties between 19z-01z this afternoon. The main impact from these
showers/storms will be gusty outflow winds where wind gusts up to 40
knots will be possible.
&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

$$

SHORT TERM...Nickerson
LONG TERM...Varian
AVIATION...Gorelow

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