922
FXUS65 KVEF 261853
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1153 AM PDT Wed Jun 26 2024

.SYNOPSIS...Monsoon moisture will continue to fuel showers and
thunderstorms across the southern Great Basin and northwestern
Arizona this afternoon. Highest flash flood threat remains in
northwestern Arizona and highest damaging wind gust threat will be
in the southwestern Great Basin. Precipitation chances will continue
to dwindle through Friday as breezy winds return and hot
temperatures persist heading into the next work week.
&&


.SHORT TERM...Today.

Another round of isolated showers and thunderstorms expected this
afternoon with widespread PWATs in excess of 1 inch across the
forecast area. That said, thunderstorm coverage will not be as
widespread as yesterday. Convection today will favor the higher
terrain of northwestern Arizona and the southern Great Basin in the
absence of synoptic forcing. CAPE values range from 500-750 J/kg in
these areas, though DCAPE approaches 1000 J/kg this afternoon in the
southwestern Great Basin - according to forecast HRRR soundings. As
such, the highest threat of flash flooding will remain across
northwestern Arizona and the highest threat of damaging wind gusts
will be across the southwestern Great Basin.

Afternoon temperatures today will range from 5 to 7 degrees above
seasonal averages. The monsoonal moisture in place has allowed
overnight low temperatures to remain fairly warm - with Las Vegas
low temperatures failing to drop below 90 degrees for the last 3
nights.

.LONG TERM...Thursday through Tuesday.

Shower and thunderstorm chances continue to dwindle on Thursday as a
shortwave originating from the Pacific Northwest ushers dry air into
the region. As the axis of this shortwave pushes through the Desert
Southwest, breezy southwest wind gusts will pick up Thursday and
Friday afternoons to between 25 and 35 mph. These winds coupled with
this dry air will increase fire danger each afternoon - particularly
along a strip from Barstow-Daggett through Las Vegas into St. George.

A zonal flow will set up aloft over the weekend. Additional
shortwave passages will result in breezy afternoons each day through
the weekend into the start of next week. Monsoonal moisture will ebb
and flow into Arizona, resulting in a fluctuation of PoPs for Mohave
County through the weekend. Meanwhile, heat remains a persistent
impact in the Desert Southwest. Temperatures will remain above-
average through the entire forecast period with HeatRisk remaining
"Moderate" or higher for desert valleys through the week and
weekend. Las Vegas remains on-track for hottest June on-record.
Current record hottest June is 2017 with an average temperature of
92.8 degrees.
&&


.AVIATION...For Harry Reid...Southerly winds with a few gusts to
25kts are expected late this afternoon through early evening.
Wind gusts should diminish after sunset with a chance (30%) that
winds could fall below 10kts between 05Z and 09Z. Gusty south to
southwest winds will redevelop tomorrow morning, with gusts to
25kts likely after 19Z. A few isolated thunderstorms are expected
once again this afternoon and early evening. However, most of the
activity should be concentrated away from the field over northwest
Arizona, and only a slight chance of an outflow impacting the
terminal exists today. Away from areas of convection, VFR
conditions will prevail through tomorrow.

For the rest of southern Nevada, northwest Arizona and southeast
California...Breezy south-to-southwest winds with a few gusts to
25kts are expected at the Las Vegas and Colorado River TAF sites
this afternoon and early evening.  Winds will diminish overnight,
potentially falling to below 10kts at times, before increasing again
on Thursday. At KBIH, northerly winds will turn west to southwest
by late afternoon but will swing back to the north after sunset.
Winds at KDAG will favor a westerly direction through tomorrow,
with gusts approaching 30kts by tomorrow afternoon. Scattered
thunderstorms are expected to develop this afternoon and evening
over northwest Arizona and the higher terrain of the southern
Great Basin. This activity is not expected to impact any of the
regional TAF sites, but gusty winds, lightning, and heavy rainfall
obscuring terrain will be possible in and near storms that do
develop.
&&


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

&&

$$

DISCUSSION...Soulat
AVIATION...Planz

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