Grasshopper Junction, Arizona Weather Forecast Discussion

889
FXUS65 KVEF 191704
AFDVEF
Area Forecast Discussion
National Weather Service Las Vegas NV
1004 AM PDT Fri Sep 19 2025
.KEY MESSAGES...
* Tropical moisture will fuel chances for more showers and
  thunderstorms today.
* Slight chances for showers and thunderstorms will linger through
  the weekend, with more uncertainty next week as additional
  tropical moisture could get pulled northward.
&&
.DISCUSSION...through Thursday. Thunderstorms are still active as of
this typing so will keep it brief. Storms will slowly track north
through the morning, with new development possible farther south in
the dry slot this afternoon, favoring the mountains. Friday night
through the weekend should be more of a low-grade monsoon pattern,
with storms developing over the mountains in the afternoons and
dissipating after sunset. The new cutoff low developing off the
central California coast will be the wild card for the upcoming
week. If and when this low moves east, it will tap into moisture
still lingering in our area and/or pull up more moisture from the
tropics, setting off another round of showers and storms. There is a
lot of model disagreement on whether and when this happens, as well
as how far north or south the low might be if and when it occurs, so
confidence in next week`s forecast is extremely low. The main
message is that thunderstorm season isn`t quite done yet.
&&
.AVIATION...For Harry Reid...For the 18Z Forecast Package...Isolated
to scattered thunderstorms are expected to develop in the vicinity
of the terminal after 20Z, with far less areal coverage compared to
yesterday. Most likely, thunderstorms and impacts will remain
outside the terminals, with the highest risk for convective impacts
being at KHND. Storms today could produce sudden gusty winds, heavy
rain, and CIGs to 7000ft. Convection will wane after 00Z, and are
not expected to redevelop on Saturday. Breezy southeast winds are
expected today with gusts 15-20KT expected. Moderate confidence in
direction, though variability between 120-180 degrees (true) is
possible. Southwest winds at 8KT or less will return around sunset
before winds become light and variable once overnight. VFR
conditions will persist as SCT-BKN clouds around 10kft before clouds
clear tonight.
For the rest of southern Nevada, northwestern Arizona and
southeastern California...For the 18Z Forecast Package...Isolated to
scattered showers and thunderstorms return to the region this
afternoon across southern Nevada into western Arizona as well as in
northern Inyo. CIGs to 5000ft, heavy rain, sudden gusty winds, and
lightning possible with any storms today, with KBIH having the
highest chances for direct impacts at a TAF site this afternoon.
KDAG, KEED, and KIFP should not see thunderstorms today as areal
coverage is expected to be too sparse to include in the prevailing
TAF. Convection will quickly diminish after sunset. Typical diurnal
winds trends are expected today and tonight outside of thunderstorm
influence. Southeast gusts up to 20KT are possible at KBIH this
afternoon but will wane after sunset. VFR conditions will persist as
SCT-BKN clouds around 10kft before clouds clear tonight.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
DISCUSSION...Morgan
AVIATION...Nickerson
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NWS VEF Office Area Forecast Discussion