Grasshopper Junction, Arizona Weather Forecast Discussion

836
FXUS65 KVEF 210536
AFDVEF
Area Forecast Discussion
National Weather Service Las Vegas NV
1036 PM PDT Sat Sep 20 2025
.KEY MESSAGES...
* Slight chances for showers and thunderstorms will linger through
  the weekend and into the upcoming week.
* Humid conditions will continue, and additional tropical moisture
  could get pulled northward around the middle of the week.
&&
.DISCUSSION...through Friday. Remnant moisture due to Mario still
remains in place over the region, but overall conditions have begun
to dry slightly. Dew points have dropped about 3-8 degrees over the
past 24-hours, but still remain about 150-200% of normal for this
time of year. Overall, we will continue to see some clouds this
afternoon along with an isolated shower over the higher terrain. The
probabilities of any thunderstorms will remain less than 10 percent,
with the greatest threat over northwest Arizona where some weak
instability remains in place. An area of low pressure off the
central California coast will drop south overnight and once again
tap into some tropical moisture. This will bring another increase in
moisture to mainly our far southern areas Sunday with PWATs rising
back to around 1.00-1.50". However, with lack of any forcing this
will mainly translate into increasing chances of light rain across
southern San Bernardino and southern Mohave counties Sunday. There
is some weak instability remaining over southern Mohave County so an
isolated thunderstorm can`t be ruled out.
By Tuesday, if the offshore low begins to move inland as most of the
clusters suggest, there could be another round of enhanced
thunderstorm chances, but exactly where this occurs would be highly
dependent on how far north or south the low is when it moves inland.
At this point, the models suggest another round of showers and
potential thunderstorms moving into western San Bernardino and Inyo
County late Tuesday into Wednesday, but with these cutoff lows,
confidence in the exact location remains uncertain.
&&
.AVIATION...For Harry Reid...For the 06Z Forecast Package...Light
southwesterly winds will continue through early tomorrow morning
when winds will become light and variable before transitioning to
the southeast around mid-morning. Breezy southwesterly winds will
pick up in the afternoon with sustained speeds of 10 to 12 knots
gusting to around 20 knots. During the early afternoon winds will
likely vary between southeasterly and southwesterly before
finally settling in from the southwest around mid-to-late
afternoon. These breezy southwesterly winds will continue into
the evening when wind gusts will drop off with winds continuing to
maintain a southwesterly direction through the evening. VFR
conditions will prevail with mid-to-high clouds pushing into the
area during the afternoon and sticking around through the evening.
For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...Overall, winds will
remain relatively light, 12 knots or less, and will follow typical
daily directional trends through late Sunday morning/early Sunday
afternoon when breezy southerly to southwesterly winds will pick
up with wind gusts around 15 to 25 knots. Areas south and east of
the Interstate 15 corridor will see a band of showers move through
beginning tomorrow morning and continuing through early Monday
morning. The Colorado River Valley TAF sites are the most likely
to see vicinity showers with the potential for light rain showers
starting tomorrow afternoon. Low confidence as to whether showers
will get close enough to DAG to have any impacts, but if DAG were
to see impacts it would likely be between mid- morning and
afternoon. Increasing mid and high clouds aoa 10 kft will
accompany these showers.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
DISCUSSION...Gorelow
AVIATION...Stessman
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NWS VEF Office Area Forecast Discussion