Expires:No;;137612
FXUS65 KVEF 040334
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
735 PM PST Tue Dec 3 2024

.SYNOPSIS...Dry conditions, above-normal temperatures, and light 
winds expected through the week. The exception will be along the 
Colorado River Valley where gusty northerly winds will increase wave 
heights on Lake Mohave each afternoon. Late-weekend into early next 
week, a pattern change will drop temperatures and increase northerly 
winds across the forecast area.
&&

.UPDATE...Scattered mid and high-level clouds will continue to 
stream across the region through the evening as a weak area of low 
pressure moves into Arizona.  Low-level moisture has been limited, 
but there was enough at mid-levels to generate a few areas of virga 
late this afternoon and early evening across southern Nevada.  Any 
lingering areas of virga will dissipate by late evening, and 
lingering clouds will help to keep temperatures several degrees 
above normal overnight.  No changes were needed to the forecast 
grids this evening. 

.DISCUSSION...Today through next Tuesday.

No major changes to forecast thinking through the period. A weak 
area of low pressure will usher inland today. The primary impact 
from this low has been partly-to-mostly cloudy skies, but they've 
resulted in stunning sunrises and sunsets over the last few days. As 
the low meanders inland this evening, these clouds will clear out of 
our area, resulting in sunny skies through the rest of the week into 
the weekend. Additionally, the increased north-south surface 
pressure gradient over the Colorado River Valley due to this low 
progression has resulted in elevated north winds and wave heights 
between 1 and 2 feet at Lake Mohave. These winds and waves will 
continue each afternoon through the week as the low remains situated 
overhead thanks to a Rex Blocking pattern (longwave ridge of high 
pressure across the western CONUS effectively locking the weak low 
in place to its south). These elevated 500 mb heights are the cause 
for our above-average temperatures through the week.

Friday, a weak shortwave will move through the upper level flow, 
which will effectively break down the blocking pattern aloft. No 
major impacts from this shortwave, but expect elevated winds along 
the lower Colorado River Valley between Bullhead City / Laughlin and 
Needles with a 60-70% chance of 40 mph north winds. The temporal and 
spatial extent of these winds may be too minor to warrant a full 
Wind Advisory, but will continue to assess the need for a wind-
related product as the week progresses.

Finally, a pattern shift is expected late-weekend into early next 
week. A broad open wave will move southeastward along the eastern 
flank of the western CONUS ridge through the Intermountain West - 
taking an "Inside Slider" trajectory. Exact depth / position of this 
system as it pushes through the southwestern states remains 
uncertain, but expect a drop in temperatures back to at-or-below 
average as well as increased northerly winds across southern Nevada, 
northwestern Arizona, and southeastern California. The latest NBM 
shows a widespread 25-35% chance of gusts over 40 mph, with 60-70% 
chance along the Colorado River Valley. To the Las Vegas dry 
streak's dismay, this system is expected to be dry, with no 
precipitation expected. Today marks the 143rd day without rain, 
assuming 0 rain falls today (which is the expectation).
&&


.AVIATION...For Harry Reid...Light winds following typical daily 
trends are expected through tomorrow evening. SCT to BKN high clouds 
are expected overnight and will gradually clear Wednesday morning.

For the rest of southern Nevada, northwest Arizona and southeast
California...Light winds will prevail for all TAF sites outside of 
the Colorado River Valley through Wednesday evening. Meanwhile, 
northerly winds of over 10 knots with gusts of 15 to 25 knots are 
expected along the Colorado River Valley, which includes KEED and 
KIFP. SCT-BKN high clouds will remain over the area overnight and 
gradually clear Wednesday morning.
&&


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

&&

$$

UPDATE...Planz 
DISCUSSION...Soulat 
AVIATION...Outler

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