390 
FXUS65 KVEF 081757
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1057 AM PDT Wed May 8 2019

.SYNOPSIS...Mostly dry conditions are expected Wednesday before a
low pressure system develops and then lingers off the California 
coast through the weekend. Periods of shower and thunderstorm 
activity along with cooler temperatures can be expected. 
Conditions will dry out and temperatures will climb early next 
week. &&

.UPDATE...Mostly dry and mild weather is expected today. An 
isolated shower or thunderstorms cannot be ruled out this 
afternoon mainly along the higher terrain of southern NV and
northwest AZ, but for the most part the lingering moisture will 
likely result in towering cumulus. Increasing moisture and chances
for scattered showers and thunderstorms will begin tomorrow 
morning mainly after 10am-11am with the best chances for 
widespread precipitation in the afternoon through the evening. 
Besides storm chances, breezy north winds will overspread the 
region today with lighter winds expected tomorrow. With any nearby
thunderstorm activity, erratic and gusty winds will be possible. 
All of this is being captured with the current forecast and no 
updates are necessary this morning. 

&&

.PREV DISCUSSION... /issued at 150 AM PDT Wed May 8 2019/ 

.DISCUSSION...through next Tuesday. 

A few showers linger early this morning as a vigorous shortwave
and some marginal instability combined to produce widespread
shower and isolated thunderstorm activity earlier this evening.
Showers will continue to diminish and push eastward the remainder
of the morning hours with generally dry conditions expected for
Wednesday. Can't rule out a stray terrain driven shower across
Lincoln or Mohave counties this afternoon but coverage and
intensity should be quite limited. Temperatures this afternoon 
should rebound to near seasonal normals.

The improved conditions won't last however as a shortwave over the
Northern Rockies digs southward Thursday before retrograding and 
forming a closed low of the California coast Friday. The result
will be a period of marked storminess across our forecast area,
which will linger through the weekend. Precipitable water values 
by Thursday afternoon are projected to be in the 0.75-1.0" range 
across the Mojave desert region, which will combine with 
increased forcing and cooling aloft to produce numerous showers 
and storms Thursday. Model guidance continues to struggle on the 
best timing and locations for this activity, but right now it 
looks like Thursday afternoon through late evening will be quite 
active across areas for areas north of I-40. Locally heavy 
downpours and gusty winds will be the primary threats along with 
the potential for lightning. 

Shower chances will continue Friday and into the weekend as the
closed low digs off the California coast and periodic impulses
rotate around the low invigorating precipitation chances. Despite
the fact that this is climatologically the driest part of the 
year, periods of widespread light to locally moderate rainfall 
still looks quite promising, though timing remains the key issue. 
Continued to keep Slight chance/chance wording of shower activity
in the forecast through Sunday as the low remains in our 
vicinity.

By Monday, the low will begin to shift east towards the Four 
Corners which will mark the beginning of a drying trend. However,
with abundant low level moisture lingering behind the storm 
system and no strong fronts to scour the moisture out, we may 
still have at least a few terrain driven showers persisting Monday
and Tuesday afternoons with warming temperatures under the 
influence of increased ridging aloft. 

&&

.AVIATION...For McCarran...Light north-northeasterly winds will set 
up after sunrise with brief bouts of easterly winds possible through 
the early-morning hours. Late-morning, winds will shift to be more 
north-northwesterly hovering around 8-12 kts through the early 
afternoon. Winds will become light and variable late-afternoon 
through sunset and remain light through the overnight hours with 
some northerly tendencies. Scattered-to-broken high clouds expected 
through the TAF period.

For the rest of southern Nevada, northwest Arizona and southeast 
California...The early-morning hours will be characterized by light 
and variable winds across the region. However, by midday, we will 
see a push of north-northwesterly winds extend southward through the 
CWA with speeds 8-12 kts that will stay in place through the 
majority of the afternoon. Early evening, these winds will quickly 
deteriorate, becoming light and variable overnight. The exception 
will be residual gusty west winds that will loiter in the western 
Mojave Desert and impact KDAG until around 06z. Scattered-to-broken 
high clouds expected through the TAF period.

&&

.SPOTTER INFORMATION STATEMENT...Spotter activation may be 
required as an unseasonably active pattern takes hold of the 
region. Thunderstorm chances look greatest Thursday and/or Friday
though sporadic activity will linger through the weekend. 

&&

$$
UPDATE...Kryston
DISCUSSION...Outler
AVIATION...Varian

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