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Area forecast discussion 
National Weather Service Las Vegas Nevada
1024 am PDT Tuesday Jun 2 2015

dry and seasonable conditions are expected through Wednesday with
afternoon breezes and variable high clouds. A vigorous low
pressure system could bring a return of cool and unsettled weather
to the region later this week.

Aviation...for McCarran...winds will turn more southerly and pick
up again by this afternoon. Sustained winds are expected to range
between 10-15 kts with gusts to around 20 kts before tapering off
later tonight. A mostly clear sky is expected.

For the rest of southern Nevada...northwest Arizona...and southeast
California...southwest winds will prevail again today at most taf
sites with sustained winds ranging from 10-15 kts with gusts 20-
25kt. Kbih will see typical diurnal wind patterns today. All areas
will see a mostly clear sky through this evening.

Previous update...
issued at 937 am PDT Tuesday Jun 2 2015

Update...just a quick update to align the near-term forecast to
current observations. Temperatures are running several degrees
cooler than this time yesterday. Latest guidance supports the
running forecast of near normal temperatures this afternoon. Our focus will
be the approaching low pressure system for Friday through this
weekend. Taking a quick look at the 12z GFS, it is aligning more
with the European model (ecmwf). This would be a drier solution for our area.

Previous discussion...
327 am PDT Tuesday Jun 2 2015

Short term...Tuesday through Thursday afternoon.

Mean southwesterly flow will prevail across the area through early
Thursday...allowing several weak embedded shortwaves to traverse the
area. This will yield breezy conditions across the Mojave Desert and
portions of the southern Great Basin as moisture and wind profiles
will again be favorable to mix wind aloft to the surface. Outside of
wind...high resolution guidance indicates cumulus developing in the
southern Sierra Tuesday and Wednesday afternoon. Available moisture
and instability in these areas during this timeframe supports that
forecast...thus increased cloud cover in the southern Sierra and
over areas east of cirrus is expected to advect
downstream into the evening hours on both days. Temperatures are
expected to run right around average for early June area-wide
through Wednesday.

Operational guidance remains in good agreement in the overall
pattern transitioning on a vigorous shortwave dives
into northern California and forms a closed low. Guidance
continues to deepen this low Thursday afternoon as it digs south-
southwestward toward the Southern California coast. As a
result...kept the mention of a chance of afternoon showers and
isolated thunderstorms in the southern Sierra Thursday there will be sufficient moisture...lift...and
enough instability to support development. The rest of the area
will see increasing cloud cover ahead of the system on
Thursday...which will cool temperatures to below average once

Long term...Thursday night through Monday. Main problem through the
period /and perhaps beyond/ will be the tropics. Models have come
into pretty good agreement in the Thursday night/Friday time frame
with the interaction between the upper level low digging over
California and the moisture plume being drawn up from
Andres...depicting the plume focusing over Arizona Thursday night
then wrapping around the northeast semicircle of the low into the
southern Great Basin on Friday. The 00z deterministic models agree
on a dry slot over southeast California...but left slight chance
probability of precipitation there due to uncertainty in the exact position of the moisture
plume and the upper low. Disagreement starts to increase a little on
Saturday...but the Main Point is that the upper low will still be
wobbling around and there will be plenty of moisture available to
justify slight chance to chance probability of precipitation areawide. By Sunday there is
model consensus on most of the moisture wrapping around the
northwest semicircle of the low and dry slotting wrapping around the
southeast semicircle over much of our County Warning Area. Took a cautious approach
and showed probability of precipitation ending over the southern County Warning Area but continuing north of
Las Vegas. For Monday there is consensus on the upper low lifting
away to the north...but all eyes turn back south as Blanca is
forecast to be moving north somewhere over the Baja California by that time.
Could be more tropical trouble next stay tuned.

Spotter information statement...spotters are encouraged to report
any significant weather conditions according to Standard operating


short term...pullin
long term...Morgan

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