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fxus65 kvef 230030 
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Area forecast discussion
National Weather Service Las Vegas Nevada
530 PM PDT Thu Jun 22 2017

Synopsis...the heat wave will remain over the region through the
weekend and into early next week. The excessive heat warning is in
effect through Monday evening. Isolated thunderstorms will be
possible over the southern Sierra each day while dry conditions
persist elsewhere.
&&

Update...fairly extensive area of cumulus development across
Lincoln and central Nye counties late this afternoon. Not seeing any
evidence of rainfall reaching the ground and humidity is extremely
low, so I do not expect any measurable precipitation with that
activity this evening. I did update to increase sky cover for the
00z-06z time frame however, based on satellite trends. -Harrison-
&&

Previous discussion...
317 PM PDT Thu Jun 22 2017

Short term...tonight through Sunday.

The upper level ridge will persist through the short term and
near-record temperatures can be expected through Monday. A very
weak disturbance will continue to move west towards an upper
level low in the east Pacific. This will nudge a ridge in the
Pacific eastward which will merge with the ridge over the
southwest tomorrow. The elongated ridge will suppress breezy
afternoon winds through Saturday, before a breezy southwest wind
develops ahead of a weak upper trough on Sunday. With the lighter
winds, temperatures were nudged down a degree or two on Friday and
Saturday as mixing heights are expected to be slightly lower.

Marginal instability and moisture along the crest of the Sierra
may support a few isolated thunderstorms each afternoon. Some
instability in northern Lincoln and central Nye counties will
support cumulus development this afternoon and Sunday. Elsewhere,
clear skies and dry conditions are expected.



Long term...Monday through Thursday.

It looks like winds will pick up on Monday as a shortwave moves into
northern California. Wind speeds at this time are not forecast to be
significant and wind related hazard products are not anticipated.
The "blow dryer" effect will be in full force however with hot
temperatures expected to linger into the beginning of the work week.
The shortwave will cross over the northern Great Basin Monday night
and Tuesday with less wind expected on Tuesday. With high pressure
suppressed to the south of US, temperatures are expected to be "less
hot" by a couple of degrees. Model temperature blends have highs on
Tuesday in Las Vegas under 110 degrees which would bring an end to a
long string of 110+ degree days here in the valley. The GFS keeps
suppressing high pressure to our south on Wednesday while the ec
and CMC have ridging beginning to build back over the area. The
difference is of little consequence however with guidance based on
the GFS/ec model solutions forecasting similar temperatures
running 3-6 degrees above normal.

Otherwise, dry and clear per the norm for this time of year.
&&



Aviation...for McCarran...gusty south to southeast winds will
become predominantly southwest by 22-23z and continue into the
evening...losing the gusts by 03 and decreasing to light and
variable by daybreak. Hot temperatures will continue through Monday
with afternoon highs at or above 110 degrees. A few clouds to the
north otherwise clear with VFR conditions through the period.

For the rest of southern Nevada, northwest Arizona and southeast
California...west/southwest winds gusting 20-25 knots will continue
across the Mojave Desert region into the early evening then decrease
overnight. Isolated thunderstorms are possible over the southern
Sierra in the evening. Elsewhere expect few to sct clouds kbih and
east across the southern Great Basin with clear conditions across
the Mojave Desert.
&&



Fire weather...hot and dry conditions are expected for the next
several days. Gusty west/southwest winds of 20-25 miles per hour can be
expected over far southern Nevada and northwest Arizona through
the afternoon and early evening. Winds expected to become lighter
across the southern Great Basin and Mojave Desert Friday and
Saturday. Breezy southwest winds of 10-15 miles per hour develop Sunday and
Monday afternoons. Isolated thunderstorms will be possible over the
southern Sierra each afternoon into the weekend.
&&



Hydrology...creek, stream and rivers along the eastern Sierra
slopes of Inyo County as well as the Owens Valley will be flowing
high and fast this week. Specifically, Rock Creek, Big Pine creek
and Independence Creek have seen a significant rise in flows since
Saturday. Minor flooding could occur near creeks as well as a few
low water crossings on some roadways. Remember, never driver through
flooded roadways or around barricades. Also, pastureland or farmland
adjacent to creeks, streams or rivers could experience areas of
standing water.
&&



Climate...
near record to record high temperatures will be possible each day
through Friday. The current record of consecutive days above 110
degrees in Las Vegas is 10 days (1961), and for 115 degrees, 4 days
(2005).

Las Vegas, Nevada climate

Forecast high temps (f) daily record Max temps (f)
Thursday (6/22): 114 115 (1954)
Friday (6/23): 111 113 (1959)
Sat (6/24): 111 113 (1961)
sun (6/25): 112 115 (1970)

Forecast low temps (f) daily record high min temps (f)
Thursday (6/22): 90 87 (2016)
Friday (6/23): 89 86 (2011)
Sat (6/24): 88 85 (2016)
sun (6/25): 88 86 (1974)
&&



Spotter information statement...spotters are encouraged to report
any significant weather or impacts according to Standard operating
procedures.
&&

$$

Short term/fire.......Boothe
long term/aviation....Salmen

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