High Wind in California, April 24, 2017

Area Forecast Discussion
National Weather Service Las Vegas NV
1148 AM PDT Mon Apr 24 2017

.SYNOPSIS...Springtime winds will continue to affect the
region through Tuesday then make a return appearance later in the
week as weather systems brush by to the north. Expect periods of
high clouds and a brief seesaw in temperatures over the next few
days.
&&

.UPDATE...Freshened up wind forecasts with the commencement of
High Wind Warnings and Advisories that kicked in at noon. No other
changes were needed.
&&

.PREV DISCUSSION... /issued 308 AM PDT Mon Apr 24 2017/

.SHORT TERM...through Wednesday night.

Increasing west to northwesterly flow aloft associated with an area
of low pressure over the Pacific NW will affect the area today and
Tuesday. Shortwave energy riding along an energetic jet will bring
strong winds to the Mojave Desert this afternoon and tonight. The
strongest winds will occur over the western half of San Bernardino
County including the cities of Barstow and Twentynine Palms where
gusts could exceed 60 MPH at times. These winds are forecast to
spread into the eastern half of the county later in the afternoon
but are not expected to be as strong. Driving could be particularly
challenging in San Bernardino County today due to strong gusts and
the potential for reduced visibility from blowing dust and sand. A
High Wind Warning goes into effect at noon for the western and
southcentral portions of San Bernardino County and continues through
tonight. Impacted roadways include Interstate 15 west of Baker,
Interstate 40 west of Ludlow, Highways 247 and 62. A Wind advisory
is in effect for the eastern portions of the county and across
southern Mohave County from noon today through 5 AM Tuesday where
gusts of 40-50 MPH are expected. Further north across the southern
Great Basin, a cold front will make its way south through tonight
with breezy north winds expected on Tuesday over much of the region.
Temperatures today are expected to remain above normal but will be
around 5 degrees cooler than yesterday. Made a fairly big change to
the Tuesday high temperature with the latest model data/MOS guidance
forecasting near to slightly below normal temperatures.

Another shortwave moving from the Pacific NW into the northern Great
Basin could keep locally breezy conditions going in some areas of
the CWA on Wednesday. Otherwise, a rebound in temperatures is
expected with highs topping out a couple of degrees above normal.

.LONG TERM...Thursday through Sunday.

Northwest flow will dominate through Thursday as a developing trough
begins to form early Friday near the four corners. Confidence has
increased on the development of this system as the ECMWF, GFS and
GFSensemble have general good agreement on timing and further
deepening of this trough. As this system develops and deepens, winds
will likely be from the north-northwest and be gusty beginning as
early as Thursday night through most of Saturday. Overall, northerly
flow will continue through Sunday, but is expected to weaken
considerably by Sunday morning as the system moves further east.
There is the possibility of precipitation for portions of northern
Lincoln Co. and northeast Mohave Co. as the low pressure system
develops Friday afternoon through Saturday afternoon. Otherwise, no
other mentionable chances for precipitation after Saturday.
Temperatures are expected to drop by at least 8-10 degrees on
Friday, which is 7-12 degrees below normal. Temperatures will slowly
rebound back up to about normal by Sunday.
&&

.AVIATION...For McCarran...Southwest winds under 10 kts this
morning becoming gusty to 20 kts this afternoon before decreasing
this evening. Periods of scattered high clouds can be expected
through the period.

For the rest of southern Nevada, northwest Arizona and southeast
California....Wind will be an issue again this afternoon and tonight
across portions of the area with the KDAG KEED KIFP and KIGM most
affected. Wind gusting over 50 kt is expected at KDAG with wind
closer to 30-35 kt elsewhere. Periods of scattered high clouds can
be expected throughout the period.
&&

.FIRE WEATHER...Dry and windy conditions will continue into
Tuesday across much of the area. RH values across eastern San
Bernardino and southern Mohave counties, including the lower
Colorado River Valley will be in the 10-15% range. Near Red Flag
conditions are expected as there will be a period, mainly this
evening, where wind will be approaching criteria in these areas. The
windiest times should coincide with a period of increasing RH during
the late evening hours.
&&

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

Update...Steele

SHORT TERM/AVIATION...Salmen
LONG TERM....Kryston

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