High Wind in Wyoming, November 23, 2017

Area Forecast Discussion...Updated
National Weather Service Billings MT
806 PM MST Thu Nov 23 2017

.UPDATE...

Extended wind highlites for western foothills through 6am. This
coincides when the cold front and gusty post-frontal winds should
be completely through these areas. Until then expect winds to
increase through about midnight tonight over western zones then
begin to trend downward overnight as showers and cold front move
through weakening pressure/thermal gradient there.

Increased winds over the Sheridan foothills overnight and already
seeing some mountain wave activity in this area. Temperatures
jumped 10 to 15 degrees over the past hour and dew points have
fallen into the 20s as downslope subsident warming increases due
to the descending winds. Do not expect warning type winds but
gusts to around 45 mph seem reasonable for the higher
hills/foothills over eastern Sheridan county, with gusts to 35 mph
in the valleys including Sheridan. Drivers on I-90 south of Crow
Agency should be prepared for sudden gusty crosswinds through the
night.

Precipitation chances still look good late tonight into tomorrow
morning along the cold front, but duration looks to be short-lived
outside of the mountains and foothills. Adjusted precipitation
chances for latest timing trends didn't make much change to
percentages. Chambers

&&

.SHORT TERM...valid for Fri and Sat...

Record highs and windy conditions prevail today. Will see a quick
shot of precipitation tonight then breezy and seasonably mild
through rest of weekend.

We did issue a high wind warning this afternoon from Big Timber to
Judith Gap as winds were trending up in this area. Proggs
indicate 700mb max of nearly 65 kts over this area through 5 PM.
Winds will decrease during the evening with warning expiring at
11 pm. Though winds may diminish earlier than that, we wanted to
give it plenty of room to subside.

Winds further south across I-90 from Livingston to Big Timber and
down into the Beartooth foothills are hitting 55-65 mph at this
time. We expect these winds to decrease by 11 pm as front goes
through and disrupts tight pressure gradient.

We do expect to see a band of precipitation develop and drop
quickly south across our CWA tonight. Strong frontogenesis pumped
by jet dynamics aloft will provide plenty of brief intense
forcing. The quickness of the front and accompanying downslope
winds off the Bull Mountains may limit overall precip at Billings.
Temps remain pretty mild, so we still think we will not see much
if any snow or mixed precip at the lower elevations.

Dry high pressure will dominate Friday. Breezy conditions are
expected in afternoon. Temps remain seasonably mild into Saturday.
Winds pick up again Saturday night in our west ahead of next
frontal system. BT

.LONG TERM...valid for Sun...Mon...Tue...Wed...Thu...

Ensembles and deterministic models still showed uncertainty with
the system that will affect the area on Monday. Also noted there
was quite a bit of temperature spread in the GEFS Plumes from Mon.
onward. Models blends gave high temperatures near normal from
Monday through Thursday, which was a cooler scenario than
previous forecasts.

High pressure ridging will be over the area on Sunday. Winds will
be fairly strong aloft central and W, but GFS soundings showed a
steep low-level inversion which will keep the winds from mixing
down. However, gap flow is possible through the day into the
evening. At this time, this flow does not look overly strong.
Sunday will be the warmest day of the period with highs in the low
to mid 60s. The next Pacific wave moves into the area while
splitting on Monday. The GFS was faster with the wave than the
ECMWF. As a result, the GFS brings the cold front through the area
by 12Z Monday, while the ECMWF holds the front back over the
western/central zones. As a result of the differences, there were
differences in QPF timing and placement through Mon. evening.
Sunday will be dry, then PoPs increase over the central and W Sun.
night per model blends. Kept PoPs across the area Mon., then moved
them out late Mon. night. This system looked too warm for any
impactful snow.

Upper ridging moves in for Tuesday, then the flow flattens out
Wednesday. There was model disagreement for Thursday, but kept the
forecast dry for now. Expect some periods of wind W of KBIL for
Tue. and Wednesday. Arthur
&&

.AVIATION...

Wind gusts will peak this evening at LVM, 50 to 60 kts as cold
front slides through the area. Light precip and some possible MVFR
CIGS along the front as it impacts LVM, BIL, and SHR late tonight
into the morning hours. Gusts 30 to 40 kts possible along the
cold front at BIL, SHR and MLS. Prior to the frontal passage and
stronger winds mixing to the surface, LLWS expected at MLS. Winds
remain gusty behind the front at KSHR into early Friday. Winds
taper off at LVM by morning, but remain breezy across the area
Friday with VFR conditions expected. Walsh

&&

.PRELIMINARY POINT TEMP/POPS...

    Fri     Sat     Sun     Mon     Tue     Wed     Thu
-----------------------------------------------------------
BIL 039/053 031/052 036/062 039/049 030/045 029/046 028/042
    61/N    00/U    00/B    23/W    20/U    00/B    11/B
LVM 037/048 030/050 038/061 038/044 026/042 026/041 024/040
    81/N    00/N    11/N    44/W    21/N    00/N    10/N
HDN 038/054 027/052 033/064 036/052 027/047 025/046 025/045
    51/U    00/U    10/B    13/W    30/U    00/B    11/B
MLS 039/053 028/051 031/061 037/051 027/044 025/046 025/041
    40/N    00/U    01/B    12/W    31/U    00/B    11/N
4BQ 041/052 027/053 033/064 038/052 027/044 026/046 026/043
    51/N    00/U    00/B    13/W    31/U    00/U    11/B
BHK 039/051 026/050 027/062 035/051 023/042 023/044 022/040
    40/N    00/U    01/B    12/W    31/N    00/U    11/N
SHR 037/052 026/053 031/066 035/050 024/043 023/045 023/043
    53/W    00/U    00/B    13/W    40/U    00/U    11/B

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...High Wind Warning in effect until 6 AM MST Friday FOR ZONES
      28-41-63.
     Wind Advisory in effect until 6 AM MST Friday FOR ZONES
      65-66.
WY...None.

&&

weather.gov/billings

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
228 PM MST THU NOV 23 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0100 PM     NON-TSTM WND GST 3 ENE LIVINGSTON        45.69N 110.50W
11/23/2017  M58.00  MPH      PARK               MT   DEPT OF HIGHWAYS

0108 PM     NON-TSTM WND GST 6 ENE LIVINGSTON        45.70N 110.45W
11/23/2017  M63.00  MPH      PARK               MT   ASOS

&&

RMS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS MT
326 PM MST THU NOV 23 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0954 AM     NON-TSTM WND GST 3 WSW NYE               45.41N 109.87W
11/23/2017  M54.00  MPH      STILLWATER         MT   MESONET

0115 PM     NON-TSTM WND GST 6 WSW RED LODGE         45.16N 109.36W
11/23/2017  M53.00  MPH      CARBON             MT   UNKNOWN

0118 PM     NON-TSTM WND GST 17 S FORT SMITH         45.07N 107.89W
11/23/2017  M64.00  MPH      BIG HORN           MT   UNKNOWN

0122 PM     NON-TSTM WND GST 3 W FISHTAIL            45.46N 109.57W
11/23/2017  M52.00  MPH      STILLWATER         MT   UNKNOWN

0212 PM     NON-TSTM WND GST 17 NE WILSALL           46.16N 110.38W
11/23/2017  M66.00  MPH      PARK               MT   UNKNOWN

&&

TRC