953 
FXUS65 KRIW 240933
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
233 AM MST Fri Nov 24 2017

.SHORT TERM...(Today through Sunday night) Issued at 210 AM MST 
Fri Nov 24 2017

The high wind warning continues through 5 am for the Absaroka 
mtns/Cody Foothills as well as the Green mtns through 5 am this 
morning. 60 knot winds at 700mb ahead of a southeast bound trough 
now over Montana and Idaho will surface during this time frame 
along with a 4.5/30 decimeter height lines at 700mb, as well as a
9 mb sfc pressure gradient between GCC and RKS to produce these 
winds in these areas. In addition, there appears to be a gravity 
wave pushing southeast ahead of the main trough. This wave is seen
seemingly gobbling up the lee enhanced clouds from nw to se. This
wave produced 40 to 50 mph wind gusts in Johnson County and now 
that it is exiting our CWA, this wave just produced an all time 
record wind speed of 95 mph at the Camp Creek RAWS in the Green 
Mtns between 11 amd and 12 midnight earlier this evening. In the 
next couple of hours, rain showers should break out in far Western
Wyoming with snow levels dropping down to about 7000 feet after 
sunrise this morning. We should see a quick shot of 3 to 6 inches
of snow above 7500 feet along with 9 inches above 10K in the 
higher Tetons. Rain will fall below 7000 feet but it will take a 
while for these elevations to cool down. Currently the 
temperature in Jackson is a balmy 50 degrees along with a warming 
southwesterly 36 knot wind gusts out ahead of the approaching 
trough. We should witness an additional spike in the winds in 
many areas between 12 and 15z this morning with the 5mb 3 hourly 
sfc pressure rises just behind the cool front. Some rain and 
mountain snow will spread across Northern Wyoming this morning as 
well but with less QPF. Up to 3 inches of snowfall is expected 
along the higher Big Horn Mtns. Clearing will take place from 
northwest to southeast early this afternoon along with partial 
clearing in the far west after mid afternoon. Only spotty showers 
are expected through the rest of the weekend in the far west if 
any. Temperatures will cool slightly Saturday along with warming 
on Sunday as the ridge rebuilds over the area. The next shortwave
will move in from the west southwest on the back side of the ridge and
produce an inch or two of snow in the far west Sunday night.

.LONG TERM...(Monday through Friday) Issued at 210 AM MST Fri Nov
24 2017

The ECMWF was the first to pick up on this last night but it now 
appears the Monday system will be splitting as it approaches 
leaving us with a weakened system. Still a shot of mountain snow 
out west Monday with rain or rain/snow in the far west lower 
elevations. Much warmer system now than it looked a few days ago. 
Amounts now look generally sub-advisory in the high country. Still
windy ahead of this trough but not as windy as it looked with a 
more consolidated system. A chance of rain changing to rain/snow 
mixture or brief snow east of the divide behind the cold front. 
Brief shortwave ridging Tuesday before a new system dives down 
from the se. GFS picked up on this last night and now the Euro and
GEM are also showing it. Could be a potent quick hitting system 
with much colder air than our Monday system. Good shot of snow 
across the wrn and nrn mountains and quite possible a period of 
snow with fropa east of the divide. As mentioned last night, we'll
have to watch this system with time as the chance of snow could 
be much greater than the model blend. Brief shortwave ridging then
Thursday before a rapid flattening occurs ahead of another 
potential system just beyond this period. Winds will be on the 
increase once again as the ridge flattens and the next system 
approaches. So increasing wind for many areas later 
Thursday/Thursday night through Friday with temperatures warming 
back up behind our midweek system. A chance of snow returning to 
the far west Friday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 210 AM MST Fri Nov 24 2017

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Routes

VFR conditions to prevail at the terminal sites for most of the time 
through 00Z. A cold front drops south into Northern WY by 12Z with a 
wind shift to the north and scattered rain showers. This front will 
push into Central WY around 18Z with scattered rain showers. There 
will be MVFR ceilings at times east of the divide. Conditions will 
improve over the north after 21Z and in the central after 00Z. VFR 
conditions are to occur after 00Z through 12Z Saturday. 

Please see the latest terminal forecasts for more details.

West of the Divide...KBPI/KJAC/KPNA/KRKS Routes

VFR conditions will prevail at most places through the period. 
Scattered rain showers with mountain snow showers in NW WY will 
spread southward today and out of the area around 00Z. KJAC airport 
should see a period of MVFR ceilings and rain showers today. A gusty 
wind will occur at KRKS airport through 01Z, then decrease. 

Please see the latest terminal forecasts for more details.

Please see the Aviation Weather Center for the latest information on 
icing and turbulence forecasts.

&&

.FIRE WEATHER...
Issued AT 210 AM MST Fri Nov 24 2017

Strong west winds aloft will continue to surface and bring high 
winds to portions of the Absarokas and Cody Foothills as well as 
along the Green Mountains and Rattlesnake Range through 5 am this
morning. Pacific moisture in strong west flow aloft will bring 
increasing snow to the higher mountains of western wyoming with 
mainly rain below 8700 feet early this morning and then lowering
to 7000 feet later this morning, and then tapering this afternoon.
Most areas above 7500 feet can expect 3 to 6 inches of snow with 
areas around 10 inches above 10000 feet with wind gusts tonight 
around 60 mph. A cold front will move south this morning bringing
increased showers to the north and colder air with a wind shift 
to the north and northeast bringing an end to the high winds. 
Temperatures will drop 15 to 20 degrees in the east with many 
areas falling around 10 degrees elsewhere from Thursdays
temperatures.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 5 AM MST early this morning for WYZ002-
003-019.

&&

$$

SHORT TERM...Lipson
LONG TERM...Skrbac
AVIATION...Ross
FIRE WEATHER...Lipson