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537
FXUS65 KRIW 180753
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
153 AM MDT Wed Apr 18 2018

.SHORT TERM...Today Through Friday night
Issued at 115 AM MDT Wed Apr 18 2018

With high pressure ridging moving in today expect clearing skies,
dry weather, and a warming trend through Thursday. Thursday
afternoon may see a shower or two in the northwest mountains. A cut-
off low will drift into the four corners region Thursday night into
Friday which will bring increased cloud cover over the FA which will
slow daytime warming just a bit in the southeastern areas. This low
will also increase winds in the wind corridor from Rock Springs to
the Green Mountains Thursday night though Friday. As the low treks
east north east, there could be enough energy to cause a few
snow/rain showers in the southeastern half of the FA. This area of
precip will dissipate from northwest to southeast through Friday
night.

.LONG TERM...Saturday through Wednesday
Issued at 115 AM MDT Wed Apr 18 2018

Warm and dry this weekend with temperatures 5-10 degrees above
average. This will cause snowmelt below 7500 feet. Ponding of
water in low-lying areas in the far western valleys will be a
concern where a deep snowpack still exists. However temperatures
reaching freezing/near freezing at night in combination with no
precipitation should keep any low-lying flood issues localized
and minor.

A low-amplitude trough is expected to push across the Northern
Rockies in the Monday/Monday night time frame. Overall models are
a bit strong with this system than 24 hours ago with a strong cold
front pulling south across the area on Monday with a decent shot
of precipitation across much of the area. The 700mb temperatures
and soundings suggest the precip in the lower elevations in wake
of the front would be mainly snow. However, overall confidence is
on the low side, and will only trend toward the cooler temperatures
and higher PoPs. This system should exit the area Tuesday with
drier conditions, and a warming trend commencing. Wednesday of
next week looks to be dry with seasonal to slightly above average
temperatures.

&&

.AVIATION...For the 12Z TAFS through 12Z Thursday morning
Issued at 115 AM MDT Wed Apr 18 2018

West of the Continental Divide...KJAC, KBPI, KPNA, and KRKS

Snow showers will occur overnight through 15Z before becoming more
scattered in nature. MVFR to IFR conditions will occur at times. At
KRKS airport snow showers will be most likely between 12Z and 18Z.
Expect frequent mountain obscuration A gusty wind will be common at
the terminal sites through 01Z. Then the wind will decrease after
01Z Wed. VFR conditions will prevail after 00Z at the terminal
sites.

East of the Continental Divide...KCPR, KCOD, KRIW, KLND, and KWRL

A cold front passes through the area morning. An area of snow will
develop over central WY after 12Z and last until 19Z. This area of
snow will impact the KBYG to KCPR area after 18Z through 00Z.
Lingering snow showers will occur until 03Z Wed. MVFR to IFR
conditions will occur during the snow showers, before returning to
VFR conditions once the area of snow moves out. Mountains will be
frequently obscured at times. VFR conditions will prevail at the
terminals after 02Z Wed.

&&

.FIRE WEATHER...
Issued AT 115 AM MDT Wed Apr 18 2018

High pressure returning to the area for the next two days. Expect a
warming and drying trends in the lower elevations. RHs in areas 277
and 279 do drop below 15 percent Thursday afternoon and have
somewhat gusty winds but strong enough at this time to cause
concern. Rain/snow returns to southern and eastern areas Friday.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...Hulme
LONG TERM...Murrell
AVIATION...Baker
FIRE WEATHER...Hulme