Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 190525

Area Forecast Discussion
National Weather Service Riverton WY
1125 PM MDT Wed Apr 18 2018

.SHORT TERM...(This evening through Thursday)
Issued at 319 PM MDT Wed Apr 18 2018

A low pressure system moves into the Pacific Northwest and digs
southeastward into the four corners region by Thursday night.
Clouds and moisture will fill into the region ahead of this low
beginning tonight and continuing through Thursday. Shower activity
should increase over the mountains on Thursday. Despite
increasing cloud cover, most of the region will see highs into 50s
during the afternoon Thursday.

.LONG TERM...(Thursday night through Wednesday)
Issued at 319 PM MDT Wed Apr 18 2018

As a low pressure system treks across southern Wyoming, winds
should increase in the wind corridor from Rock Springs to the
Green Mountains Thursday night though Friday. Snow and rain
showers most likely in southeastern portions of the state and in
the mountains on Friday into Friday night. This area of precip
will dissipate from northwest to southeast Friday night as the low
pushes into the Plains.

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


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1123 PM MDT Wed Apr 18 2018

An upper level low pressure system will move across the southern
Great Basin Thursday into the Four Corners area early Friday
morning.  VFR conditions with mainly some SCT-BKN mid and high
clouds will prevail ahead of the system through 00z Friday.
Scattered showers and possibly an isolated thunderstorm will then
spread into southwest Wyoming, vicinity KRKS-KBPI-KPNA, 00z-06z
Friday.  Surface NE winds will increase to 20-35 knots from South
Pass across the I-80 corridor Thursday evening.  A line of showers
and local MVFR conditions is expected to begin to rapidly spread
north along the Laramie Range to vicinity KCPR 08z-12z Friday with
ceilings also lowering along (and obscuring) the east slopes of the
Wind River Mountains, vicinity KLND.


Issued AT 319 PM MDT Wed Apr 18 2018

Generally warmer and drier at lower elevations Thursday. 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 as
low pressure system crosses the divide.




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