Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Cheyenne Wyoming
1040 am MST sun Feb 14 2016

issued at 1009 am MST sun Feb 14 2016

Strong gusty winds continue to blow across the wind prone portions
of southeast Wyoming at this time. Winds however have decreased
somewhat from earlier this morning with winds mainly below high
wind thresholds. Winds should mainly stay below high wind levels
today through this evening but will remain elevated.


Short term...(today through Monday night)
issued at 310 am MST sun Feb 14 2016

Relatively quiet early this morning across the forecast area as
the first of a series of weather disturbances is already moving
into the Mississippi River valley. Winds are still pretty strong
across southeast will continue the High Wind Warning
for the southern wind prone areas. Gusts have continuously been
between 52 to 58 miles per hour after a brief lull late last night. A few
gusts around 60 miles per hour are still expected by sunrise across the
Arlington area and more-so over the southern Laramie
range/foothills. Expect winds to be elevated across southeast
Wyoming through today with slightly cooler temperatures in the
upper 30s to upper 40s. Kept pop between 15 to 25 percent across
the High Plains with higher valleys west of the Laramie range for
isolated to scattered rain/snow shower activity this afternoon and
into this evening. Models Show Low level instability and moisture as
the next disturbance digs southward across the High Plains and
into NE Colorado by late this evening. A brief period of moderate
to heavy rain/snow mix is possible...and may produce a quick half
inch of snow accumulation before ending late this evening.
Widespread snow accumulations will mainly be confined to the
mountains. A Winter Weather Advisory has been issued for this
afternoon through Monday to include the Sierra Madre range. Kept
the Snowy Range out of the advisory for now...since it appears the
highest peaks will receive respectable snow accumulations with
very little in the southern slopes and Lee-side slopes of the
Snowy Range.

For Monday...models show yet another disturbance moving across
Montana and Wyoming...but this time producing light rain across
the east Central Plains into the northern Panhandle instead of
snow due to warming low to midlevel temperatures. Of more
significance...low level pressure gradients will increase ahead of this
disturbance by early Monday morning possibly resulting in another
high wind event. This event appears a bit more widespread...due to
the position and strength of the jet stream which will be more
anticyclonic and model 700mb-500mb Omega which shows widespread
subsidence even across the Laramie valley and into northwest
Platte and Laramie counties. Issued a high wind watch for gusts
around 70 miles per hour for our wind prone areas in addition to the Laramie
valley...and all of Platte County. May need to include Laramie
County and Converse County as well...with the new 06z NAM showing
the best subsidence between 00z to 06z Tuesday over these areas
and 50 to 60 knot winds just off the surface. Expect these winds
to slowly diminish Monday night with pretty mild temperatures in
the 30s for overnight lows this time of the year.

Long term...(tuesday through saturday)
issued at 252 am MST sun Feb 14 2016

Tuesday...the atmosphere starts to dry out thus only a few snow
showers over the snowy and Sierra Madre ranges. Continued mild per
prognosticated thickness trends.

Wednesday...ridge axis aloft moves overhead inducing decent surface
Lee troughing...and combined with a dry atmosphere...will produce a
quite mild day for middle February with highs near 50 west of I-25 and
middle 50s to lower 60s east of I-25.

Thursday...continued mild in the warm sector ahead of the next fast
moving shortwave trough aloft. Models similar in depicting a cold
front entering our western counties in the afternoon along with the
progressive shortwave trough aloft...spreading showers over our
snowy and Sierra Madre ranges in the afternoon. Dry elsewhere.

Friday...zonal flow aloft and weak ridging develops in the wake of
the shortwave trough aloft feature. A bit cooler in the wake of the
cold front...though still relatively mild for middle February.

Saturday...models project another fast moving and low amplitude
shortwave trough feature moving east across Montana or
Wyoming...though with limited no precipitation
expected. Continued relatively mild for middle February based on
projected thicknesses.


Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1028 am MST sun Feb 14 2016

Winds will be the main aviation concern through the afternoon over
southeast Wyoming. Gusts to 30-40 kts will be common. The winds
will decrease some by late this evening. VFR ceilings with bases
around 10000 feet will be possible through the period.


Fire weather...
issued at 252 am MST sun Feb 14 2016

Minimal fire weather concerns this week. After a brief cool down
today...mild temperatures will return to the area by the middle of
the week with high temperatures 15 to 20 degrees above normal.
Daytime relative humidities will trend lower by Wednesday and
Thursday with values between 20 to 30 percent.


Cys watches/warnings/advisories...
Wyoming...Winter Weather Advisory until 11 PM MST Monday for wyz112.

High wind watch from late tonight through late Monday night for



short term...tjt
long term...Rubin
fire weather...tjt

National Weather Service Glossary of Abbreviations