Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus65 kcys 170524 
afdcys

Area forecast discussion
National Weather Service Cheyenne Wyoming
1024 PM MST Sat Nov 16 2019

Short term...(late this afternoon through Monday night)
issued at 215 PM MST Sat Nov 16 2019

Latest surface analysis shows the cold front has already pushed
south to the I-80 corridor in southeast Wyoming and the NE Panhandle
early this afternoon, supported by 6-hr pressure rises of 5 to 6
mb. Temperatures ahead of the front warmed into the 50s and lower
60s, falling quickly through the 40s and 30s behind it. Parameters
are favorable for a couple of convective snow bands to set up and
move southeast across portions of I-25 between Douglas and
Cheyenne, and I-80 between Laramie and Cheyenne mid to late
afternoon. Localized snow accumulations of an inch are possible,
especially on grassy and elevated surfaces. Snow showers will
taper off from northwest to southeast later this evening, followed
by clearing skies and colder temperatures.

Attention turns to a period of strong and gusty west winds across
portions of southeast Wyoming Sunday. Models have been consistent
with 700/850mb gradients of 55-70 meters from Craig to Casper.
700mb winds peak around 50 kt Sunday along the I-80 corridor from
Rawlins to Cheyenne. Upgraded the high wind watches to warnings
for Arlington/Elk Mountain and I-80 Summit/vedauwoo/Buford areas
beginning at 8 am MST Sunday. Confidence is moderate for the I-25
corridor between Chugwater and Wheatland Sunday where 700mb winds
are slightly lower despite decent 700/850mb gradients. Lee surface
trough shifts east into the plains Sunday afternoon ahead of a
upper level disturbance moving across northern Wyoming. This will
shift winds from northwest to west direction at that time. Issued
a high wind watch beginning at 11 am MST. Winds will remain strong
through early Sunday evening, then subsiding with the weakening
pressure gradients.

Upper ridge over the intermountain west will shift eastward toward
the Front Range Monday. Dry northwesterly flow aloft and
downsloping winds will produce above normal temperatures with
highs in the 50s to lower 60s. It will be breezy with west to
northwest winds gusting 25 to 35 mph across much of the County Warning Area.

Long term...(tuesday through saturday)
issued at 215 PM MST Sat Nov 16 2019

A dry and quite mild day expected across the County Warning Area Tuesday with a
weak upper ridge moving across. Looks rather windy across parts of
se WY as Lee troughing deepens over the High Plains ahead of the
next upper trough that will drop over the Pacific northwest. Models in
decent agreement in splitting the energy of this system, dropping
one batch southward and cutting off an upper low near the
southern cal coast by late weds while bringing the rest of the
energy into the northern rockys. A surge of colder air will drop
south and across the County Warning Area early weds setting up low level upslope
across the County Warning Area. Expect to see rain and snow, changing to all snow,
spread across the County Warning Area later weds as the atmosphere moistens and
the upper trough approaches. Snow should continue into Thursday
before ending by late in the day as the upper trough moves by.
Some accumulating snows look a decent bet. Friday and Saturday
look cool and mainly dry for now but will have to watch what
happens with the upper low near the cal coast as the ec moves it
east while weakening it.

&&

Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1017 PM MST Sat Nov 16 2019

VFR conditions for all terminals will prevail overnight. Cigs
should elevate significantly with sky clear overnight at terminals in
the Panhandle. Winds will be 12 knots or less overnight and have a
west to southwest orientation by morning. Winds will begin to pick
up after sunrise quickly to 20-25 knots by midday over southeast Wyoming.
Winds will increase up to 20 knots by 18z in the Panhandle. Overcast
skies with high cigs will begin to occur in the afternoon.

&&

Fire weather...
issued at 215 PM MST Sat Nov 16 2019

A fast moving cold front will produce scattered rain and snow showers
to the districts this afternoon and early evening. It will be windy
and milder Sunday. Dry, breezy and unseasonably mild weather is
forecast early next week, followed by colder and wetter conditions
mid to late next week.

&&

Cys watches/warnings/advisories...
Wyoming...High Wind Warning from 8 am to 8 PM MST Sunday for wyz110-116.

High wind watch from Sunday morning through Sunday evening for
wyz106.

NE...none.
&&

$$

National Weather Service Glossary of Abbreviations