Area Forecast Discussion
Issued by NWS Cheyenne, WY

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865
FXUS65 KCYS 251731
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1130 AM MDT SUN SEP 25 2016

.SHORT TERM...(Today through Monday night)
Issued at 149 AM MDT Sun Sep 25 2016

The main concern with this forecast is the potential for frost in
portions of the Nebraska Panhandle tomorrow night.

Today:
Latest water vapor loop was showing the upper level trof that gave
us rain/snow last night now near the North Dakota/Manitoba border.
As a result, we are seeing clearing skies with very little if any
precip. on the radar scope. We are bit concerned that the
potential vorticity anomaly currently moving through the eastern
third of Wyoming will play a role in downward momentum of the
strong winds aloft in the Nebraska Panhandle late this morning
into the early afternoon. Latest Vad Wind Profile at Cheyenne was
showing about 50kts at the first gate. As a result, strong wind
gusts of at least 30 mph will be possible in portions of the
Nebraska Panhandle around early afternoon. However, these winds
should begin to subside late in the afternoon. Temperatures will
be about 5 degrees cooler in the panhandle today due to the
colder air aloft from the upper level trof.

Tonight-Monday night:
Surface high pressure will continue to settle over the area with
temperatures possible dropping into the low 30s in the valleys
with mid to upper 30s elsewhere. Day shift will need to monitor
the potential for frost especially in the Nebraska Panhandle.
Beyond this timeframe we are looking at mild temperatures and
light winds due to the influence of the upper level ridge building
across the Rockies.

.LONG TERM...(Tuesday through Saturday)
Issued at 149 AM MDT Sun Sep 25 2016

Tuesday...Dry and mild with large scale ridge aloft over our
counties. Will stick close to guidance maximum temperatures based on
projected 700 mb temperatures.

Wednesday...Continued mild as the ridge aloft moves just to our east
with low level easterly winds limiting the warming. Minimal low and
mid level moisture will help keep it dry.

Thursday...Slightly cooler with more cloud cover from a passing
shortwave as well as some thickness cooling. Slight increase in low
and mid level moisture will help produce isolated showers over and
near the mountains.

Friday...Mild weather continues based on progged thicknesses.
Isolated mountain showers again with some mid level moisture.

Saturday...Winds aloft increase as heights lower with the approach
of a trough aloft. Continued mild with progged thicknesses. Similar
scenario to Thursday and Friday with isolated showers over the

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 525 AM MDT Sun Sep 25 2016

VFR conditions will continue today and through tonight. Northerly
winds may gust around 30 knots at times early this afternoon...but
will gradually subside by late this afternoon and this evening.

&&

.FIRE WEATHER...
Issued at 149 AM MDT Sun Sep 25 2016

The strong upper level trof will continue to lift northeast today,
but on the back side of this trof strong northwest winds are
favorable for the Nebraska Panhandle late this morning into the
early afternoon. Could see some gusts up to 30 mph with relative
humidity values dropping to around 20-25 percent. However, if this
air mass really mixes out we may see afternoon humidities drop
even more and yield to more critical fire weather conditions. Looking
ahead to the rest of the week an upper level ridge will build over
the region and provide lighter wind speeds and mild temperatures.

&&

.CYS Watches/Warnings/Advisories...
WY...None.
NE...None.
&&

$$

SHORT TERM...REC
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...REC



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