Area Forecast Discussion Issued by NWS Cheyenne, WY
000
FXUS65 KCYS 162112
AFDCYS
Area Forecast Discussion
National Weather Service Cheyenne WY
312 PM MDT Sat Mar 16 2024
.KEY MESSAGES...
- Near to slightly below average temperatures expected for the
weekend, with a slight chance of snow showers over the high
terrain Saturday night.
- Well above normal temperatures are expected to return next
week
&&
.SHORT TERM /REST OF TODAY THROUGH TOMORROW/...
Issued at 105 PM MDT Sat Mar 16 2024
Very quiet weekend/short term forecast on tap for much of the
region. Post storm much of Wyoming sits under a cool northwest
flow as upper level ridging begins to expand across the
Intermountain West. Some mid-level moisture is still hanging
around the region which could help initiate some light snow
showers across the mountains this afternoon and into the
evening. The backdoor cold front has edged its way across
portions of SE Wyoming and this coupled with the cold NW flow
will keep temperatures right at seasonal normals even under full
sun. Temperatures are expected to remain near seasonal again on
Sunday with the increased mid to high level could moving in
form the west, but some clearing is expected toward the late
afternoon in which temperatures could approach 50 across the
lower elevations and across parts of the Nebraska Panhandle.
With this clearing occurring, and the combination of light
winds and ridging building aloft, there could be a decent setup
for radiational cooling to drop temperatures especially across
the typical cool spots and in those sheltered valleys.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 105 PM MDT Sat Mar 16 2024
The first half of next week looks warm and dry with minimal weather
impacts, but we could turn more unsettled Thursday through Saturday,
although uncertainty is quite high.
By Monday, the ghost of last week`s storm system will be suppressed
to the south across southern AZ/NM as it runs out of moisture and a
strong ridge builds in over top in the Pacific Northwest and
northern Rockies. As the northern branch shortwave ejects to the
east, our area will see rapid warm air advection as the Rex Block
shifts more directly over our area. 700-mb temperature is forecast
by the ensemble mean to rise from about -6 to -9C at midnight Sunday
night to near 0C by sunset Monday. Skies are also expected to clear
out nicely as drier air moves in with the Rex Block. Thus, looking
at temperatures climbing back above normal for the whole area, and
overall a pretty nice day. Looking similar on Tuesday with light
winds, mostly sunny skies, and highs 10-15F warmer than average. We
may get grazed by a weak backdoor front on Wednesday, so forecast
highs for Wednesday in the NE panhandle are slightly cooler than
Tuesday, but similar elsewhere.
Forecast uncertainty increases considerably Thursday and beyond. The
cutoff low to our south will finally be swept up by the subtropical
jet, while a more active storm track simultaneously returns to the
Pacific Northwest. Most ensemble members have some progressive but
not very moisture rich shortwaves grazing the area between Thursday
and Saturday but different members have varying timing and strength
for each one, which makes it difficult to discuss any specifics.
Overall, there is high confidence in above normal temperatures
continuing into Thursday, but this reduces somewhat Friday and
Saturday, particularly further north and east. Due to these timing
differences, also trended PoPs down slightly through this period, to
mostly slight chance over the plains/valleys, and chance to low-end
likely in the mountains. The closer storm track will also mean a
return of the westerlies, but any signal for high wind is not very
prevalent at this time.
&&
.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1133 AM MDT Sat Mar 16 2024
Weak northerly flow aloft will continue. Mostly clear skies will
prevail this afternoon and into the early evening, then
scattered to broken clouds from 4000 to 10000 feet will occur.
Winds will gust to 27 knots at Cheyenne and the Nebraska
terminals until 01Z, then gust to 22 knots at Cheyenne after
15Z Sunday.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...AW
LONG TERM...MN
AVIATION...RUBIN