Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 282349
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
549 PM MDT SUN AUG 28 2016

.SHORT TERM...(This evening through Tuesday night)
Issued at 316 PM MDT Sun Aug 28 2016

A cluster of showers with a few embedded t-storms has developed
near the CO/WY/NE borders this afternoon within an area of sfc
convergence along the leading edge of southerly return flow.
Instability east of this boundary is roughly 500-1000 J/kg
(sbcape) with practically no shear analyzed on mesoanalysis.
Therefore, expect this activity to be pulse in nature with mainly
light to moderate rain at times and perhaps gusty downdraft winds.
Further north and west, dry conditions prevail under mostly sunny
skies, with winds gusting 15 to 25 mph at times. Lower elevations
along and west of the I-25 are seeing the strongest winds, with
Converse and Niobrara a close second. Fire weather concerns are
elevated in these areas as a result. Expect these conditions
through sunset.

East-southeast flow will deepen to at least 500 mb on Monday ahead
of the upper low that is currently over the 4-corners region, and is
projected to shear apart over Colorado by Tuesday. Although the
strongest vorticity will remain south of our area, the associated
upper level deformation zone will move over the forecast area
through Tuesday, with llvl moisture advection strengthening
within persistent east-southeast flow. Should see a better
coverage of showers and t-storms in this pattern on Monday,
especially along upslope favored locales. The best upper level
lift will shift southeast over Nebraska/Colorado with subsidence
moving into Wyoming from the northwest. Thus the focus for best
coverage for activity may be just south and east of our area, but
can`t rule out isolated activity across our southeastern zones in
the afternoon. Temperatures will trend cooler each day.

.LONG TERM...(Wednesday through Sunday)
Issued at 316 PM MDT Sun Aug 28 2016

Dry and warm on Wednesday as an upper ridge axis slips slowly
east of the CWA. this will allow for some moisture return to ensue
on Thursday and continue Friday and Saturday so should see an
uptick in convection on those days...particularly across southeast
Wyoming Friday and Saturday. Some breeziness also expected Friday
into the weekend as an upper trof approaches from the west so may
see an increase in fire weather concerns. Sunday looking somewhat
drier as the upper trof nears and advects some drier air into the
area from the southwest. Temperatures remaining on the warm side
through the period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 539 PM MDT Sun Aug 28 2016

No real major concerns with this taf issuance. Could see a few
light showers around between KCYS and KSNY through 02z.
Otherwise, cirrus shield will be in place across much of
southeast Wyoming and the Nebraska Panhandle. There is a slight
chance that KSNY may clear out late tonight which may cause some
patchy fog to develop. Otherwise, vfr conditions will be the rule.

&&

.FIRE WEATHER...
Issued at 316 PM MDT Sun Aug 28 2016

Humidities in the low/mid teens and winds gusting 15 to 25 mph
will maintain elevated fire weather concerns this afternoon mainly
lower elevations along and west of I-25, in addition to Converse
and Niobrara Counties. Winds should diminish and humidities
will rise by early evening. A few showers/t-storms will continue
near the CO/WY/NE borders through sunset. Monday and Tuesday will
see slightly cooler temps with improving humidities. Chances for
isolated showers and storms will increase for Monday, especially
for areas favored by east-southeast upslope flow.

&&

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

$$

SHORT TERM...RJM
LONG TERM...RE
AVIATION...REC
FIRE WEATHER...RJM



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