Area Forecast Discussion
Issued by NWS Cheyenne, WY

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877
FXUS65 KCYS 202353
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
553 PM MDT WED JUL 20 2016

.SHORT TERM...(This evening through Thursday)
Issued at 235 PM MDT Wed Jul 20 2016

Hot temperatures ongoing over the northern Panhandle with Chadron
currently at 105...with a couple 107s at some mesonet sites.
Relative humidity not so bad but will keep heat advisory going.
Might be able to cancel it later tonight if temperatures cool
fast enough in that area.

Some convection has developed over Carbon and Albany counties
this afternoon...possibly in response to a weak impulse lifting
northeastward over western Colorado. Expect this activity to
continue and expand some for the rest of the afternoon as the
impulse moves closer to the CWA before ending this evening with
loss of heating. Some clouds should hold across the CWA overnight
in monsoonal flow. Otherwise a weak cool front should slip south
across the CWA tonight with temperatures a little cooler on
Thursday...enough to alleviate the hot conditions of today...
but still quite warm over the Panhandle. Next impulse should lift
into the region later Thursday so expect widely sctd showers and
tstms again Thursday afternoon...with activity possibly focusing
along weak surface boundary over the southern Panhandle.

.LONG TERM...(Thursday night through Wednesday)
Issued at 235 PM MDT Wed Jul 20 2016

Pattern with the midlevel ridge to our southeast persists into
Friday keeping most of any significant PoPs out in the higher
terrain of Carbon and Albany counties for the afternoon and early
evening hours...with less coverage farther east where midlevel
temperatures will still be relatively warm capping off most
convection.  By Saturday we see a weakening of the western edge of
the Southern Plains ridge as a shortwave rides east across Montana.
That passing shortwave to the north will send a modifying cold front
down into SE Wyoming and the western Nebraska Panhandle during the
day on Saturday.  Moisture along that front looks to be fairly
limited and we don`t expect to see much in the way of showers and
thunderstorms along it with the exception of maybe some isolated
activity in the Snowy, Sierra Madre and south Laramie Ranges.  By
Sunday we start to see a little moisture return in the low level
southeasterly flow setting up and thinking is Sunday and Monday we
should see an increased coverage of afternoon and evening
thunderstorms forming up over the Snowy and South Laramie Ranges
eventually moving off to the east onto the High Plains into the
evening hours. If the GFS is to be believed, we should see a fair
amount of instability (1000-1500 J/KG CAPE) around Monday
afternoon over the eastern Plains...so that may be the day to
watch out for some stronger to potentially severe storms, although
shear doesnt look overly impressive.  A little less coverage on
Tuesday with minimal coverages of afternoon and evening
thunderstorms by next Wednesday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 553 PM MDT Wed Jul 20 2016

Isolated showers with perhaps a t-storm or two will linger at
KCYS, KRWL, and KSNY through sunset. Gusty erratic winds remain
a possibility with this activity, otherwise generally light winds
are expected through tonight. A cold front dropping south across
the area Thursday morning will switch winds to the north, with
occasional gusts to 20 kts. May see a few t-storms develop along
the I-80 corridor late Thursday afternoon.

&&

.FIRE WEATHER...
Issued at 235 PM MDT Wed Jul 20 2016

Fire weather concerns will remain generally low for the next few
days with mainly light winds. Some elevated concerns are possible
over zone 301 Friday with a little stronger wind expected. A weak
front will pass across tonight bringing a little cooler air for
Thursday. Widely scattered mainly late day showers and storms are
expected mainly over southeast Wyoming Thursday and Friday.

&&

.CYS Watches/Warnings/Advisories...
WY...None.
NE...Heat Advisory until 6 AM MDT Thursday for NEZ002-003-095-096.

&&

$$

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



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