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fxus65 kcys 261746 

Area forecast discussion
National Weather Service Cheyenne Wyoming
1147 am MDT Wed Jun 26 2019...corrected aviation

Short term...(today through Friday night)
issued at 230 am MDT Wed Jun 26 2019

Not out of the Woods yet for severe thunderstorms this afternoon
and evening. Concerns deal with timing/location of severe
thunderstorms today...followed by warm/dry weather leading to
elevated fire weather concerns end of week.

Currently...surface front that was the focus of thunderstorm
development yesterday still has not shown much eastern movement so
far this morning. Surface analysis showing a closed low near
Casper...with surface front extending southeast to near
Wheatland...continuing southeast to Kimball and eventually into
northwest Kansas this morning. Dewpoints in the 50s across the
Panhandle...with upper 30s west of the front across Carbon and
Albany counties. Off the coast of Washington state...a closed
upper low remains...has not shown much movement over the past
several hours.

For today...some differences between the GFS and NAM on movement
of the front over our area. GFS pushes front into western Nebraska
and southwest South Dakota before peak heating today. NAM...on the
other hand much slower with the eastward movement of the front.
MUCAPE from the NAM up near 4500 j/kg across the northern
Panhandle by 00z with around 3800 j/kg over Niobrara County. Mid
level lapse rates on NAM soundings on the order of 9c/km. Hrrr
and hires guidance showing supercells developing along and north
of a line from near Scottsbluff to Torrington to Lusk shortly
after 3 PM today...moving northeast towards Chadron and Alliance
by 6pm. Should the NAM solution come true...we are looking at huge
hail...and possibly a small tornado threat as well. Will be
highlighting this area in morning social media for elevated

Front finally shifts east early this evening as a dryline with
much drier air moving into the Panhandle. Severe threat should be
done after 02z or so this evening.

A drier and warmer forecast through Thursday and Friday as 700mb
temperatures climb to +16c Thursday. 850mb humidity down near 10
percent over the very dry and breezy conditions
expected both days.

Long term...(saturday through tuesday)
issued at 230 am MDT Wed Jun 26 2019

Southwest flow aloft prevails and with adequate low and mid level
moisture, isolated to scattered afternoon and evening showers and
thunderstorms are expected each day,, mainly east of Interstate 25,
with the most numerous on Monday for the first day of July, when
moisture will be most prevalent. After the warmest day on Saturday,
temperatures will be somewhat cooler for Sunday through Tuesday due
to more cloud cover and an increased coverage of showers and


Aviation...(for the 18z tafs through Thursday morning)
issued at 1146 am MDT Wed Jun 26 2019

VFR conditions are expected to prevail this afternoon through
tonight. Thunderstorms are possible near klar and kcys, but coverage
should be limited to a few, so will keep thunderstorms in the vicinity out both tafs. Further
east, a better chance for strong thunderstorms exists which may
result in very gusty outflow winds and some hail between 21z this
afternoon and 03z this evening, mainly for kcdr, kbff, and kaia.


Fire weather...
issued at 230 am MDT Wed Jun 26 2019

Very warm temperatures and dry weather still expected the next
several days as high pressure over western Colorado prevails.
Looking at critical afternoon humidity on a daily basis through
Friday. Very warm temperatures will allow winds from very high
levels in the atmosphere to mix down to the ground for pretty
gusty winds...especially west of the Laramie range.
Fortunately...fuels are still green from recent fire
weather concerns remain minimal.


issued at 230 am MDT Wed Jun 26 2019

Trends on headwaters gauges coming out of the snowy and Sierra
Madre ranges have shown river levels coming down slowly. Still
need to wait to see effects of increased snowmelt over the next
several days before we can say for certain that flooding threat is
over. Warmer temperatures over the next several days will let US
know that impact. Rain still forecast for late weekend into next
week and a rain on snow event is still not out of the question.


Cys watches/warnings/advisories...


Short term...gcc

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