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Area forecast discussion 
National Weather Service Riverton Wyoming
1036 am MDT Tuesday Sep 2 2014

Short term...today through Thursday night

Water vapor satellite is confirming what the models have been
advertising for a few days...there is a much drier air mass moving in
as the flow turns more southwest. High pressure building in from the
south will also bring some warmer air with temperatures rebounding
back to near 80 east of The Divide. There will be some gusts to 30
miles per hour across the south working their way into portions of central
Wyoming...leading to increased fire danger this afternoon.

Wednesday...models are advertising another upper level trough with
sharp cold front and baroclinic zone dropping south into
Montana...at this time it looks like we would not see much from the
front until late with not much if any precipitation making it this
far south...but cooler temperatures and a wind shift to the north is
expected if this scenario actually plays out as advertised.
Otherwise...the warming trend continues across the south with steady
20 to 30 knot southwesterlies and continued fire weather concerns as
min rhs are expected to drop into the teens again on Wednesday
afternoon.

Thursday...much cooler behind the front with some cloud cover
hanging around along and east of The Divide. Dry southwesterly flow
remains across the west and south...though winds will not be as
strong and the temperature changes will not be as sharp.

Long term...Friday through Tuesday

A little warmer on Friday with isolated showers and storms for
southwest Wyoming in the afternoon and evening where better instability
will occur. Dry elsewhere as air mass looks to be stable with very
isolated activity. West southwest flow aloft for Saturday and
Sunday with weak disturbances in the flow per the GFS and European model (ecmwf)
models. Isolated to widely scattered afternoon and evening showers
and storms both days. High temperatures to warm a few degrees Saturday
and Sunday. Monday looks to be more of the same with isolated
showers and storms. Expect some breezy areas Monday and seasonably
warm. The GFS and European model (ecmwf) differ next Tuesday with the strength and
movement of a weather system across the northern rockies. A brisk
cold front is forecast by both models to move through Wyoming next Tuesday
with the GFS being the colder model solution for high temperatures. Have
played highs 10 to 15 degrees cooler over the north and 8 to 12
degrees cooler over the south. Precipitation chance looks higher on the
GFS versus the European model (ecmwf). For now will play a blend and have isolated
to widely scattered showers/storms next Tuesday.

Aviation.../18z issuance/

VFR conditions will prevail through 18z Wednesday. A few high
clouds will move over the north in west flow aloft. The rest of
western and central Wyoming will be sky clear. Areas of southwest
surface winds 15 to 25 kts with gusts to 35 kts will persist
across the south and central areas through 02z and redevelop on
Wednesday around 16z.

Note...FAA informs National Weather Service that observation fro kcod will be unavailable
until sometime today when repairs are expected. Taf continued as
VFR conditions are anticipated at kcod through the forecast
period.

Fire weather...

.Red flag conditions expected across portions of Rawlins...Cody
and Casper dispatch this afternoon and again on Wednesday...

Much warmer and drier today and tomorrow...in addition to windier.
Very low relative humidity and strong gusty winds will develop
across the southwest and central portions of Wyoming after noon on
continuing until around 8 PM MDT. The very low relative humidity and
strong gusty winds will redevelop after noon on Wednesday continuing
until around 8 PM MDT Wednesday evening...at which time a dry cold
front will be dropping into northern Wyoming...shifting the winds to
the north with winds remaining in the 20 to 30 miles per hour range with gusts
over 45mph in areas prone to northerly wind. Red flag warning is in
effect from noon to 8 PM MDT today for wind and low relative
humidity for fire weather zones 279...280... 283 and 289. Red flag
warning again in effect from noon to 8 PM MDT Wednesday for wind and
low relative humidity for fire weather zones 279...280...283 and
289.

&&

Riw watches/warnings/advisories...
red flag warning until 8 PM MDT this evening wyz279-280-283-289.

Red flag warning from noon to 8 PM MDT Wednesday
wyz279-280-283-289.

&&

$$

Short term...Allen
long term...Arkansas
aviation...c.Baker
fire weather...Allen

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