Red Flag Warning 6, NWS Riverton, WY

806 
WWUS85 KRIW 262046
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
246 PM MDT Sat Aug 26 2017

WYZ280-270100-
/O.CON.KRIW.FW.W.0001.000000T0000Z-170827T0100Z/
Natrona County/Casper BLM-
246 PM MDT Sat Aug 26 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM MDT THIS
EVENING...

* IMPACTS: Low Humidities...Hot Temperatures...Strong Gusty 
  Winds...and Wind Shift with a Cold Front will create conditions
  favorable for erratic fire behavior and new fire starts. 

* AFFECTED AREA: 
  In Central WY...Fire Weather Zone 280.

* COUNTIES AFFECTED: 
  In Central WY...Natrona.

* COLD FRONT: A cold front will pass south through the area from 
  4 pm mdt to 7 pm mdt with a wind shift to the north.

* WIND: Northwest 20 to 25 mph with gusts up to 35 mph shifting
        to the north.

* HUMIDITY: as low as 10 percent.

* TEMPERATURES: In the upper 80s to lower 90s.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

WYZ283-270100-
/O.CON.KRIW.FW.W.0001.000000T0000Z-170827T0100Z/
Upper Wind River Basin/Wind River Basin-
246 PM MDT Sat Aug 26 2017

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM MDT THIS
EVENING...

* IMPACTS: Low Humidities...Hot Temperatures...Strong Gusty 
  Winds...and Wind Shift with a Cold Front will create conditions
  favorable for erratic fire behavior and new fire starts. 
 
* AFFECTED AREA: 
  In Central WY...Fire Weather Zone 283.

* COUNTIES AFFECTED: 
  In Central WY...Fremont.

* COLD FRONT: A cold front will pass south through the area from 
  4 pm mdt to 7 pm mdt with a wind shift to the north.

* WIND: Northwest 20 to 25 mph with gusts up to 35 mph shifting
        to the north.

* HUMIDITY: as low as 10 percent.

* TEMPERATURES: In the upper 80s.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions are
either occurring now....or will shortly. A combination of strong
winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

http://weather.gov/riverton

333 
WWUS85 KRIW 270106
RFWRIW

URGENT - FIRE WEATHER MESSAGE
National Weather Service Riverton WY
706 PM MDT Sat Aug 26 2017

WYZ280-283-270215-
/O.EXP.KRIW.FW.W.0001.000000T0000Z-170827T0100Z/
Natrona County/Casper BLM-Upper Wind River Basin/Wind River Basin-
706 PM MDT Sat Aug 26 2017

...RED FLAG WARNING HAS EXPIRED...

A cold front had moved through the area early this evening with
winds generally diminishing behind the front and relative humidity
rising above critical thresholds.

$$

http://weather.gov/riverton

Area Forecast Discussion
National Weather Service Riverton WY
217 AM MDT Sat Aug 26 2017

.SHORT TERM...(Today through Monday night)
Issued at 210 AM MDT Sat Aug 26 2017

...Transition to Warm Dry Period Begins This Forecast...

...Elevated Fire Weather Conditions Today...

Imagery shows complex upper level pattern with (now) rather flat
flow across the CONUS with large trof over the nern states, Bermuda
High intruding under the trof all the way across the srn
CONUS...only interrupted by Hurricane Harvey in the Gulf. Upstream
west, embedded shortwave trof moving through the PAC NW with a broad
closed low well to the west of California. SFC has general low
pressure across the wrn CONUS with a weak meso-high intruding across
wrn WY, weak SFC trof over ern WY and a weak front located to the
nw, stretching from wrn MT to nrn California. A few showers and
isolated thunder from Johnson County into ern WY.

Today, the  relatively flat upper level flow transitions to
nwrly...with a dry SFC front moving south through the region east of
the Divide and across southern WY with high pressure building into
the region. Monsoonal flow will be held/diverted well south of the
FA with weak low to mid flow aloft over and east of the Desert SW
point south or southeast toward Harvey. As the FA drains of moisture
with much more deep stability in place, only a couple of mainly
mountain showers/storms will be possible perhaps over or near the
Uinta Mountains. Sunday will be a repeat of today but with even
smaller chances (if that's possible) for precipitation to occur
anywhere in the CWA. Elevated fire weather concerns will be noted
for both days mainly due to very dry conditions at the SFC. Winds
will remain seasonal today...with a few mixed out afternoon gusts 15
to 25 kts in the mountains above 8000 feet and across southern to
central Wyoming in the usual places ahead of a weak frontal passage.
Near/brief Red Flag conditions possible across ern Sweetwater, srn
Fremont and most of Natrona counties this afternoon. SPS for these
locations reflect concern. Sunday will see less wind in general
behind the front. Monday, some weak moisture return is possible
across sern WY, perhaps into parts of central or northern WY, as low
pressure develops over swrn WY and high pressure drifts into/over
the Central Plains. This may be just enough with some weak upslope
conditions to get a shower/weak storm going over the Needles or
Bighorn Mountains...but probably not.

.LONG TERM...(Tuesday through Friday)
Issued at 210 AM MDT Sat Aug 26 2017

Strong upper ridge that expands into early next week is showing
some signs of weakening around the middle of next week which will
allow some energy from the eastern Pacific to work across the
area. In addition, the gradual swd shrinkage of the upper high
will allow a little monsoonal mid level moisture to start edging
around the high and into wrn WY Tuesday and Wednesday. A little
more each day will try and work off the foothills into the nearby
Wind River Basin and Cody Foothills by late afternoon early early
evening with some gusty outflow winds. Potential stronger
shortwave could move across on Thursday with a better chance of
showers and thunderstorms, especially over and near the mountains
along with a few degrees of cooling. Until then it'll continue
quite warm/hot with 80s and some 90s east of the divide and upper
70s to mid 80s west. Mountains overall will be in the 60s and 70s.
System moves off to the east for a dry Friday and Saturday period
with Saturday likely becoming quite warm/hot again as ridge tries
to build back in.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 210 AM MDT Sat Aug 26 2017

VFR conditions will prevail through the period.  A large wildfire
near Rexburg, ID may bring smoke into KJAC; KJAC TAF currently 6SM
FU Saturday morning, with uncertainty on whether smoke plume will
move into the Jackson Valley, which could reduce visibility into
MVFR range.  Surface high pressure will build across Montana on
Saturday with a northerly surface wind 10-15 knots prevailing across
much of central Wyoming during the day.  KRKS should have a wind
shift from the NE shortly after 06z Sunday.

&&

.FIRE WEATHER...
Issued AT 210 AM MDT Sat Aug 26 2017

...Elevated Fire Weather Conditions Today Across Portions of
Southern and Central Wyoming...

Fuels at critical levels for most of the low elevation forecast
zones in addition to mountain zones below 8500 feet. (Please see the
Fire Weather Forecast product for more information). Widespread
warming and drying conditions expected this weekend. High
temperatures today mainly in the mid 80s to lower 90s across the
lower elevations...mid 60s to mid 70s in the mountains. Minimum RH
values will drop into the lower/mid teens to lower 20s across the
lower elevations and foothills...25 to 35 percent in the mountains.
Afternoon mixed out winds ahead of a weak surface front today will
give occasional wind gusts 15 to 25 mph...elevating fire weather
concerns from Sweetwater County to the northeast across Natrona
County. Mainly dry across the entire forecast area today and Sunday.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

SHORT TERM...Braun
LONG TERM...Skrbac
AVIATION...Meunier
FIRE WEATHER...Braun

Hazardous Weather Outlook
National Weather Service Riverton WY
220 AM MDT Sat Aug 26 2017

WYZ001>020-022>030-271200-
Yellowstone National Park-Absaroka Mountains-Cody Foothills-
North Big Horn Basin-Southwest Big Horn Basin-
Southeast Big Horn Basin-Owl Creek and Bridger Mountains-
Bighorn Mountains West-Bighorn Mountains Southeast-
Northeast Johnson County-Southeast Johnson County-
Teton and Gros Ventre Mountains-Jackson Hole-
Wind River Mountains West-Wind River Mountains East-
Upper Wind River Basin-Wind River Basin-Lander Foothills-
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-Casper Mountain-Star Valley-
Salt River and Wyoming Ranges-Upper Green River Basin Foothills-
Upper Green River Basin-South Lincoln County-
Rock Springs and Green River-Flaming Gorge-East Sweetwater County-
220 AM MDT Sat Aug 26 2017

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and Tonight

Elevated fire weather conditions for portions of southern and central
Wyoming today due to very dry conditions.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Tuesday and Wednesday...A slight chance of late day thunderstorms
in and near the mountains.

Thursday...A chance of mainly afternoon and evening thunderstorms.
Most numerous in the mountains.

.SPOTTER INFORMATION STATEMENT...

No hazardous weather is expected at this time.

Team Riverton