Red Flag Warning 18, NWS Cheyenne, WY

366 
WWUS85 KCYS 041932
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
132 PM MDT Sat Aug 4 2018

WYZ303-304-050200-
/O.CON.KCYS.FW.W.0018.000000T0000Z-180805T0200Z/
Central and Northern Carbon/Ferris-Seminoe-Shirley Mountains-
Southwest Carbon County-
132 PM MDT Sat Aug 4 2018

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR GUSTY WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 303 AND
304...

* AFFECTED AREA...Western and central Carbon county, including 
  Fire weather zone 303 and Fire weather zone 304. 

* WIND...West 20 to 30 mph with gusts around 35 mph.

* HUMIDITY...10 to 15 percent in the afternoon.

* THUNDERSTORMS...Isolated thunderstorms possible. Some 
  thunderstorms may contain gusty outflow winds.

* IMPACTS...Any fires that develop will likely spread rapidly. 
  Outdoor burning is not recommended.

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.

&&

$$

966 
WWUS85 KCYS 050154
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
754 PM MDT Sat Aug 4 2018

...RED FLAG WARNING FOR FWZ 303 AND 304 TO EXPIRE ON TIME AT 8 PM
THIS EVENING...

WYZ303-304-050300-
/O.EXP.KCYS.FW.W.0018.000000T0000Z-180805T0200Z/
Central and Northern Carbon/Ferris-Seminoe-Shirley Mountains-
Southwest Carbon County-
754 PM MDT Sat Aug 4 2018

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR GUSTY
WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 303 AND 304...

Humidities have increased into the low to mid 20s and winds are
beginning to decrease. Widespread Red Flag weather conditions are
no longer expected tonight.  Therefore...the Red Flag Warnings
will be allowed to expire on time at 8PM this evening.

$$

Area Forecast Discussion
National Weather Service Cheyenne WY
1014 PM MDT Fri Aug 3 2018

.SHORT TERM...(This evening through Sunday)
Issued at 240 PM MDT Fri Aug 3 2018

Main forecast concerns through the weekend will be thunderstorm
activity, with the potential for strong thunderstorms each day,
and Fire Weather concerns further west (please see Fire Weather
section for more information). For this evening, thick cloud cover
along and east of the Laramie Range has been slow to dissipate
this afternoon. Therefore, lowered the chances for thunderstorms
based on current satellite trends, although kept the same POP for
shower activity. Showers and thunderstorm will likely linger
through late this evening with activity dissipating after
midnight.

For Saturday and Sunday, active zonal flow is expected as a weak
surface boundary moves southward and stalls near the I-80
corridor. In addition, models show a weak shortwave aloft and an
active jet moving into southeast Wyoming through the day,
resulting in a greater coverage of thunderstorms compared to
recent days. Some strong thunderstorms are possible east of the
Laramie Range/I-25 corridor each afternoon, but the chances for
severe weather will be relatively low due to skinny CAPE profiles
and the best lapse rates appearing to be above 400mb, at least on
Saturday. Shear appears to be greater on Sunday as the upper level
jet slides eastward, so there may be a greater risk of severe
thunderstorms Sunday afternoon, but with shower and thunderstorms
persisting into the late night and early morning hours, daytime
instability may be considerably lower than what model soundings
currently suggest. Daytime temperatures in the 80's to low 90's
are expected, with slightly lower readings on Sunday behind the
weak frontal boundary.

.LONG TERM...(Monday - Thursday)
Issued at 316 AM MDT Fri Aug 3 2018

No significant changes made to previous forecast for most of next
week. Showers and thunderstorm may linger through Wednesday due to
northwest flow aloft and moist upslope flow near the surface. /tt

Upper-level ridging will gradually build into the area through the
extended forecast period. Warmer and drier weather will prevail w/
minimal chances for precipitation, except earlier in the week with
lingering northwest flow on the edge of the ridge.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1011 PM MDT Fri Aug 3 2018

Wyoming TAFS...VFR. Isolated thunderstorms near sites after 19Z.
Wind gusts to 32 knots from 15Z to 02Z.

Nebraska TAFS...VFR. Isolated thunderstorms near Scottsbluff and
Sidney after 19Z. Wind gusts to 24 knots from 15Z to 02Z.

&&

.FIRE WEATHER...
Issued at 151 PM MDT Fri Aug 3 2018

A Fire Weather Watch is in effect for most of central and western
Carbon county on Saturday due to low humidities, gusty winds up to
40 mph in the afternoon, and the potential for daytime
thunderstorms. Not very confident about zone 305 with marginal
humidities, especially if thunderstorms/cloud cover develop too
early in the day, but with widely scattered thunderstorms possible
with very little rain initially, decided to add them to the watch
anyway. For the other zones in the Watch, really concerned about
persistent sustained winds through the day with current models
showing 20 to 30 mph sustained along and north of I-80.  Sunday
will be another elevated day across portions of Carbon county, but
winds appear to be somewhat higher with higher daytime humidities.
Further east, low Fire Weather concerns are expected due to
moderate daytime humidities and lighter winds.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Fire Weather Watch from Saturday afternoon through Saturday
     evening for WYZ303>305.

NE...None.
&&

SHORT TERM...TJT
LONG TERM...CLH
AVIATION...RUBIN
FIRE WEATHER...TJT

Hazardous Weather Outlook
National Weather Service Cheyenne WY
616 AM MDT Fri Aug 3 2018

NEZ002-003-019>021-054-055-095-096-WYZ101>119-041230-
Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne-
North Sioux-South Sioux-Converse County Lower Elevations-
Niobrara County-North Laramie Range-
Ferris/Seminoe/Shirley Mountains-Shirley Basin-
Central Laramie Range and Southwest Platte County-
East Platte County-Goshen County-Central Carbon County-
North Snowy Range Foothills-Southwest Carbon County-
Sierra Madre Range-Upper North Platte River Basin-Snowy Range-
Laramie Valley-South Laramie Range-South Laramie Range Foothills-
Central Laramie County-East Laramie County-
616 AM MDT Fri Aug 3 2018

This hazardous weather outlook is for portions of western
Nebraska...east central Wyoming...south central Wyoming and
southeast Wyoming.

.DAY ONE...TODAY AND TONIGHT

Scattered showers and thunderstorms will occur across much of the
area over the next 24 hours. Severe weather is not expected.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

An active weather pattern will continue on Saturday and Sunday,
with scattered to numerous showers and thunderstorms expected each
afternoon and evening. A few thunderstorms may be strong to
severe, with hail and wind the primary hazards.

.Spotter information statement...

Spotter activation is not anticipated.