Fire Weather Outlook Discussion

Day 1 - Storm Prediction Center Norman, Oklahoma

180 
FNUS21 KWNS 141608
FWDDY1

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1108 AM CDT Mon Oct 14 2019

Valid 141700Z - 151200Z

...Central High Plains...
The elevated fire weather area over portions of Wyoming and
northwest Colorado has been extended eastward across southeast
Wyoming, northeast Colorado, and western Nebraska. While fuels
receptiveness has remained uncertain-to-very marginal over these
areas the last several days owing to recent snowfall (and subsequent
snow melt), recent fuel guidance suggests fuels -- especially fine
fuels -- have dried enough to support large fire spread.

Surface observations at 16Z from KEHY/KRWL/KSAA/KCYS as well as the
RTMA suggest elevated to locally critical meteorological conditions
are already ongoing across portions of southern Wyoming, with 15-20
mph sustained surface winds and RH values around 15-20%. Strongly
considered upgrading parts of southern Wyoming to Critical with this
update, as critical meteorological conditions are likely for at
least a few hours this afternoon. However, the overall lack of fuels
(where the strongest winds are expected) and somewhat marginal fuel
receptiveness precluded upgrading.

...South-central Colorado...
An elevated fire weather area was introduced across portions of
south-central Colorado (including in the vicinity of the Decker
Fire). Here, the latest ensemble guidance indicates several hours of
elevated to near critical fire weather conditions resulting from
gusty downslope gap winds amidst a very dry low-level air mass. The
worst conditions (i.e., sustained winds near 20 mph and gusts to
30+) are expected from 12 pm - 5 pm MDT.

Please see previous discussion below for more information on today's
fire weather forecast.

..Elliott.. 10/14/2019

.PREV DISCUSSION... /ISSUED 0123 AM CDT Mon Oct 14 2019/

...Synopsis...
A progressive shortwave trough will drop southeastward from Alberta
into the northern Rockies today. This feature will amplify through
the period. Farther south, a shortwave trough within the subtropical
jetstream will move through the southwest, weakening with time. At
the surface, lee troughing, deepening the most in the north, will
occur within the High Plains. A cold front will make fairly rapid
progress southward through the northern/central Rockies and into the
central Plains by the end of the period.

...Southern Wyoming and northwest Colorado...
The combination of the approaching surface trough/cold front and
strong mid-level flow aloft will lead to 15-20+ mph winds across
southern Wyoming and portions of northwest Colorado. Afternoon RH
within the lower elevations will reach 10-20%. Critical
meteorological conditions are probable in portions of southern
Wyoming, but between lack of fuels and marginal fuel dryness, large
fire spread potential is low enough that a critical area will not be
introduced.

...Decker Fire in south-central Colorado...
An uptick in fire activity is possible as areas of localized
downslope flow reach 15-20 mph over very dry fuels. RH during the
afternoon will fall to 15-20%. The main uncertainty is the duration
of elevated conditions.

...Parts of northeastern New Mexico...
Locally elevated conditions may occur briefly during the afternoon,
particularly where terrain enhances the surface flow. Winds of 15-20
mph and RH of 15-20% during the afternoon should remain spatially
and temporally confined and no elevated area will be introduced this
outlook.

...Please see www.spc.noaa.gov/fire for graphic product...

$$