Fire Weather Outlook Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
FNUS21 KWNS 180700

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0159 AM CDT Fri Jun 18 2021

Valid 181200Z - 191200Z


Widespread dry thunderstorms are expected today as mid-level
moisture seeps around the edges of an upper-level high anchored over
the Four Corners. Elevated and locally critical fire weather
conditions will be possible across the northern Rockies and upper
Midwest through the day ahead of increasing westerly flow aloft.

...Great Basin and Four Corners Dry Thunder...
Monsoonal flow around the periphery of the ridge across the
Southwest will support thunderstorm development from the Great Basin
eastward to the Four Corners and Colorado/New Mexico. Record heat
ongoing across the region will continue, with widespread surface
temperatures of 95-100+ F expected through the afternoon. The very
warm temperatures and dry surface conditions, RH less than 15%, will
increase evaporation potential, limiting precipitation from
thunderstorms. Dry thunderstorms appear likely, with the greatest
concentration expected along the higher terrain from eastern Utah
into western Colorado. While forcing for ascent will be relatively
weak, scattered storm coverage appears likely given robust buoyancy
profiles and abundant heating across the higher terrain. Fuels are
extremely susceptible to lightning starts given ongoing drought and
record heat. Critical dry thunderstorm probabilities will be
maintained through the forecast period.

Elevated to locally critical fire weather conditions appear likely
across portions of the Red Desert and northern Colorado this
afternoon and evening. Dry surface conditions with RH of 10-20% will
be in place within a very warm arimass with temperatures of 90-100+
F. While surface flow will be somewhat weak, west-southwesterly
surface winds of 10-15 mph, enhanced by thunderstorm outflow, will
be common through the afternoon. Given very dry fuel conditions and
the favorable meteorological circumstances, elevated to
near-critical fire weather conditions are likely.

...Western Minnesota...
A dry airmass will be advected into portions of the upper Midwest
tomorrow afternoon behind a departing cold front. While slightly
cooler than the preceding days, temperatures in the 80s F, with
decreasing surface moisture content, will favor dry boundary-layer
profiles supporting RH values near 25%. Northwest surface flow of
10-15 mph will be adequate for locally elevated fire weather
conditions through the afternoon, given widespread dry fuels.

..Lyons.. 06/18/2021

...Please see for graphic product...

$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.