Fire Weather Outlook Discussion
Issued by NWS
FNUS28 KWNS 172144
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0343 PM CST Tue Jan 17 2017
Valid 191200Z - 251200Z
The beginning of the forecast period will be the onset of
substantial longwave troughing over the Western U.S. as a powerful
(125 kt) mid-level jet approaches the Southern California coast.
Multiple shortwave troughs will traverse the Southwest and Great
Plains throughout the extended forecast period, with the most
significant of these (for fire weather concerns) traversing the
Southern Plains and Lower Mississippi Valley region on D6/Sun. The
surface response to the series of significant mid-level troughs will
be multiple days of westerly downslope flow over portions of the
Southern Plains, which will gradually heighten fire weather concerns
in portions of Texas late in the forecast period.
...D4/Fri through D8/Mon - Eastern New Mexico and Parts of Texas...
Multiple days of westerly downslope flow will develop in the region
due to both vertical mixing of very fast flow aloft to the surface
and multiple substantial areas of low pressure traversing
Kansas/Oklahoma and parts of the Mid-South. While elevated to
perhaps critical atmospheric conditions will likely exist on most
days (especially in parts of west and south Texas), concern about RH
and receptiveness of fuels to fire spread (especially across
portions of central Texas where copious amounts of rain have fallen)
casts some doubt on the extent of the fire weather threat. Portions
of south Texas, however, have been relatively rain free and fuels
should be more supportive of a fire weather threat there.
Models are consistent in developing elevated to critical fire
weather conditions along the Rio Grande river valley in south Texas
on D5/Sat and D6/Sun. On each of these days, very strong (20-40
mph) westerly/northwesterly surface flow will develop with Rh values
falling to near 15-25% (possibly lower in a few areas). With drier
fuels likely to reside in this region, a few areas may need an
upgrade to 70%/critical probabilities in later outlooks as details
in the overall fire weather scenario become clearer.
Beyond D6/Sun, models exhibit good agreement in continued westerly
low-level flow and an active mid-level pattern across the region.
This flow pattern will likely keep the area dry, and highlights will
likely be needed once specific areas of heightened fire weather
concerns can be pinpointed.
...Please see www.spc.noaa.gov/fire for graphic product...