Fire Weather Outlook Discussion
Issued by NWS
FNUS28 KWNS 232123
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0423 PM CDT Thu Mar 23 2017
Valid 251200Z - 311200Z
Medium-to-long-range model consensus suggests an active period of
elevated to critical fire weather conditions throughout the extended
forecast period in portions of the Southern Rockies and adjacent
Plains as a train of frequent mid-level disturbances traverse the
southern tier of the Lower 48.
...D3/Sat - Southeastern Arizona, much of New Mexico, and West
Mid-level flow will strengthen in the region as a negative-tilt, yet
low-amplitude wave approaches the region from the west. Localized
areas of 20 mph west-southwesterly flow will develop in the
afternoon amidst a very dry airmass (widespread critical RH values)
and areas of dry fuels. Locally critical fire weather conditions
are possible in a few areas, although concerns about the duration of
20+ mph surface winds precludes addition of any highlights with this
forecast. This region will be monitored in later outlooks.
...D4/Sun - Portions of New Mexico and west Texas...
The aforementioned low-amplitude wave will eject over the central
Plains by the D4/Sun timeframe in conjunction with a deepening
surface cyclone over Colorado/Kansas. The steepening pressure
gradient across the region will foster areas of westerly downslope
flow exceeding 20 mph over a widespread area. Fuels are also
expected to remain dry in the region, and afternoon RH values should
fall to near 15% in portions of the Texas Panhandle/east-central New
Mexico and as low as single digits near the Big Bend region of
Texas. An attendant critical fire weather delineation has been
expanded to reflect greater confidence in a widespread critical fire
weather threat developing D4/Sun afternoon.
...D6/Tue - Portions of New Mexico, west Texas, and southeastern
Mid-level flow will strengthen across the region as an amplifying
mid-level disturbance begins to cut off from the westerlies over the
Lower Colorado River Valley. As this occurs, vertical mixing
processes should allow for southerly low-level flow to strengthen
during peak heating hours, resulting in elevated to near-critical
fire weather conditions in the region. One potential negating
factor for a more widespread fire weather threat would be relatively
high boundary layer RH expected due to a modest influx of low-level
moisture from the western Gulf of Mexico and also mid-level moisture
ahead of the advancing wave.
...D7/Wed and D8/Thu - Portions of far west Texas and adjacent
Models vary with handling of the mid-level cut off low moving into
the southern Plains during the time period, although it appears that
some enhancement of westerly mid-level flow (and associated surface
cyclogenesis) will develop across the southern Plains during the
time period. As this occurs, a dry sector will develop most likely
over far west Texas where enhanced westerly surface flow and dry
low-level conditions will exist. Forecasting the specific location
of this dry sector at this time frame is difficult owing to varied
model guidance regarding the evolution of attendant synoptic
features. Hence, probabilities remain too low for any delineated
areas at this time, although trends will continue to be monitored.
...Please see www.spc.noaa.gov/fire for graphic product...