Fire Weather Outlook Discussion
Issued by NWS
FNUS21 KWNS 301556
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1055 AM CDT Sun Apr 30 2017
Valid 301700Z - 011200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF FAR WEST TEXAS...
A critical area was introduced in the Transpecos region of Texas for
this outlook. Here, models/high-res guidance support 20-25 mph
westerly surface flow developing for sufficient duration this
afternoon to justify a critical delineation as temperatures rise
into the 70s during peak heating hours. Critical RH will also
develop in the region, with many areas exhibiting single-digit RH
values by early afternoon.
Elsewhere, stronger flow will develop in the afternoon into central
New Mexico, which may elevate fire weather conditions despite
relatively cool surface temperatures (50s to mid 60s F) and only
15-25% RH values. The previous elevated delineation has been
altered some to include more of central New Mexico as a result of
the latest guidance.
Elsewhere, the previous forecast is on track with minimal changes
needed. See the previous discussion below for more information.
.PREV DISCUSSION... /ISSUED 0255 AM CDT Sun Apr 30 2017/
An upper low centered over the TX/OK Panhandles early this morning
will move northeastward across the central/southern Plains today,
reaching the upper MS Valley and Upper Midwest by the end of the
period. A cyclonically curved belt of enhanced mid-level winds will
remain across parts of the Southwest into the southern Plains
through this evening, before gradually weakening through early
Monday morning across this region. At the surface, a low over KS/OK
will develop northeastward in a similar fashion to the upper low
through the period. A dry, post-frontal airmass will reside across
the Southwest and southern Plains.
...Portions of Southeastern AZ into Southern NM and South TX...
Elevated fire weather conditions are anticipated today from portions
of southeastern AZ into southern NM and continuing into south TX.
Across this region, sustained northwesterly post-frontal winds
should increase into the 15-20 mph range as diurnal mixing of the
boundary layer allows for efficient downward transfer of enhanced
mid-level winds to the surface. Although temperatures will generally
not be overly warm given the post-frontal airmass, diurnal heating
and some downslope warming/drying with low-level trajectories off
higher terrain in Mexico and NM should allow RH values to fall into
the 7-15% range for a few hours this afternoon from southeastern AZ
into southern NM and far west TX (roughly the Big Bend region). From
the middle Rio Grande Valley southeastward into deep south TX, RH
values should generally fall into the 15-25% range this afternoon.
Sustained winds above 20 mph are expected on just a localized basis
across parts of far west TX, which precludes the introduction of a
...Please see www.spc.noaa.gov/fire for graphic product...