Fire Weather Outlook Discussion
Issued by NWS
FNUS21 KWNS 291439
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0939 AM CDT Wed Mar 29 2017
Valid 291700Z - 301200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHWEST TEXAS...
Ongoing forecast is on track with only minimal changes to the
elevated area in southwest Texas. Critical conditions remain likely
in areas near the Rio Grande Valley this afternoon. See the
previous forecast below for more information.
.PREV DISCUSSION... /ISSUED 1247 AM CDT Wed Mar 29 2017/
A deep midlevel cyclone and an associated surface cyclone are
forecast to move across portions of the South-Central States. A
deep/dry boundary layer west of a Pacific boundary (extending to the
south of the surface cyclone) will linger across southwest TX. A
comparatively stronger cold front is forecast to advance southward
across the southern High Plains.
...Portions of southwest TX...
Across the Critical area, downslope trajectories and related
warming/drying will support minimum RH around 10-15 percent.
Diurnally enhanced vertical mixing into enhanced flow aloft
surrounding the deep midlevel cyclone will support westerly to
west-northwesterly surface winds of 20-25 mph, combining with the
aforementioned RH. Winds will turn more northwesterly/northerly
through the late afternoon/evening behind the southward-moving cold
front, which will be accompanied by an influx of cooler air
supporting higher RH.
Elevated fire-weather conditions are forecast to surround the
Critical area, though any areas of strong winds are not expected to
coincide with sufficiently low RH for Critical designation.
...Portions of the lower CO River Valley...
Strong vertical mixing amid a dry air mass will support minimum RH
around 7-10 percent, while slightly enhanced flow aloft is
manifested at the surface as wind speeds around 15 mph. With areas
of dry fuels, an Elevated area is in effect.
...Please see www.spc.noaa.gov/fire for graphic product...