SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1059 AM CST Thu Mar 02 2023
Valid 021700Z - 031200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND SOUTH
TEXAS...
The previous forecast (see below) remains on track, and only minor
westward expansions were made to the Elevated and Critical areas
based on the latest observations and high-resolution guidance.
Farther east over much of eastern and central FL, efficient diurnal
heating/mixing amid a dry antecedent airmass should yield critically
low RH (i.e., 30-35 percent) this afternoon. While sustained surface
winds of around 10 mph or less should mitigate fire-weather
concerns, at least locally elevated conditions are possible given
dry fuels across the area. However, current thinking is that any
elevated conditions should be too spotty for highlights.
..Weinman.. 03/02/2023
.PREV DISCUSSION... /ISSUED 0104 AM CST Thu Mar 02 2023/
...Synopsis...
A potent upper-level wave will eject across the Southern Plains
during the day on Thursday. By the afternoon, a 100+ kt mid-level
jet will overspread portions of west and south TX. This will support
deep boundary-layer mixing and drying prior to the arrival of a
Pacific cold front in the evening. Scattered convection yesterday
has resulted in locally higher fuel moisture content. However, for
the most part, the area has observed minimal precipitation for the
past several days. These factors will contribute to critical fire
weather conditions from the late morning through mid-afternoon in
portions of central and south TX.
...Big Bend region, the Edwards Plateau, and portions of
south-central TX...
Critical fire weather conditions are expected to develop relatively
early in the day as the powerful upper-level wave ejects eastward.
By late Thursday morning (around 17z), a deepening surface cyclone
centered in west-central TX will support strengthening
west-southwesterly flow (25-30 mph) across the Big Bend region. Dry,
downsloping winds will result in boundary-layer relative humidities
around 10-15 percent. This area has experienced several days of
minimal precipitation and generally dry, windy conditions, resulting
in fuels that support large fire spread. The prior Critical area has
been expanded into the Big Bend region and vicinity to account for
these expected conditions starting early in the day.
The expected area of critical conditions will gradually shift
eastward throughout the afternoon. Its zonal area will be bounded by
substantial moisture return to the east and an approaching Pacific
front from the west. Some uncertainty in the timing of the front --
and associated quick reduction in elevated/critical fire weather
conditions -- remains, but recent guidance suggest the most likely
timing of passage through the Big Bend region should be around
19-21z. Thereafter, critical conditions should exist ahead of the
front prior to nightfall through portions of south TX. Fuels are
generally receptive to fire spread along the Rio Grande River
Valley, except in a small area in south-central TX that experienced
locally heavy convective precipitation yesterday. The Critical area
has been trimmed slightly westward in this region, which would
otherwise support a critical fire weather threat.
...southeastern NM...
There is also some signal for the development of post-frontal,
elevated fire weather conditions in southeastern NM in the
afternoon. However, uncertainty regarding the timing of frontal
passage, moisture quality behind the front, and somewhat
less-receptive fuels preclude introducing an Elevated area there.
...Please see www.spc.noaa.gov/fire for graphic product...
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