ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 211635
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1035 AM CST Tue Nov 21 2017
Valid 211700Z - 221200Z
Recent surface analysis places a low near ABI with a cold front
extending northeastward into the middle MS Valley and southwestward
through the Edwards Plateau. Dry, post-frontal conditions are
expected across the region today but the colder air associated with
this new airmass will remain north of the region until later
tonight. As a result, despite the frontal passage, high temperatures
will still reach the upper 60s to upper 70s F (8-12 degrees
above-average) this afternoon. Afternoon RH values in the low
20s/upper teens are anticipated across the majority of the region.
Additionally, a strong surface pressure gradient and enhanced flow
aloft amidst deep boundary layer mixing will contribute to gusty
winds (i.e. sustained 20-30 mph with gusts around 45 mph. These dry
and windy conditions will result in elevated to locally critical
fire weather conditions. Highest likelihood for locally critical
conditions will occur across the TX South Plains.
Poor overnight recovery was realized across the higher elevations
and weak offshore flow is currently ongoing with several sites
experiencing wind gusts over 20 mph. Locally elevated conditions
will continue for the next few hours before the gradient diurnally
decreases. Similar conditions are expected early tomorrow morning.
.PREV DISCUSSION... /ISSUED 0147 AM CST Tue Nov 21 2017/
The mid-level ridge across the western United States will build
northward today. Downstream from the ridge, a series of mid-level
troughs will move across the eastern United States, helping to
produce mean troughing. The result will be a relatively dry airmass
entrenched across most of the United States.
Strong northerly winds in excess of 20 mph, with gusts between 40-50
mph, will develop in the wake of a surface cold front. These winds
will usher in a very dry airmass during the day in the wake of a
surface cold front. Despite cold-air advection, relative humidity
should manage to fall into the 20-30% range across much of the area,
with locally favored areas falling into the teens. The combination
of winds in excess of 20 mph and relative-humidity values in the
20-30% range will result in elevated to locally critical
fire-weather conditions. Peak fire-weather concerns will occur
during the late morning and early afternoon across northern portions
of the outlook area and then shift southward with time as falling
temperatures in the north allows relative humidity to recover
The overall large-scale pattern will favor weak, easterly, off-shore
flow early on Tuesday. However, the flow looks to remain weak,
precluding the need for fire-weather highlights.
...Please see www.spc.noaa.gov/fire for graphic product...
CLICK FOR DAY 1 FIREWX AREAL OUTLINE PRODUCT (KWNSPFWFD1)