242
FXUS63 KEAX 180921
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
321 AM CST Thu Dec 18 2025

.KEY MESSAGES...

- Very strong winds are expected today, coming in several
  rounds. Round 1 this morning and Round 2 mainly this
  afternoon. Wind gusts of 40-45 mph are likely. It`s still very
  possible we see a few wind gusts of 50+ mph to near High Wind
  Warning Criteria.

- Dangerous fire weather conditions are expected this afternoon
  from eastern KS and parts of western MO due to a combination
  high winds and low humidity values.

- Snow showers are possible across northern MO as cold air
  spills into the region and the strong upper-level storm
  system moves overhead. There is a signal for snow squalls as
  well given the strength of the system.

- Very cold air move into the area Thursday night - Friday,
  with lows in the teens and 20s and wind chill values in the
  single digits and teens.

&&

.DISCUSSION...
Issued at 321 AM CST Thu Dec 18 2025

Strong Winds Today:

Water vapor imagery shows a powerful storm system moving into the
middle country early this morning, with strong drying noted across
northeastern CO, northwestern KS, and southwestern NE. Strong
southerly flow ahead of this storm system, is leading to wind gusts
near or just above 45 mph across eastern KS and western MO. Given
that, moved the start time of the western segment of the wind
advisory up to start at 2 AM and the eastern segment to start at 6
AM. There will be a relative lull from mid to late morning, as the
initial front is moving through the area and winds weaken. But
behind that front, lapse rates steepen and mix into 40-50 kt
winds between 1 and 1.5 KM. The secondary front will move
through the area during the afternoon hours with similar steep
lapse rates and mixing into more widespread 45-55 kt winds
aloft. This continues past 00Z this evening and have extended
the advisory through 03Z. It`s possible this will need to be
extended even later, especially for our northeastern zones.
When looking at cross sections through the PV anomaly, as the
system is moving over eastern KS and western MO, it appears
there is some stratospheric/ PV intrusion and we see high PV
air down to nearly 850mb. This is indicative of a very strong
storm system and it`s quite possible, even with going on the
high end of model guidance for winds, that we see even stronger
wind gusts. It`s still possible we see gust near High Wind
Warning criteria (58+mph) as the system is moving overhead.


Critical Fire Weather Conditions This Afternoon:

Afternoon humidity values will drop off quickly behind the initial
front. And with winds increasing at the same time, critical fire
weather conditions are expected to develop. A red flag warning has
been issued for our eastern KS counties, the KC metro and southward,
including Johnson and Henry counties. While some of the areas in the
Red Flag Warning may not see humidity values drop into the 20s,
given the strength of the system, seeing fires breakout to our west
overnight, as well some concerns from area emergency managers, have
brought Red Flag Warning northward into areas that are forecast to
see humidity values only fall into the mid 30% range, which includes
the KC metro area. As the secondary front moves south, with strong
cold and dry advection behind it, humidity values increase. But winds
will continue to be strong and gusty after the expiration time of
the warning.

Snow Showers This Afternoon:

With the upper-level PV anomaly moving overhead this afternoon, and
strong cold advection occurring, there will likely be some snow
showers and/or snow flurries across northern and northeastern
MO. Forecast soundings show some shallow instability at the
base of very low dendritic growth zone. Saturation is fairly
shallow, though still around 5K ft. I went back and looked at
the aircraft sounding for the February 14, 2010 snow squall
event here, and that event had greater instability with it, as
well as a more distinct, cutoff PV anomaly. This event has
shallower instability and an attached PV anomaly that may
actually extend deeper into the troposphere given the PV
intrusion noted on cross sections. Regardless, have added some
mention of snow to the forecast for northern and northeastern
MO. It`s possible, given the weak instability/ steep lapse
rates, low DGZ, and saturation in that DGZ, that brief drops in
visibility in snow occur. The NAM even shows positive values of
the snow squall parameter this afternoon.

Cold Air Dropping Into the Area Tonight - Friday AM:

Strong cold advection behind the secondary front will drop
temperatures quickly Thursday evening and overnight into Friday
morning. This will result in low temperatures falling into the teens
and 20s by Friday morning with wind chill values in the single
digits to teens above zero. This isn`t extreme cold for the area but
it is slightly below normal for lows this time of year. And it`s
quite a contrast to the relatively balmy conditions currently across
the area. The cold will also be short-lived as high pressure to our
southeast quickly allows the surface flow to return to the south,
leading to highs Friday climbing back into the upper 30s, in
our northeast, to near 50 degrees, in our southwestern zones.

Rest of the Forecast:

The rest of the forecast continues to look relatively quiet. Upper
ridging expands over almost the entire CONUS, with the ridge axis
through the middle of the country. Our forecast shows highs climbing
into the 60s across the southern half to two-thirds of the forecast
for next week, which, given the strength of the ridging, makes
sense.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1133 PM CST Wed Dec 17 2025

Winds will be the main issue at the terminals for the next 24
hours. Strong south to southwest winds (10 to 20 kt with
occasional gusts to 30 kt) will persist overnight, becoming
westerly to northwesterly as showers move through around
daybreak. Brief gusts to 40+ kt may occur with the showers
(30-50 percent chance). A lull in the winds will occur 13z-15z
before strong northwest winds develop and last through at least
00z Friday. Speeds of 15 to 30 kt with gusts in excess of 40 kt
are expected during the afternoon before diminishing slowly
after sunset.

MVFR ceilings will persist through around 12z, as showers
approach the area from the northwest. Showers are most likely to
impact the terminals in the 10z-13z time window. Brief IFR may
occur with the showers, but these probabilities are rather low
(<20%). Skies should rapidly clear after the showers move
through this morning, but a stratocumulus deck is expected to
develop during the afternoon with ceilings 3500-6000 feet. This
cloud deck should dissipate quickly after dark Thursday evening.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Red Flag Warning from noon today to 6 PM CST this evening for
     MOZ020-028-029-037-043-044-053-054.
KS...Red Flag Warning from noon today to 6 PM CST this evening for
     KSZ025-057-060-102>105.

&&

$$

DISCUSSION...CDB
AVIATION...CMS