Olathe, Kansas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

670
FXUS63 KEAX 251128
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
528 AM CST Thu Dec 25 2025

.KEY MESSAGES...

- Dense fog will continue across the region through this
  morning. Conditions should improve during the afternoon.

- Very warm and dry conditions will continue through Saturday.
  Record highs may be approached, but the extent of cloudiness
  increases uncertainty in the temperature forecast, especially
  today and Saturday.

- A strong system will affect the area on Sunday. Temperatures
  will turn much colder, and windy conditions are expected
  Sunday afternoon. Precipitation chances have increased on
  Sunday as well (20-50 percent; best chances east of U.S.
  Highway 65). Wind chills in the single digits above and below
  zero are forecast Sunday night and Monday morning.

&&

.DISCUSSION...
Issued at 158 AM CST Thu Dec 25 2025

Today is Christmas Day, but it may seem like Groundhog Day given
the dense fog that is plaguing much of the area again early this
morning. Satellite and webcam presentations are impressive, with
widespread areas of very dense fog (visibilities as low as
100-200 feet). It will not be a fun drive out there this
morning, so give yourself extra time and use those low-beam
headlights.

The main question today, like yesterday, is how quickly
conditions will improve. If we use yesterday as a proxy, fog
would erode by midday with sky cover improvement from south to
north an hour or two after that. Synoptically, conditions are
not a whole lot different, but there will be an approaching
perturbation to our northwest this afternoon (and a developing
surface low in South Dakota). This could generate sufficient
southerly surface winds to mix out the low clouds and fog
sooner, but it could also generate increased cloudiness higher
up in the atmosphere to reduce mixing. Given the extent of low
clouds and the strength of the warm advection, I think it will
be quite challenging to erode the cloud cover north of U.S.
Highway 36, but areas to the south and especially south of I-70
have a good shot of seeing some filtered sunshine this
afternoon. Based on how yesterday`s temperatures played out, it
will not take much insolation to get temperatures to climb
rapidly. For this reason, raised temperatures in the KC area to
around those seen on Wednesday. This will be pretty close to
today`s record high (67 at MCI); current forecast is 2-4 degrees
shy of it. Ensemble probabilities indicate a 30% chance of KC`s
record high being tied or broken today, which seems about
right. Meanwhile, to the south, temperatures well into the 70s
seem probable once again. And to the north, we may only see the
50s. Another large-temperature gradient day in our forecast
area, with larger than typical forecast errors likely for a
12-hour forecast.

As the sun sets, low clouds and fog may quickly set in again,
especially in the northern CWA. However, tonight will be
different, as that aforementioned surface low in South Dakota
races east-southeast into eastern Iowa by 12z Friday, bringing
a weak front through the forecast area overnight. This should
quickly and effectively scour out the fog, and probably the low
clouds too. Fog and low clouds may linger in northeastern
Missouri by daylight Friday, but expecting other areas to see
much less coverage by sunrise than what we have seen the past
three mornings.

This will also set the stage for a much sunnier day on Friday,
with weak cold advection at best (and quickly becoming
neutral). The upper ridge axis will be near or over our area
Friday afternoon. This suggests that Friday could be quite warm,
and ensemble guidance has been trending warmer for the past
several days. The record high in KC is 66; this seems quite
breakable to me. NBM probabilities are around 40%, but I would
probably lean a little higher than that at this point.

As the next system approaches the area this weekend, another
round of warm advection and low clouds seems to be a good bet on
Friday night and Saturday, rendering the temperature forecast
more uncertain for this time frame. Current forecast is in the
upper 60s (KC area) again Saturday afternoon, but this may be a
little optimistic given the overall pattern suggestive of
substantial lift and moist advection.

Our attention turns to the most interesting part of the
forecast, both from a sensible-weather and a model-
predictability perspective: the sharp return to winter on Sunday.
Deterministic and corresponding ensemble solutions depicting a
potent northern-stream trough digging into the northern Plains
Saturday night have trended much slower over the past 24-48
hours. This is tied strongly to its interaction with a southern-
stream trough ejecting from the southern California vicinity. A
couple of days ago, the model consensus decidedly kept the
northern-stream system separate and very progressive, with a
general location of the vort max near the Great Lakes by 00z
Monday. However, models have consistently shown more interaction
between the two perturbations in recent runs, and have slowed
the now-phased trough to the central Plains vicinity by 00z
Monday. This significant change in the trough
evolution/progression would allow sufficient moisture return in
advance of the system and much stronger large-scale ascent to
affect our forecast area late Saturday night into Sunday
afternoon. This results in a substantial increase in PoPs for
our area -- now mostly 20-50% (highest south and east parts of
the CWA). Furthermore, the strong forcing attendant to the
system will allow for marginal instability to develop in advance
of the stout cold front sweeping southeastward Sunday morning.
Yes, that`s right -- thunderstorm chances exist as well. Now,
instability will be marginal at best (likely 500 J/kg MUCAPE at
most), but deep-layer shear will be strong (40-50+ kt). It is
not impossible a rogue severe storm or even a strongly-forced
squall line develops in advance of the system (though I think
better chances are south and east of our forecast area).
Whatever the case, we will appreciate any rainfall the
atmosphere is willing to offer right now! It is not out of the
question a rogue snow shower occurs upstream of the front Sunday
afternoon, though these chances are rather low at the moment
(less than 25%).

Unfortunately, the price of this increased precipitation
potential is the intrusion of much, much colder air. It will be
quick, it will be sharp, and it will come with wind. The
pressure gradient upstream of the front will be quite strong
given the strength of the building surface high. Advisory-level
winds may occur (about a 20-40% chance) Sunday afternoon. And
temperatures will fall sharply, bottoming out in the teens on
Sunday night with elevated winds continuing. Wind chills near
zero seem likely (60+% chance) Sunday night and Monday morning.
Monday`s highs will be below freezing everywhere. Compare that
to the 60s and 70s of Friday and Saturday...

Temperatures will rebound to near-to-slightly-above-average
highs by the middle of next week, with no appreciable chances
for precipitation after the Sunday system.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 521 AM CST Thu Dec 25 2025

Dense fog continues at the terminals early this morning.
LIFR/VLIFR CIGs/VSBYs are expected to continue through at least
15z and perhaps as far out as 18z, with VSBYs likely to improve
more quickly than CIGs thereafter. IFR ceilings early this
afternoon are expected to improve from south to north, though
exact timing is uncertain. STJ may see little improvement in
CIGs most of the day, though VSBYs should improve to VFR by mid
afternoon. A period of VFR at the KC terminals is anticipated
late this afternoon and this evening. Restrictions may set in
again after 02z (especially at STJ), but a weak front will move
through the area overnight (around 05z to 08z), which is
expected to scour any low ceilings and/or fog in place. Light
and variable winds this morning will become southeasterly and
then southerly around 10 kt this afternoon. Winds will continue
veering to the southwest and then west tonight as the front
moves through.

&&

.CLIMATE...
Issued at 157 AM CST Tue Dec 23 2025

Record High Temperatures:

December 25:
KMCI: 67/1922
KSTJ: 65/2019

December 26:
KMCI: 66/2008
KSTJ: 65/2008

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Dense Fog Advisory until 10 AM CST this morning for MOZ001>008-
     011>017-020>025-028>033-037>040-043>046-053-054.
KS...Dense Fog Advisory until 10 AM CST this morning for KSZ025-057-
     060-102>105.

&&

$$

DISCUSSION...CMS
AVIATION...CMS
CLIMATE...CMS