St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

657
FXUS63 KEAX 181735
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1135 AM CST Sun Jan 18 2026

.KEY MESSAGES...

- Brief Warm Up This Afternoon, Some Snow Flurries or Sprinkles
  Possible Today

- Cold Tonight and Monday Morning

- Back to Normal Temperatures After Tuesday

&&

.DISCUSSION...
Issued at 320 AM CST Sun Jan 18 2026

Primary mid and upper-level long-wave trough axis has shifted
southeastward toward the western Ohio River Valley, with a stronger
dAVA regime trailing this allowing a surface anticyclone to develop
over the eastern Plains and lower Missouri River Valley. There are a
few mid-level vort maxima and short-wave trough axes over portions
of the Northern Plains associated with a 140+ kt jet streak moving
southward from Canada. On the leading edge of this stronger dCVA
lift has been resulting in decreasing surface pressure, resulting in
a weak cyclone moving across the Northern Plains and upper Midwest
this morning. This will also push a colder airmass toward Iowa. This
larger scale setup will result in some adiabatic compression heating
over the Front Range into the High Plains. As that short-wave drops
southward, expecting the east-central Plains to see a few hours of
west-southwesterly flow this afternoon providing modest WAA that may
help temperatures reach the back into the upper 30s, perhaps lower
40s for the southwestern two-thirds of the forecast area. The far
northeast portions, near Kirksville, may struggle to climb above
freezing today. Will need to watch the cloud cover moving
southeastward though. If this does not clear, temperatures may be a
few degrees cooler this afternoon. Mid-level lift gradually
increases through the morning and afternoon hours, along with
another eventual CAA push heading into the evening. This may be
enough to generate flurry or sprinkle activity (depending on
temperatures). Surface pressure gradient will increase throughout
the day as this next wave moves through, therefore expecting breezy
winds to develop especially heading into the evening hours. Once the
main mid-level lobe of vorticity moves through eastern Iowa, flow
through most of the troposphere over our area turns northwesterly,
pushing in an Arctic Airmass that will start a period of temperature
below normal through Tuesday morning. Breezy winds on Monday morning
will result in wind chills around 10 to 15 below zero in northern
Missouri, with sub zero wind chills elsewhere across the area.
Afternoon wind chills will generally be in the teens, with some
single digits possible especially in northern Missouri. While
moisture content will limited, times of subtle convergence may be
able to prompt some flurry activity, as the DGZ will basically be in
the boundary layer with the cold airmass.

Tuesday into Wednesday, another vort maxima moves across the western
Great Lakes Region and will arrive in some parts of the middle
Mississippi River Valley. Most guidance though keeps most of the
cyclonic jet action northeast of the area, and allows a surface
anticyclone spread across our area and move eastward. A few
disturbances over the Rockies will make an attempt at cyclogenesis.
This should turn flow southerly Tuesday afternoon and help
temperatures climb back to near normal.  Through the middle of the
week, the closed-low system over Hudson Bay has a lot of its forcing
pushed northward, as the southwestern CONUS experiences a mid-level
ridge moving in, while a PV anomaly off the Pacific Northwest sends
trough toward the Northern High Plains. This sets up a short period
of brisk mid-level zonal flow across the Central CONUS. Toward the
end of the week, trough moves through the central CONUS. Ensemble
spread is quite large due to timing differences in the propagation
of the end of weak disturbance. There continues to be low end
probabilities for detectable precipitation. If this moves far south
enough, the area would be looking mainly at a wintry precipitation
type. But inner-quartile spread for temperatures for the end of the
week are large enough resulting in low confidence in p-type for end
of the week activity.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1135 AM CST Sun Jan 18 2026

VFR conditions will prevail through the period. Winds will be the
primary concern with gusty southerly winds today and tonight. Gusts
to 25 to 20 knots are expected through tonight with winds turning
northwesterly this afternoon. Winds then diminish late in the
period. Can`t rule out an isolated flurry or two through this
afternoon, but they should not lead to any impacts.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Cold Weather Advisory from 3 AM to 10 AM CST Monday for MOZ007-
     008-017.
KS...None.

&&

$$

DISCUSSION...Krull
AVIATION...BJH