St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

711
FXUS63 KEAX 172131
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
331 PM CST Wed Dec 17 2025

.KEY MESSAGES...

- A strong storm system will bring rain and wind overnight through
Thursday. Expect rain chances (30% south -80% north) through early
Thursday across the area. The most favorable areas will be north of
I-70 and east of I-35.

- Strong winds expected with gusts of 40-45 mph likely tomorrow and
will spread eastward across the area by afternoon. Areas west of I-
35 may briefly see a few wind gusts +50 mph.

- Fire weather concerns increase Thursday afternoon, mainly due to
the strong winds but also with humidity values dropping into the 25-
35% range for a few areas near central MO.

- Wind chill values fall into the single digits and teens above
  zero Thursday night into Friday morning.

&&

.DISCUSSION...
Issued at 327 PM CST Wed Dec 17 2025

A relatively quiet day ahead of the expected storm system with a
flattened mid to upper-level ridge moves through the region and a
deepening mid to upper level trough pushes over the Pacific
Northwest. Highs today expected to be fairly similar to yesterday
ranging from the upper 40s to upper 50s. This is result of a surface
high pressure situated to our southeast and a surface low moving
through Calgary into Saskatchewan. As the surface low tracked to the
east today, our winds shifted to the south as we enter the warm
sector.

As we transition into the evening, the mid to upper level trough
will continue to deepen becoming a closed low. It will then begin to
sink into the lower 48 passing through the Dakotas overnight into
early Thursday. This closed low will push a cold front through the
area which will provide lift for showers starting a little after
midnight tonight. The best chances reside east of I-35 and north of
I-70. Despite the abundance of shear, no thunderstorms are
anticipated given the extremely limited instability or it will be
low probability. Rain accumulation totals will range from several
hundredths of an inch to just under a quarter-inch. Rain chances
taper off by the late morning/afternoon as the cold front tracks to
the east. As we head into the afternoon hours, winds shift to the
north/northwest allowing a colder, drier airmass to move through the
area which will rapidly clear out skies. This, coupled with
steepening lapse rates will result in deep mixing through the day.
With multiple model soundings suggesting 40-50 kts at the top of the
mixed layer, 40-45 mph winds gusts are expected Thursday afternoon.
A few locations may even approach High Wind Warning Criteria (wind
gusts 58 mph or greater). Ensemble guidance (LREF) continues to
suggest the areas most likely to see the strongest winds will be
mostly west of I-35. Even still, most of the area will likely see
wind gusts at/or above 40 mph as the LREF keeps probabilities above
50% for the majority of the area. Given these conditions, a wind
advisory has been issued for the areas of most confidence (areas
west of a line from Putnam to Johnson counties).

Additionally for Thursday afternoon, there will slightly elevated
fire weather conditions across most of the area given how strong the
winds will be. Relative humidity values dip into the upper 20s to
lower 30s for a few areas near central MO further increasing fire
weather concerns for those areas. There a potential that few areas
could meet Red Flag Warning criteria. With widespread wind gusts
exceeding 40 mph, burning is discouraged across the area for
Thursday afternoon as fires could rapidly spread.

Winds slowly diminish late Thursday, as a transient high pressure on
the backside of the cold front ushers in a colder air mass. Clearing
skies and weakening winds will set the stage for radiational cooling
which will allow morning temperatures to sink into the upper teens
to low 20s. Wind chills could possibly reach the single digits to
preteens for areas north of HWY-36. Luckily, these cold temperatures
will be short-lived as the surface high moves to the east of the
area by late morning returning our winds to the south. High
temperatures rebound quite nicely, ranging from the upper 30s to
upper 40s. This weekend, a closed mid to upper low moves into
Ontario, keeping precip chances farther to the north. By Monday,
broad mid to upper level ridging begins to move into the area
keeping us dry and warm through most of next week. Extended guidance
suggests temperatures will be well-above normal (nearly 20 degrees)
approaching Christmas with highs approaching the 60s
(probabilities show 50-60% chance).

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1122 AM CST Wed Dec 17 2025

VFR conditions are anticipated to last through the day with fairly
light winds out of the southeast/south. Heading into this
evening, winds will increase to around 15-20 kts ahead of an
approaching system and associated cold front. This cold front
will bring lowered ceilings and light showers across the area
during the overnight hours into Thursday morning. Winds will
then gradually shift to the north/northwest on the backside of
the cold front. Skies will slowly begin to clear out and wind
gusts will increase during the late morning/early afternoon
hours. By tomorrow afternoon, just beyond the TAF period, strong
wind gusts to around 40-45 kts are anticipated.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory from 8 AM to 6 PM CST Thursday for MOZ001>005-
     011>014-020>022-028>030-037-043.
     Wind Advisory from noon to 6 PM CST Thursday for MOZ006-007-
     015-016-023-024-031-038-044.
KS...Wind Advisory from 8 AM to 6 PM CST Thursday for KSZ025-057-
     102>105.

&&

$$

DISCUSSION...Collier
AVIATION...Collier