St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

215
FXUS63 KEAX 250718
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
218 AM CDT Fri Apr 25 2025

.KEY MESSAGES...

- Showers and storms early Friday, give way to drier conditions through
  Saturday with rain chances moving back into the area Sunday

- Severe weather chances increase Monday and Monday night.

&&

.DISCUSSION...
Issued at 217 AM CDT Fri Apr 25 2025

Quasi-stationary front draped across north central KS into
northwestern MO as of 07Z is the primary focus for convection
overnight. As a weak shortwave trough moves east across the
area today, the front will slowly sink southward through the
day. A drier and more stable air mass moves in behind the front.
As such, chances for new showers and storms are mainly tied to
that front so have those chances sliding south with time through
the day today. The threat of severe storms looks low due to
weak CAPE and weak shear. A few strong storms can`t be ruled out
but at this point it seems unlikely given the weak CAPE and
shear.

For Saturday, cooler and especially drier air, associated with high
pressure moving into the Upper Midwest, settles into the region.
This will give us at least one dry day to the weekend. Saturday
night into Sunday, that high pressure shifts to the east, allowing
southerly low-level flow to build back into the region. Isentropic
ascent in the 300K and 305K surfaces, combined with modest moisture
transport, will lead to the next chance for showers and storms
starting overnight and lingering through much of the day. Sunday
doesn`t look like a washout but precipitation chances are in the 50-
70% range across the western and southwestern portions of the
forecast area Sunday morning.

Focus then shifts to a better setup for thunderstorms Monday and
Monday night. The southerly flow that started Saturday night/
Sunday, will advect ample moisture northward. Dewpoints will warm
into the mid to upper 60 degree range. This unseasonably high
moisture will combine with unseasonably warm temperatures in the
middle 80s, and along with steep mid-level lapse rates will
lead to CAPE values climbing into the 2300 to 2700 J/kg range.
In the upper- levels, a shortwave trough will eject from the
Southwest into the Northern Plains and Upper Midwest. This wave
takes on a more positive tilt as it`s doing this, which is not
ideal. The jet structure, while having some diffluence due to
weak cyclonic curvature and more so a result of downstream upper
ridging, is also not in favorable position, at least
intitially. It`s not until Monday night that the area moves into
the right entrance region of the upper jet. This stronger mid
and upper-level flow does lead to strong deep-layer shear
though and shear vectors, while not orthogonal to the front,
would favor storm motions off of the front leading to more
discrete cells. Overall, given the strong shear, favorable CAPE,
and modest diffluence aloft, severe storms seem likely late
Monday into Monday night as the front moves south. With discrete
cells possible, large hail and a few tornadoes look possible,
along with damaging winds.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1223 AM CDT Fri Apr 25 2025

Isolated thunderstorms have been slowly moving across MCI and
MKC as the overnight hours start. This activity should push
eastward of these sites by 07z. Another area of showers is
pushing across northwest Missouri and northeast Kansas. High
resolution model guidance has not had a good handle on the
evolution of these showers. Based on trends as this moved
through Nebraska, thinking this will reach STJ and KC Metro
terminals between 09-10z, and could last for few a hours. After,
area of low-end MVFR to IFR ceilings moves in, and may be around
for few hours this morning. STJ will most likely be under IFR
conditions. Given increasing model probabilities and the
current track of IFR ceilings moving in from Nebraska, have
added a few hours of IFR ceilings to the KC metro terminals as
well. Improvement back to MVFR should occur after 18z this
afternoon.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.

&&

$$

DISCUSSION...CDB
AVIATION...WFO EAX