St. Joseph, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

136
FXUS63 KEAX 061737
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1137 AM CST Fri Mar 6 2026

...18z Aviation Update...

.KEY MESSAGES...

- Multiple rounds of showers and thunderstorms possible
  overnight into Friday morning. A few storms could produce hail
  approaching quarter size.

- Conditional threat for supercells capable of producing all
  severe hazards Friday afternoon and evening.

- A line of showers and thunderstorms are likely late Friday
  night out ahead of an approaching cold front, with damaging
  wind gusts being the primary hazard.

- Cooler behind the front on Saturday, but temperatures quickly
  rebound to above normal by Sunday and into Monday.

- Another chance for strong to severe storms on Tuesday.

&&

.UPDATE...
Issued at 245 AM CST Fri Mar 6 2026

Updated to include mesoscale details based on 00z HREF and 06z
CAMs.

Overall synoptic scale pattern description from 03/05/2026 1125pm
update still holds with respect to the 00z HREF run and incoming 06z
HRRR and other CAMs. As the main H5 trough ejects eastward along
with deepening surface low and cold front, kinematic parameters with
the strong jet streak will be supportive of severe storms. For the
discrete storm potential in the open warm-sector through the
afternoon and early evening hours, still largely unsure about
boundary layer`s ability to destabilize. A few of the 06z CAMs
continue to produce shower activity as late at 18z across portions
of the forecast area. HREF members that quickly clear out morning
activity achieve MUCAPE by the middle of afternoon around 1750 J/kg,
while those keeping cloud cover struggle to get above 1000 J/kg.
Perhaps some type of disturbance ahead of the main vort maxima could
promote an hour or two of H5 height rises with weak subsidence that
provides a few pockets of insolation and initiates a storm, or
perhaps provide some kind of differential heating boundary. However,
model sounding analysis is not showing favorable lapse rates in any
particular vertical level, a hindrance to updraft strength. The
shear environment in the open warm sector is fairly healthy, with
deep layer bulk shear values generally around 30-40 kts. And as the
surface low deepens over the Plains, surface winds across the
forecast area back which drastically increases low-level SRH (0-1km
potentially hitting above 200 m^2/s^2). Low-level hodographs are
curved sufficiently for initial mean wind moving storm to develop a
low-level meso, and drastically increase streamwise vorticity with
anything that takes a right hand turn, which would drive the tornado
potential. The kinematics are there for a strong storms this
afternoon across the warm sector, but mesoscale influences on the
thermodynamics are not. CAPE through the hail growth zone is not
looking great based on CAM soundings currently available for this
afternoon. The large hail threat will largely be tied to storm-scale
processes, and may need the H5 jet to kick in to reshape the
hodograph a bit to get the extra lift needed. The wind will be tied
to any precipitation loading, or RFD action with anything discrete.
All of this potential is tied to how the thermodynamic environment
pans out today. And the last few runs of CAMs, are not favoring
this.

A line of storms is still expected to form along the cold front
later Friday evening. Large scale lift should spread most of the
lower Missouri River Valley from the H5 vort maxima moving through,
along strongest jet streak axis moving through. 0-3km CAPE along the
leading edge is fairly high, with increasing deep layer shear along
the initiating front. This should help generate a stronger cold pool
as the system evolves, resulting in severe wind gusts of 60-70 MPH.
The 0-3km shear vector is currently progged to align parallel the
line of storms, which largely limiting mesovort generation along the
leading edge. As with most linear events with strong forcing though,
will need to monitor for local surges that could alter the
orientation of the shear vector. This line moves west to east, and
should move into eastern Missouri between 06-08z overnight into
Saturday morning. Pockets of heavier rainfall are possible, but
system should remain progressive enough to avoid any substantial
hydro issues.

&&

.DISCUSSION...
Issued at 1125 PM CST Thu Mar 5 2026

Current H5 analysis shows a longwave trough over the Four
Corners into the Desert Southwest with southwesterly mid/upper
flow in place across the Plains and into the mid and upper
Mississippi Valleys. The H850 low is centered over eastern
Colorado, with a south southwesterly oriented low level jet in
the process of developing, with 50 knots analyzed across eastern
Kansas. Meanwhile, at the surface, a 998 mb surface low spins
over southeastern Colorado, with a warm front lifting north
toward our CWA. This helped blossom relatively robust convection
across northeastern Kansas by Thursday evening, with these
storms moving across NE Kansas into NW Missouri at present time.
A few storms could be strong to marginally severe, with hail
being the primary hazard. Moisture advection will continue
tonight thanks to the low level jet and as the warm front
progresses northward through the region, with dew points rising
into the mid to upper 50s by 6 AM. Another cluster of showers
and storms currently across northern Oklahoma near the Kansas
line should eventually make their way into the region,
potentially impacting the KC metro in the 2 to 5 am time frame,
with yet round of showers and storms potentially impacting the
region by mid to late morning per the most recent HRRR runs. It
will be very interesting to see how these potential rounds of
convection impact or alter the environment heading into Friday
afternoon and evening.

By mid Friday afternoon, the aforementioned broad mid/upper
trough currently over the Four Corners/Desert Southwest is
progged to split into two distinct impulses, with the leading
shortwave trough ejecting into the Central Plains, with a 60+
knot cyclonic jet streak rounding the base of the trough from
New Mexico into far SE Nebraska. At the surface, one surface low
will slide eastward over the SD/NE/IA tri state border while
another moves into west central KS, with an accompanying cold
front bridging the two surface lows and approaching the region
from the northwest. This will place our CWA within the open warm
sector, with high temps reaching the the low to mid 70s, SSW
winds of 15 to 20 mph with gusts up to 30 mph, and dew points
into the upper 50s to lower 60s. By 4 pm Friday, SPC HREF SB
CAPE ensemble mean is around 750 to 1000 J/kg, with around 40
knots of deep layer shear. However, a fair amount of convective
inhibition looks to be present due to a cap at the 750 to 850 mb
layer, and could be hard to overcome, especially with quite a
bit of cloud cover likely remaining into Friday afternoon. If
storms are able to initiate and take root, supercells capable of
all severe hazards will be possible. Most recent CAM guidance
is not particularly excited about robust convection Friday
afternoon and early evening, only suggesting strong to severe
storms as the cold front pushes through late Friday night, which
would likely be in the form of a line of thunderstorms with
damaging wind gusts and a few mesovortices given 30 knots of 0-3
km bulk shear. Severe threat should decrease as the line
progresses further east, with the front likely to completely
exit the CWA to the east by around 5 AM Saturday.

Temps will be cooler behind the front on Saturday, but
temperatures are projected to rebound quickly, with highs in the
upper 60s on Sunday and into the upper 70s on Monday. Dry
conditions are likely Saturday into Monday, as well. By Tuesday,
a closed H5 low centered over NW Mexico is projected to become
an open wave and eject out across the Southern Plains, bringing
another chance for showers and thunderstorms, with strong to
severe storms possible yet again.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1134 AM CST Fri Mar 6 2026

A messy TAF period on deck across the sites given ongoing and
subsequent potential showers and storms. Have attempted to hone
in on windows of greatest confidence as well as signaling that
worst conditions will be more transient/temporary via the use of
TEMPO groups this afternoon and then this evening/tonight.
Gusty SW winds prevail ahead of the front, then shift gusty out
of the NW, in both cases gusting in to the 20s kts. Some lower
30s kt gusts are possible/likely daytime today. Additional
restrictions are likely via ceilings with plethora of guidance
zeroing in on MVFR ceilings pre and post frontal. Given the
messy situation, expect there to be multiple amendments through
06z, aside from the routine issuance times.

&&

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

&&

$$

UPDATE...Krull
DISCUSSION...Williams
AVIATION...Curtis