mo discuss
Office: LSX
FXUS63 KLSX 130834
AFDLSX
Area Forecast Discussion
National Weather Service Saint Louis MO
334 AM CDT Sun Jul 13 2025
.KEY MESSAGES...
- Temperatures will be cooler with scattered to numerous thunderstorms
this afternoon and evening, mainly along and south of I-70.
Locally heavy rainfall may result in isolated flooding.
- Thunderstorm chances will ebb and flow through the course of the
upcoming week, peaking each afternoon and evening.
&&
.SHORT TERM... (Through Late Monday Afternoon)
Issued at 332 AM CDT Sun Jul 13 2025
Regional analysis shows a surface trough situated over southern IL
into southeastern MO. The trough precedes a cold front (moreso
wavering stationary boundary) extending from the Great Lakes through
northern IL and northern sections of MO. Water vapor imagery shows
moisture streaming northeast into the mid-Mississippi Valley ahead
of an upper level trough, the base of which extends southward
through Texas.
These features will be the key players in today's forecast as an
upper level shortwave rotates over eastern OK and ejects lobes of
vorticity northeastward into MO/IL. The trough remains pronounced at
least down through 700mb, depicting the deep mid/upper ascent that
will progress east-northeast overhead late this morning through this
evening. Mid-level southwesterlies will continue to draw moisture
northward out of the western Gulf as anti-cyclonic flow rotates
around a mid-level ridge centered over the northern Gulf.
A weak surface inflection/low is progged to track east-northeast
through southern sections of MO and into IL from late this morning
through this evening. RAP guidance shows two relative maxima of
MLCAPE developing ahead of these features this afternoon. One is in
a narrow corridor along the boundary over northern MO into west-
central IL with values peaking at 1000-1500 J/kg. The second is a
broader pool of buoyancy running from southeastern/east-central
MO through southern IL with values reaching 1500-2000 J/kg. Mass
convergence fields stand out along the I-44 corridor in MO
eastward along and south of I-70 in IL, but a lesser pronounced
area of convergence runs along the boundary to the north. As the
upper wave and weak surface low progress east, modest instability
will give rise to showers and thunderstorms in a broad, moisture-
rich airmass, where dewpoints remain in the low to mid-70s with
PWATs reaching an impressive 1.9-2.25".
Fortunately, cooler temperatures are expected today with extensive
cloud cover west of the Mississippi River. Mid-level lapse rates
remain <6C through the afternoon with soundings showing saturation
through much of the modeled environment. Though a localized gust of
wind isn't out of the question, it looks to be the exception rather
than the rule. With deep layer shear around 25 knots, scattered to
numerous thunderstorms are expected to develop as ascent increases
overhead. With anomalously high PWATs, thunderstorms will be very
efficient and producing locally heavy rainfall. HREF ensembles
show 60% of the members suggesting 1" or more of rainfall running
from southeast MO through southwest IL and 40% of the members
favoring 2" or more. LPMM data suggests amounts may reach 4-5" on
a localized scale, mainly along and east of the Mississippi River
into southwestern IL. Considering the performance of last
evening's thunderstorms, this doesn't sound terribly off. The
difference today will be thunderstorm movement, as individual
cells track eastward at 30-40 mph, leaving less residence time
over a specific location. Areas that stand a chance to reach these
amounts will be those affected by multiple rounds in a few hours
time. Localized flooding is possible, but given the localized
nature, a Flash Flood Watch was not warranted.
Thunderstorms are expected to weaken this evening as the upper
trough departs to the east and instability wanes. Drier air is
pulled southward in the wake of the departing trough with dewpoints
dropping into the 60s along and north of I-70. Upper vorticity over
eastern OK kicks east along the MO/AR border Monday with much of the
deeper moisture south of I-70. Scattered thunderstorms will largely
be confined to this region with dry conditions favored to the north.
Maples
&&
.LONG TERM... (Monday Night through Saturday)
Issued at 332 AM CDT Sun Jul 13 2025
Guidance is in fairly good agreement through the early portion of
the long term period, but quickly diverges from midweek on.
A vertically stacked system slingshots out of central Texas as
ridging over the southeastern U.S. begins to show signs of building
westward through midweek. The stalled surface boundary/trough to the
south lifts back to the north as a warm front late Monday night into
Tuesday. Though guidance differs in the strength of this system, the
general track/timing has come into better alignment, taking it
overhead Tuesday afternoon/evening. This draws warm, moist air
northward with scattered showers and thunderstorms Tuesday afternoon
and evening during diurnal peak.
From midweek onward, specifics are less certain as key, small scale
features become more difficult to resolve. A big part of this is how
global guidance handles the strength and westward extent of the
southeastern ridge, while zonal flow is maintained aloft over the
northern U.S. As multiple waves continue to track west to east
through the zonal pattern to the north, the ridge to the southeast
ejects weaker systems northward around its western periphery.
Guidance diverges in time, especially later in the week as a cold
front attempts to drop south behind a shortwave to the north. The
strength/placement of the ridge will determine whether the front
even makes it into the area or stalls out somewhere over the
region. The large spread between NBM interquartiles persists with
temperature spread of 7-10 degrees from Thursday through the end
of the period. What looks somewhat more certain is that the
diurnal ebb and flow pattern for thunderstorms will continue.
Maples
&&
.AVIATION... (For the 06z TAFs through 06z Sunday Night)
Issued at 1044 PM CDT Sat Jul 12 2025
VFR conditions are expected at the start of the period, but some
patchy fog will be possible in a few locations due to lingering
humidity and recent rain. However, the persistence of high level
cloud cover may limit coverage, and confidence is low that
significant visibility reductions will occur at local terminals.
Showers and a few thunderstorms will be possible early this
morning at COU/JEF, and at St. Louis area terminals by mid
morning. Shower and thunderstorm chances will continue through the
mid to late afternoon, and will diminish during the evening.
Bursts of heavy rain, lightning, and occasional erratic gusty
winds are all possible if a storm moves directly over the
terminal, along with brief ceiling/visibility category
reductions.
Showers will diminish in the evening, but low ceilings and fog
will be possible overnight. Most of this is likely to occur after
06Z, and confidence is low regarding the extent of impacts at this
time.
BRC
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Office: SGF
FXUS63 KSGF 130830
AFDSGF
Area Forecast Discussion
National Weather Service Springfield MO
330 AM CDT Sun Jul 13 2025
.KEY MESSAGES...
- Heavy rainfall will be the main threat overnight with
nighttime flash flooding a concern for southern Missouri.
Never drive down flooded roadways and remember to turn around,
don't drown.
- Showers and thunderstorms will continue through the morning
and early afternoon hours. Rain chances diminish this evening.
- Active summertime pattern continues next week with daily
afternoon shower and thunderstorm chances.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 257 AM CDT Sun Jul 13 2025
Rain showers will linger over the area for today as a shortwave
pushes east. Both SPC and WPC have backed off on the severe and
flooding potential for today. This is likely due to the lack of
lift available over the area. The CWA is now only in a general
thunder outlook and a Marginal risk (1/4) for flooding today.
This means that any rain that occurs today may still lead to
nuisance flooding or flash flooding, but that it will likely be
sub-severe. Though, we could see a rumble of thunder or two if
the showers can become strong enough.
So far, most of southern MO has seen at least a trace of rain
with the highest rainfall totals occurring over Texas and
Shannon counties where they saw around 2-3 inches Saturday
afternoon. An additional 0.5-1.0" of rain can be expected today
across the area.
The upper level low will still hangout over us on Monday
allowing for afternoon thunderstorms to occur. Right now, there
is a 30-50% chance for rain mostly south of I-44.
As for high temperatures, today and tomorrow will be partly
cloudy with highs in the low to mid 80s. Lows will still be warm
in the upper 60s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 257 AM CDT Sun Jul 13 2025
The upper-level low finally moves out of the area by Tuesday and
zonal flow returns. Though, shortwaves will move through the
area bringing daily storm chances favoring afternoon convection
as instability builds.
NBM QPF is generally around a quarter inch daily though high
precipital water and weak flow will need to be monitored for
the potential for flooding.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1226 AM CDT Sun Jul 13 2025
Showers and thunderstorms are moving through southern MO
tonight. Most of this activity will remain sub-severe, though
heavy rainfall is occurring. This has led to reduced
visibilities and MVFR/IFR ceilings. Southerly winds may become gusty
in and around these thunderstorms. Expect intermittent
thunderstorms to occur through most of the period with activity
diminishing by Sunday evening and VFR ceilings returning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.
&&
$$
SHORT TERM...Soria
LONG TERM...Soria
AVIATION...Soria
Office: EAX
FXUS63 KEAX 130749
AFDEAX
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
249 AM CDT Sun Jul 13 2025
.KEY MESSAGES...
* Isolated to scattered showers and storms today, mainly south and
east of a Kansas City to Macon, MO line.
- Locally heavy rainfall is possible with any storm that
develops.
* Several additional chances for showers and storms this week.
&&
.DISCUSSION...
Issued at 249 AM CDT Sun Jul 13 2025
Water vapor imagery with 500mb heights plotted shows a positively
tilted shortwave trough from northern MO into TX and potentially a
closed low over northern OK. 00Z soundings from TOP, SGF, and OUN,
show precipitable water values of roughly 1.6" at TOP, 1.8" at SGF,
and 1.9 at OUN. At the surface, a weak front was stalled over the
area that appears to be oriented from central OK northeastward into
northeastern MO. Showers and a storms have developed in the vicinity
of this front. Even the low to mid-level circulation is notable on
the regional 0.5 degree reflectivity plot. This shortwave will
slowly track eastward through the day and as a result, we should see
an increase in coverage of the convection as the day progresses
and the boundary layer becomes more buoyant. With only about
1000-1500 J/kg of MUCAPE and weak shear, the threat of
organized severe weather is nil. However, given the airmass,
water-loaded down drafts are possible. Additionally, locally
heavy rainfall can be expected in any shower or storm that
develops given the high precipitable water values, high freezing
levels, and slow movement. By late this afternoon into this
evening, it looks like the shortwave will be moving east of the
forecast and that should lead to a winding down the showers and
storms for our forecast area. With thick cloud cover today
associated with the showers and storms, temperatures will be
cooler than normal, especially for the southeastern half of the
forecast area.
We'll see a lull in activity Monday as we temporarily have a drier
(for July) airmass over us. Things change Tuesday into Wednesday.
Models continue to show a mid-level shortwave moving northeastward
into the area from OK. However there is some variability in the
location and thus the location for potential heavy rainfall. The GFS
is further east, keeping the best rain chances south and east of the
area. The NAM is further west, stronger, and tracks the shortwave
right over the forecast area with heavy rain associated with the
wave. Most other models are weaker and closer in line to the
GFS. This leads to the NAM being an outlier for rain amounts
with this system with it showing pockets of 2-2.5 inches. While
some of the higher end ensemble members have backed off their
rain amounts for midweek, there are still some members in the
GEFS showing 24-hour totals of 2.5-3". While this is unlikely
to occur, it remains a small possibility so we'll need to
continue to watch this system given the environmental
parameters. Ensemble guidance continues to show mean
precipitable water values of around 1.8" with the 75th
percentile near 2".
While temperatures look more seasonal Monday and Tuesday, highs may
climb into the low 90s across eastern KS and western MO on
Wednesday. And with increased humidity, heat index values will
climb to around 100 again. For late in the week, temperatures
return to more seasonal levels with highs in the upper 80s to
near 90 degrees.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1201 AM CDT Sun Jul 13 2025
Conditions will likely be VFR through the forecast but there may
be periods of MVFR. Showers and potentially a few thunderstorms
will be present in the area but for now it looks like this
activity will remain east of the terminals. If activity drifts
or develops westward, will amend as needed but for now will
keep it dry. Winds will be light through the forecast.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.
&&
$$
DISCUSSION...CDB
AVIATION...CDB
