mo discuss
Office: LSX
FXUS63 KLSX 291116
AFDLSX
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
616 AM CDT Mon Apr 29 2024
.KEY MESSAGES...
- Lingering showers along with a few thunderstorms are forecast through
much of the day today in parts of southeast Missouri and
southwest Illinois. Further northwest, dry weather is expected.
- Temperatures will remain above-normal through the work week,
with on/off rain chances. The highest chance for rain will
accompany a cold front in the Thursday - Friday timeframe.
&&
.SHORT TERM... (Through Late Tuesday Afternoon)
Issued at 343 AM CDT Mon Apr 29 2024
(Today)
Widespread showers and embedded thunderstorms continues to push
eastward along with an area of low-level moisture convergence. This
forcing is expected to weaken by 1200 UTC, so the expectation is for
the intensity of the convection and associated rainfall rates to
decrease across southeast Missouri and southwest Illinois as well.
The synoptic cold front still lags to the west a bit, located near a
KCOU>>KIRK axis as of 0700 UTC. This front is expected to wash out
over the next several hours. However, look for showers along with a
few thunderstorms to remain possible most of the day in parts of
southeast Missouri and southwest Illinois as a midlevel shortwave
trough moves across the mid south this afternoon. Nothing strong to
severe is expected, but some brief downpours are possible.
High temperatures today are expected to be similar to yesterday in
most locations, generally in the low to mid 70s. The coolest
locations are forecast to be in parts of northeast Missouri behind
the cold front and in parts of southeast Missouri/southwest Illinois
where clouds will be prevalent into the afternoon hours.
(Tonight - Tuesday)
Decreasing cloudiness is forecast across southeast Missouri and
southwest Illinois this evening, with a clear sky overnight for the
entire area. Light/variable winds along with this clear sky should
allow for temperatures to cool back into the low to mid 50s for
overnight lows. These values are near the 25th percentile of
available model guidance. Given that these lows or below afternoon
crossover temperatures, would think fog may be a concern. This will
especially be true in favored river valleys and where there is
excess surface moisture from recent heavy rainfall.
A quick warmup is expected during the day on Tuesday as low-level
warm air advection strengthens. Highs in the upper 70s to low 80s
are forecast, or about 10 degrees above normal for the last day of
April.
Gosselin
&&
.LONG TERM... (Tuesday Night through Sunday)
Issued at 343 AM CDT Mon Apr 29 2024
(Tuesday Night - Wednesday Night)
Deterministic models show a midlevel shortwave trough moving quickly
across the Upper Midwest Tuesday night, with a surface low north of
the Twin Cities at 0600 UTC Wednesday. An attendant cold front will
be draped to its south, with this frontal boundary nearing parts of
northeast and central Missouri. This will bring a chance of showers
and thunderstorms to this part of the CWA in the 0600-1200 UTC time
period, with chances rapidly decreasing by Wednesday morning as the
mid/upper level forcing for ascent is becomes even more displaced to
the north and the surface cold front washes out. Mostly dry weather
is forecast on Wednesday, before the chances of showers and
thunderstorms returns to parts of central and northeast Missouri as
well as west-central Illinois Wednesday night. Similar to Tuesday
night, this area gets brushed with mid/upper level ascent southeast
of the track of a midlevel shortwave trough. However, the better
chances of elevated convection reside further to the north where the
warm front should reside and the stronger low-level moisture
convergence.
Temperature wise, the well-above normal values will continue, with
lows in the low 60s each night and highs Wednesday afternoon mostly
in the low 80s.
(Thursday - Friday)
The period with the best chances of showers and thunderstorms (60-
80%) remains Thursday through Friday. The broad time period is due
to uncertainty with the timing of a cold frontal passage across the
region. Ahead of this front, the continuation of well-above normal
temperatures day and night is expected. There is more uncertainty
with Friday's high temperatures across much of the area due to the
differences in frontal timing. Differences between the 25th/75th
percentile of the NBM increase more toward 6-10F degrees in most
locations.
(Friday Night - Sunday)
There is high uncertainty in sensible weather heading into next
weekend. WPC 500-hPa height clusters show vastly different solutions
across the central CONUS, ranging from continued southwest flow
aloft to much cooler weather behind a stronger cold front. Slightly
above normal temperatures with PoPs below climatological normals are
forecast at this time, but confidence is very low.
Gosselin
&&
.AVIATION... (For the 12z TAFs through 12z Tuesday Morning)
Issued at 607 AM CDT Mon Apr 29 2024
The rain has moved off to the south and east of the metro
terminals, with dry conditions across much of the area through the
remainder of the period. The exception is for some scattered
showers along with a few thunderstorms through this afternoon in
parts of southeast Missouri and southwest Illinois. Ceilings are
variable behind the rain, but generally range from 500 to 2500
feet AGL. This area of stratus will advect out from west to east
through the morning, with metro terminals improving closer to
noon. After the stratus moves out, look for VFR conditions through
this evening. The next concern will be fog late tonight into
Tuesday morning. The best chances are at river valley sites
(KSUS/KJEF/KCPS) and added MVFR visiblities starting between 0700
and 0900 UTC Tuesday. IFR visibilities are possible at these
sites, particularly at KSUS. If confidence increases in fog
potential, worse visibilities than currently forecast may need to
be added.
Gosselin
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Office: SGF
FXUS63 KSGF 291040
AFDSGF
Area Forecast Discussion
National Weather Service Springfield MO
540 AM CDT Mon Apr 29 2024
.KEY MESSAGES...
- Widespread flooding is ongoing in a majority of the forecast
area with significant flooding continuing over parts of west
central Missouri and southeast Kansas from earlier heavy rain.
- Dense Fog Advisory until 9 AM for extreme southwest Missouri.
Some light drizzle may also occur within this area and along
the Ozark Plateau (15-30% chance).
- The unsettled pattern continues with additional storm chances
this week (20-40% chances). Highest chance for showers and
thunderstorms occurs Thursday (70-90% chance).
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 330 AM CDT Mon Apr 29 2024
Widespread flooding is ongoing in a majority of our area:
A decaying thunderstorm complex associated with a mid/upper-
level shortwave is currently exiting our CWA bringing a much
needed dry weather break. Some lingering stratiform rain will
continue in the eastern Ozarks through the morning, but much of
the heavy rain is over. Unfortunately, effects from the heavy
rain will continue today with at least 90% of our forecast area
under some sort of flood headline for at least minor flooding.
In the last 72 hours, MRMS QPE estimates put almost our entire
area at over 2 inches of rain with several corridors of at least
4 inches. Pay attention to the roadways when traveling,
especially near low-water crossings and rivers. Turn around,
don't drown!
Significant flooding continues over parts of W MO/SE KS:
The hardest hit area was in west MO and SE KS, including areas
like Nevada, Pittsburg, KS, and Fort Scott, KS. These areas
received 6-10 inches of rain in the last 72 hours on top of
4-5 inches from days prior. AHPS precipitation analysis puts
Fort Scott in the 10-15 inch range over the last 7 days.
Needless to say, this has led to some dangerous and significant
flooding in that area. The Little Osage and Marmaton Rivers have
notably reached Major Flood stage. While no rain is expected in
the short-term, it will take a bit of time for these rivers and
areal flooding to recede. Once again, pay attention to alerts
and stay away from any suspected flood waters.
Dense Fog Advisory until 9 AM for extreme southwest Missouri:
With the upper-level shortwave trough and surface low lifting
to the NE, an associated cold front will sag through the area
this morning. Ahead and just behind the front, dewpoint
depressions have dropped to 0 and below (lows and dewpoints are
in the mid-50s). This, paired with weak surface winds and
generally clearing skies will promote fog formation, especially
in extreme SW MO along the NW edge of the Ozark Plateau where
NW'ly upslope surface flow will enhance saturation/condensation.
Locations including Joplin and Pittsburg have already seen a
narrow band of fog associated with the front briefly drop
visibilities to a half mile.
Additionally, with the low-level relative humidities generally
>80%, no cloud ice present, a band of upward omegas moving in
along the front, and NW'ly upslope flow along the plateau,
light drizzle will also be possible within and around the
regions of fog. Both the fog and drizzle will dissipate by 9 AM
at the latest when clear skies promote increased surface heating
and mixing after sunrise, leading to high temperatures in the
mid-70s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 330 AM CDT Mon Apr 29 2024
Additional storm chances return this week:
After the upper-level wave exits, the longwave pattern that sets
up will exhibit a broad trough axis over the northern Rockies
with the jet stream max staying within the northern Plains. This
will keep surface low tracks generally well to the NW of our
area. Indeed, a surface low will move across the northern Plains
beneath the longwave, allowing for S'ly surface flow across our
area. This will lift the cold front back to the north out of SW
MO and advect in high temperatures in the lower 80s for
Tuesday/Wednesday with lows in the lower 60s for those nights.
Within the aforementioned longwave pattern, several shortwaves
are expected to revolve around the axis. Though the waves should
stay to our NW, each one will force rounds of convection that
could clip our area, generally along and NW of I-44. This brings
20-40% PoPs for Tuesday/Wednesday evening/night NW of I-44. With
GEFS probs bringing 80-100% chances for CAPE >1000 J/kg along an
axis generally west of Hwy 65, severe weather may be possible
with these rounds of convection. However, with the mid-level waves
displaced well to our NW, the threat appears to be more focused
within the OK/KS/NE area. The SPC tends to agree with only a
Marginal (1/5; 5%) risk just clipping our western counties
Tuesday/Wednesday. This means we would most likely see scattered
remnant convection Tuesday/Wednesday evening/night that could at
times be marginally severe for our western counties.
Our best chance for showers/thunderstorms looks to be Thursday
as a deeper shortwave rounds the broad longwave axis. This will
allow for greater shear and surface frontal forcing to
overspread our area. This will bring 70-90% chance for showers
and thunderstorms Thursday evening/night. GEFS probabilities
give a 40-60% chance for CAPE values >1000 J/kg, and with the
wave passing closer to our area, shear would be greater, so
severe weather could be possible. However, uncertainty in exact
details is still too high to give a probability on severe
weather. CSU machine learning guidance does put much of our CWA
in a 15%, though the centroid is out to the west in KS. Later
updates will further evaluate this system for severe weather
potential.
After the shortwave clears the area, cooler weather will filter
in behind with highs going from near 80F Thursday to the mid-70s
for the weekend. Lows will hover in the 50s for the same period.
Model spread increases after Thursday, but more chances for some
showers/thunderstorms exist into the weekend. PoPs are currently
at 15-30% highlighting the timing and ensemble uncertainties.
GEFS has a shortwave ejecting out of the SW, bringing widespread
rain chances. EPS and Canadian ensembles do not show this
shortwave, generally keeping our area dry. We will see how
models come to agreement in the future, but with the late-spring
warm sector settling in across the central/southern CONUS,
showers and thunderstorms appear more possible from a day-to-day
basis, especially with ensembles hinting at a longwave trough
setting up over the western US in the long range.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 526 AM CDT Mon Apr 29 2024
Fog is currently impacting JLN and lowered ceilings and
sometimes decreased visibilities are impacting SGF and BBG.
These conditions will continue until 14-15Z at the latest in
which VFR conditions will prevail. Calm winds today will be
variable as a cold front passes through the TAF sites, then
lifts north back through them again after 00Z. These winds
should settle in a SE'ly direction by 06Z, but remain calm.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...Dense Fog Advisory until 9 AM CDT this morning for MOZ088-093-
094-101>103.
&&
$$
SHORT TERM...Price
LONG TERM...Price
AVIATION...Price
Office: EAX
FXUS63 KEAX 290759
AFDEAX
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
259 AM CDT Mon Apr 29 2024
.KEY MESSAGES...
- Quiet, seasonal weather conditions for Monday and Monday night.
- Strong to severe storms possible Tuesday afternoon and evening.
- Active weather pattern continues through at least Thursday
night, with a lull possible Friday into Saturday. This could
aggravate ongoing flooding concerns across the area.
&&
.DISCUSSION...
Issued at 259 AM CDT Mon Apr 29 2024
Surface analysis at 2 am shows the cold front splitting the forecast
area generally north to south, east of I-35. This front will
continue to move east and should be east of the forecast area by
12Z. There will be a few showers and possibly a thunderstorm
along the front as it moves east in the predawn hours. A cooler
and less humid airmass will move into the region behind the
front and give the area seasonal temperatures with dry
conditions. Highs today should range from the upper 60s across
northern MO to the middle 70s south of Highway 50.
This dry and seasonal weather will be short-lived as the surface
shifts into the Southeast by Tuesday afternoon. With lee troughing in
the High Plains, a tighter pressure gradient develops across the
central to eastern Plains. This allows for southerly flow to develop
and moisture, which wasn't displaced that far south to begin with,
surges northward. In the mid and upper-levels, a strong shortwave
trough will eject into the central Plains and push a cold front
eastward across Nebraska and Kansas. This helps tighten the pressure
gradient further and by the afternoon we should be seeing wind gusts
of 30-35 mph across eastern KS and western MO. The return of
moisture and temperatures climbing into the lower to middle 80s will
help build modest instability across eastern KS and western MO.
HREF probabilities show a 70+ chance of greater than 1000 J/kg
of surface based CAPE. These percentages drop off at 2000 J/kg
so eastern KS and western MO will likely end up in the 1000-2000
J/kg range for SBCAPE as the front is moving into the area.
There's also a high probability of effective shear between 30-40
kts with it's orientation nearly orthogonal to the cold front.
This will favor the potential for supercells with large hail,
damaging winds and a tornado or two. The greatest area looks to
be from far northwest MO in eastern KS and west central MO.
With the strongest forcing associated with the shortwave trough
passing north of the area, the southward push of the front dies and
the front stalls in the vicinity of the forecast area. Models vary
significantly with this but the consensus is generally in our south
or possibly just south of the forecast area. As the next shortwave
digs into the Four-Corners region, southerly flow increases and
pushes the front north again as a warm front. Convection may be
ongoing Wednesday as the warm front lifts into Northern MO or just
north of the area. This warm and moist low-level pattern leads to
moderate instability with the area likely to see 2000-3000 J/kg of
CAPE by Wednesday afternoon. This could be lower if convection and
cloud cover are more widespread. Wednesday evening, a strong low-
level jet develops and noses into the boundary. As a result,
the coverage of showers and storms become more widespread after
sunset Wednesday evening. The focus of this round of convection
looks to be across northwestern to northern MO, in the vicinity
of the front.
For Thursday, a strong shortwave trough will move into the
northern Plains and push the front southward as a cold front.
Instability will be more uncertain depending on how the
Wednesday night/ Thursday AM convection evolves. But if the area
does recover from that earlier activity, we should be the
right-rear quadrant of the upper jet with stronger mid to upper-
level flow leading to stronger shear. So there is a more
conditional risk of severe weather Thursday depending on how the
area destabilizes from the earlier convection.
Similar to today, a cooler and drier airmass moves into the region
Friday. That should lead to a period of quieter weather before the
moisture recovers. Models show the high shifting into the Southeast
with southerly flow returning, allowing moisture to return to the
area late in the weekend and into next week. Models vary on the
pattern more for this time frame so confidence is lower on any one
day being more likely than another for rainfall. This results in a
broad brushing of lower PoPs for Sunday and Monday.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1155 PM CDT Sun Apr 28 2024
A cold front moved through the terminals in the last 1-2 hours.
This will lead to light westerly winds and drier air moving into
eastern KS and western MO, which will result in VFR conditions
through the forecast.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.
&&
$$
DISCUSSION...CDB
AVIATION...CDB
