Marine Weather and Tide Forecast for Cuba, MO

SHORT TERM
(Through Late Tuesday Night)
Issued at 225 PM CDT Mon May 12 2025

The pesky mid/upper level low is currently over the mid south early this afternoon, with a water vapor time loop showing a movement slightly west of due north. This feature will continue to play a major role in our sensible weather through Tuesday before it shifts off into the Upper Ohio Valley. Scattered showers and thunderstorms mainly over eastern Missouri and western Illinois should gradually wane late this evening into the early overnight hours as diurnal instability fades after sunset. Did keep isolated showers around though most of the night as there is weak low-level moisture convergence in the vicinity of a subtle frontal boundary at the surface. The coverage of showers along with a few rumbles of thunder should uptick again by early Tuesday afternoon as instability rises.
Tuesday's activity should shift a bit further to the east compared to this afternoon and be focused more across far southeast Missouri and southwest Illinois. These locations will be closer to the track of the mid/upper level low.

After a mild night tonight with lows in the upper 50s to low 60s, look for slightly warmer conditions on Tuesday afternoon. This is due to lesser chances of rain shower activity along with more pockets of sunshine. There is a bit of a caveat however as there should be quite a bit of low stratus (and maybe even some fog)
ongoing Tuesday morning. The current expectation is for this low stratus to rise and then scatter out during the morning hours on Tuesday. However, if this is slower to occur than forecast, these clouds may hamper temperatures a bit than is currently anticipated.
This does not seem like a particularly likely scenario however given the strong sun angle of mid May and lack of widespread mid/upper level clouds above the stratus to help limit the insolation on the lower deck. Highs in the mid 70s to near 80 degrees are forecast, with coolest locations in south-central Illinois where more clouds should linger and highest chances for shower activity reside.

Gosselin

LONG TERM
(Wednesday through Next Monday)
Issued at 225 PM CDT Mon May 12 2025

(Wednesday - Thursday Night)

A surface warm front is forecast to move through the area on Wednesday, with increasing low-level warm air advection in its wake.
Temperatures not surprisingly will climb on Wednesday, with highs in the low to mid 80s forecast. Surface winds are expected to stay southeasterly for a majority of the daylight hours, which is not the ideal wind direction for anomalously warm temperatures. Therefore, stuck pretty close to the 25th percentile of the NBM for highs.

Dry weather should continue Wednesday night, though cannot totally rule out an isolated shower/thunderstorm across northeast Missouri and west-central Illinois. Stronger low-level moisture convergence stays to the north, but some elevated convection may try and from near those locations if the warm front is a bit slower than forecast. Otherwise, look for a very mild night with increasing southerly surface winds. Lows are only expected to drop back into the mid to upper 60s. These values would be 10-15+ degrees above normal for the date.

A strong mid/upper level shortwave trough is forecast to move across the Upper Midwest on Thursday, with a trailing (Pacific) cold front sweeping across the mid-Mississippi Valley. This front should clear the eastern CWA just before 0Z Friday. Ahead of the front, look for winds to veer more to the southwest, which is a favorable wind direction for anomalously warm temperatures. These winds downslope off of the Ozark Plateau and aid in the warmup downstream across portions of central, east central, and southeast Missouri. Plenty of sunshine is also expected during the day, with increasing cirrus from the south very late in the day likely having very little impact on temperatures. The air mass in place ahead of the front is also quite conducive for anomalous warmth, with 850-hPa temperatures of +18 to +22C, above the 99th percentile of climatology and near daily records. Deep mixing is also favored on Thursday. All in all, the expectation is for highs to climb into the upper 80s to low 90s.
These readings would be the warmest so far this year for a majority (if not all) of the area and may threaten daily records for the date. Please see the CLIMO section below for more details. The main source of uncertainty with respect to Thursday's highs is the timing of the front itself. A faster (slower) timing of the front could lead to highs a couple of degrees cooler (warmer) than forecast.
However, even a faster timing won't have huge negative implications on highs. As alluded to above, this is a Pacific cold front. The air mass behind it is not really much cooler at all, and the fact that winds only veer to the west behind the boundary suggest the low- level cold air advection in some areas at least may be offset by downslope flow.

In terms of precipitation chances, dry weather is favored for the entire area even with this frontal passage. There are a lot of negating factors for convective initiation, including: 1) strong capping between 600 and 750 hPa, 2) weak surface convergence along the Pacific cold front, and 3) strongest mid/upper level forcing for ascent residing across the Great Lakes. All of these factors strongly suggest that any convective initiation should not occur in our CWA, but to our east/northeast. The "best" chance (~10%) of any thunderstorms would be across far eastern sections of the CWA Thursday afternoon/evening. This would also likely be contingent upon a slower frontal passage and/or weaker cap than is currently forecast.

(Friday - Next Monday)

Another weak cold front is expected to approach from the west on Friday. This boundary looks to have a bit more to work with Friday afternoon/evening than its predecessor. The cap is quite a bit weaker with deterministic models also suggesting a subtle midlevel shortwave trough moving out of the mid-Missouri Valley.
Six hour probabilities for measurable rainfall on the LREF are also quite a bit higher, in the 30-50% range Friday evening in parts of southeast Missouri and southwest Illinois. This is a period that we will have to keep an eye on as there should be plenty of instability (LREF probabilities for 1500+ J/kg of CAPE 40-60%) with 40-50+ knots of deep-layer shear. So, while convective initiation along this boundary definitely seems more likely, the question is more so focused on the timing/speed of the front and when convective initialization occurs. Most guidance suggests it will be across southeast Missouri and southwest Illinois near our southeastern CWA border. Supercells should be the primary convective mode given a very orthogonal component to the deep-layer shear vector to the initiating boundary. Splits may also be common given very straight hodographs. Large hail certainly looks like the main potential threat given very high CAPE within the hail-growth zone.

Forecast uncertainty increases substantially heading into the weekend (and beyond) with respect to where Friday's front stalls out. The deterministic ECMWF (and a majority of its ensemble members) have a stronger mid/upper level trough across the northeastern CONUS. This allows for a more northerly component to the mid/upper level flow across the eastern third of the country and helps get the surface front into the mid south. This would mean slightly cooler temperatures and mostly dry weather for our neck of the woods. The deterministic GFS and many of its individual ensemble members have a weaker midlevel trough with the surface front stalling near or in the southern part of the CWA This would mean additional rounds of showers and thunderstorms would be possible this weekend. A middle of the road approach seems wise at this juncture, showing dry weather favored on Saturday with PoPs increasing Sunday night into Monday as the front is more likely to at least begin to wobble back north as a warm front.

Gosselin

AVIATION
(For the 00z TAFs through 00z Tuesday Evening)
Issued at 638 PM CDT Mon May 12 2025

Scattered showers are expected to dissipate over the next couple of hours this evening. While most of the area will see VFR ceilings this evening, there will likely be patches of MVFR ceilings between 2000-3000ft...most likely over east central Missouri. Ceilings are expected to fall to low MVFR and IFR overnight. It's unclear how low the clouds will get, some guidance shows ceilings at or below 200ft with 1/4sm visibilities. Not sure about ceilings/visibilites that low, but IFR ceilings do seem likely. Low ceilings should improve through mid-late morning.
Showers will redevelop during the late morning/early afternoon, but are most likely along and east of the Mississippi River.

Carney

CLIMATE
Issued at 227 PM CDT Mon May 12 2025

Record maximum temperatures and warmest minimum temperatures for May 15.

MAY 15

ST Louis: MAXIMUM 94 1944 WARMEST MIN 72 2013

Columbia: MAXIMUM 90 1944 WARMEST MIN 71 1941

Quincy: MAXIMUM 93 1944 WARMEST MIN 69 1962



LSX WATCHES/WARNINGS/ADVISORIES
MO...None.
IL...None.