Marine Weather and Tide Forecast for Jonesburg, MO

SHORT TERM
(Through Late Wednesday Night)
Issued at 232 PM CDT Tue Apr 22 2025

High pressure currently centered over the Ohio Valley will drift east through Wednesday. Warm southerly flow on the western flank of the high is producing above normal temperatures, and this will continue tonight and Wednesday. The axis of the surface ridge extends through southeast Missouri into northern Arkansas and the southeast Plains, blocking deep moisture return from the Gulf.
The relatively dry air over the Mid Mississippi Valley should keep our area largely precip-free through Wednesday night. However, weakening convection generated along a stalled front over Iowa or from clusters expected over the Plains tonight may wander into central or northeast Missouri. The chance this will happen though is very low (20 percent or less).

Carney

LONG TERM
(Thursday through Next Tuesday)
Issued at 232 PM CDT Tue Apr 22 2025

The Thursday through Friday evening time frame still looks like the best shot for significant precip in the next 7 days. Aloft, a short wave will move from the Desert Southwest on Thursday morning, across the Plains and into the Mississippi Valley by 12Z-18Z Friday. The low level reflection of the wave doesn't look very strong at this time, and is a little difficult to track in the guidance. However, it appears the low will move across northern Missouri or Iowa into Illinois on Friday. The blocking ridge axis finally erodes Thursday morning and southerly flow ahead of the system will bring Gulf moisture back into the Mid Mississippi Valley. The low level jet never really kicks into high gear due to the relatively weak low level cyclone, but it's strong enough to produce some modest low level moisture convergence across our forecast area Thursday afternoon through Friday evening. This combined with broad-scale lift ahead of the approaching short wave should produce periods of showers and thunderstorms, mainly Thursday night through Friday afternoon. The wind fields with this system isn't very strong, and the atmosphere doesn't get particularly unstable either. However, the best chance for strong/severe storms would be Friday afternoon when MLCAPE around 1000 J/Kg is coupled with 0-6 km shear between 20- 30kts. This might be good enough for multicell clusters with a marginal hail/wind threat.

The front associated with this system sweeps through the area Friday night bringing the threat for widespread precip to an end. Medium range guidance shows the front stalling over southern Missouri or northern Arkansas Saturday, and a few showers or a thunderstorm may stray into southeast Missouri depending on how far south the front gets. Another wave moves across the Rockies on Sunday forcing low level cyclogenesis over the western Plains, and turning the low level flow back to the south. This will push the front back north across Missouri which could produce some scattered convection, although forecast soundings look pretty well capped at this time.

Another long wave trough digs into the Desert Southwest in the Monday/Tuesday time frame. LREF EOF patterns are indicating variance in the position and amplitude of this trough in the ensemble, so confidence is low in the forecast for early next week.
Deterministic guidance shows at least one short wave rounding the base of the trough and ejecting northeast across the Great Plains.
This produces a fairly strong surface low which drags a cold front into Missouri Monday night or Tuesday. Temperatures look well above normal in the mid 80s in deep southwest flow ahead of the front.
Depending on how much instability and shear is available, the front could be the trigger for our next round of precip and severe thunderstorms.

Carney

AVIATION
(For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1224 PM CDT Tue Apr 22 2025

VFR flight conditions and light southerly flow are expected to prevail through the period. There is a small chance that a stray shower or weak thunderstorm could move through far northeast Missouri or west central Illinois late this afternoon or evening, but the chance for rain is too low to mention in the KUIN TAF.

Carney

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