Marine Weather and Tide Forecast for Portage Des Sioux, MO

SHORT TERM /THROUGH SATURDAY NIGHT/
Issued at 205 PM CST Fri Nov 6 2026

A compact upper-level trough can be seen in water vapor imagery spinning over the Great Lakes this afternoon, with a shortwave digs into the Desert Southwest. Locally at the surface, yesterday's cold front has departed the region well to the southeast, with an area of high pressure moving southward into the Midwest. This area of high pressure will continue to push the current cloud cover south- southwestward through this evening, with skies across much of the CWA expected to be clear.

In addition to the clearing skies, the high will also serve to calm winds through the overnight hours. These factors will lead to efficient radiational cooling across the CWA, with temperatures expected to drop to around freezing by sunrise. This will particularly be the case for low-lying rural areas. The Freeze Warning remains on track, and will be the last one of the season given how far into the fall we are.

Through the day Saturday, the upper-level trough will move further eastward as the southwestern shortwave becomes cut off. The eastward phasing of the trough will allow for the surface high to drift slightly eastward as well. With the center of the high moving overhead through the day, our weather will remain calm, though a piece of the southwestern cutoff will shear off and pass overhead, producing some upper-level clouds. Even so, with the lack of low- level clouds and the eastward movement of the trough, temperatures will tick up slightly during the afternoon relative to today.

LONG TERM /SUNDAY THROUGH FRIDAY/
Issued at 205 PM CST Fri Nov 6 2026

Guidance consensus is that the upper-level flow over the Middle Mississippi will remain generally northwesterly through the extended forecast period. Despite this, low-level ridging centered over the region will continue feeding warm air into the region, supporting above normal surface temperatures through the first portion of the week.

Starting Wednesday and continuing through the end of the workweek, an upper-level trough will deepen over the eastern CONUS and send a series of shortwaves through the Midwest. This phasing of the upper levels supports flow through the depth of the atmosphere becoming north-northwesterly. Despite both deterministic guidance and ensemble clusters favoring this solution, how the trough and subsequent shortwaves evolve varies among guidance sources. This will dictate the placement of a cooler, more seasonable air mass as it moves across the eastern CONUS through the latter portion of the workweek. A more glancing blow, which is currently favored by a majority of guidance and the NBM, will gradually cool temperatures through the period to around climatological normals. A more direct hit from the air mass would lead to daily highs struggling to break 50 degrees by Friday per cooler ensemble members. With the CWA expected to be on the periphery of this air mass, I do expect our temperature forecast for this portion of the period to fluctuate in the coming days as guidance hones in on a common solution.

As for precipitation chances, a lack of notable return flow from the Gulf through the period and dry antecedent conditions lead to low confidence in precipitation chances, including toward the end of the week when the upper-level trough deepens over the eastern CONUS.
Depending on the potency and track of embedded shortwaves, there is a very low chance (10%) for light rainfall roughly on Friday.
Subsequent waves would have less moisture to work with, leading to even lower chances as we move into next weekend.

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/
Issued at 1015 PM CST Fri Nov 6 2026

MVFR stratus continues to slowly push south through the southern half of Missouri. By sunrise, it is expected to be nearly completely out of the area. 04z satellite imagery shows steam fog developing in the wake of the stratus. Continued mention of fog at river valley terminals with TEMPOs for IFR, though vsbys less than 1SM will likely be intermittent at least. Elsewhere, dry and VFR conditions with near calm winds will prevail through the TAF period.



LSX WATCHES/WARNINGS/ADVISORIES
MO...Freeze Warning until 8 AM CST Saturday for MOZ018-019-026-027- 034>036-041-042-047>052-059>065-072>075-084-085-099.
IL...Freeze Warning until 8 AM CST Saturday for ILZ058>060-064-065- 069-070-074-079-095>102.