Marine Weather and Tide Forecast for Ozora, MO

SHORT TERM
(Through Late Tuesday Night)
Issued at 253 PM CST Mon Jan 20 2025

An upper-level trough will traverse the Mid-Mississippi River Valley tonight, forcing an Arctic cold front through the CWA Broad, mid- level ascent and weak, transient low-level frontogenesis combined with steepening low-level lapse rates could result in snow flurries this evening into overnight. However, a lack of deep, continuous saturation in forecast soundings and only up to 20 percent of HRRR membership depicting any measurable snowfall decreases confidence that there will be any accumulating snowfall. Of greater impact will be an anomalously cold Arctic airmass and surface high pressure center invading the region behind the front, characterized by 850- hPa temperatures below the 5th climatological percentile and MSLP exceeding the 99th climatological percentile. Any lingering snow cover will not significantly enhance cooling, but this airmass will support temperatures cooling to between -5 and 5 F by Tuesday morning across most of the area, with temperatures approaching -10 F in northeastern MO. Despite the Arctic high pressure center nearing the area, strong low-level CAA will keep the boundary layer mixed overnight into Tuesday morning with northerly surface winds sustained 7 to 12 mph, even gusting to 20 mph at times. As a result, a Cold Weather Advisory is now in effect for the entire CWA overnight through Tuesday morning for wind chill values ranging from around -20 F in northeastern MO and west-central IL to -10 F in southeastern MO.

On Tuesday, the Arctic high pressure center will pass through the Mid-Mississippi River Valley beneath rising mid-level heights overhead. Large-scale subsidence will permit strong insolation aside from a few stratocumulus, helping temperatures to warm to between the upper single digits and mid-teens F. Winds will also become gradually lighter, but they will remain strongest through the afternoon in portions of west-central/south-central IL with wind chill values taking longer to rise, necessitating extension of the Cold Weather Advisory in those locations through mid-afternoon.
Increasing clouds and strengthening low-level WAA Tuesday night will likely result in a late evening low temperature in the single digits F, before temperatures actually warm overnight.

Pfahler

LONG TERM
(Wednesday through Next Monday)
Issued at 253 PM CST Mon Jan 20 2025

On Wednesday, model guidance are in agreement that an upper-level shortwave trough will track from the Central Plains through the Mid- Mississippi River Valley. Ahead of this trough, the strong WAA ensuing Tuesday night will persist into Wednesday acting to produce thick mid-level clouds during the morning as mid-level moisture arrives. Forecast soundings and ensemble guidance all support these clouds not producing any precip that reaches the surface with a pronounced layer of dry air below. These clouds will likely impede initial daytime insolation, but strong WAA will still allow high temperatures 20 to 25 F warmer than Tuesday and in the 30s F across most of the CWA

Another shortwave trough closely following the first will track across the region Wednesday evening, which has more support for measurable snowfall. Broad large-scale ascent is able to interact with relatively greater moisture and any saturation from the preceding trough is expanded upon. Currently, ensemble model guidance 24-hour probabilities of measurable snowfall centered on Wednesday evening are 40 to 60 percent across northeastern MO and west-central IL but these probabilities fall below 10 percent for even 0.5" of snowfall. Since there are slight timing differences that remain, the latest 6-hourly PoPs are lower than these probabilities and 20 to 30 percent. Through early Friday, additional shortwave troughs will round upper/mid-level cyclonic flow, providing at least periods of snow flurries through the time period. However, there is still variability among ensemble model guidance on how vigorous/organized associated ascent will be to support measurable snowfall and anything more than flurries. NBM temperature distributions remain steady or warm slightly through Friday, albeit still below average, with only short-lived CAA behind at times, transitioning to increasing WAA on Friday.

Global model guidance are in agreement that a pattern change will take place late Friday into the weekend, as an upper-level trough becomes cutoff near the California coast or the Four Corners region and quasi-zonal, confluent flow becomes established across the central CONUS. In this pattern, there is consensus for weakening shortwave troughs to be shed and subsequently ejected eastward from the cutoff, but the timing and track of these features are uncertain. As a result, rolling 24-hour probabilities of measurable precipitation gradually increase late Saturday through Sunday, highest along/south of I-70 at 30 to 50 percent. The vast majority of the members driving these probabilities also have light QPF (less than 0.25") and predominantly rain, with NBM temperatures generally near to slightly above average over the weekend.

Pfahler

AVIATION
(For the 06z TAFs through 06z Tuesday Night)
Issued at 1043 PM CST Mon Jan 20 2025

A cold front is moving through the region currently, with brief gusty winds and some snow flurries along it. Winds stay out of the northwest through the night and into the morning, but speeds should decrease through the day tomorrow as high pressure moves in. In fact, by tomorrow evening winds turn back to the south. VFR conditions are expected outside of the potential for a brief flurry. If this occurs it will be in the next few hours at the St Louis metro or in central Missouri. Brief visibility restrictions and MVFR ceilings are possible with it, but significant accumulations are not expected.

Kimble

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