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Thursday Night: Clear. Low: 31°F
Friday: Cloudy, Sleet and Snow. High: 34°F
Friday Night: Decreasing Cloud Cover. Low: 19°F
Saturday: Mostly Sunny. 34°F
Saturday Night: Clear. 26°F
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General Discussion:
Temperatures are veering back to average numbers this weekend. Precipitation is expected to start early Friday morning and end in the afternoon. The precipitation will start as sleet and change into snow as we get into the late morning and early afternoon. 1-3” of total accumulation is expected. Saturday will be much dryer as the moisture moves to the east out of Missouri.
-Melton
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Forecasters: Thomas, Melton, Peine
Date Issued: 2/15/2024 5:00 PM CST
Technical Discussion:
Key Messages:
- Uncertainty on how snow will accumulate on the ground
- Warmer weather looks likely early next week
The NAM and the GFS were both used for this forecast, with the GFS being used more extensively as it has a better handle on this forecast and has been the most consistent throughout the week. At 300mb, there is no divergence aloft and with an upper-level trough directly overhead the region, which is leading to no active weather over the region tonight and allowing for temperatures to cool to the low 30s. However, this changes early Friday morning as a disturbance tracks over the region, leading to divergence aloft which would lead to a more active weather pattern.
This is also observed at 500 mb. There is a vorticity max that is centered over the region at about 15Z, which would be all attributed to a low pressure system that is centered over Southeastern Canada, and there is also, a positively tilted trough that is situated over the Eastern CONUS.
At 700 mb, there is significant amount of moisture that then moves over the region between 09Z and 15Z, and there is some WAA present as well. This is also seen at 850mb, with a weak LLJ present, which would help with lift. The 540 line is to south of Columbia, which would mean that any precipitation that falls will be frozen. At 12Z, there is a high likelihood that the precipitation starts out as sleet as the Dendritic Growth Zone is not completely saturated, which means that there will be liquid droplets and that there is a warm layer at about 850 mb. At about 18Z, the DGZ is completely saturated and there is no warm layer aloft which would then mean that snow would be falling at this time. Snow totals will be in the range of 1-3 inches, however ground temperatures will likely be too warm to see most of this snow accumulate on roads, unless the snow comes down hard enough to overcome the warm ground. This system then begins to move out at around 21Z and CAA begins to move into the region, leading to the atmosphere drying out as seen at both 700 mb and 850 mb.
Heading into Saturday, at 300 mb, the upper-level trough moves directly overhead, as mentioned earlier, CAA will be present over the region which will lead to no moisture being present at 700 mb or at 850 mb. However, temperatures will be in the 30s because of the trough being directly overhead.
Heading late into Saturday, the upper-level trough will begin to move out of the region and an upper-level ridge will build into the region, which will lead to warmer temperatures heading into Sunday.
-Thomas