Current Conditions at Sanborn Field
Friday: Overcast with showers throughout the day. High: 50
Friday Night: Mostly cloudy with scattered showers. Low: 42
Saturday: Mostly Sunny High: 60
Saturday Night: Partly Cloudy. Low: 43
Sunday: Partly Cloudy. High: 55
Discussion:
The end of the workweek will be soggy as showers continue to slowly pull out of Mid-MO. Expect an overcast and chilly day for Friday with rain beginning to clear up late afternoon. Showers will fully exit the area early overnight and clouds follow by Saturday afternoon. Conditions will be warmer on Saturday under the sun before our next front brings another batch of cool air in. A cold front will move through the area near midnight Saturday; it won't bring any rain but temperatures will suffer a small blow heading into Sunday. Halloween still looks dry and enjoyable this year - just don't forget a jacket with your costume! A potentially frigid pattern is setting up early next week which may bring our first frost of the season!
-Splater
====================================================================
Forecasters: Splater, Schneringer, Bongard
Date Issued: 10/29/21 10:00AM CST
Technical discussion:
A strong, stacked closed low exiting the region and a dry frontal passage present the main challenges for this forecast period. The 06Z run of the GFS was used used in this forecast, due to its slightly better handling of morning temperatures and precipitation amounts compared to the NAM. Model soundings and cross sections were also utilized in the creation of this forecast.
A closed low at the 250-mb level is positioned over the Missouri Bootheel region into western Kentucky this morning. The associated troughing with this system dives down through Missouri and Arkansas, into northern Louisiana. By 12-15Z Saturday, a slight ridging pattern will have moved over the forecast area, before transitioning into zonal flow throughout the day and into Saturday night. Divergence aloft is relatively non-existent, although a strengthening jet streak centered over the Sioux Falls, SD to Marshall, MN region will begin to spread into the forecast area beginning 15Z Sunday. This jet will continue to strengthen as the weekend closes out.
The low at 15Z this morning is centered over Southern Tennessee/Northern Alabama at the 500-mb level, and it will drag vorticity through the forecast region until 06Z Saturday. This, combined with areas of abundant moisture Friday afternoon into the evening at the lower levels indicates continuing rain at those times. Flow patterns at this level mirror those present above, as troughing transitions into zonal flow as the weekend progresses.
Missouri is dominated by high RH values at 700-mb. As low continues to exit to the east, this moisture is tugged along with it, and the region will be mostly dried out by 09Z Saturday. Any significant amounts of vertical velocity associated with the system exits the region by this afternoon as well, further indicating that rain won't continue past Friday night. A shortwave will move through the northern plains Saturday morning, moving southeast as it passes over the forecast area between 06-09Z Sunday.
The 850-mb level is as moisture rich as the layer above, and a time-height chart of Columbia indicates 100% RH through 0Z Saturday. As is happening aloft, the low tracking farther to the east will serve to dry this level out, altough moderate amounts of moisture will still be present until 03Z Sunday. Moisture associated with the shortwave aloft will track through between 09Z and 15Z Sunday, but the amount won't be significant enough for precipitation.
A dry surface front will pass through the region Sunday between 06Z-09Z, capping off a relatively calm weekend following a week of active weather.
No comments:
Post a Comment