Wednesday, February 27, 2019

Tonight - Cloudy . Low: 18-22.

 Thursday - Mostly cloudy  High: 34-38.

Thursday Night - Cloudy. Low: 22-26.

Friday - Cloudy. High: 42-46.

Saturday- Cloudy with snow overnight into Sunday. High: 32-36.

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Cloudy skies will linger for the forecast period. A cold front has made its way through the area making our temperatures much cooler than what we experienced yesterday. We will see a slight warming of temperatures on Friday as a high pressure system will influence our area. Winds out of the south will help bring our temperatures up as well as increase the moisture in the atmosphere. This warm spell will be short lived however, as we brace for another blast of arctic air that will bring cold temperatures, strong winds and even snow. A cold front will move into the area overnight Saturday, this will be our next chance for precipitation. Further monitoring of this system will be needed for snowfall amounts as we are still too far out from the event to accurately predict totals.

Forecasters: Bongard, Sumrall and Hirsch
Issued: 2:49 p.m., February 27, 2019

Technical Discussion (The nerdy stuff we are discussing in class!)
Zonal flow presides over the forecast area overnight tonight as a subtle ridge begins to sets up over the southwestern CONUS by 12Z Thursday morning. Marginal vorticity will creep into the northern Plains including northwest Missouri in response to a shortwave ejecting out of the northern Rockies trekking into the Plains by morning. Closer to Columbia, low level winds will help to drive overnight lows into the upper teens. Moisture profile is tricky as both NAM and GFS both depict a warm inversion and a moistening up of these levels (700-850 mb). NAM is bullish on a chance for snow over central MIssouri though with minimal accumulation. GFS is void of precipitation for the area at this time.
Thursday will be a dry day for central Missouri as a dry layer near the surface will prevent any of the moisture in the low levels attempting to advect into the area from the south from developing sufficient precipitation at the surface. While low level clouds will keep the region overcast through 21Z Thursday the atmosphere will be hard pressed to generate enough precipitation to penetrate the aformentioned dry layer. A relatively weak zonal flow keeps things moving along in the upper levels. The shortwave over the northern Plains will carry moisture through southern Iowa but will not impact the forecast area. Despite northerly winds at the surface temperatures will struggle into the mid 30's for afternoon highs. Model charts show southerly winds over southern Missouri so if the quasi-stationary warm front to our south does lift far enough north we could see a bump into afternoon highs.
Light winds will swing from a northerly course closer to southeasterly by Friday morning. Zonal flow continues aloft though amplified ridging over the southwestern CONUS houses a building jet streak that will place the area in its left exit region by 12Z Friday morning. Yet another shortwave ejects off the front range and heads into the central/northern Plains by daybreak. A dry night for the area is in store as model soundings promote a moisture deficient profile promoting only scattered to broken clouds through the evening. With some cloud cover and light winds temperatures will drop slightly into the mid 20's for overnight lows.
The ridge out west begins to influence the forecast area with the nose of its axis based jet streak creeping into eastern Kansas through the day Friday. To our north over central Canada a large trough and associated low pressure center will drag a cold front through the northern Plains Friday and Friday night. Impacts of this cold front will be minimal Friday besides a wind shift occurring late Friday night before 06Z Saturday. Closer to the surface, low level southerlies will help to increase temperatures into the mid to upper 40's Friday afternoon while also advecting moisture up into southern Missouri that could touch off some precipitation there while central Missouri looks dry for Friday.
Saturday is a tale of model disagreement as the profiles for GFS and NAM take dramatic turns over the course of the day. GFS moistens up quite a bit in the mid to afternoon hours Saturday promoting a chance for snowfall. Meanwhile, NAM promotes a significant dry layer holding snow off until later Saturday night or even Sunday morning. Temperature profile will be below freezing in response to the cold front the Canadian trough dragged through the Midwest early Saturday morning. Northerly surface winds will keep temperatures cold for Saturday in the 20's.

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