Tuesday Night – Party cloudy. Low: 31
Wednesday – Sunny. High: 55
Wednesday Night – Mostly Clear. Low: 36
Thursday – Partly Cloudy. High: 63
Thursday Night – Mostly clear. Low: 43
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DISCUSSION:
Temperatures across the board this week are much above the annual averages, with temperatures reaching nearly 20 degrees above average on Thursday. Current cloud cover will slowly shift out of the region overnight, with sunny sky conditions persisting throughout Wednesday. An increase in cloud cover is expected throughout most of the day on Thursday, but strong southerly winds will maintain the current temperature forecast.
Yost
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Forecasters: Yost, Thee
Date Issued: 01/30/2024 5:00 PM CST
Technical Discussion:
Current surface analysis displays a weakening surface cyclone centered over the Great Lakes region, with a cold front draped to the south and extending through the Ohio River Valley to southern MO. The cold frontal passage generated a subtle temperature drop this morning and induced the redevelopment of cloud cover. However, temperatures in Columbia were still able to climb to the upper-40s this afternoon due to breaks in cloud cover. Visible satellite imagery displays most of the cloud cover confined to portions of northeast MO,. However, the northerly component of the wind will nudge the band into the CWA early this evening. A large temperature spread can be noted across the state due to the variation in cloud cover, with temperatures in southwest MO reaching upper-50s due to more efficient surface heating. Overnight cloud cover will diminish gradually as surface high pressure builds in the west. However, low temperatures will remain slightly above average due to the lingering cloud cover.
With NAM guidance accurately displaying observed surface features, the NAM was used for the forecast period. Deterministic model guidance (NAM) shows a high-amplitude trough ejecting northeast, with the western periphery of the trough over the CWA. Upstream, broad upper-level ridging is building to the west of the CWA throughout tonight, with heights aloft increasing significantly throughout Wednesday. The associated anticyclone will center over the CWA by 09Z Wednesday and slowly meander east-southeast throughout the morning/afternoon. A broad WAA regime will set up west of the anticyclone early in the afternoon and allow high temperatures to reach above annual averages (avg. high 41). Likewise, surface high pressure will induce large-scale sinking air throughout the CWA, which will generate dominant sunshine all day on Wednesday. As Wednesday night approaches, a high-amplitude trough begins digging into the CONUS from the northwest. Downstream, a fast moving shortwave embedded within the flow will shift east and weaken over time. The shortwave will induce cyclogenesis on the lee-side of the Rocky Mountains Thursday morning as it pivots across the Central Plains. The shortwave will induce subtle forcing for ascent, which will result in clouds slowly increasing throughout the day as well. The associated cyclone will linger in the west but still will enhance the WAA regime. A warm front will be in place to the north of the CWA, and slowly retreat south overnight as the cyclone begins to undercut the strong anticyclone to the east. Strong, southwesterly flow throughout Thursday will result in high temperatures skyrocketing 20 degrees above annual averages. In terms of cloud cover, sounding analysis depicts an increase in upper-level moisture throughout the early afternoon hours on Thursday, which is conducive of upper-level cirrus. However, the Planetary boundary layer (PBL) air mass will be slow to modify (in terms of moisture), so low-level cloud cover is expected to generate in the evening/overnight hours on Thursday. With that said, cloud cover is not expected to have much of an impact on temperatures due to PBL moisture waning till the evening hours. Therefore, temperatures are forecast to be in the low-60s.
This weekend, the upper-level flow pattern becomes much more dynamic, displaying a textbook Omega-block pattern in place across the CONUS. The aformentioned upper-level trough in the northwest will continue to surge southward on Friday and take on a negative tilt. At the same time, the leeward cyclone near the Rocky Mountains finally begins shifting into the region. Future forecasters should keep this in mind when analyzing the set-up on Friday into the weekend.
-Yost, Simmons