Wednesday, September 11th – Morning Forecast
Wednesday: Hazy from wildfire smoke. Mostly Sunny. High: 85°F
Wednesday Night: Clear then partly cloudy. Low: 62°F
Thursday: Increasing clouds. High: 85°F
Thursday Night: Mostly Cloudy. Low: 64°F
Friday: Scattered Showers possible. Overcast. High: 73
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General Discussion:
The warming trend will continue today and tomorrow with clouds moving in by tomorrow morning ahead the approaching remnants of Hurricane Francine. This system will bring plenty of cloud cover with limited chances for scattered showers on Friday. With the overcast conditions and cooler temperatures, Friday will be on the chilly side.
– Peine, Latlip, Brucker, McCurdy
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Forecasters: Peine, Latlip, Brucker, McCurdy
Date Issued: 09/11/2024 9:00 AM CDT
Technical Discussion:
Key Messages:
- Slightly above average (Avg. H: 82 L: 60) temperatures continue through Thursday.
- Beneficial rain may be hard to come by with a 30-40% chance of rainfall totals exceeding 0.10” on Friday.
At the surface, there is currently a high pressure system positioned over the Appalachian mountains that is leading to southeasterly winds at the surface and clear conditions this morning. Wildfire smoke will persist in the upper levels today leading to hazy conditions.
The main problem of this forecast shift is Hurricane Francine due to the uncertainty in its exact speed and position as it approaches the region. The current upper level pattern over the CONUS is mainly zonal with a small split flow signature over the Midwest. In the northern stream, there is a longwave trough over the Pacific northwest and a ridge downstream with its axis over Manitoba. In the southern stream, the main driver is Hurricane Francine that is currently about to make landfall on the Gulf coast of Louisiana. The ridge to our north is expected to deepen by Friday and shunt the trough over the Pacific Northwest north into Canada away from our area. This will result in the remnants of Francine to slow down and meander around the confluence of the Mississippi and Ohio rivers throughout the weekend with no synoptic features around to move it away from the region.
The remnants of Hurricane Francine are expected to begin impacting the region by early Friday morning. There is a lot of dry air over us in the low to mid levels that Francine will have to fight as its moisture field moves north. The deep level moisture, and best forcing, associated with bands of mid level vorticity, should arrive by Friday morning. However, mid level dry air tries to stick around over mid Missouri throughout the entire event, which would lead to very light rainfall amounts during the day on Friday. Temperature through Thursday will be seasonably warm with southeasterly flow and plenty of solar insolation. Regardless, the remnants of Francine will bring cooler temperatures with highs only reaching the lower 70s on Friday under overcast conditions. Future forecasting shifts should monitor the remnants of Hurricane Francine as it is expected to sit just off to our southeast throughout the weekend.
– Peine, Latlip, Brucker, McCurdy