Issued: 8pm on Sunday, December 22nd 2024
Technical Forecast Discussion
Short-term Forecast (Sunday 12/22/2024 through Tuesday 12/24/2024):
Surface high pressure centered over the region tonight will maintain mostly clear skies and light winds, promoting strong radiational cooling overnight. An upper-level ridge will remain in control through Monday, keeping conditions dry with weak southerly flow allowing for a slight warming trend. A minor shortwave embedded in the zonal flow aloft will pass north of the area Monday afternoon, increasing mid-level cloud cover, but moisture availability and lift are insufficient for precipitation development. On Tuesday, the surface high shifts eastward, allowing for a more robust southerly return flow to develop. This will lead to increasing warm air advection (WAA) and slightly higher dew points, though conditions will remain dry. Skies will feature a mix of sun and clouds, with increasing high clouds by late Tuesday as a broad trough begins to approach the region from the west.
Long-term Forecast (Wednesday 12/25/2024 through Saturday 12/28/2024):
By Wednesday, a well-defined mid-level trough will approach from the central Plains, accompanied by a surface low tracking through the Great Lakes. Strong WAA ahead of this system will bring increasing cloud cover during the day, with isentropic ascent supporting the development of scattered rain showers by Wednesday evening. Model consensus keeps temperatures well above freezing, precluding any potential for wintry precipitation. The associated cold front will push through Thursday morning, bringing widespread showers to an end by midday. Post-frontal conditions will feature subsidence and drying, with clearing skies and cooler air advecting into the region under northwesterly flow. High pressure will build back into the area Friday, leading to dry and seasonable conditions. Model guidance indicates persistent zonal flow aloft, with no significant weather systems expected through Saturday. Skies will remain mostly clear, with seasonal daytime highs and chilly overnight lows typical for late December.
