Issued: 8pm on Sunday, December 1st 2024
Technical Forecast Discussion
Short-term Forecast (Sunday 12/01/2024 through Tuesday 12/03/2024):
High pressure remains in control across the region tonight, promoting strong radiational cooling under clear skies and calm winds. Temperatures will plummet to the mid-teens (around 16°F) as the boundary layer decouples. Surface observations confirm the persistence of a dry air mass, with dewpoints in the single digits to low teens, ensuring minimal cloud cover or precipitation chances. On Monday, the surface high will begin to shift eastward, allowing for weak return flow to develop. Increasing mid- and upper-level moisture ahead of a subtle shortwave will bring periods of high cloudiness, especially in the afternoon. Despite this, high temperatures will remain below average, peaking near 33°F. By Monday night, a 500mb trough advancing from the Midwest will tighten the pressure gradient slightly, leading to increasing southwest winds at the surface. Cloud cover will increase, but the dry low levels will initially prevent precipitation. However, moisture advection may produce scattered rain or snow showers late Monday into early Tuesday, particularly north of the Ohio River. Tuesday will see improving conditions as the trough exits eastward and drier westerly flow establishes itself. Highs will climb to the upper 30s to near 40°F under partly sunny skies.
Long-term Forecast (Wednesday 12/04/2024 through Saturday 12/07/2024):
The long-term period begins with a more active weather pattern as a series of weak disturbances traverse the region. By Wednesday, a deeper mid-level trough begins to amplify over the eastern U.S., with an embedded shortwave bringing an increase in cloud cover and precipitation chances. A warm front lifting northward ahead of this feature will allow highs to reach the low 40s during the day. Rain showers are expected by Wednesday evening, transitioning to snow overnight as the associated cold front moves through and temperatures drop to the low 20s. Thursday will feature lingering snow showers early, particularly in upslope-prone areas, as the cyclonic flow aloft and strong cold air advection persist. Highs will remain near freezing (low 30s), with gusty northwest winds adding to the wintry feel. Friday and Saturday will be dominated by a broad upper trough, allowing for continued cold conditions with highs in the low to mid-30s and overnight lows in the teens. Embedded vorticity maxima within the trough could trigger scattered snow showers, particularly Friday evening into Saturday, though accumulations are expected to be light given limited moisture availability. Ensemble guidance highlights below-normal temperatures through the period, consistent with the seasonal pattern shift as we transition fully into meteorological winter
