12/4 – The Chief’s “Recap Of Heavy Rain” Monday Morning Forecast
A broad upper level disturbance over the eastern third of the CONUS will be the primary feature impacting the forecast area through Wednesday. Pacific based moisture will continue to feed into the region on the back of the westerly flow, and this will keep scattered to broken cirrus deck in place through tomorrow. At the surface, high pressure building in from the north and west will keep a light northerly flow in place. Conditions will remain very dry in the low levels of the atmosphere due to this ridging. The cirrus deck will inhibit radiational cooling tonight, and have stuck with models for overnight temperatures as it is on the upper end of the model solutions for overnight lows. Temperatures will be near average with highs in the 60s and lows in the upper 30s and lower 40s.
A reinforcing disturbance and associated front will sweep through the region Tuesday night, and this will drive a cooler airmass into the area. The front will also serve to clear out any linger high level cloud cover as winds shift to the northwest in the mid and upper levels. Temperatures Tuesday night will be about the same as seen tonight, and this will be due to increased gradient flow keeping the boundary layer thermally mixed. However, the cooler air moving will push daytime highs down into the upper 50s on Wednesday. By Wednesday night, lighter winds and clear skies will allow for stronger radiational cooling to occur. Lows should dip into the lower to middle 30s over inland areas and the lower 40s along the beach.
High pressure will be pushing across the area on Thursday and this will keep a highly subsident airmass with clear skies and low humidity in place. The thermal trough axis will also begin to pull to the east as winds begin to shift to a more onshore component in the afternoon hours on the southwest periphery of the departing surface high. This will allow for slightly warmer temperatures in the low to mid 60s Thursday afternoon. The onshore flow will gradually usher in more Gulf moisture and this will keep lows a good 10 degrees warmer on Thursday night with readings generally falling into the 40s and lower 50s.
