Tuesday Evening Technical Discussion

Tranquil conditions should continue throughout the state on Wednesday with a few low level clouds possible due to afternoon heating. Relative humidity's are over 70% above 850 mb across the Western portion of the state on Wednesday, so expect most cloud cover to exist in Western Pennsylvania. Temperatures will be on the increase Wednesday as winds shift from the south leading to some warm air advection. Expect many areas to reach the upper 70's with some areas reaching the lower 80's. NAM and GFS MOS are both showing that many areas of the state will reach at least 80 on Wednesday. Cloud cover may slow afternoon warming in some of the western regions. Temperatures will fall in to the upper 50's Wednesday night, with cloud cover keeping them from falling back to the lower 50's. Some showers should be expected in the afternoon on Thursday as a weak front moves through the state. Showers should end in the evening as the day time heating is lost, so most shower activity will not reach the eastern portions of the commonwealth. Due to evaporative cooling, showers and cloud cover will keep temperatures in the upper 70's. The 12z GFS does allow the showers to hold together better than the 12z NAM and allows many of the showers to reach the Harrisburg-Lancaster area. Best option is probably the NAM solution as there will likely not be enough energy for the showers to last long into the night. Cloud cover will move through the state Thursday night, which will keep overnight lows in the upper 50's to the lower 60's. Skies will clear for the most part on Friday allowing temperatures to rise back in to the lower 80's. NAM keeps some low level cloud cover in the western portions of the state Friday which may keep temperatures in the upper 70's across the West. Expect cloud cover and dew points to be on the increase Friday night as a front begins to approach the area. This should keep temperatures in the mid to lower 60's overnight Friday. A warm front will move in from the south on Saturday leading to some afternoon showers and thunderstorms across the state. While still in long range, runs of the NAM keep most of the showers in the eastern portions of the state, while the GFS allows showers to form statewide. Expect pre frontal advection to push temperatures well into the mid 80's on Saturday. Showers will die off during the evening as daytime heating is lost. Some cloud cover will remain across the state Saturday night keeping temperatures in the lower 60's. Temperatures on Sunday will reach the lower 80's again as winds shift to the southwest. A cold front will push into the state later in the day on Sunday allowing for more showers statewide Sunday afternoon. Showers may last through part of night before again dying off due to lose of solar heating. Winds will shift from the northwest Sunday night allowing for temperatures to fall back into the mid 50's across the state.

 

Zachary Fasnacht