Thursday Afternoon Technical Discussion

Synopsis: For this upcoming weekend we can expect below normal temperatures with a couple storm systems coming through the region. Tonight we can expect partly clear conditions with diminishing winds overnight. Our next storm system, a clipper, will then enter the region late Friday night and continue into Saturday afternoon. Temperatures appear to be cold enough to support snow, so the threat exists for light accumulations with this system. Then, as we head into Monday a larger storm system will begin to affect the region. The precipitation will likely start as snow, then eventually change to rain. Keep in mind that this storm is still several days out, so a lot can change.

 Short Term: A weakening low centered over the Canadian Maritimes will be the source of strong, NW winds throughout the day. As this system moves further away, we can expect to see these winds diminish overnight. Low temperatures will dip into the low 20's as a result of weak cold air advection. Our next system is a clipper and will move through the region Friday night into late Saturday morning. The 18Z NAM run shows a colder trend as well as a southern dip affecting mainly the southern half of the Commonwealth. Light to moderate snow accumulations are possible with this system, especially in the higher terrain of the Laurel Highlands and Ridge and Valley Regions.

 

Long Term: After the clipper moves through, we will come under the influence of a weak area of high pressure. This high won't last long as a rapidly strengthening system over the Northern Plains moves to the ENE over the Great Lakes late Monday afternoon. A shortwave upper level disturbance is expected to trek ahead of this system moving in from the SW causing precipitation to begin earlier. Cold air is expected to still be in place to support some snow before changing to a mix of rain, then eventually all rain. This shortwave disturbance will then join the ENE moving storm system early Tuesday causing more precipitation that may be heavy at times. We will be affected by this storm's cold front around 12Z Tuesday. The 12Z EURO and GFS models show the potential for a changeover to snow at the wake of the cold front, but this should be nothing more than a nuisance.

Michael DiDomizio
The Pennsylvania State University | Class of 2013
B.S. Meteorology | Forecasting and Communications Option
Minor | Climatology