An uncertain forecast. #PAwx A shift is expected to occur in the jet stream during this coming week and the models are having a tough time predicting the path of the next storm.
Originally, low pressure was expected to move from the US Southwest to the Atlantic coast and then move up as a nor’easter Tuesday night into Wednesday.
Things have changed and now the storm is expected to move up and straight off the coast to our south Monday night into Tuesday morning, ending late morning Tuesday. Different timing and different amounts of snow. The GFS has a QPF of about 0.20 inches water, so 2-4 inches is the best guess.
Tonight will be a good test of the weather models. Both the GFS and the NAM are showing the precipitation associated with an artic front to dissipate before reaching Philadelphia. The GFS cranks out a snow flurry around daybreak with a QPF of 0.01 inches water.
On Sunday, another weather forecasting dilemma presents itself as a stalled front in our area will allow disturbances to develop and move along the front. It’s impossible to know where the front will end up, but recent similar scenarios have the front stalling further south than model predictions. As a result, light snow is seeming more possible than light rain or sleet in PHL. A stronger low pressure system may develop along this front Monday, bringing snow. Amounts not predictable at this time. Stay tuned.
