Cold Blast headed for Eastern PA. Snow on Monday?

By: Ryan Fannock
November 12, 2014

Good morning! With highs topping out in the 50's today, it will be the warmest day through AT LEAST next Wednesday. Colder air is moving in and it's packing a punch (especially next week). In the short term, highs on Thursday will make it to the mid 40's. By Friday, temps will top out near 40 degrees. 

Colder temps will continue through the weekend. Daytime highs will reach the 30's while nighttime lows will bottom out in the 20's.

The forecast becomes tricky Sunday Night into Monday. The American Model and European Model have completely different scenarios unfolding. I'll break apart the differences in each model below:

GFS (American) - Sunday Night lows bottom out in the lower 30's. Snow showers would start moving into the area just before daybreak Monday morning. Light to moderate snow would stick around for the majority of the day. It would move out of Eastern PA by 12am Tuesday. Highs on Monday would not make it above 35 degrees. This particular model prints out 3-6" of snowfall. However, the ground is still very warm so those totals would probably be more on the lines of 1-2" in the valleys with 2-4" in elevations. This is precisely breaking down what the model shows. This is NOT a forecast.

EURO - (European) - Sunday Night lows bottom out in the lower 30's. However, warmer air would move in from the South; rising our temperatures overnight. By daybreak, everyone would see light to moderate RAIN. Highs on Monday would top out in the mid to upper 40's. Rain moves out of Eastern PA by 12am Tuesday. This model dumps between 0.5" and 1.0" of RAIN. A snow shower or two is possible early Tuesday morning. However, accumulations would not occur. Again, this is precisely breaking down what the model shows. This is NOT a forecast. 

So now that you've seen the comparisons, which one would you choose? It's virtually impossible to make a forecast at this time regarding the event. This is exactly why you've seen varying forecasts floating around Facebook. At this point, I'm not calling for rain or snow. I'll strictly say precipitation is likely. I prefer to be as realistic as possible. I don't want to hype snow or rain. Today is only Wednesday, so there are plenty of model runs to go before the event unfolds. I'll have another update regarding the storm on Friday. One thing is for sure, after the storm moves through, even colder air will filter in behind it.

Regarding Temps next week: 

If you think the weather this weekend is cold, here's an image showing potential LOWS early Wednesday morning (November 19th):

Click image to view LARGER

Single digits in Western PA?! Hey, it's possible. For us in Eastern PA, teens are possible North of I-80 during the morning. Highs in the afternoon would struggle to hit 30 (if this model verified). Since it's not until next Wednesday, don't be too worried about it. Just know that it's in the cards and could happen. 

In conclusion, there's some very cold weather headed our way. A storm is possible Monday. It's unclear if it will be rain or snow at this point. Another update will be posted Friday evening regarding that event.

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