Small Clippers Moving Through with Light Snow Showers; Arctic Chill Next Week


Snow showers associated with a weak clipper system will pass through the area today. Many people could see some light snow fall by the evening, a taste of a much-anticipated winter. The snow should not stick, even on grassy surfaces. Another clipper will pass to the north of us New Years Eve, giving us a similar scenario as today. Arctic air will invade the region on the 2nd after a weak cold front passes through the area (with more snow showers).

Tuesday and Wednesday will be very very cold. Low temperatures could go into the single digits in some places with highs not even getting out of the 20s. This will be our first real arctic freeze of the season. By Friday, a storm system will head out to sea and bring back some warmer air. The temperatures should remain in the low 40s and upper 30s into next weekend and beyond.

 

5 Day Forecast
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No More Boxing Day Storm, But Still Something to Watch for Tuesday


Well, our Boxing day storm has officially been ruled out by the forecast models and meteorologists alike. A few days ago, it seemed that a few of the models weren’t handling the storm correctly, creating a bit of uncertainty. But, as we got closer and closer to the event, all models were in agreement: no storm on Boxing Day.

So, for our upcoming weather. Christmas Eve should be nice, but cold. Highs may not make it out of the 40s tomorrow. Christmas day should be a bit warmer, but still dry. No white Christmas this year folks… hey, there’s always next year! Monday will be the transition day, as it looks like a piece of energy will intensify into a low pressure system and turn northward. Where the turn takes place is still in question. Right now snow does not look likely from this storm, even if it takes a favorable path. Not enough cold air aloft will make it difficult for snow to fall. Things could change though, and the nao is turning negative, which is usually a sign of a stormy pattern coming up. Stay tuned.

5 Day Forecast

And finally: GO EAGLES (AND JETS)!!

Heavy Rains Coming Tonight; Very Small Possibility for a Boxing Day Snowstorm


Major rains will spread over the area tonight as a low pressure system passes just to our east. Areas north and west of the region could see some snow or ice mixed in with the rain. Unlike the unusual squall lines that passed through last night, this storm will be mostly heavy rain with some gusty winds on the backend Temperatures should plunge as the storm pulls away. This cold air should continue through Christmas.

Rainstorm Tonight

Our possible Boxing Day storm:

There is a chance of a nor’easter affecting our area Sunday night into Monday. I have been very pessimistic with this system. The nao teleconnection does not support any storm riding the coast (aka it stays positive: see image) and none of the models have been showing the snowstorm. Most models have been showing a flat jet stream, which would  propell the storm out to sea. Under this scenario, we would have a beautiful, sunny Christmas Day and Boxing Day. But, there is a slight chance that the trough turns negative and brings the storm up the coast. Cold air would be in abundance, and we would recieve a substantial snowstorm. The likelyhood for this scenario, however, is around 10%. As we have seen so far this winter, the computer models have done a terrible job pinpointing the location of storms. Under most cases, I would say that there is no chance for a storm to affect the area Monday. But, because of the forecast models’ inconsistencies this year with storms, I still believe that there is a slight chance this storm rides the coast.

Current NAO Projections

 

I have heard many people saying winter is over because we have been so seasonably warm. I would not worry at all about the current temperatures. What goes up, must come down. I am expecting one large storm that will change our pattern to a wintery one. Whether it is the upcoming Boxing Day possibility, or something in January, a major nor’easter will come. Remember, winter just started yesterday. We still have plenty of time for a storm.

Snowy Pattern Just Hasn’t Started Yet… Long Range Looking a Little Promising


Well, it has been a while since I last posted. The weather pattern has really slowed down since our giant rainstorm two weeks ago. Currently, the teleconnections just haven’t been supporting a snowy weather pattern. While many people are concerned that we will have a warm and dry winter, I do not think there is anything to worry about. We have not even started winter (well, the meteorological winter started December 1st, but that’s beside the point) and temperatures have been close to normal for this time of year. We need to be patient about the snow and stay calm. Remember: if you wait, snow will come.

We Want Snow! Well, maybe not THIS much snow...

So, enough of my weather pep talk and back to our current weather. I have been looking in the long-range (around New Years) and there have been signs of a storm affecting our area any time from the 26th-31st. Right now, I am not sure how much cold air will be in place during this time frame and the forecast models have been quite inconsistent with temperatures so far this winter. We will see what happens over the next week!

Stay posted!

Snow Map for December Snowstorm/Rainstorm of 2011


Rain will get heavy at times tomorrow morning and afternoon as a frontal boundary pulls through ahead of an impending nor’easter. Forecast models have been trending West with the nor’easter. It is looking very likely that scenario 3 (see past post) is going to come true. The low is expected to move off the Delaware coast and hug the coast. Rain will fall much of the time as the cold air just will not be able to wrap around the storm in time. As the storm is pulling out, I expect the rain to change to snow late Wednesday night for a 4-5 hour period. 1-3 inches of slushy wet snow should fall around the I-95 corridor, with 3-6 in the Lehigh Valley and areas north.

Possibility for an increase in snow totals:

There are a many weather junkies (including myself) who are willing to “nowcast” (forecasting as the storm happens) and disregard the models for this storm. The forecast models have had an extremely hard time and may not be portraying the rain/snow line correctly.

The words, “dynamic cooling,” are crucial for the early changeover to snow.  In simple terms, dynamic cooling is like continually putting ice cubes into a cup of water. The water will eventually cool down to near freezing, even though the initial temperature was above. We encountered major dynamic cooling during the Halloween storm: When the snow started falling in the morning, it slowly dropped the temperatures to freezing, making the changeover to snow much earlier than any model had anticipated.  This is what I am concerned will happen with this upcoming storm. I will continue to watch what develops later tonight and throughout the day tomorrow. Stay tuned!

Here is my snow map:

December Snowstorm of 2011

Still Three Scenarios, But Confidence is Higher for Thursday Storm


It has been a very interesting day to track the forecast models. We are dealing with a storm very similar, with regard to the amount of cold air, to the October storm. The cutoff for snow will be sharp. The snow will also be wet and heavy where it falls. The storm should start Wednesday late night and end by Thursday afternoon. What type of precipitation will fall is still in question.

I am going to stick with the three scenario method I started yesterday:

Scenario 1: Like before, the storm takes the benchmark and rides up the coast. Storm will rapidly strengthen and bring in enough cold air for snow to fall around the area. If this scenario comes true, 3-6 locally 8 inches of snow would fall. I am currently favoring this scenario.

NAM Scenario 1

 Scenario 2: Once again, like yesterday, the storm would go out to sea and not affect the area. Would not strengthen in time to bring in cold air and heavy precipitation. Right now I am not leaning toward this solution.

GFS Scenario 2: Out to Sea

Scenario 3: This is a little different from yesterday. The low would strengthen faster than scenario 1, and hug the coast. We would not have enough cold air to support snow until the very end. Minimal snow totals likely from this scenario. This setup is the current trend shown by the models. I am not sure if it will come true or not.

NAM Scenario 3

Stay tuned!!

Here is an overview of the three scenarios:

Overview Map

 

Regarding the Possible Snowstorm Later in the Week


An exciting and stressful week is coming for many meteorologists around the country. As you can see from the title, we are looking at our possible 2nd snowstorm of the year Thursday and Friday. Many models have been showing some sort of nor’easter later this week. The storm will come from piece of energy associated with a cold front that will sweep past the area on Wednesday. After the cold front moves through, a nor’easter is expected to form.

The questions right now are:

1. How much cold air will the storm bring in?

  • We all know from October that we don’t need much cold air aloft to create a major snowstorm. So, if the storm takes a favorable path, it should be mostly snow (maybe a little sleet at times).

2. Where will this storm go?

Three possible scenarios:

Scenario 1: The storm takes the benchmark (favorable path). Strengthens rapidly and brings in cold air. Significant snows possible from this scenario.

GFS scenario 1

Scenario 2: Storm does not strengthen and does not wind up. Jet flattens out and storm goes out to sea. Minimal precipitation likely from this scenario.

European Scenario 2

Scenario 3: Storm goes inland. Strengthens sooner than expected and rides the cold front before it passes through the area. This scenario would bring us a nice rainstorm.

NAM Scenario 3

All three of these scenarios are possible at this point. As we progress through the week, I will be able to narrow it down to two, then one scenario. Stay tuned.