Say It Ain’t Snow! Well There Ain’t Much Snow To Talk About Yet!

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Southern New England has had its real first good shot of cold air for the season this past week and that will continue through today and tomorrow.That was all thanks to the Low Pressure system that brought us intense thunderstorms Friday night into Saturday Morning. This allowed an area of cold High Pressure from the Northwest to settle into the region, bringing the strong wind gusts we saw along with unseasonably cold temperatures.

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This sets us up nicely for our next round of precipitation that will move through the region tomorrow morning and afternoon. There is suggestion in the models right now that temperatures in the lower atmosphere will be well below zero for the morning hours so there is support for some flakes to fly when the precipitation first starts. However, a look at the surface map shows that surface temperatures for most of the region are still slightly above zero and since we haven’t had a hard freeze yet (being a prolonged period of below freezing temperatures) the ground itself is still too warm below the surface and any snow that falls would melt right away. The caveat to that being that if it snowed at an intense enough rate or for a prolonged period of time, then it would be able to stick, but that is nothing to worry about in this case.

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Areas in Central and Western MA are most likely to be the ones to see any flakes tomorrow as the coldest air will stay at the highest elevations the longest, so for us here in Lowell, we most likely will be spared seeing the first flakes of the season for another couple weeks :(. Warm air moves in quickly with this Low Pressure system, so any snow that does fall will quickly switch to plain rain for the rest of the day. That leads into more seasonable temperatures and weather for the weekend!

 

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The Backdoor Cold Front

Last Tuesday, October 18, was supposed to be warm and sunny.  So warm in fact, that the high temperature record in Boston was in jeopardy.  Forecasts were for highs to reach 80 degrees F throughout Northeastern Massachusetts.

The high in Boston came close to 70 degrees F, but only rose out of the 60s at 8pm that night.  The same thing happened in Lawrence, MA as well as Beverly, MA.  What happened?  We had a Backdoor Cold Front.

Regular cold fronts come from the west, usually the northwest.  A Backdoor Cold Front is a cold front that comes into New England from the “Backdoor”, often from the Gulf of Maine.  Backdoor Cold Fronts are very shallow and small in scale – only affecting part of Massachusetts and Southern New Hampshire in this case.  The cold air slips into New England as a High Pressure Area in Eastern Canada moves into the Gulf of Maine, and intensifies.  The cold air comes into New England from Canada and the Gulf of Maine.  Instead of sunny and 80 degrees, we had drizzle, fog and 57 degrees   Once in place, it can be slow to move out.  The following images show the “before”, “during”, and “after” phases.

Yellow lines are sea-level pressure in hPa (millibars), blue lines and color coding shows temperatures in degrees F, and the red symbols show the winds (conventional meteorological notation – the back half of the wind vector).

BEFORE:  8 pm Monday Night2016-10-18-ruc04

DURING:  8 AM Tuesday Morning2016-10-18-ruc16

DURING: 11 AM Tuesday Morning2016-10-18-ruc19

AFTER: 8 pm Tuesday Night2016-10-18-ruc28

AFTER: 8 AM Wednesday Morning2016-10-18-ruc40

Wednesday turned out to be the beautiful day with temperatures reaching into the low 80s!

 

Hurricane Matthew and The Track of Confusion

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Satellite Image of Hurricane Matthew from this morning

Hurricane Matthew has been an impressive storm so far and it doesn’t look like it is going to stop any time soon. It has been one of the most powerful storms the Atlantic has seen in the past Decade. Yesterday the storm made its first landfall in Haiti, dumping anywhere between 10″ to as much as 40″ of rain on the country.

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Dominican Republic rainfall for 24 hours starting yesterday

Our thoughts and prayers go out to all the people of Haiti that they may be kept safe and can rebuild from the destruction this storm brought them. Above is a current satellite image from the storm this morning. It made landfall in Cuba last night and is on track to reach Florida over the next couple of days.

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Current Hurricane Track

This is the current track right now for Matthew based on current model data. However, with Tropical Storms such as this, the models really have trouble 3-4+ days out, so other than the storm hitting Florida, not much else is known about what will happen after that. The thought earlier this week was that the storm would move towards Florida and Georgia, then move off the Coast of the Carolinas and north up to New England. However, as of yesterday, the models began to agree that the storm would not have much of an impact on New England (as seen in the Spaghetti Plots below)

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Yesterday: Looks like New England may see some of Matthew

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6 hours later: Oh wait……never mind New England won’t see Matthew

There was a massive shift in the model forecasts from the yesterday morning to last night and this morning. The models have since shifted the storm from moving off into the Atlantic right away, to lingering off the coast of the Carolinas and even spinning back towards Florida before moving away into the Atlantic. Why has there been such a dramatic shift? That is the question everyone is trying to answer.gfs_z500_vort_us_2

First off, this is our main player to the storm track, a trough over the Western part of the United States. The shortwave which helped to form this trough only reached the coast of the United States last night and is only just beginning to form said trough. This means the models are basing the storm track after Florida on the formation of said trough, but the data for the trough isn’t fully there for input since it hasn’t formed yet. With the shortwave finally reaching land, this will allow for better data to help better establish how strong this trough will be and where it will set up.gfs_z500_vort_us_15.png

Current thinking this morning is the trough will move to the Northeast by the end of this week and set up high pressure over the region, extending down the East Coast into Pennsylvania. This would create a blocking High, preventing the Hurricane from moving up the coast and causing the backlash at Florida the models are suggesting. This would have to be a pretty strong high and the timing of the trough would need to be exactly as it is for this to set up perfectly.

Keep in mind, this storm is days out and there is really low confidence on its track after it hits Florida. Florida will see Hurricane strength winds and heavy rains, so anyone in the area of Florida and Georgia should take Tropical Storm precautions seriously and prepare for this event.