Cut-off Lows and Forecast Woes

This has been one of the hardest weeks to forecast for New England so far this Fall. It all started with the cold front that moved through on Tuesday. This brought some much needed rain to the region, but it also helped to move the High Pressure that was over the Region out to sea.

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High Pressure we hardly knew you

This allowed for an area of Low Pressure to make its way south from the Great Lakes, however it cut-off from the stream and has stayed spinning over the Ohio River Valley for the past week. This was caused due to strong closed circulation at the surface and a blocking High that set up over Northeast New England.

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TODAY’S SPECIAL FEATURE: As The High Blocks

This has caused us to be stuck in this cool, grey pattern that we have seen over the past week. Based on recent research into Weather Patterns seen in the Northeast during the Fall season, this would e considered Weather Type 3, as seen below.

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Weather Type 3 Features rain, rain and some more rain.

This pattern is defined by an offshore high pressure system along with a Low Pressure system over the Great Lakes. This pattern typically persists anywhere between 1-3 days, but there have been cases of it lasting as long as 6 days. This would occur when such blocking as we have seen this week sets up. This allows the East Coast to see abundant rainfall due to the Southwest flow of moisture into the region at low-levels. However, as we have had a blocking High to the North, we in New England have seen more of a North/Northeast flow into the region. This has caused us to see average to below average temperatures and little rainfall as cool, dry air has been constantly fed into the region. As the Low begins to lift North back into the stream over the next couple of days, this is when we will see the rain come into the region as the High begins to lift out as well.

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This should help with the drought a bit, but it still isn’t enough.

This will bring us rain showers beginning in the evening Friday and heavier rain moves in overnight and lasts through the late Saturday morning before turning back to showers by the afternoon. This should bring some much needed rain to the region as Northern parts of MA see around .35-.60″ and areas in the Southern half see around 1″+ of rain. Rain showers look to stick around on and off throughout the day Sunday and Monday. These look to be lighter in nature meaning that the days will not be complete washouts. Temperatures also look to increase as the High Pressure moves out and a more Southerly Flow takes over meaning Sunday and Monday will see Highs back in the mid 60s.

Sunshine looks to return for a bit next week but we have to watch out for Hurricane Matthew as it begins to trek northwards next week.al1416w5_nl

 

 

 

Autumnal Equinox is here!

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While Autumn started for Meteorologists back in the beginning of September, today marks the Autumnal Equinox! What is the Autumnal Equinox you ask?? To start, Equinox finds its roots in Latin, meaning Equal Night. Here’s a quick look at the science behind it:

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The Earth is always tilted, with the tilt fluctuating between 22.1°and 24° (which the change in the tilt angle occurs over thousands of years). Currently the Earth is tilted at an angle of 23.5° towards the sun. When the Equinox occurs, the way the Earth is tilted and its position in the orbit cause it to be almost perpendicular to the incoming rays from the sun.

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Now even though equinox means, equal night, the earth is not entirely perpendicular to the solar rays at all points due to its spherical nature. We can also look at the spherical nature and the nature of the atmosphere causing the light from the sun to refract and keep most areas light for more than half of the day. The equator never sees equal day and night due to this fact, but areas north and south of there see these days occur at different times after the equinox. The furthest points from the equator see the equal day and night closer to the equinox and points closer to the equator see equal day and night further away from the equinox.

This may seem a bit confusing as we traditionally think of the equinox as 12 hours of sunlight and 12 hours of darkness, but the Equinox also plays a big role for our seasons. After the Equinox, the Earth begins to move further on in its orbit, so that the Northern Hemisphere becomes tilted away from the sun.

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This brings shorter days and longer nights due to less solar radiation in the Northern Hemisphere. This brings us our Autumn and Winter Climate as the reduced amount of solar radiation plays a role in keeping temperatures cooler in the Northern Hemisphere. There is also much more interaction in the atmosphere that also affects the temperatures changes.

So what will this Autumn bring to us? Hopefully more rain as the summer was too dry and the drought in the area keeps getting worse!

 

Tropical Storm Hermine: Impacts on New England

Hurricane Hermine was downgraded yesterday after it passed over Florida to a Tropical Storm. It inundated Florida with torrential rains (up to 10″ in some areas) and flooding (thanks in part to a storm surge of up to 12′ on the coast) and broke a streak that saw the state go almost 10 years without seeing a hurricane hit! Now that it is out into the Atlantic Ocean waters again, what does that mean to us in New England?? Here is a current look at the storm:

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Right now the Carolinas and Virginia are seeing the worst of the winds and the rain from the storm, but this storm is projected to stay near the East Coast for the next few days. Here’s a look:

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Right now the cone of uncertainty is very high for the end of the week, but for the most part, it seems the storm will take a slow trek up the east coast and track further east as each day goes along. This does bring it close enough to New England for us to see some of the aftereffects of the storm, but the question is how much will we see? Our Ocean temperatures are still warm due to summer just ending, so the storm can still churn out some good rain as it won’t run into the cold water that usually kills hurricanes, but it is unlikely that the storm would strengthen any more.

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First off is the rain situation. Looking at the projected radar image, we can see that bands will keep flowing into New England throughout the day Tuesday and Wednesday and even into Thursday on the coast. This will bring some much needed rainfall to the area, with areas along the coast seeing the most rainfall (around 1-3″), while areas further to the North and West see less rainfall (anywhere from .05″ to 1). This unfortunately will not bring much relief to the droughts in the area, but any rain is good rain in our books.

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A look at the current probabilities for Tropical Storm force winds puts the best chance for strong winds off the coast of New England with coastal areas seeing between a 40-50% chance of those winds. Areas over the whole of Southern New England should expect to see gusty winds between 20-40mph with stronger winds along the coastlines. This is not too dangerous usually, but as we have had such a drought this summer, the trees are dry and can easily break apart and be pushed over by gusty winds, so caution needs to be taken. Any boats or small crafts off the coast of Connecticut and Rhode Island need to dock and take caution as the gusty winds out there will cause rough surf for the area.

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This is further exacerbated by the GIF above showing the storm sitting and spinning right off the coast of Connecticut and Rhode Island for a good two days before finally moving out to sea. This is just a preliminary analysis and does not represent what actually will happen by Thursday. Looking at the 10m winds, there are strong winds around 35-50 kts along the coastlines, meaning that there is a good chance for some strong surf in the areas as well as some minor storm surge along the coastline. REMEMBER: Storm surge is not a wave, it is water that is raised to a higher level due to the winds of a storm. This water will not just hit an area and go away as it keeps the depth that it had when it hits the land, unlike a wave, so areas that get hit by it will remain flooded with the extra water for awhile. It is not safe and anyone affected by it should stay out of the water as it could be dangerous.

Overall, New England is going to be spared from the brunt of Tropical Storm Hermine, but we still will see some of the winds and the rain from the storm over the coming week.