Record Heat for Some, Why Maria will turn OTS

It hit 92 in Hartford and 86 in Worcester yesterday, both new record highs for the date.  Both cities will have a chance to set records again today as summer-like weather continues into early fall.  High pressure is responsible for the warm temperatures but it is also helping to keep Hurricane Maria offshore.  Cooler temperatures will arrive by the end of the week.

NWS Max Temps with forecast record highs circled (image Weatherbell)

It will be mostly sunny today but there is a slight chance of a an afternoon/evening shower in Western Mass.   You will certainly notice the humidity today.  Dew points are already climbing into the upper 60’s to near 70.  There will be relief at the coast thanks to a sea breeze.    Most areas inland will max 85-90.

06z GFS 10 day metrogram Worcester (image Weatherbell)

Temperatures will have a chance to climb into the mid to high 80’s again tomorrow and perhaps Wednesday (though probably cooler on Wednesday than today and tomorrow) with a chance of a shower/thunderstorm Wednesday night into Thursday AM.

NWS AM Headlines

Ocean temperatures are still pretty warm but there is a high surf advisory for the South Coast, Cape, and Islands.  The high surf is being generated by Hurricane Maria.  The high surf advisory runs through Tuesday at 6 PM but will likely stay in place until Thursday AM. The Outer Banks are under a Tropical Storm Warnings but no major impacts are expected.  The NC/Mid-Atlantic coasts will see some beach erosion from the storm.

NHC 8 AM Hurricane Maria Advisory

Here is the Hurricane on visible satellite.  The storm hasn’t moved much overnight as it slowly creeps north at 7 MPH.

COD NEXLAB Northeast Regional Visible Satellite

So what is it that makes the weather community think Maria is going to bend out to sea in a few days and not continue north right into Southern New England?  First, high pressure is centered over New England.  The hurricane feels this and has slowed its forward motion as a result.  Next, check out the location of this cold front at 8 PM this evening.

WPC Surface Fronts/Precipitation Monday 8 PM

This is easier to see at the mid-levels of the atmosphere.  The deep blues out west are a trough of low pressure while the reds are ridges or positive height anomalies.  There is nowhere for Maria to go except to slowly drift north.  The kick out will come out of the trough in the west.  Its warm in the east and cool in the west (relative to average) so while all of this is going on it will stay warm in Southern New England.

06z GFS 500 mb height anomaly Monday 8 PM (image Weatherbell)

By tomorrow night a piece of energy will move across the Upper Midwest which will start to move the high pressure to the east.

06z GFS 500 mb height anomaly Tuesday 8 PM (image Weatherbell)

A cold front will begin to advance east Tuesday night into Wednesday AM.  Here is the surface chart for Wednesday 8 AM.   The low near Hudson Bay on the surface chart (below) is being driven by the piece of energy that is moving through the upper Midwest (above).

WPC Surface Fronts/Precipitation Wednesday 8 AM

Some precipitation will be possible out ahead of this cold front but most of it will be confined to Northern New England closer to the low/warm front.  The front will pass Wednesday evening into Thursday AM.  Maria will link up with the front and be carried away out to sea.

WPC Surface Fronts/MSLP Thursday 8 AM

Temperatures will fall as this front passes.  I think Thursday will be pleasant and we will notice a dramatic drop in humidity during the day.   Max temperatures by the end of the week will be in the low to mid 60’s.  I cannot wait.

-Zack Green

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