Hermine - Professional MET Vendor Forecasts

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Latest from WeatherBell

This is a simple post to define where this storm will beat Sandy , From Atlantic city south to Ocean City Maryland, a looping track like this would be a devastating event. At this time we dont want to change our foreacast which would be worse than Sandy anyway in these places as Sandy went north of them and shut the surge down. Further north a 4-8 foot surge would not beat Sandy where south, it would and there is a threat that it can reach as high as 10 feet;

Our track right now remains the same as this morning but if the loop to near the coast occurs, then an 8-12 foot surge would hit areas from ACY the Del MD border and back into the Lewes Delaware and Cape May

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Latest this PM from NJPAWEATHER

Let me start off by saying what needs to be said.  Get off the beaches and get away from the shores.  Sorry guys, that Labor Day party is going to have to be postponed and you better get yourself and your family to safety because for those of you along the coast, this storm is going to be dangerous.  There is no need to compare this storm to Sandy, it will stand on it’s own just fine.  I will discuss the overall forecast and then below that the technical details.

OVERVIEW:

The remnants of Hermine and a powerful 500 MB shortwave trough will interact and form a powerful Sub-Tropical Storm off the New Jersey coast.  The impacts will begin on Saturday night with a steady increase in winds, exceeding 20 mph along the coast.  Showers with the capability with tropical downpours will first reach southeastern New Jersey and build north and west into the rest of New Jersey, the New York City metro, Long Island, and southern Connecticut by Sunday morning.

Waves of showers can be expected while the steady heavy rain stays off shore through noon on Sunday.  Winds will steadily increase at 20 to 40 mph away from the coast and 40 to 75 mph along the coast with higher gusts.  Coastal flooding will become increasing worse as the Atlantic Ocean is driven into the coastline.

The worst impacts will be from Sunday afternoon on through Monday evening as the storm stalls over the New Jersey coastal waters.  Showers will work back into the interior while waves of intense heavy rainfall work into the coast.  Winds will be 10 to 25 mph west of the Delaware River, the central Hudson River Valley, and northern Connecticut; 25 to 50 mph along the Delaware River, western New Jersey, the southern Hudson River Valley, and coastal Connecticut; and 50 to 75 mph along the New Jersey coast, New York City metro, and Long Island with higher gusts.

The storm will exit slowly on Tuesday with lingering showers and slowly declining winds.  Coastal flooding will remain a threat at high tides.  The storm will completely exit the region by Wednesday morning in a far weaker state.

Overall impacts include coastal flooding, flash flooding, poor visibility, power outages, and wind damage.  Travel will be severely hindered on Sunday and Monday.

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Technical discussion (released to public) from NJPAWeather

As you can see with the Water Vapor Satellite, Hermine is starting a process of moving away from being purely tropical.  A strong jet streak at 250 MB over the Mid Atlantic Coast is help to enhance lifting and keeping the core of Hermine strong and the warm core low intact.

Meanwhile, the 500 MB shortwave is diving south on cue over the Tennessee River Valley and starting to capture Hermine.  Note the structure of this storm now and especially the dry air over southwestern Georgia.  What is developing is a warm air seclusion with the core of Hermine remaining a warm core low up to around 850 MB.  Meanwhile, the rest of the storm is taking on extratropical characteristics with an expanding wind shield, an intense precipitation shield to the north and northwest of the surface low, and intensification of a 500 MB low feature starting to take shape to the west of the storm which is enhancing lifting.

Eventually by tomorrow afternoon, this storm will be a complete hybrid which will move off the North Carolina coast and move towards the Delaware coastal waters.  Two distinct processes will be evolving here.  The extracyclonic features will mature with an expanding precipitation shield and intensifying mid level and surface winds.  A 500 MB low will form just to the west of the surface warm core low, which will act like an anchor dragging the storm and slowly down the progression northward.  This process will be aided by the blocks discussed in this morning’s video.

Meanwhile, the warm core surface low will also intensify with the very warm waters off the Delaware and New Jersey coast.  This will allow for intense latent heat release leading to a rapid intensification of the surface low and strengthening of the core winds around the center of circulation which will be very close to the New Jersey coast by Sunday afternoon.  As a result, wind speeds in the wind field will increase overall but the strongest winds will be focused along the coast.

In terms of rainfall, the sharp cut off is due to the intense lifting on the coast aided by both the 500 MB low and the latent heat release from the warm core low.  With such strong lifting along the coast, strong sinking air will be found to the west of the Delaware River which will lead to a sharp cut off in the heavy rainfall.

There is potential for this storm to become more warm core than cold core on Sunday night into Monday afternoon, however this will not last.  By Monday evening, the influences of the 500 MB low wins out and the storm becomes vertically stacked, which is a signal that the storm has peaked in strength.  From Monday night on through Wednesday morning the storm slowly weakens and exits out into the Atlantic Ocean.

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Just watched Joe Bastardi's latest video update on the storm....he maintains this will be worse from Sandy Hook down to Cape May NJ then Sandy was....so no changes in the current WB forecast.

I am in the middle of building (finished early in October) a new home down in Sea Isle City but still maintain my camera at my brother's place in Sea Isle - so will keep an eye on things and post some pics as long as power stays on

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Latest from JB at 300am today

Jersey Shore etal spared Worst of this not coming back at coast, and will stay out at sea. Some tidal flooding but not as bad as I feared.

This will be no more than a noreastern for the Cape and Outer banks and tidal flooding but nothing extraordinary for the coast

The feared loop west on my part is a bust

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JB with his post mortem on Hermine....taking his lumps...

"I am sure you can and will add to the shortcomings, but these are things that standing out now. Above all , I can draw no consolation from busting. You would think after all these years and all the forecasts that have come up short, I would be reasonable, but I am not. Its gotten worse over the years. I cant smile and say, oh well. And while I always look forward to the challenges of tomorrow, I have to dissect what I did wrong today. Hermine had deeper lessons than just track and intensity error to me. In the end, Brownings words come back to me, "a mans reach must exceed his grasp or whats a heaven for". Storms like this show me their much beyond my grasp, but it does not give me the excuse to not reach. I guess thats the Price you Pay"