Models Finally Agreeing on Track, Intensity

Today, the models have gathered new info and have come into agreement about where Sandy will make landfall. Right now it looks like Centeral NJ will recieve Sandy’s center with up to 10 feet of surge as well as 80mph+ winds and 12″ of rain. This though will not be the biggest impact. NYC will recieve a 8-12′ surge which will easily overtop the skimpy little 5′ sea wall. The surge will then roar into lower Manhattan possibly flooding the subway system. Irene caused a 5-6′ surge and cane within inches of flooding the subways. Also, wind gusts will reach hurricane force.

I will point out that the NHC refused to issue tropical storm/hurricane watches/warnings farther north than NC. This is due to Sandy forecast to be non-tropical by then so that they would not issue a TROPICAL storm warnings. Just thought that was interesting. Just warning everyone… High wind watches/warnings ARE THE SAME AS TROPICAL STORM OR HURRICANE WATCHES/WARNINGS!!

-Jack

New day, New Forecasts

Today, we are looking at only slight adjustments to the forecast. I now think it will make a direct landfall on NYC. There are a couple reasons that I differ from the NHC track taking it into Southern NJ.

 

NHC track with landfall in southern NJ.

1) Most of the models have my back. All but the GFDL, and the operational Euro make landfall in NYC.

The CMC, just one of the many many models taking Frankenstorm into NYC.

2) Upper air steering. The steering setup would favor a NYC track due to the position and intensity of the trough. The position of the trough and the ridge from the Canadian Maratimes suggests a landfall from North NJ to Mid-Long Island.

This mornings satellite image showing an active Atlantic basin.

Sandy is clearly seen as the storm off the SE coast. There is a normal extratropical mid latatude low SE of Newfoundland. The area in question is that blob in between the two systems. Will nthis blob continue up the coast with Sandy? Or will it join the extratropical low? This is the big question in my mind because if that band makes it up the coast New England could see major impacts. If not, then it would be up to Sandy and her megastorm to create an east side to her. She has planty of time to do that as she moves up the coast first intensifying as a warm-core system over the Gulf Stream then becoming cold-core over the waters south of NYC and feeding of the trough energy. Either way there would be major impacts.

I think 3-5″ of rain would be likely in New England with amouts possibly reaching 12-15″ over parts of NJ and Southern NY.

Winds will likely peak around 60mph along coastal sections of ME with higher gusts possibly reaching hurricane force. This along with our tropical downpours will be cause for insane power outages. Prepare for anywhere from 2-14 days depending on your priority level (hospitals, cities are high priority, island communities, communities high in the mountains and low priority. Anywhere in between like suburbs or the mid sized town would be mid priority). Winds in NYC will likely be hurricane force with NJ also seeing hurricane force winds. DE, PA, New England, MD, and VA, NC will see tropical storm force winds.

Also, changes this morning, timing. Effects will begin Monday and linger possibly into the end of the workweek. This is because of the effects that I think the mountainous regions of NY will have on slowing the Frankenstorm down. Earlier, it was thought to move over less mountainous terrain and be moved along very quickly by the trough.

-Jack

 

 

2 PM Update for “Frankenstorm”

The Sandy/Nor’ easter hybrid superstorm set to impact the Eastern Seaboard this weekend into early next week has officially been dubbed “Frankenstorm”. I would assume it as a halloween joke but this storm is not joking around. Power outages could top 10 million customers if the underground power plants for NYC are flooded. Even though this sounds far fetched, it is really not. The NHC (National Hurricane Center) has Sandy Moving onshore in Delaware.

 

The 2PM track from the hurricane center has Sandy moving onshore in DE as a hurricane.

This would push a 7-11 foot storm tide into NYC. The city has 5 foot flood walls that would easily be overtopped and flooding lower Manhattan and the financial district. The water would rush into the subway system shorting out the electric 3rd rails. Also this surge would rush through the intricate tunnel system making for a huge mess. The power plants are located in these tunnel systems and would be shut down on purpose in anticipation for the storm or, they would get knocked out of service by the surge flooding.

This is supported by few models however and is only there for the European model (ECMWF) which predicts a DC landfall. This is the number one performer among models. There are several less reliable models that like this scenario as well. The second best performer has Sandy making a direct hit on NYC Sunday evening.

The black and purple swath is the Frankenstorm Nor’easter hitting NYC as shown by the American GFS model.

This is a very reasonable scenario for a few reasons. 1) There is a low pressure system located in the Central Atlantic Ocean now and this will act to pull Sandy towards the sea. 2) There is a trough of low pressure moving in from the west as well.

 

Radar Imagery from 2:50 PM today of the colds front and trough moving in from the west.

This trough will act to pull in Sandy from the SE hitting the NYC area. The max surge would be 15 feet. The trough will also give Sandy a boost of energy which will allow the storm to “bomb out” or undergo cyclogenisis (the rapid deepening or strengthening  of a low). The trough will then pull Sandy to the north through western MA and VT.

The cold front and trough will act to create the heaviest October rains ever recorded by taking moisture saturated air and slamming it into cold Canadian air which will mass condense it. The result? Up to 15″of rain for some areas.

 

The HPC (Hydrometerological Prediction Center) forecast for rainfall. This is in connection with the NHC track so these 15″+ amounts might stretch farther north into NJ and NY. Also, this is only to Wednesday, it will be raining all the way through Thursday for parts of Northern New England.

Speaking of cold air… there will be a snowy side to this system. The storm is very lopsided due to shear, and that will cause the storm to spin energy way to the NW of the center where the cold pocket aloft is. This cold pocket will help to create snow for Pennsylvania and any mountains north of NYC.

As you can see, there is no hurricane like anything in this inferred satellite image.

Instead is a mass of clouds that stretch all the way from the Caribbean Sea to the Del-Marva Peninsula. The east side has the most activity so even if the storm hits NYC, New England will feel harsh impacts. Although the east side is larger, the storm will grow substantially by the time of landfall and will be able to push activity well to the NW of the center.

-Jack

 

Large Storm to Impact Eastern Seaboard

There is a complex weather situation at play now as Hurricane Sandy moves up the Eastern Seaboard. The latest advisory puts Sandy as a 105mph Hurricane with a lowest pressure is 964mb. Sandy has just moved off the northern coast of Cuba.

Sattellite imagery of Sandy moving off of Cuba.

Now Sandy will continue moving north and then the second factor comes into play. This second factor is a trough of low pressure moving in from the west. This trough will pull in sandy towards the US. Sandy will then “bomb out” off of the NJ coast. Pressures will fall like a rock bottoming out near 949 mb. This is the general consensus of the numerical models. (These are super computers located around the world that take in weather data from around the world. Then this data is fed through a prisim of equations that produce graphs that we weather geeks/ meteorologists then interpert and make forecasts from).

Sandy will then be a Nor’Easter on steroids. This super-noreaster will then move into the coast south or on top of New York City. Surge flooding will be of great concern. There is a 5 foot seawall protecting the financial district from New York Harbor. This storm will be over 2500 miles wide and close to 3500 miles long. This huge storm will generate a 9-12 foot surge on top of the astronomical high tide caused by the full moon on Monday. This would most likely cause flooding in lower Manhattan.

There will be a snowy side to this storm as well. This will be the tropical moisture from Sandy moving up the coast meeting the arctic airmass behind the trough. Pennsylvania and Western New York State as well as the mountains from the Allegheny Mountains in Pennsylvania to the mountains near Mt. Katahdin, Maine could see snow.

CMC Numerical model plot for Mega Noreaster Sandy.

Snow amounts will be on the order of 4-8″ for lowland Pennsylvania to over 28-36″ on the higher peaks.

Rainfall will also be greatly enhanced by the warm moist air hitting the cold air from Canada causing the heaviest October rains in history. Rainfall amounts could reach over 20″. 12″ is expected over most regions.

Winds will be on the order of potentially 80mph in NYC where the worst of the storm will be. 55-70mph will be widespread with higher gusts. The coast of ME, MA, RI, CT, NY, NJ, and DE will see highest winds peaking around 50-65mph in many places. Exposed areas could get even higher gusts.

Timing will be Saturday-Monday for areas south of VA beach area, Sunday-Tuesday for CT to VA beach area, and Monday-Wednesday for New England.

Quick East Coast Storm Update

A developing storm is moving into Ontario this evening spreading rain across the eastern seaboard. A line of severe storm reaches from the Adirondack mountains to Cape Hatters and beyond to the northern Bahamas. Winds will be gusty with 30 mph winds across most areas with winds up to 70 mph in severe thunderstorms. 40-50 mph winds will be common along Cape Cod,  Coastal ME and Long Island. 1-5+ inches of rain will be common with highest totals in the Adirondack Mountains.

-JAck

Reliably hype-free weather info for Western Maine and New Hampshire from amateur forecaster Jack Sillin

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