SANDY - Probs/Obs/Reports - Mid-Atlantic/Northeast/E Canada

[CrazyC83]

Decided to start a new thread since this is getting serious mention now and appears highly likely to be a strong impact.

[cycloneye]

Interesting discussion by Dr Jeff Masters about the scenarios for New England and Mid Atlantic states.

The Northeast U.S. scenario

If Sandy makes landfall farther to the north near Maine and Nova Scotia, heavy rains will be the main threat, since the cold waters will weaken the storm significantly before landfall. The trees have fewer leaves farther to the north, which will reduce the amount of tree damage and power failures compared to a more southerly track. However, given that ocean temperatures along the Northeast U.S. coast are about 5°F above average, there will be an unusually large amount of water vapor available to make heavy rain. If the trough of low pressure approaching the East Coast taps into the large reservoir of cold air over Canada and pulls down a significant amount of Arctic air, the potential exists for the unusually moist air from Sandy to collide with this cold air from Canada and unleash the heaviest October rains ever recorded in the Northeast U.S., Nova Scotia, and New Brunswick. This Northeast U.S. scenario would probably cause damages near $100 million dollars.

The mid-Atlantic U.S. scenario

Landfall Monday along the mid-Atlantic coast on Monday, as predicted by the ECMWF and NOGAPS models, would likely be a billion-dollar disaster. In this scenario, Sandy would be able to bring sustained winds near hurricane force over a wide stretch of heavily populated coast, causing massive power outages, as trees still in leaf fall and take out power lines. Sandy is expected to have tropical storm-force winds that extend out more than 300 miles from the center, which will drive a much larger storm surge than its winds would ordinarily suggest. The full moon is on Monday, which means astronomical tides will be at their peak for the month, increasing potential storm surge flooding. Fresh water flooding from heavy rains would also be a huge concern. Given the ECMWF's consistent handling of Sandy, I believe this mid-Atlantic scenario has a higher probability of occurring than the Northeast U.S. scenario. However, it is likely that the models are overdoing the strength of Sandy at landfall. The models have trouble handling the transition from tropical storm to extratropical storm in these type of situations, and I expect that the 940 mb central pressure of Sandy predicted at landfall Monday in Delaware by the ECMWF model is substantially overdone.

Jeff Masters

[CrazyC83]

$100M in damage? That seems unlikely IMO. I say $10B is more likely than that.

[CrazyC83]

A tweet suggested that Michael Bloomberg is already starting to work on a possible evacuation plan for low-lying areas in NYC. That would affect about 350,000 people (the same people forced out in Irene).

[brunota2003]

Per one of the mets here, they have to start evacs at least 48 hours in advance...and with this storm, they might need to think a lot bigger than Irene's effects! What does it take to overtop the subway and flood the actual city itself?

[CrazyC83]

Per one of the mets here, they have to start evacs at least 48 hours in advance...and with this storm, they might need to think a lot bigger than Irene's effects! What does it take to overtop the subway and flood the actual city itself?

I believe about 6-7 feet storm surge, similar to the December 1992 Nor'Easter. A track south of NYC could do just that.

[angelwing]

I am wondering about Phila PA...I work at 2 jobs there, one of them is downtown and I am worried about the Delaware River going out of its banks.

[CrazyC83]

I am wondering about Phila PA...I work at 2 jobs there, one of them is downtown and I am worried about the Delaware River going out of its banks.

Not out of the question - that's a tidal river too? Although freshwater runoff could be a bigger issue.

[angelwing]

I am wondering about Phila PA...I work at 2 jobs there, one of them is downtown and I am worried about the Delaware River going out of its banks.

Not out of the question - that's a tidal river too? Although freshwater runoff could be a bigger issue.

I think it is, I am not totally sure

[cycloneye]

In some places boarding is underway.

http://philadelphia.cbslocal.com/2012/1 ... -our-area/

[anarchiver19]

I'm wondering what we can expect here in Virginia Beach and whether it matters if it has evolved into a post-tropical storm as it approaches the mid-atlantic in terms of it's effects and for how long it will last???
I've lived here since 97 and some nor'easters have been worse than the hurricanes we've had. With Irene in my immediate area we had mostly branches down/power lost for less than 24hrs and that's less than 1/2 mile from the ocean and 1/2 a block to the inlet). The 2009 nor'easter was much worse and lasted 3 days- with extended power outages, neighborhoods underwater, crazy rain totals, record high water levels, and huge trees down throughout the Tidewater area)- I think it even beat some records set by Isabel which was the worst storm since I've lived here.

I just hope that people realize that even if this isn't a hurricane when/if it gets closer to them it can still be dangerous.

[JC380]

Hi folks!

I'm in Salisbury and based on the current track by the NHC, what should I expect in terms of conditions? Will Sandy still be a hurricane by the time she makes it close to the Delmarva Peninsula or will she have already transitioned into something extra-tropical?

[CrazyC83]

I've analyzed my own situation: 4 to 8 inches of rain, possibly more if the cold front stalls. Also the winds? Based on comparison of the 850mb level (up to 80 kt), perhaps gusts as high as 75 mph if from the east or northeast (funnelling effect) or 45 to 60 mph elsewhere. What should I do to prepare for that?

[cycloneye]

NWS Taunton, MA
Zone Forecast: Coastal Waters East of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary (ANZ250) Mobile Weather Information
Last Update: 117 PM EDT THU OCT 25 2012


Hazardous marine condition(s):

Hazardous Weather Outlook

Synopsis...HIGH PRES WILL REMAIN ANCHORED ACROSS THE WATERS THROUGH SAT. MEANWHILE...HURRICANE SANDY IS EXPECTED TO MOVE NORTH OF THE BAHAMAS AND INTO THE ATLANTIC THIS WEEKEND. IT WILL THEN INTERACT WITH SEVERAL WEATHER SYSTEMS EARLY NEXT WEEK. THIS WILL RESULT IN A DANGEROUS AND POTENTIALLY LIFE THREATENING STORM FOR MARINERS. THE STRONGEST IMPACT APPEARS TO BE IN THE SUNDAY NIGHT TO TUESDAY TIME FRAME. SEAS MAY EXCEED 25 FEET ACROSS THE OPEN WATERS...ALONG WITH THE POTENTIAL FOR WINDS TO GUST TO HURRICANE FORCE. MARINERS ARE URGED TO RETURN TO PORT BY SATURDAY AND PAY VERY CLOSE ATTENTION TO THE LATEST FORECASTS OVER THE NEXT FEW DAYS!

FOR INFORMATION ON POSSIBLE HAZARDOUS WEATHER BEYOND THE 24-36 HOUR FORECAST PERIOD...PLEASE VISIT http://WWW.WEATHER.GOV/BOSTON AND FOLLOW THE HAZARDOUS OUTLOOKS LINK AT THE TOP OF THE BLUE BAR ON THE LEFT.

[cycloneye]

Afternoon HPC discussion.

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
313 PM EDT THU OCT 25 2012

VALID 12Z SUN OCT 28 2012 - 12Z THU NOV 01 2012


...HIGH IMPACT MERGING OF ENERGETIC SYSTEMS ANTICIPATED OFF THE
MID ATLANTIC COAST...


FINAL...

UPDATED THE TRACK OF SANDY TO FIT THE 15Z/25 NATIONAL HURRICANE
CENTER TRACK THROUGH 5 DAY, WHICH DOVETAILS WELL INTO THE HYBRID
LOW POSITIONS THEREAFTER FOR DAYS 6 AND 7. BOTH THE 12Z/25 GFS AND
GEM GLOBAL BRING THE LOW INTO THE NEW YORK CITY AREA, WITH THE
ECMWF DIRECTING IT INTO THE LOWER DELMARVA PENINSULA. THE UPSHOT
FOR SENSIBLE WEATHER IS THE SAME- HIGH WINDS AND HEAVY RAINS FOR
AREAS ALONG THE TRACK OF THE TROPICAL REMNANT, WITH HEAVY SNOWS
POSSIBLE ON THE SOUTHWEST EDGE WHERE THE CONTINENTAL POLAR AIR
RUSHES ACROSS THE UPPER OHIO VALLEY AND CENTRAL APPALACHIANS AND
ADJACENT LOWLANDS TO THE EAST.


CISCO

[Bizzles]

I've heard some talk about the Northern side of the storm being worse than the Southern for the Mid ATL/NE landfall. Is this plausible and why so?

[HarryPotter]

I believe about 6-7 feet storm surge, similar to the December 1992 Nor'Easter. A track south of NYC could do just that.

Greetings from near ground zero...Connecticut. Florida hasn't seen a hurricane in 7 years..and we get 2 tropical systems in a year. Time to go hit the lottery!

I was on the NWS NYC webinar today, and the NWS met said that if he had to compare this storms probable intensity to anything...that's exactly what he would compare it to: the '92 nor'easter.

Could get interesting! No offense to anyone, but I'm hoping it curves in as far south as possible as the Maine solution no longer looks valid...keep it as far away as possible.

[CrazyC83]

I believe about 6-7 feet storm surge, similar to the December 1992 Nor'Easter. A track south of NYC could do just that.

Greetings from near ground zero...Connecticut. Florida hasn't seen a hurricane in 7 years..and we get 2 tropical systems in a year. Time to go hit the lottery!

I was on the NWS NYC webinar today, and the NWS met said that if he had to compare this storms probable intensity to anything...that's exactly what he would compare it to: the '92 nor'easter.

Could get interesting! No offense to anyone, but I'm hoping it curves in as far south as possible as the Maine solution no longer looks valid...keep it as far away as possible.

Yeah I doubt it will hit north of Cape Cod now. Most likely between Ocean City and Montauk Point IMO.

[brunota2003]

A snippet of NWS Buffalo's AFD:

ALTHOUGH A MORE RIGHT TRACKING SOLUTION IS POSSIBLE...THE LIKELIHOOD OF THIS CONTINUES TO DECREASE AND CONFIDENCE OF A POTENTIALLY HIGH IMPACT EVENT EARLY NEXT WEEK IS INCREASING. POTENTIAL IMPACTS LOOK TO BE THE POSSIBILITY FOR A PROLONGED HEAVY RAINFALL EVENT...WITH NOT ONLY LOCALIZED FLOODING BUT ALSO SIGNIFICANT RISES ON AREA CREEKS AND STREAMS...STRONG NORTHEAST WINDS IN A MONDAY THROUGH TUESDAY TIME FRAME. IN ADDITION...DEPENDING ON HOW MUCH COLD AIR CAN MOVE IN FROM THE WEST THERE IS SOME LIMITED THREAT FOR ACCUMULATING SNOWS OVER THE HIGHER TERRAIN OF THE WESTERN SOUTHERN TIER.

Rain chances, for me, Friday night through the end of the period on Thursday of next week. All of the chances, except for Friday night, are 50% or greater.

[CrazyC83]

A snippet of NWS Buffalo's AFD:

ALTHOUGH A MORE RIGHT TRACKING SOLUTION IS POSSIBLE...THE LIKELIHOOD OF THIS CONTINUES TO DECREASE AND CONFIDENCE OF A POTENTIALLY HIGH IMPACT EVENT EARLY NEXT WEEK IS INCREASING. POTENTIAL IMPACTS LOOK TO BE THE POSSIBILITY FOR A PROLONGED HEAVY RAINFALL EVENT...WITH NOT ONLY LOCALIZED FLOODING BUT ALSO SIGNIFICANT RISES ON AREA CREEKS AND STREAMS...STRONG NORTHEAST WINDS IN A MONDAY THROUGH TUESDAY TIME FRAME. IN ADDITION...DEPENDING ON HOW MUCH COLD AIR CAN MOVE IN FROM THE WEST THERE IS SOME LIMITED THREAT FOR ACCUMULATING SNOWS OVER THE HIGHER TERRAIN OF THE WESTERN SOUTHERN TIER.

Rain chances, for me, Friday night through the end of the period on Thursday of next week. All of the chances, except for Friday night, are 50% or greater.

My forecast:

Tomorrow - Sunny with cloudy periods, near 75

Saturday - Periods of rain (cold front), near 55

Sunday - Periods of rain (stalled cold front), near 55

Monday - Rain, especially later, winds increasing (Sandy starts to overtake), near 55

Tuesday - Rain at times heavy, extreme winds possible (Sandy at its worst), low 50s

Wednesday - Rain continues, winds decreasing (Sandy weakens but closes on me), high 40s

Thursday - Showers ending, low 40s