ATL: SANDY - Remnants - Discussion

[OuterBanker]

Don't give up on tropical yet. Let her get away from the ULL. She might redeepen after. Lots of warm water in front, and less shear. Wait till end of day.

[cycloneye]

Todays discussion of Sandys impacts on East Coast of U.S by Dr Jeff Masters.

Forecast for Sandy

Wind shear is expected to remain a high 30 - 55 knots for the next four days, as Sandy interacts with a trough of low pressure to its west. The high shear should keep Sandy from intensifying the way most hurricanes do--by pulling heat energy out of the ocean. However, the trough approaching from the west will inject into Sandy what is called "baroclinic" energy--the energy one can derive from the atmosphere when warm and cold air masses lie in close proximity to each other. This transition will reduce the hurricane's peak winds, but strong winds will spread out over a wider area of ocean. This will increase the total amount of wind energy of the storm, keeping the storm surge threat high. This large wind field will likely drive a storm surge of 3 - 6 feet on Monday and Tuesday to the right of where the center makes landfall, on the mid-Atlantic or New York coasts. These storm surge heights will be among the highest ever recorded along the affected coasts, and will have the potential to cause hundreds of millions of dollars in damage.

The latest set of 00Z (8 pm EDT) and 06Z (2 am EDT) computer model runs still have wide differences in the timing and landfall location for Sandy. The ECMWF has been very consistent in its handling of Sandy, and continues to predict that Sandy will hit Delaware or Maryland on Monday afternoon--basically the same forecast it has had for three days. Our other top model for forecasting hurricane tracks, the GFS, has been more inconsistent, and predicts a landfall on Long Island, New York on Tuesday afternoon.

Severe impacts likely in the U.S.

Sandy's expected landfall along the mid-Atlantic coast is likely to be a billion-dollar disaster. Sandy should bring sustained winds of 50 - 60 mph with gusts over hurricane force to a large section of coast, and the storm may be moving slowly enough that these conditions will persist for a full 24 hours. With most of the trees still in leaf, there will be widespread power outages due to downed trees. Sandy is expected to have tropical storm-force winds that extend out more than 400 miles from the center, which will drive a much larger storm surge than its winds would ordinarily suggest. The latest H*Wind analysis from NOAA's Hurricane Research Division put the destructive potential of Sandy's winds at 2.1 on a scale of 0 to 6, and the destructive potential of the storm surge much higher, at 4.2 on a scale of 0 to 6. The full moon is on Monday, which means astronomical tides will be at their peak for the month, increasing potential storm surge flooding. With Sandy's strongest winds expected to last at least 12 hours near the time of landfall, the peak storm surge will affect the coast for at least one high tide cycle, and possibly two. This will greatly increase the potential for storm surge damage and coastal erosion. If Sandy hits Long Island, as the GFS model predicts, the storm surge will be capable of over-topping the flood walls in Manhattan and flooding portions of the New York City subway system. Fresh water flooding from heavy rains is also a huge concern. Rainfall amounts of 5 - 10 inches will occur over several hundred mile-long swath of coast, with isolated amounts of 15 inches possible. Fortunately, soils are dry and river levels are low over most of the threatened region, which should keep Sandy's river flooding lower than that experienced last year during Hurricane Irene. Nevertheless, Sandy is shaping up to be a historic storm for the mid-Atlantic and Northeast U.S. that has few precedents.

Jeff Masters

[wxman57]

Don't give up on tropical yet. Let her get away from the ULL. She might redeepen after. Lots of warm water in front, and less shear. Wait till end of day.

Sandy will intensify again, but not as a tropical cyclone. Once the cold air starts wrapping into the center it will transition to an extratropical storm and its pressure may drop (and wind field expand more). This will happen before landfall.

[Aric Dunn]

here is a video I did of a squall line that came through here in Melbourne that had the gust to near 60. quality is not the greatest.

http://www.youtube.com/watch?v=zKAkn7DC ... tube_gdata

[KBBOCA]

I hope this info about storm surge (copied from Dr. Masters' blog post, cited above) will get wide circulation:

The latest H*Wind analysis from NOAA's Hurricane Research Division put the destructive potential of Sandy's winds at 2.1 on a scale of 0 to 6, and the destructive potential of the storm surge much higher, at 4.2 on a scale of 0 to 6.

[CrazyC83]

Tropical Storm Watch now for Bermuda, which shows the immense size.

[Weatherguy173]

how confident is everyone in the delaware/cape may area landfall? any thoughts? does anyone disagree with the current landfall location?

[HurrMark]

I hope this info about storm surge (copied from Dr. Masters' blog post, cited above) will get wide circulation:

The latest H*Wind analysis from NOAA's Hurricane Research Division put the destructive potential of Sandy's winds at 2.1 on a scale of 0 to 6, and the destructive potential of the storm surge much higher, at 4.2 on a scale of 0 to 6.

Wasn't Ike's IKE at 4.2 at landfall? If that is so, and it stays 4.2, I don't think we are talking one billion dollars...but multiple billion in potential damage. Irene's losses were at $10 billion, if I recall...

[anarchiver19]

The Governor of Virginia just declared a State of Emergency for the entire Commonwealth.
An excerpt from the bulletin: "...forecasters are predicting significant weather impacts across much of Virginia, and a long duration event. Due to the track of this storm, and the fact that it will be a hurricane transitioning into a more nor’easter-like system, we could see severe weather lasting for 48 hours or more in the state. In that scenario, saturated soil coupled with high winds could lead to major tree damage and extensive power outages."

[CrazyC83]

I hope this info about storm surge (copied from Dr. Masters' blog post, cited above) will get wide circulation:

The latest H*Wind analysis from NOAA's Hurricane Research Division put the destructive potential of Sandy's winds at 2.1 on a scale of 0 to 6, and the destructive potential of the storm surge much higher, at 4.2 on a scale of 0 to 6.

Wasn't Ike's IKE at 4.2 at landfall? If that is so, and it stays 4.2, I don't think we are talking one billion dollars...but multiple billion in potential damage. Irene's losses were at $10 billion, if I recall...

Total losses were about $19 billion in Irene, mostly from freshwater flooding.

[Weatherguy173]

how accurate does the HPC tend to be with the rainfall potentials?
this is the most recent map: http://www.hpc.ncep.noaa.gov/qpf/zoom/R ... ys_1-5.gif

[CrazyC83]

how accurate does the HPC tend to be with the rainfall potentials?
this is the most recent map: http://www.hpc.ncep.noaa.gov/qpf/zoom/R ... ys_1-5.gif

Either reasonable or conservative usually.

[Weatherguy173]

how accurate does the HPC tend to be with the rainfall potentials?
this is the most recent map: http://www.hpc.ncep.noaa.gov/qpf/zoom/R ... ys_1-5.gif

Either reasonable or conservative usually.

what model(s) are the rainfall estimates made off of? i know there is a "cone of uncertainty" for the track. is there anything like that for rainfall?

[Aric Dunn]

satellite showing sandy on the move again after little slight jog the nne it appears to be on a n to nnw heading again /

[shortwave]

here is a video I did of a squall line that came through here in Melbourne that had the gust to near 60. quality is not the greatest.

http://www.youtube.com/watch?v=zKAkn7DC ... tube_gdata

aric are you over by lake washington?

[GCANE]

Core:

6C above ambient - in the boundary layer.

http://rammb.cira.colostate.edu/product ... 6_TANO.GIF

Don't even want to think what would happen if this gets raised back up to the 10 to 12 km level.

[Evil Jeremy]

I wonder what Ortt would have to say about this system.

[itglobalsecure]

I am inland about 20 miles from Rehoboth Beach DE, at the first inland "H" on the NOAA map, in the north central part of Delmarva. I can tell you, the discussion here is barely picking up. Morning talk shows are beginning to give it a passing mention, since the state of emergency has been announced.

[rosethornil]

I am inland about 20 miles from Rehoboth Beach DE, at the first inland "H" on the NOAA map, in the north central part of Delmarva. I can tell you, the discussion here is barely picking up. Morning talk shows are beginning to give it a passing mention, since the state of emergency has been announced.

I'm in Virginia Beach.

News is just now starting to discuss it at length.

Store's are still very un-busy.

[AdamFirst]