Hurricane Sandy has taken on the appearance of a mid-latitude nor’easter-type cyclone as seen from satellite. However, data from NOAA and Air Force reconnaissance aircraft confirm that Sandy is indeed still a hurricane with sustained winds of 75 mph and a central pressure of 951 mb. The latest forecast from the National Hurricane Center (NHC) keeps Sandy as a tropical cyclone for the next 36 hrs – through 8 pm (Eastern) Mon the 29th – before transitioning to an extratropical cyclone. However, as mentioned previously, this extra-tropical transition will not weaken the cyclone. Hurricane Sandy will become co-located with a region of favorable upper-level jet dynamics and baroclinic forcing, which will allow the cyclone to remain strong, if not intensify, right on through landfall. In layman’s terms, this means that a deep trough of low pressure over the Great Lakes region will re-energize Sandy. The global models did a very good job depicting the phasing between Sandy and the mid-latitude trough over a week in advance. Everything is on track for Sandy to become a “Perfect Storm” or “Frankenstorm” as previously predicted.
In terms of impacts, coastal NC all the way north into NY state are currently experiencing squally rainbands ahead of Sandy. Sustained winds of 49 mph with gusts to 63 mph have recently been reported as Cape Hatteras, NC. A tropical storm warning is currently in effect for much of coastal NC as well as Bermuda. These regions are either currently experiencing, or may experience during the next 48 hrs, winds sustained at tropical storm force (≥39 mph). While flooding has not been a major issue so far, rain has been persistent and slow-moving and is expected to worsen. Due to the abundance of rich tropical moisture, combined with the size of the system and slow movement, locations directly in the path of Sandy could see 5-10″ of rain, with up to 15″ locally.
Storm surge of 1-3 feet has been reported so far along the FL coast through GA, SC and NC, but should also get worse as Sandy grows larger and approaches the Mid-Atlantic coast. The current official NHC track forecast has Sandy making landfall anywhere from the MD/VA boarder through western Long Island on Mon night. While it is difficult to predict exactly how great the storm surge will be without knowing the exact strength, location, and angle of approach the storm will take, there is the potential for a 5-10 ft or greater storm surge in the hardest-hit areas to the right of where the storm makes landfall, anywhere from MD through Long Island or CT. Storm surge will be worst along SE to NW oriented coastal channels parallel to the wind field, as all the water is driven up-channel unimpeded, especially if landfall corresponds to astronomical high tide. Coupled oceanic models are also indicating that large waves of 10-15 ft will occur on top of this (and potentially even taller offshore).
Strong wind will also be a serious concern. Hurricane force winds will likely occur along the coast near and to the right of the landfall location. However, due to the very large size of the storm, tropical storm force winds will likely occur inland away from the coast. Power outages will likely be widespread, especially since trees blow over more easily in saturated grounds. Lastly, 1-2 feet of snow are likely to fall over parts of WV, with some lighter snow possible for western PA, western VA, and eastern OH. Please refer to your National Weather Service forecast office for official forecasts of local impacts and weather conditions. For evacuation and safety information, please refer to your local emergency management or law enforcement office.
Meteorology & Physical Oceanography
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