Chesapeake Bay tides:

I want to discuss the affect on the Chesapeake Bay. As a longtime resident with 40 miles of Northeast exposure, tides can make or break a storm. During Isabel, water was halfway to the house, but we got no waves. With Ivan, Francis, and Jeanne remnants, the water didn't rise, but the waves did damage to the bulkhead.

The Chesapeake Bay is very heavily affected by wind directions. The following general assumptions can be made:

1. If the storm tracks east of the bay, as the GFS and most global models are showing, the western quadrant of the hurricane will blow water out of the Bay. The dominant wind directions will be Northeast, North, and Northwest, meaning that areas with Northeast exposure are most vulnerable due to the earlier impact of winds from that region of the storm, but as the storm continues, lower and lower tidal levels will cause the waves to have less and less impact. This is in many ways the best case scenario.

2. If the storm tracks west of the bay, as the GFDL is showing, then the eastern quadrant of the hurricane will blow water into the Bay, causing storm surge effects unrelated to the pressure of the storm. The dominant wind directions will be Southeast, South, and Southwest. Significant erosion will occur for any locations with East, South, or West exposure. Individuals with Northeast through Northwest exposure will be relatively safe from wave action, but may still experience significant flooding.

3. If the storm begins over the west of the bay, but transitions to the east of the bay, then all bets are off: we will get wind driven storm surge plus potential erosion on all regions of the storm.

Now remember I am talking about just wind driven surge effects and not pressure driven storm effects. Pressure effects may increase tidal height relative to just the wind driven scenario. The closer the storm passes to the mouth of the bay, the more affect on the bay the pressure will have. If the eye of the storm is inland, then the lowest pressure will be unable to drag as much water up the bay with it.

Chesapeake Bay Operational Forecast System - tide heights and wind speeds: http://tidesandcurrents.noaa.gov/ofs/cbofs/cbofs.html

Also note that a number of NOAA websites are hosted in the DC Metro area due to NOAA being headquartered in Bethesda, MD. With power outages, some NOAA websites might go down. Based on traceroutes, this looks to include the National Hurricane Center, the Satellite Services Division site (www.ssd.noaa.gov), and Weather.gov (including the radar websites). There may be backup locations for these servers.