Hurricane Joaquin rapidly intensified over the past 24 hours. It is now a Category 3 tracking west into
portions of the Bahamas. Though there continues to be a high amount of uncertainty in the forecast,
Hurricane Joaquin could track toward the East Coast this weekend, which is now in the cone of the
National Hurricane Center forecast.
At 11 p.m. Wednesday, Hurricane Joaquin had sustained winds of 115 mph and a central pressure of 951
millibars. Further intensification is expected in the short term; the National Hurricane Center is
forecasting that Joaquin will strengthen into a Category 4 with winds of 140 mph on Friday and Saturday
as it tracks north toward the East Coast.
In their 11 p.m. update, the National Hurricane Center was forecasting a possible landfall anywhere from
North Carolina to Delaware, noting that their forecast remains similar to earlier today and is slightly east
of model consensus. Additionally, hurricane watches may be hoisted for the U.S. tomorrow.
Hurricane warnings are in effect for the Bahamas, where Joaquin will continue to linger and intensify
over the next 48 hours.
Track forecast for Hurricane Joaquin as of 11 p.m. Wednesday. (National Hurricane Center)
Regardless of an exact track, moisture associated with Joaquin will get pulled into an advancing low
pressure and almost certainly deliver dangerous amounts of rain over the eastern United States, from the
Carolinas to Maine.
Forecast accumulated rainfall totals from Wednesday morning through next Wednesday morning.
(NOAA) Forecast accumulated rainfall totals from Wednesday morning through next Wednesday
Joaquin has the potential to be a very significant storm for the mid-Atlantic and northeastern states.
Heavy rain will be the first threat to the region on Thursday and Friday. The latest guidance from the
National Weather Service includes an enormous swath of rainfall totals in excess of 6 inches over the
coming week, with as much as 10 inches falling on the Virginia, Maryland and Delaware coasts.
By Saturday, coastal erosion and storm surge flooding could become a huge problem starting in the
Carolinas and working its way up to New England by Sunday.
The most recent wave forecast from NOAA shows significant heights higher than 30 or 40 feet on Sunday
— a very ominous scenario. Even if the storm center remains offshore, or it begins to transition to a
non-tropical cyclone, strong onshore winds will generate a substantial storm surge flooding along the
coast, particularly during the regular astronomical high tides.
Over the past 24 hours, the vertical wind shear that was keeping Joaquin at bay has gradually decreased,
and the storm was quick to respond. The peak winds increased from 40 mph on Tuesday morning to 80
mph on Wednesday morning. The very warm ocean water under it is also undoubtedly fueling the
hurricane. Environmental conditions are expected to remain favorable for Joaquin to intensify until
Saturday, with a window for rapid intensification now through Friday.
Joaquin has been moving slowly and is forecast to drift to the southwest for another two days before
getting picked up by the trough moving over the East Coast. At that point Hurricane Joaquin will head
north, but there is great uncertainty in the details of how that will happen.
Some models suggest Joaquin will turn quickly to the north and then curve toward the East Coast, while
others push the hurricane out into the Atlantic and away from land.The uncertainty in track forecast
right now cannot be overstated, and it is not even represented well by the official track forecast by the
National Hurricane Center. Unfortunately in this situation, the spread in the forecast models is far
greater in size than the cone of uncertainty in the official forecast.- WP