Hurricane Joaquin: 5 Things That Have Changed Since Yesterday
Published:
Oct 2 2015 12:00 AM EDT
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Powerful Hurricane Matthew Takes Aim on Florida
Category four Hurricane Matthew is expected to bring high winds, heavy rain and high surf to the Florida Coast.
Here are five changes in the storm since yesterday.
(MORE: Joaquin Forecast | Interactive Storm Tracker | Eastern Flood Threat | Versus Sandy | East Coast Prepares)
1) Forecast Track Trended Eastward
Ensemble Model Forecast Tracks
The lines on
this graphic represent several of the many ensemble track forecasts from
various computer models. This is not an official forecast, but models
such as these are often used as guidance for creating the projected path
for a storm.
NOAA Gulfstream aircraft surveillance missions and extra balloon soundings launched from National Weather Service offices on the mainland may have contributed to the eastward shift in some of the model guidance.
It's not uncommon to have a large amount of uncertainty with a forecast track three to four days in advance of a direct hit from a tropical storm or hurricane. Average track errors in the three- to four-day forecast range have been between 113 and 157 nautical miles in the last five years, according to the National Hurricane Center. This could be the difference between hurricane-force winds and winds remaining below tropical storm force at any point down the line.
The National Hurricane Center says hurricane watches could be issued for parts of the East Coast Friday, should the storm be expected to pass close to the U.S. coastline.
Regardless, if you live on the East Coast, remain vigilant and monitor for forecast changes. Even if the storm stays hundreds of miles offshore, effects will still reach parts of the Eastern Seaboard.
(MORE: Joaquin Forecast)
2) Joaquin Rapidly Intensified
Satellite, Track History
Visible
satellite (daylight hours) and track history (colored lines) of Joaquin.
Note the rapid change in intensity over the past day or so.
Finally early Thursday afternoon, Joaquin strengthened to a Category 4 hurricane with winds of 130 mph and a pressure of 936 millibars. The pressure decreased to 931 millibars Thursday evening, making it the fourth strongest hurricane, in terms of lowest pressure, near the Bahamas on record.
Joaquin moved into an environment of diminished wind shear, which typically tears tropical cyclones apart, and developed its inner core of convection over warm water near the Bahamas. This caused rapid intensification.
Dr. Matt Sitkowski, science and weather coordinator for The Weather Channel, says the last hurricane with a central pressure below 940 millibars in the Atlantic Basin was Igor in 2010.
3) Central Bahamas Slammed
Bahamas Satellite, Winds
Some reporting
stations, particularly in times of the most intense winds, may stop
reporting either due to broken instrumentation or the need for an
observer to seek safe shelter.
A Wunderground weather station at Pitts Town on Crooked Island measured winds up to 84 mph Thursday. The Bahamas Press reported significant flooding in The Acklins, which was in the southern eyewall of Joaquin at the time.
Joaquin will also bring hurricane-force winds to Rum Cay, San Salvador, Long Island and Cat Island.
(MORE: Latest Bahamas Impacts/News)
Colorado State University tropical meteorologist Dr. Phil Klotzbach said Joaquin is the strongest hurricane to impact the Bahamas since Hurricane Ike in 2008 and the first major -- Category 3 or stronger -- October hurricane to impact them since Hazel in 1954.
Joaquin should linger through sometime Friday in the central Bahamas, producing storm surge flooding, up to 20 inches of rain, and destructive winds.
(MORE: Joaquin Forecast | Interactive Storm Tracker)
4) Flooding Causes First Fatality
Southeast U.S. Radar
These are the steady areas of moderate to heavy rain that are forecast to pivot westward into parts of the Appalachians, Carolinas, Virginia and Mid-Atlantic states and potentially persist, in some form, through the weekend or early next week.
(FORECAST: Dangerous, Destructive East Flooding)
One person was killed near Spartanburg, South Carolina, in a vehicle submerged in flood waters. Flooding was also reported Thursday in Savannah, Georgia and Charleston, South Carolina.
Even if Joaquin well offshore of the East Coast of the U.S., torrential, persistent rainfall will likely trigger widespread, major life-threatening flash flooding and river flooding in the areas mentioned above.
(INTERACTIVE: Flood Alerts)
5.) Coastal Flooding Already Occurring
Coastal Flood Alerts
The latest coastal flood alerts issued by local National Weather Service offices.
As of Thursday afternoon, water levels were already running about 3 feet above normal at Wachapreague, Virginia, 2 feet above normal at Cape May, New Jersey and about 1.5 feet higher than normal at Duck, in the northern Outer Banks of North Carolina.
Similar to the rainfall threat, there will be significant coastal flooding, beach erosion, and high surf regardless of where Joaquin tracks, thanks to the difference between high pressure over eastern Canada and low pressure near or off the Southeast Coast.
(INTERACTIVE: Marine Alerts)
Waves will build along the East Coast the next few days, and larger swells from Joaquin should arrive along the East Coast beginning in Florida, then spread up the East Coast Friday and Saturday.
In fact, this could be one of the longest-lived coastal flood events in the modern era along the Mid-Atlantic coast, storm surge expert Hal Needham said in a Thursday morning blog post discussed in Dr. Jeff Masters and Bob Henson's Thursday Wunderblog.
Coastal flooding may occur over eight or more high tide cycles along parts of the Jersey shore, Delmarva peninsula, Virginia Tidewater and Outer Banks of North Carolina. "Each high tide, accompanied by battering waves, erodes more sand, which means less resistance for the next high tide and its waves," said senior meteorologist Stu Ostro in an internal email.
Rip currents will also occur. Stay out of the water if red beach hazard flags are flying. Rip currents claim 100 lives in the U.S. each year.
MORE ON WEATHER.COM: Retired Atlantic Hurricane Names
1 of 80
Hurricane Joaquin hammered the central Bahamas in early
October 2015, as a Category 4 hurricane. Joaquin stalled near the
islands, producing widespread storm surge and rainfall flooding. Joaquin
was the second latest-in-season Cat. 4+ hurricane to affect the
Bahamas. (NOAA via Getty Images)
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