Hurricane Delta
Moon-lit look at Tropical Storm Delta at 3:05 a.m. CDT October 10, from the NOAA-20 satellite. Delta at that point was well inland over Louisiana, and had weakened to 45 mph winds. (Image credit: University of Wisconsin CIMSS)

Hurricane Delta made landfall at 6 p.m. CDT October 9 near Creole, Louisiana – just 12 miles east of where category 4 Hurricane Laura hit on August 27. At landfall, Delta was a category 2 storm with 100 mph winds and a central pressure of 970 mb. Delta knocked out power to more than 750,000 customers in Louisiana, Texas, and Mississippi as of 7:30 a.m. CDT Saturday, according to poweroutage.us.

Figure 1
Figure 1. Radar image of Hurricane Delta at landfall in southwest Louisiana at 5:59 p.m. CDT Friday, October 9. (Image credit: Mark Nissenbaum/Florida State University)

Hurricane-force winds in Louisiana and Texas

Delta brought hurricane-force wind gusts to Louisiana and Texas, causing extensive wind damage. The highest winds observed in Louisiana were at Lake Arthur, which recorded sustained winds of 77 mph, gusting to 96 mph, around the time of Delta’s landfall. Some other peak wind gusts from Delta:

Texas Point, TX: 100 mph;
Lake Charles Regional Airport, LA: 94 mph;
Calcasieu Pass, LA: 90 mph;
New Iberia, LA: 90 mph;
Port Arthur, TX: 90 mph;
Cameron, LA: 89 mph;
Jennings, LA: 81 mph;
Lafayette, LA: 75 mph;
Opelousas, LA: 75 mph;
Lacassine, LA: 75 mph;
Alexandria, LA: 61 mph;
Baton Rouge, LA: 56 mph; and
New Orleans, LA: 49 mph.

Figure 2
Figure 2. 24-hour precipitation amounts ending at 7 a.m. CDT Saturday, October 10, based on a blend of radar estimates and rain-gauge reports. Delta dumped over 10 inches of rain (white colors) over portions of Louisiana. (Image credit: NOAA)

Rains in excess of 15 inches

Delta dumped torrential rains over much of Louisiana, with radar-estimated rainfall amounts of more than 15 inches between Lake Charles and Alexandria. The heavy rains led to serious flash flooding, and at least three rivers in Louisiana are predicted to go into major flood stage by Monday.

A significant storm surge

Delta generated a significant storm surge along the Louisiana coast near and to the right of where the center came ashore. The highest water level at any monitoring station was observed at Freshwater Canal Locks, where a storm surge of 9.3 feet occurred and was still rising before the gauge stopped transmitting data. Even so, this broke the site’s all-time record set during Hurricane Ike in 2008 by 0.25 feet. The station has recorded data only back to 2008, and it is likely that Hurricane Rita of 2005 brought a higher storm surge to the site.

The live storm surge tracker at Trabus Technologies documented these top storm surge heights from Delta:

Freshwater Canal Locks, LA: 9.3 feet;
Calcasieu Pass, LA: 6.6 feet;
LAWMA, Amerada Pass, LA: 6.3 feet;
Eugene Island, LA: 6.2 feet;
Texas Point-Sabine Pass, TX: 4.4 feet; and
San Luis Pass, TX: 3.3 feet.

Figure 3
Figure 3. Continental U.S. landfall in 2020. (Image credit: Steve Bowen, Aon)

Delta is record-breaking tenth named storm of a season to hit U.S.

Delta was the tenth named storm to make landfall in the U.S. in 2020, beating the record of nine U.S. landfalls in a single year, set in 1916. Third place is jointly held by 2004, and 1985, with eight. Remarkably, none of the 2020 landfalls have occurred in Florida, which is the most hurricane-prone state. From 1851 through 2019, the U.S. averaged 3.2 named storm landfalls per year, 1.6 hurricane landfalls, and 0.5 major hurricane landfalls.

Delta was the first U.S. landfalling “Greek” hurricane ever. On September 22, Tropical Storm Beta became the first U.S. landfalling “Greek” named storm in history. The only other year with “Greek” named storms, 2005, had three that made landfall: Alpha, Beta, and Gamma, all in the Caribbean.

Delta was the fifth landfalling hurricane in the continental U.S. this year, which is tied with 2004 and 2005 for the third highest on record. The record is held jointly by 1985 and 1886, with six landfalling hurricanes.

Delta was the fourth named storm to make landfall in Louisiana this year, along with Tropical Storm Cristobal, Tropical Storm Marco, and Hurricane Laura. This ties the record for most landfalls in a single season in Louisiana, set in 2002, when Tropical Storm Bertha, Tropical Storm Hanna, Tropical Storm Isidore, and Hurricane Lili all made landfall. Six previous seasons have had three landfalls in Louisiana: 1860, 1885, 1923, 1957, 2005, and 2017.

Delta rapidly intensified on its approach toward Cancun, Mexico, becoming the fifth 2020 hurricane to intensify by at least 35 mph in 24 hours, which is the National Hurricane Center definition of rapid intensification. The 2020 list of rapid intensifiers:

Hurricane Hanna, July 24 – 25, 35 mph in 24 hours
Hurricane Laura, August 26 – 27, 65 mph in 24 hours
Hurricane Sally, September 14 – 15, 40 mph in 24 hours
Hurricane Teddy, September 17 – 18, 45 mph in 24 hours
Hurricane Delta, October 5 – 6, 80 mph in 24 hours

Hurricanes Isaias, Marco, Nana, and Paulette did not rapidly intensify.

Figure 4
Figure 4. Departure of sea surface temperature (SST) from average on October 10. SSTs were approximately 0.5 degrees Celsius (0.9°F) above average in the Caribbean and in the waters surrounding Florida and the Bahamas. Hurricane Delta had caused substantial cooling of the Gulf of Mexico. (Image credit: Tropical Tidbits)

A quiet period ahead for the Atlantic

There was only one area of interest in the Atlantic that NHC was monitoring on Saturday for tropical development – a tropical wave in the central Atlantic, midway between Africa and the Lesser Antilles Islands. This wave was under moderate wind shear of 15 – 20 knots, heading westwards at about 10 – 15 mph, and producing a modest amount of poorly organized heavy thunderstorm activity. In an 8 a.m. EDT Saturday tropical weather outlook, NHC gave the system 2-day and 5-day odds of development of 10% and 20%, respectively. By Wednesday, when the wave will be approaching the Lesser Antilles, wind shear is expected to rise to a high 20 – 30 knots, discouraging further development. Later in the week, this system will have to be watched for development when it enters the western Caribbean or waters near the Bahamas.

The top three models for predicting tropical cyclone genesis show nothing popping up over the next week, and the Madden Julian Oscillation (MJO) – a pattern of increased thunderstorm activity near the equator that moves around the globe in 30 to 60 days – is weak, and is not expected to be in a phase that will enhance Atlantic activity during the coming week. However, with ocean temperatures still much above average in the Caribbean and in waters surrounding Florida and the Bahamas (Figure 4), and in a season with a track record for spitting out record numbers of named storms, at least one or more likely will form in October. The next name on the Atlantic list of storms is Epsilon.

If the tropics remain quiet, as expected, our next post in this series will be on Wednesday, October 14.

Also see: At least three named Atlantic storms likely during October

Website visitors can comment on “Eye on the Storm” posts (see below). Please read our Comments Policy prior to posting. (See all EOTS posts here. Sign up to receive notices of new postings here.)

Posted on October 10, 2020 (1:25pm EDT).

Jeff Masters, Ph.D., worked as a hurricane scientist with the NOAA Hurricane Hunters from 1986-1990. After a near-fatal flight into category 5 Hurricane Hugo, he left the Hurricane Hunters to pursue a...

107 replies on “Delta is record-setting 10th named storm to make U.S. landfall in a season”

  1. Coastal Hazard Message
    National Weather Service Miami FL
    1022 AM EDT Sun Oct 18 2020
    
    FLZ168-172-173-182230-
    /O.CON.KMFL.CF.Y.0004.000000T0000Z-201020T0000Z/
    /O.CON.KMFL.RP.S.0049.000000T0000Z-201020T0000Z/
    Coastal Palm Beach-Coastal Broward-Coastal Miami-Dade-
    1022 AM EDT Sun Oct 18 2020
    
    ...COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT
    MONDAY...
    ...HIGH RIP CURRENT RISK REMAINS IN EFFECT THROUGH MONDAY
    EVENING...
    
    * WHAT...For the Coastal Flood Advisory, minor coastal flooding.
      For the High Rip Current Risk, dangerous rip currents expected.
    
    * WHERE...Coastal Palm Beach, Coastal Broward and Coastal Miami-
      Dade Counties.
    
    * WHEN...For the Coastal Flood Advisory, until 8 PM EDT Monday.
      For the High Rip Current Risk, through Monday evening.
    
    * IMPACTS...Flooding of lots, parks, and roads with only
      isolated road closures expected. Rip currents can sweep even
      the best swimmers away from shore into deeper water.
    
    PRECAUTIONARY/PREPAREDNESS ACTIONS...
    
    If travel is required, allow extra time as some roads may be
    closed. Do not drive around barricades or through water of
    unknown depth. Take the necessary actions to protect flood-prone
    property.
    
    Swim near a lifeguard. If caught in a rip current, relax and
    float. Don`t swim against the current. If able, swim in a
    direction following the shoreline. If unable to escape, face the
    shore and call or wave for help.
    
    &&
    
    $$
    
  2. well it changed path once again thank goodness in this early mornings run..it seems the other storm out in the atlantic has some effects on our caribbean storms path..still 8 days out..we’ll see better next weekend

Comments are closed.