Hurricane Delta, now a major category 3 hurricane, is traveling over the warm waters of the Gulf of Mexico, headed for the Louisiana coast. With sustained surface winds over 115 mph, it is expected to strengthen to 125 mph winds in the next 12 hours, before weakening a bit and making landfall late Friday evening.
The storm will bring strong winds, heavy rainfall and tornadoes in its path through LA and MS and into TN.
Here is the projected path and timing of Hurricane Delta —
Delta will be the 7th major storm to hit the beleaguered gulf coast this year.
Some areas hit by Hurricane Laura 6 weeks ago will unfortunately see a repeat performance.
Latest Advisory
From the 5:00 pm NHC bulletin -
- The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline.
- Hurricane conditions are expected within the hurricane warning area by Friday afternoon or evening, with tropical storm conditions expected within this area by early Friday. Tropical storm conditions are expected within the tropical storm warning areas on Friday, and are possible in the tropical storm watch area Friday night.
- Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 160 miles (260 km).
- RAINFALL: Friday through Saturday, Delta is expected to produce 5 to 10 inches of rain, with isolated maximum totals of 15 inches, from southwest into south-central Louisiana. These rainfall amounts will lead to significant flash, urban, small stream flooding, along with minor to major river flooding.
- Delta will landfall along the northern U.S. Gulf Coast later Friday.
Hurricane Delta forecast positions and max winds
INIT 08/2100Z 24.8N 93.4W 100 KT 115 MPH
12H 09/0600Z 26.3N 93.9W 110 KT 125 MPH
24H 09/1800Z 28.6N 93.5W 105 KT 120 MPH
36H 10/0600Z 31.0N 92.5W 65 KT 75 MPH...INLAND
48H 10/1800Z 32.9N 91.1W 40 KT 45 MPH...INLAND
60H 11/0600Z 34.3N 89.2W 30 KT 35 MPH...INLAND
72H 11/1800Z 35.8N 87.2W 20 KT 25 MPH...POST-TROP/INLAND
96H 12/1800Z...DISSIPATED
Storm Surge
Up to 11 feet of storm surge in some coastal areas
Rain Forecast
Through Saturday, Delta is expected to produce 5 to 10 inches of rain, with isolated maximum totals of 15 inches, from southwest into central Louisiana. These rainfall amounts will lead to significant flash, urban, small stream flooding, along with minor to major river flooding.
Power Outage Forecast
Forecast Models
Forecasts about storm track and intensity are based on computer models which are fed current atmospheric conditions and which calculate weather and storm conditions several days into the future. There are many such models and most graphs like the ones above are based on the average results from several models. Here is an example of the results for Delta from several models at the NOAA National Hurricane and Weather Forecast System (HWRS).
The various models are in very close agreement at this point.
Delta’s track and intensity were predicted several days ago, as it scraped over Cancun, Mexico. The models have undergone small adjustments as the storm approached the Gulf and now the Gulf coast.
Satellite and radar imagery
Flying into the eye of the Hurricane
NOAA and the 53rd Weather Reconnaissance Squadron (53rd WRS) send aircraft with special instrumentation several times a day into the hurricane to make more precise and frequent measurements of parameters within hurricanes. The aircraft are equipped with radar and other instruments. Typically, they fly straight across the hurricane at altitudes between 1,000 feet to 10,000 feet. It sounds dangerous to fly into through the eye-wall of a hurricane swirling at 185 mph, but they have been doing so for decades with a near perfect record.
www.tropicaltidbits.com/… is an interesting site that plots the data from these recon flights in near real-time. Here is an example of the flight path across Delta today of the NOAA recon plane. The aircraft also drop dropsonde devices into the storm, which measure and relay vital signs of the hurricane as they fall down towards the ocean.
Hurricane Season 2020
Delta is the 26th tropical cyclone, 25th named storm and the 9th hurricane of the very active 2020 Atlantic hurricane season.
The average number of named Atlantic storms per season is 11.3; we are well past that number and the season is not over yet.
The 2020 Atlantic hurricane season so far is shown below (the chart also shows wind speeds for different storm categories based on the Saffir–Simpson hurricane wind scale).
How the 2020 Atlantic Hurricane season (so far) compares with the average season -
North Atlantic Tropical Cyclones
Unlike most major Atlantic tropical cyclones, which start as a tropical wave over western Africa, Delta was born in the the Caribbean.
Delta’s history and track so far -
The following map from NASA shows the tracks of all tropical cyclones during the 1985-2005 time period. The Pacific Ocean west of the International Date Line sees more tropical cyclones than any other basin, while there is almost no activity in the Atlantic Ocean south of the Equator. Tropical cyclones do not form around the equator.
A large number of Atlantic hurricanes originate near the Cape Verde islands, off the west coast of Africa and are know as the “Cape Verde hurricanes.” These hurricanes form from a tropical wave that has passed over or near the Cape Verde islands after exiting the coast of West Africa. Hurricanes Dean (2007), Ivan (2004), Floyd (1999) Hugo (1989), Fran (1996), Isabelle (2003) are examples of Cape Verde hurricanes.
The following diagram shows the trajectories of the storms of the 2020 Atlantic hurricane season (excluding Delta) -
Hurricanes and Climate Change
Yes, hurricanes are not uncommon, but there is a link between climate change and increased hurricane intensities. According to this paper from Yale, How climate change is making hurricanes more dangerous -
There’s now evidence that the unnatural effects of human-caused global warming are already making hurricanes stronger and more destructive. The latest research shows the trend is likely to continue as long as the climate continues to warm.
Generally speaking, the warmer the water temperatures, the more heat energy is available and the higher the potential for tropical cyclones to develop. So it’s reasonable to assume that as humans continue to release planet-warming greenhouse gases, the likelihood of tropical cyclone activity increases. The conventional wisdom is that storm intensity will increase but storm frequency will either decrease or remain unchanged.
Here is a fresh article on the subject — “Hurricane Delta grew from a tropical storm to a Category 4 hurricane in 1 day. Here's how cyclones are now intensifying so quickly.”
Climate change makes hurricanes more frequent and devastating, on average, than they would otherwise be. That's because storms feed on warm water, and higher water temperatures lead to sea-level rise, which in turn increases the risk of flooding during high tides and storm surges. Warmer air also holds more atmospheric water vapor, which enables tropical storms to strengthen and unleash more precipitation.
Here is a statement from the esteemed climatologist Michael Mann about Hurricanes, climate change and politics —
Epilogue
For those in the path of the storm, please make preparations and stay safe. The best advise is to listen to forecasts and instructions from the NHC and local authorities, prepare for the worst and hope for the best. The window to evacuate from coastal regions is closing; seek shelter.
Also, this will only make the COVID-19 situation worse, with limited testing and people possibly congregating in shelters.
Let’s send our prayers, best wishes and donations to those in harm’s way.
And let’s keep reminding people that trump and his republican enablers are fraudsters; they are incapable of governing since the only skill they have is trashing others and picking the pockets of their supporters.
Further Reading
- National Hurricane center — www.nhc.noaa.gov
- weather.com/…
- trackthetropics.com/… Lots of charts and imagery
- Aircraft Reconnaissance — www.tropicaltidbits.com/…
- Real-time GOES-16 satellite imagery — rammb-slider.cira.colostate.edu/...
- Atlantic Basin Storm Names and Pronunciations — www.weather.gov/…
- How To Tame a Hurricane — www.dailykos.com/…
- Hurricane Dorian Forecasts, Updates and Science - Part 2 (2019) — www.dailykos.com/…