1. Extremely dangerous storm surge and hurricane conditions areexpected within portions of the northern Yucatan Peninsula ofMexico beginning tonight, and a Hurricane Warning is in effect.

2. Heavy rainfall will affect portions of the Cayman Islands, western Cuba and the northern Yucatan Peninsula through midweek. This rainfall could lead to significant flash flooding and mudslides. The potential for heavy rain and flash flooding will increase across portions of the central Gulf Coast, Tennessee Valley, and southeastern United States as Delta moves inland later this week.

3. There is an increasing likelihood of life-threatening storm surge and dangerous hurricane-force winds, especially along the coasts of Louisiana and Mississippi, beginning on Friday. Residents in these areas should ensure they have their hurricane plan in place and monitor updates to the forecast.

CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
- Tulum to Dzilam Mexico
- Cozumel

A Tropical Storm Warning is in effect for...
- Cayman Islands including Little Cayman and Cayman Brac
- Cuba province of Pinar del Rio
- Isle of Youth
- Punta Herrero to Tulum Mexico
- Dzilam to Progresso Mexico

A Tropical Storm Watch is in effect for...
- Cuba province of La Habana

A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should be rushed to completion.

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

For storm information specific to your area, please monitor products issued by your national meteorological service.

Key messages for Delta can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1, WMO header WTNT41 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT1.shtml.

STORM SURGE: An extremely dangerous storm surge will raise water levels by as much as 6 to 9 feet above normal tide levels along coast of the Yucatan peninsula within the hurricane warning area, near and to right of where the center makes landfall. Near the coast, the surge will be accompanied by large and destructive waves.

WIND: Tropical storm conditions are expected in portions of the the Cayman Islands today. In the Yucatan Peninsula, hurricane conditions are expected in the warning area early Wednesday, with tropical storm conditions beginning later today or tonight. Tropical storm conditions are expected in the tropical storm warning area tonight and Wednesday. In Cuba, tropical storm conditions are expected tonight in the warning area and possible in the watch area near the same time.

RAINFALL: Delta is expected to produce 4 to 6 inches of rain, with isolated maximum totals of 10 inches, across portions of the northern Yucatan Peninsula through midweek. This rainfall may result in areas of significant flash flooding.

Over the next few days, Delta is expected to produce 2 to 4 inches of rain, with isolated higher amounts, across portions of the Cayman Islands and western Cuba. This rainfall may result in areas of flash flooding and mudslides.

Later this week, Delta is expected to bring heavy rainfall and flash and urban flooding to portions of the central Gulf Coast, Tennessee Valley, and southeastern United States.

SURF: Swells generated by Delta will affected land areas around the northwestern Caribbean Sea for the next day or so. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

At 1100 AM EDT (1500 UTC), the center of Hurricane Delta was located near latitude 18.2 North, longitude 82.6 West. Delta is moving toward the westnorthwest near 16 mph (26 km/h). A west northwestward to northwestward motion is expected over the next couple of days. A slower northwestward to northnorthwest motion is forecast to begin by late Wednesday or Wednesday night. On the forecast track, the center of Delta is expected to continue to pass southwest of the Cayman Islands through early this afternoon, and move over the northeastern portion of the Yucatan peninsula late tonight or early Wednesday. Delta is forecast to move over the southern Gulf of Mexico Wednesday afternoon, and be over the southern or central Gulf of Mexico through Thursday.

Reports from a NOAA Hurricane Hunter aircraft indicate that the maximum sustained winds have increased to near 115 mph (185 km/h) with higher gusts. Delta is a category 3 hurricane on the SaffirSimpson Hurricane Wind Scale. Additional strengthening is forecast during the next 24 hours, and Delta is forecast to be an extremely dangerous category 4 hurricane when it reaches the Yucatan peninsula Wednesday. Although some weakening is likely when Delta moves over the Yucatan peninsula, restrengthening is forecast when the hurricane moves over the southern Gulf of Mexico. Hurricaneforce winds extend outward up to 25 miles (35 km) from the center and tropicalstormforce winds extend outward up to 90 miles (150 km).

The estimated minimum central pressure from NOAA reconnaissance aircraft data is 955 mb (28.20 inches).

Satellite imagery and recent NOAA Hurricane Hunter aircraft datashow that Delta is a very symmetric and compact hurricane. Theaircraft reported a tiny 5-nmi-wide eye, which has also beenseen in radar imagery from the Cayman Islands, and there is a hintof a pinhole eye in infrared satellite data. The central pressurehas continued to fall, with the lastest center dropwindsonde data supporting a pressure of 955 mb. The plane has reported a peak flight-level winds of 109 kt, and believable SFMR winds of 102 kt. Therefore, the initial intensity is set at 100 kt, making Delta the third major hurricane of the 2020 Atlantic hurricane season.

Delta has continued to rapidly strengthen over the past 24 hours,with an estimated 55-kt increase in wind speed between 1200 UTCMonday and 1200 UTC today. Environmental conditions of low vertical wind shear, deep warm waters, and sufficient mid-levelmoisture are expected to support additional rapid intensificationthrough today, and the only reason that the strengthening couldslow is if a difficult-to-predict eyewall replace cycle begins.The SHIPS Rapid intensification index continues to indicate a highlikelihood of at least an additional 25-30 kt of intensity increase before the system reaches the northeastern portion of the YucatanPeninsula. Given that, the NHC intensity forecast is above the various intensity aids and call for Delta to be an extremely dangerous category 4 hurricane when it nears the Yucatan. It could be stronger than indicated below since landfall is predicted to occur between the 12 and 24 h forecast points. Some reduction in intensity is likely when Delta moves over land, but the environmental conditions over the southern Gulf of Mexico are expected to support re-strengthening, and the NHC intensity forecast shows a second peak in 48-72 hours. As mentioned before, increasing southwesterly shear and cooler shelf waters near the northern Gulf coast are expected to cause some reduction in wind speed, but Delta is still expected to be a dangerous hurricane when it nears the northern Gulf coast.

Delta is moving west-northwestward at about 14 kt. A mid-levelridge that extends westward across Florida and the northeasternGulf of Mexico should continue to steer Delta west-northwestward tonorthwestward during the next couple of days. As the hurricanenears the western portion of the ridge it should slow down. Byday three a developing trough over the south-central United Statesis expected to cause Delta to turn northward toward the northernGulf coast. The track guidance is tightly clustered through 48hours, but there is still a fair amount of spread thereafterregarding the timing and details of the northward turn. The ECMWFand its ensemble mean are well west of the bulk of the remainder ofthe guidance. The NHC track lies near the TVCA multi-model consensus which is close to a blend of the GFS, HWRF, UKMET ensemble mean.