Mainly Sunny, Hot Labor Day; CAT 5 Dorian Staying Well East

LABOR DAY: For today, the weather looks generally dry, with mainly sunny conditions. Expect another hot day with highs again in the lower to perhaps mid 90s.

THE FIRST WEEK OF SEPTEMBER: With Dorian staying well to the east of the state, we expect no impacts on Alabama. If anything, the subsidence around the system and northerly wind flow on this side of the system, our weather should be generally dry and mainly sunny with highs in the lower to mid 90s and lows in the upper 60s to lower 70s. Nothing too unusual for the first week of September.

WEEKEND SNEAK PEAK: The mainly dry pattern looks to continue into next weekend as it doesn’t appear there is any real significant to change our weather pattern. For now, Saturday should feature mainly sunny conditions with highs in the mid 90s. The models hint a weak boundary trying to move in here Monday day, which could bring a few more clouds and perhaps some showers, but still it doesn’t look too promising.

HURRICANE DORIAN: At 500 AM EDT, the center of Hurricane Dorian was located by NOAA Doppler radar near latitude 26.6 North, longitude 78.2 West. Dorian is moving toward the west near 1 mph. A slow westward to west-northwestward motion is forecast during the next day or so, followed by a gradual turn toward the northwest and north. On this track, the core of extremely dangerous Hurricane Dorian will continue to pound Grand Bahama Island through much of today and tonight. The hurricane will move dangerously close to the Florida east coast tonight through Wednesday evening.

Maximum sustained winds are near 165 mph with higher gusts. Dorian is a category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale. Although gradual weakening is forecast, Dorian is expected to remain a powerful hurricane during the next couple of days. The estimated minimum central pressure is 916 mb (27.05 inches).

Satellite imagery continues to show that Dorian has an extremely well-defined eye embedded within very cold cloud tops. The diameter of the eye appears to have expanded to near 20 n mi, and radar data, especially from the Bahamas Department of Meteorology radar, show that there are concentric eyewalls. The hurricane also continues to exhibit strong upper-tropospheric outflow. During the next few days, Dorian should be encountering some increase in shear, which will likely result in weakening. However it is anticipated that the system will remain a dangerous major hurricane for the next several days.

Steering currents have weakened, and Dorian has almost come to a standstill over eastern Grand Bahama Island. The mid-tropospheric high to the north of the hurricane that had been steering Dorian westward has collapsed. Global models indicate that, in a couple of days, a weakness in the ridge will develop. This would likely cause Dorian to move northwestward to northward toward and through this weakness. Later in the forecast period, the system is expected to accelerate northeastward on the southern side of a broad mid-tropospheric trough. The official track forecast is very close to the previous one. Although the official forecast does not show Dorian making landfall along the Florida east coast, it is still possible for the hurricane to deviate from this forecast, and move very near or over the coast. Users are reminded not to focus on the exact forecast track.

Key Messages:

1. A prolonged period of catastrophic winds and storm surge will continue to affect Grand Bahama Island through today and tonight. Everyone there should remain in shelter and not venture into the eye.

2. Life-threatening storm surges and dangerous hurricane-force winds are expected along portions of the Florida east coast through mid-week, and storm surge and hurricane warnings are in effect. Only a slight deviation to the left of the official forecast would bring the core of Dorian near or over the Florida east coast. Residents should listen to advice given by local emergency officials.

3. There is an increasing likelihood of strong winds and dangerous storm surge along the coasts of Georgia, South Carolina, and North Carolina later this week. Residents in these areas should continue to monitor the progress of Dorian and listen to advice given by local emergency officials.

4. Heavy rains, capable of producing life-threatening flash floods, are expected over northern portions of the Bahamas and coastal sections of the Southeast and lower Mid-Atlantic regions of the United States into Friday.

ELSEWHERE IN THE TROPICS: As expected, as we head into September, the tropics are very active as we are in the heart of the season. There are several other areas of interest the NHC is monitoring for development in the coming days:

1. Recent satellite-derived surface wind data indicate that the low pressure system located about 150 miles west-southwest of the Cabo Verde Islands has become better defined. Shower and thunderstorm activity is beginning to show signs of organization, and environmental conditions appear conducive for a tropical depression to form during the next day or so while the system moves generally northwestward across the eastern tropical Atlantic Ocean. Locally heavy rainfall will be possible over the Cabo Verde Islands through Tuesday. Formation chance through 48 hours…high…80 percent. Formation chance through 5 days…high…80 percent.

2. A broad area of low pressure located over the south-central Gulf of Mexico continues to produce widespread cloudiness and disorganized showers and thunderstorms. Some gradual development of this system is possible during the next few days while the low moves slowly westward across the south-central and southwestern Gulf of Mexico toward the coast of Mexico. Formation chance through 48 hours…low…30 percent. Formation chance through 5 days…medium…50 percent.

3. A trough of low pressure is located several hundred miles south-southeast of Bermuda. Shower and thunderstorm activity has increased since yesterday and has also become better organized this morning. Gradual development of this system is possible during the next few days while the disturbance moves slowly northward or north-northwestward. Interests in and around Bermuda should monitor the progress of this disturbance. Formation chance through 48 hours…low…30 percent. Formation chance through 5 days…medium…50 percent.

4. A tropical wave is forecast to emerge over the far eastern tropical Atlantic between Africa and the Cabo Verde Islands by the end of the week. Some gradual development of this disturbance will be possible over the weekend while it moves westward to west-northwestward. Formation chance through 48 hours…low…near 0 percent. Formation chance through 5 days…low…20 percent.

The next names up on the list at Fernand, Gabrielle, Humberto, and Imelda.

Have a great and safe Labor Day!
Ryan