Delta is Nearly at Hurricane Strength; Gamma Has Weakened Into a Depression

DELTA

From the latest reconnaissance data, Tropical Storm Delta continues to strengthen at a rapid pace. Maximum sustained winds are now up to 70 MPH, just 4 MPH away from becoming a hurricane, while the pressure has dropped down to 983 MB. Movement was to the west at 8 MPH and the center was located around 160 miles south-southwest of Negril, Jamaica. The aircraft also observed an 18 nautical-mile-wide-eye that was open to the west-northwest.

Visible satellite imagery shows that the convective banding of Delta has continued to quickly improve since this morning. The primary convective band now wraps entirely around the center, with what appears to be a banding-type eye feature occasionally noted. There are some dry slots between the convective bands but those appear to be gradually filling in. Conditions are conducive for strengthening at a rapid pace and shall remain that way over the next 24 to 36 hours. The NHC intensity forecast follows suit by calling for rapid intensification over the next day or so, and Delta is forecast to be a major hurricane when it passes near or over the northeastern portion of the Yucatan peninsula.

Increasing southwestern vertical wind shear and cooler shelf waters over the northern Gulf are likely to result in some reduction in wind speed as the system nears the northern Gulf coast. Although there is still significant uncertainty regarding Delta’s intensity when it nears the northern Gulf coast, it is becoming increasingly likely that the system will pose a significant wind and storm surge threat to a portion of that area.

Although the track forecast has not changed much during the latter portion of the period, there is more cross-track spread in the model guidance than before, which has increased the uncertainty regarding potential landfall and the timing of Delta’s approach to the northern Gulf Coast.

KEY MESSAGES:

1. Dangerous storm surge and hurricane conditions are expected within portions of the northern Yucatan Peninsula of Mexico and are possible in extreme western Cuba beginning Tuesday night, and a Hurricane Warning is in effect.

2. Heavy rainfall will affect portions of Jamaica, the Cayman Islands, western Cuba and the northern Yucatan Peninsula during the next few days. This rainfall could lead to significant flash flooding and mudslides.

3. Tropical storm conditions are expected in portions of the Cayman Islands beginning tonight or early Tuesday, and a Tropical Storm Warning is in effect.

4. Delta is forecast to approach the northern Gulf Coast late this week as a hurricane. While there is large uncertainty in the track and intensity forecasts, there is an increasing risk of dangerous storm surge, wind, and rainfall hazards along the coast from Louisiana to the western Florida Panhandle beginning Thursday night or Friday. Residents in these areas should ensure they have their hurricane plan in place and monitor updates to the forecast of Delta.

GAMMA

Gamma continues to weaken as it moves slowly to the southwest just offshore of the northwestern Yucatan Peninsula, with the center positioned around 135 miles northwest of Cozumel, Mexico. Maximum sustained winds have decreased near 35 MPH with higher gusts. Gradual weakening is forecast, and Gamma is expected to degenerate to a post-tropical remnant low tonight and dissipate over the northern portion of the Yucatan peninsula Wednesday. On the forecast track, the center of the depression should move inland over the northwest coast of the Yucatan peninsula Tuesday and remain over the northern portion of the peninsula and dissipate Wednesday.

Category: ALL POSTS, Severe Weather, Tropical