Tropical Depression Nine Forms, Forecast to Move Across the Bahamas As A Tropical Storm on Saturday.

At 5:00 PM AST, the National Hurricane Center upgraded Potential Tropical Cyclone Nine to Tropical Depression Nine, 384 kilometers east-southeast of Freeport, Grand Bahama Island.

The center of Tropical Depression Nine was located near latitude 25.6 North, longitude 75.0 West. The depression is moving toward the northwest near 13 KM/H. A turn toward the north-northwest is expected on Saturday. On the forecast track, the system is anticipated to move very near the northwestern Bahamas tonight and Saturday, and east of the east coast of Florida during Saturday and Sunday.

Maximum sustained winds are near 45 KM/H with higher gusts to 65 KM/H. Some strengthening is forecast during the next 48 hours. The depression is forecast to become a tropical storm on Saturday. The next tropical storm will be named Humberto.

The estimated minimum central pressure is 1009 millibars.

Forecast Cone for Tropical Depression Nine
Forecast Cone for Tropical Depression Nine

Watches & Warnings

Watches and Warnings for Tropical Depression Nine

A Tropical Storm Warning is in effect for the Northwestern Bahamas excluding Andros Island.

The government of the Bahamas has issued a Tropical Storm Warning for the following islands in the northwestern Bahamas the Abacos, Berry Islands, Bimini, Eleuthera, Grand Bahama Island, and New Providence.

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

A Tropical Storm Watch is in effect for Jupiter Inlet to Flagler-Volusia County line, Florida. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.

Interests elsewhere along the east coast of Florida should monitor the progress of this system. Additional watches and warnings may be required for portions of this area later today.

Hazards Affecting Land

Wind: Tropical storm conditions are expected within the warning area in the northwestern Bahamas tonight and early Saturday. Tropical storm conditions are still possible in the watch area on the Florida peninsula by Saturday or Saturday night.

Rainfall: The tropical depression is expected to produce total rainfall accumulations through Sunday:

  • The Bahamas – 2 to 4 inches (50-100 mm), isolated maximum amounts 6 inches (150 mm).
  • The U.S. Atlantic Coast from central Florida into South Carolina – 2 to 4 inches (50-100 mm).

    Street and flash flooding are likely.

Storm Surge: This system is not expected to produce significant storm surge in the northwestern Bahamas.

This tropical depression is of no threat to the Lesser Antilles, including Trinidad and Tobago.

Tropical Depression Nine Discussion

An Air Force plane extensively investigated the disturbance near the Bahamas during the past several hours, and in the last portion of the mission, the crew was able to locate a center of circulation, although weak, near the convection. The center was a little bit to the east of the previous estimates. Satellite images also indicate that the cloud pattern has become a little better organized and Dvorak estimates are T2.0 and 1.5 from TAFB and SAB, respectively. On this basis, the disturbance has been classified as a tropical depression with 25 kt winds.

Conditions are not ideal for strengthening since the depression is still embedded within a moderate shear environment, but this parameter is not expected to be strong enough to halt additional development. The NHC forecast still calls for this system to become a tropical storm on Saturday with gradual intensification thereafter. Global models insist on further development, and the reliable guidance suggests that the cyclone could even reach hurricane intensity in about 3 days, and so does the NHC forecast. By then, the system is expected to be over the Atlantic waters well
southeast of the coast of the Carolinas.

Due to the reformation of the apparent center, the initial motion is highly uncertain. The best estimate is toward the northwest or 305 degrees at 7 kt. A weakness in the ridge over the western Atlantic is forecast to develop, and this pattern should steer the system slowly toward the northwest and then northward. In about 3 days, an eastward-moving mid-latitude trough will force the system to recurve away from the coast toward the Atlantic. The track guidance has shifted to the east again, and this shift is larger due to the eastward formation of the center. Consequently, the NHC track forecast was adjusted in that direction, but it remains on the western edge of the guidance envelope.

Humberto is the next name on the list of names for the 2019 Atlantic Hurricane Season.

Key Messages:

  1. The depression is forecast to become a tropical storm within the next 24 hours and will likely bring tropical-storm-force winds and heavy rainfall to portions of the northwestern Bahamas later today and Saturday. Significant storm surge is not expected in the northwest Bahamas from this system. Residents there should follow any advice given by local officials.
  2. The system could still bring tropical storm conditions to portions of the Florida east coast. Residents there should monitor the progress of this system and follow any advice given by local officials.
  3. Heavy rainfall and scattered flash flooding is possible this weekend in coastal sections of eastern Florida, Georgia, and South Carolina. The chance of heavy rainfall affecting coastal North Carolina early next week continues to diminish.

Facebook Comments