MIAMI – A slow and steady Erika continues to plod westward and forecasters are not expecting her to become a Category 1 hurricane until early Saturday.

The latest track has it aimed for the southeastern coast of Florida and tropical storm warnings and watches have been issue for many of the island in this path.

The National Hurricane Center issued the following advisory and discussion at 7 a.m. on Aug. 26:

The center of Tropical Storm Erika was located near latitude 16.2 North, longitude 56.8 West. Erika is moving toward the west near 17 mph and a west to west-northwestward motion is expected over the next 48 hours.

On the forecast track, the center of Erika will move near or over portions of the Leeward Islands tonight and move near the Virgin Islands and Puerto Rico on Thursday.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate the maximum sustained winds have increased to near 45 mph with higher gusts. Some slow strengthening is forecast during the next 48 hours.

Tropical storm force winds extend outward up to 105 miles primarily to the east of the center. The latest minimum central pressure reported by an Air Force Reserve Hurricane Hunter aircraft is 1005 mb (29.68 inches).

Convection has increased near and to the east of the estimated center position of Erika during the past few hours. The central pressure of 1003 mb is based on a dropsonde from a NOAA aircraft that reported 1004 mb and

25 knot of wind south of the apparent surface center.

The intensity forecast remains very uncertain. Despite the recent improvement in the convective pattern, the statistical guidance shows only very gradual strengthening during the forecast period due to 15 to 25 knot of westerly to northwesterly shear.

Another major negative factor is the weakening of the in one. Another model is also very slow to strengthen Erika in the short term, but continues to show intensification late in the period.

The latest of yet another model run shows a more robust cyclone in its latest forecast, while another, as mentioned above, weakens the vortex to a wave in 2 to 3 days. Given this uncertainty, the NHC forecast remains close to the intensity consensus and shows very slow intensification in the first two to three days followed by steadier strengthening at days four and five.

Erika will be steered westward to west-northwestward during the next two to three days by the Atlantic subtropical ridge to the north, and the track model guidance is in good agreement on this scenario. After that time, the track model guidance shows increasing spread with a lack of run to run consistency.

Overall, the track guidance envelop has shifted a little to the left this cycle, with the majority of the aids showing a west-northwestward to northwestward motion as the cyclone nears the western edge of the ridge by day five.

The NHC forecast follows this trend. Given the uncertainty, this is a good time to remind users that average NHC track forecast errors during the past five years are 180 miles at day four and 240 miles at day five.

New tropical storm warnings have been issued for Puerto Rico, the Virgin Islands, and several other islands in the northeastern Caribbean by their respective Meteorological Services.