1500Z Tropical Update

TROPICAL UPDATE ON TROPICAL DEPRESSION 11 FORECAST #1
TROPICAL FORECAST CENTER
10:15 AM EST WEDNESDAY NOVEMBER 4, 2009

A Tropical Storm Warning has been issued for the Islands of San Andres and Providencia by the Colombian Government.

A Tropical Storm Warning has been issued for the East Coast of Nicaragua by their Government. A tropical storm warning mean that tropical storm conditions are expected...generally within 24 hours.

At 10 AM EST (1500Z)...the center of newly developed Tropical Depression 11 is located near 11.6 N 82.0 W. Maximum sustained winds are near 35 mph...and the depression could become a tropical storm later today or tonight. Movement is toward the northwest at 8 mph and this motion is expected to decrease this afternoon. On the forecast track...the depression will cross into Nicaragua by late tonight or on Thursday. Estimated minimum central pressure is 1006 mb/29.71 in.

Area of low pressure that I have been monitoring for the past day or so have developed enough thunderstorms to be classified as a tropical depression. Recent satellite pictures are showing a new batch of thunderstorms developing near the center so this could push this depression into tropical storm strength actually within the next few hours. Air Force Recon will be investigating this system later this afternoon to see if we indeed have Ida on our hands. Initial intensity is at 30 kts...representative of the Dvorak Estimates around 2.0. With the closeness to land...the intensity forecast is a little tricky. SHIPs as in previous model runs show very little intensification and while GFDL show the storm becoming a hurricane. While the latter scenario is possible...the proximity to land will make it difficult so I/m expecting the depression to make to around 40 or 45 kts before moving over Nicaragua in about 18 to 24 hours or so and weakening before possibly crossing into the Yucatan Peninsula where if not disrupted should regain tropcial storm status.

Initial motion is 315/7 kts. Steering currents is rather weak so fully expecting that this storm will slow down or even stall later this afternoon. Forecast is rather complex on the tracking of the depression as there are several different scenarios that can play out. The first is a possible developing system in the Eastern Pacific...if this system develop quickly...then the depression could be absorbed into the system or have its circulation basically ripped apart. The second is the remnants of a cold front in the Gulf of Mexico. Forecast models show an area of low pressure developing along this front later in the week...which could steer the depression north...possibly into the Gulf of Mexico. Right now...will follow close the NHCs track for now and the system move over Nicaragua and cross back over water by the end of the forecast period.

Note: Graphics and forecast track and intensity will be updated later today.


Byron Jackson
Tropical Specialist