Subtropical Depression #17 forms in Caribbean

Subtropical Depression #17 has formed in the Caribbean Sea and is expected to soon become Tropical Storm Otto. This system has been classified as "subtropical" because it has some non-tropical characteristics. These include interaction wuith a standard upper level low pressure system and a wide circulation around the system's center.

10/6: Cool mornings, warm afternoons ahead(MyFOXLubbock.com)

Here's part of the morning Hurricane Center discussion stating right now this is more like a tropical system but likely to become more extratropical (think regular low pressure system)

WHILE THE LOW IS NOT FAR FROM BEING MORE TROPICAL THAN SUBTROPICAL...ITS CURRENT LARGE RADIUS OF MAXIMUM WINDS...AT LEAST 120 N MI...AND ITS ENTANGLEMENT WITH AN UPPER LOW LEAD ME TO START THE SYSTEM AS A SUBTROPICAL DEPRESSION.

MOST OF THE MODEL GUIDANCE SHOW THE UPPER-LEVEL LOW TO THE WEST-SOUTHWEST OF THE DEPRESSION MOVING SLOWLY OUTHEASTWARD AND WEAKENING OVER THE NEXT DAY OR SO. THIS SHOULD ALLOW THE DEPRESSION TO MOVE ON THE NORTHERN SIDE OF THAT LOW...WHICH WOULD PLACE IT INTO A MORE FAVORABLE AREA FOR STRENGTHENING WITH LIGHTER WIND SHEAR. SINCE THE SYSTEM IS OVER WARM WATERS AND THE MODELS WEAKEN THE UPPER-LEVEL LOW...TRANSITION TO A TROPICAL CYCLONE SEEMS LIKELY IN A DAY OR SO. BECAUSE OF THE CURRENT STRUCTURE OF THE CYCLONE...ONLY A SLOW INTENSIFICATION IS EXPECTED BECAUSE IT COULD TAKE SOME TIME TO SHED ALL OF ITS SUBTROPICAL CHARACTERISTICS.

VERTICAL WIND SHEAR IS LIKELY TO INCREASE IN A COUPLE OF DAYS... WHICH WILL PROBABLY HALT ANY STRENGTHENING AFTER THAT TIME. THE NHC INTENSITY FORECAST IS ON THE LOW SIDE OF THE GUIDANCE IVEN THE INITIAL SUBTROPICAL STRUCTURE...AND IS GENERALLY BETWEEN THE MODEL CONSENSUS AND THE LGEM.

Even if this sytem does strengthen to a tropical storm as expected, there is no threat to land as the storm is moving away from land into the open Atlantic.

Sub Tropical Depression 17 forms in the western Atlantic Ocean(NOLA)

As of 4 a.m. the center of subtropical depression 17 was located about 270 miles northwest of San Juan, Puerto Rico and about 710 miles south of Bermuda west. The depression is moving toward the northwest near 8 mph. A turn toward the north-northwest and a decrease in forward speed are expected by late tonight. A turn toward the northeast and an increase in forward speed are forecast on Friday.

Maximum sustained winds are near 35 mph with higher gusts. Slow strengthening is forecast during the next 48 hours and the system could become a tropical or subtropical storm later today.