The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.
NOTE: I hope to do some type of verification with these forecasts. Stay tuned...
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UNOFFICIAL...FOR THAT STUFF THAT IS KNOWN AS OFFICIAL, REFER TO NHC/TPC FORECASTSWXMANN TD 4 DISCUSSION 1
0600Z AUG 14 2007....TD 4 churns in the Central Atlantic.......SYNOPSIS....TD 14 continues to churn in the eastern Atlantic. Intensification has been styfled so far by easterly shear from the African jet. The Azores subtropical ridge to the north will remain rather strong, if not intensify, so the depression will likely continue to move in a westerly direction for at least the next 48 hr.
....TRACK....I expect the track to remain westerly for the next 72 hr. Through 120 hr, the track is to the left of the model guidance envelope and the Official NHC/TPC track. This is due to mid and low level winds remaining westerly for the time being. In addition, model guidance may be too slow with the progression with the system, especially considering that the Azores ridge is progged to intensify in the next 72 hr. I expect the cyclone to intensify slowly over the next 48 hours (see next section), and thus be mainly steered by the low level winds. Past 48 hr, the storm may begin to intensify and feel a weakness in the ridge, allowing a more poleward movement.
Confidence in this forecast is
MEDIUM-HIGH.
....INTENSITY....TD 4 is expected to be removed from the African easterly jet within the next 48 hr, but the strong Azores ridge may present a problem to the forecast. Low level wind shear may remain quite strong, limiting developing through the forecast period. But, caveats aside, models develop a strong upper level low in the central Atlantic in around 3 days. Given the position of the storm relative to the ULL, an easterly outflow channel may open up, as the low-mid level shear weakens. A trough to the west may also help induce a polar outflow channel. In addition, past 48 hr, TD 4 is expected to enter warmer SST's and an overall healthier thermodynamic environment.
Given the above, gradual strengthening is forecast past 48 hr. Rapid intensification is possible in the 96-120 hr period. Possible land interactions due to deviations in track and effects of any low level shear or SAL intrusions from the east are complicating factors.
Confidence in this forecast is
HIGH for the first 48 hr,
LOW thereafter.
....EXTENDED....After the 5 day period, the track forecast becomes problematic. Models are still incongruent regarding the synoptic pattern. The weakness is expected to fill in and be replaced by a ridge. This ridge might send the system back west, but the timing and strength of this ridge is still up in the air. A weaker and/or slower ridge would result in a possible recurvature just off the U.S. east coast, or some landfalls as it rides up the east coast. A stronger ridge may result in a more westerly track, threatening Florida and the Gulf Coast.
As of the latest global model projections, the pattern progged would support steady and possibly rapid intensification of this system, with a building upper ridge, the exiting trough providing a polar outflow channel, and the ULL to the east still possibly providing easterly outflow. The GFS has been consistently building a large 200mb anticyclone over the system as it nears the SE coast in 7-10 days. Although it is too early to call for a U.S. landfall, if it does occur from SC south, it could very well do so as a major hurricane. Of course, any land interactions with the Greater Antilles may affect this forecast.
Confidence in the extended track forecast is
LOW, in the intensity forecast,
MEDIUM.
....LAND EFFECTS....Persons in the Lesser Antilles and Puerto Rico should begin preparations for a hurricane in about 4-5 days. Watches/warnings may be necessary for the Islands in about 2-3 days.
Persons in the Greater Antilles (outside of Puerto Rico), and interests in the Western Atlantic and Caribbean should watch this system closely.
Persons along the U.S. southeast coastline, including the northern Gulf Coast, Florida, and the east coast should be aware of this system. However, given the uncertainty of forecasts a week out, it is best to monitor, and not panic, as details are fine-tuned in future days.
HOUR......TIME.........INTENSITY
0 HR......14/0600......30 kt
12 HR.....14/1800......35 kt
24 HR.....15/0600......35 kt
36 HR.....15/1800......40 kt
48 HR.....16/0600......45 kt
60 HR.....16/1800......50 kt
72 HR.....17/0600......60 kt
96 HR.....17/1800......80 kt
120 HR....18/0600......95 kt
