1500 UTC 9/25/2003 TROPICAL DEPRESSION 15 FORECAST DISCUSSION #1
This is an independent product and not from the National Hurricane Center
Tropical Depression 15 has formed from an upper low. The motion is to the north and most guidance suggests a track mainly to the north over the next few days. All guidance suggests a slight west of north track, followed by a track mainly to the north over the next few days, in the general direction of the Canadian Maritimes. This is due to the large, approaching trough to its west.
Initial intensity is 30KT. Global models suggest slight intensification before merging with the frontal system. However, SHIPS suggests more intensification to near hurricane intensity. GFDL suggests little intensification. Due to the fact that the center is exposed, we will go with the slow intensification scenario, though will bring the system to 35KT in 12 hours, followed by only slow intensification afterwards. Guidance suggests a merger in 72 to 96 hours. With the trough approaching, I will follow this scenario as well.
Initial: 29.5N 61.0W 30KT
12 Hour: 31.0N 61.1W 35KT
24 Hour: 32.7N 61.5W 35KT
36 Hour: 34.5N 62.0W 40KT
48 Hour: 36.5N 62.5W 40KT
72 Hour: 40.0N 62.5W 40KT
USE WITH EXTREME CAUTION AS FOLLOWING IS SUBJECT TO LARGE ERROR
96 Hour: Merged with Trough
Next Discussion: 0300 UTC
Forecaster: Ortt
0300 UTC 9/26/2003 TROPICAL STORM JUAN FORECAST #2
This is an independent product and not from the National Hurricane Center
Tropical Depression 15 has now been upgraded to Tropical Storm Juan. Juan is located near 31.3N 62.0W, approximately 170 miles ESE of Bermuda. The motion is to the north/northwest near 8 mph. All guidance suggests a slight west of north track, followed by a track mainly to the north over the next few days, in the general direction of the Canadian Maritimes. This is due to the large, approaching trough to its west.
Initial intensity is 50KT. Juan appears much better organized than earlier today, and is currently in a favorable environment for further strenghtening. This forecast brings Juan to hurricane strength in about 24 hours. Juan will pass very close to Bermuda within 24 hours; condititons are expected to deteoriate over this island as rain and tropical storm force winds are approaching from the east/southeast.
Initial: 31.3N 62.0W 50KT
12 Hour: 32.8N 62.4W 55KT
24 Hour: 34.5N 62.8W 60KT
36 Hour: 36.5N 63.1W 65KT
48 Hour: 38.5N 63.5W 65KT
72 Hour: 43.0N 63.5W 60KT
USE WITH EXTREME CAUTION AS FOLLOWING IS SUBJECT TO LARGE ERROR
96 Hour: 49.0N 62.0W 45KT
120 Hour: Extra-Tropical
Next Discussion: 1500 UTC
Forecaster: Cangialosi
1500 UTC 9/26/2003 TROPICAL STORM JUAN FORECAST #3
This is an independent product and not from the National Hurricane Center
Tropical Storm Juan continues to become better organized and strenghten. Juan is located near 32.3N 62.2W, approximately 150 miles ESE of Bermuda. The motion is just west of north near 9 mph. All guidance suggests a slight west of north track,
followed by a track mainly to the north over the next few days, in the general direction of the Canadian Maritimes. This is due to the large, approaching trough to its west. The CMC, GFS, and GFDL are all in close agreement on Juan's track.
Initial intensity is set at 60KT. Juan appears much better organized than yesterday, and is currently in a favorable environment for further strenghtening. A great deal of deep convection is noted on the IR satellite. This forecast brings Juan to
hurricane strength within 24 hours. Juan will pass east of Bermuda; but condititons are expected to deteoriate over this island as rain and strong winds are approaching from the east/southeast. Juan is expected to make landfall in the Canadian
Martime within 3 days.
Initial: 32.3N 62.2W 60KT
12 Hour: 33.8N 62.6W 60KT
24 Hour: 35.5N 63.1W 65KT
36 Hour: 37.5N 63.5W 70KT
48 Hour: 40.0N 64.0W 65KT
72 Hour: 47.0N 64.0W 50KT (inland)
USE WITH EXTREME CAUTION AS FOLLOWING IS SUBJECT TO LARGE ERROR
96 Hour: Extra-Tropical Merged with trough
Next Discussion: 0300 UTC
Forecaster: Cangialosi
0300 UTC 9/27/2003 HURRICANE JUAN FORECAST DISCUSSION #4
This is an independent product and not from the National Hurricane Center
Juan has continued to move nearly due north throughout the day. Water vapor imagery, along with 0Z guidance indicates that the system should be steered to the north or NNW by the approaching trough. Therefore, this track is being shifted slightly to the right of the previous forecast, though landfall is still expected in Nova Scotia.
Initial intensity is being raised slightly to 70KT based upon the increase in the cold cloud top coverage. There seems to be some room for additional intensification before interacting with the cooler waters, though this may be offset as many systems are through baroclinic means.
Initial: 33.9N 61.9W 70KT
12 Hour: 35.5N 62.0W 75KT
24 Hour: 37.1N 62.3W 75KT
36 Hour: 39.1N 62.3W 70KT
48 Hour: 41.5N 62.3W 70KT
72 Hour: 46.5N 61.5W 50KT (inland)
USE WITH EXTREME CAUTION AS FOLLOWING IS SUBJECT TO LARGE ERROR
96 Hour: Merged with Front
Next Discussion: 1500 UTC
Forecaster: Ortt
1500 UTC 9/27/2003 HURRICANE JUAN FORECAST DISCUSSION #5
This is an independent product and not from the National Hurricane Center
Juan has continued to move nearly due north throughout the night. Water vapor imagery, along with 0Z guidance indicates that the system should be steered to the north or NNW by the approaching trough. Therefore, this track closely follows the
previous forecast with landfall is still expected in Nova Scotia.
Initial intensity is being raised slightly to 75KT based upon the increase in the cold cloud top coverage. There seems little room for additional intensification before interacting with the cooler waters, though this may be offset as many systems are
through baroclinic means.
Initial: 35.5N 62.5W 75KT
12 Hour: 37.1N 62.9W 80KT
24 Hour: 39.5N 63.3W 75KT
36 Hour: 43.5N 63.4W 70KT
48 Hour: 49.0N 62.3W 65KT (inland)
72 Hour: Extra-Tropical (inland)
USE WITH EXTREME CAUTION AS FOLLOWING IS SUBJECT TO LARGE ERROR
96 Hour: Merged with Front
Next Discussion: 0300 UTC
Forecaster: Cangialosi
0300 UTC 9/28/2003 HURRICANE JUAN FORECAST DISCUSSION #6
This is an independent product and not from the National Hurricane center or Canadian Hurricane Center
Juan has continued to move to the west of due north. Therefore, it appears as if the western end of Nova Scotia will be the landfall zone. The reason for this west of north track is the ridge of high pressure to the east of Juan and the fact that the trough to the west has been moving at a very slow face. The thinking is that the hurricane will turn before reaching the longitude of Maine; however, the system may pass close enough to bring some wind and rain to the area.
Initial intensity is being raised slightly to 95KT, based upon the eye becoming better defined. A slight weakening is being forecast before landfall; however, category 2 intensity will be retained until the eye crosses the coast as the system may be able to maintain most of its intensity via the energy from the approaching trough.
Initial: 36.7N 63.9W 95KT
12 Hour: 39.0N 65.0W 90KT
24 Hour: 44.0N 65.0W 70KT (inland)
36 Hour: Extra-Tropical
Next Discussion: 1500 UTC
Forecaster: Ortt
1500 UTC 9/28/2003 HURRICANE JUAN FORECAST DISCUSSION #7
This is an independent product and not from the National Hurricane Center or Canadian Hurricane Center
Juan is accelerating northward as expected. Water Vapor imagery indicates that the steering flow ahead of the trough is out of the south; thus, Juan is expected to cross Nova Scotia and not make landfall in Maine, though some wind and rain appears likely. This forecast track is right of CMC, which indicates a Maine landfall.
Initial intensity is being lowered to 90KT and some slow weakening is expected until landfall as the system moves over cooler waters.
Initial: 39.4N 64.1W 90KT
12 Hour: 46.0N 64.5W 60KT (inland)
24 Hour: Extra-Tropical
Next Discussion: 0300 UTC
Forecaster: Ortt
0300 UTC 9/29/2003 HURRICANE JUAN FORECAST DISCUSSION #8
This is an independent product and not from the National Hurricane Center or Canadian Hurricane Center
Juan began its acceleration about an hour or so later than it was expected; thus, a rather large 12 hour forecast error has resulted. The heading was corect though, so there is no change in the landfall zone, which is very near Halifax. Since the system has been caputed by the approaching frontal system, the forecast will continue to reflect the previous trend and go with extra-tropical transition in 12 hours; therefore, no forecast points are given beyond the initial position.
Initial: 44.2N 64.0W 80KT
12 Hour:Extra-Tropical
24 Hour: Absorbed
This is the final forecast planned on Juan
Forecaster: Ortt