Tropical storm Jerry personal forecast

[Matt-hurricanewatcher]

Subtropical depression 11
2am pst/5am est
9-23-2007
Forecast 1#

...Subtropical system becoming less organized over the Northern Atlantic...Expected to slowly move eastward and become more organized.


...Earlier this afternoon and into the evening, the system was looking very well developed. In fact it developed minus 70 degree convection over its LLC, windsat data shown 40-45 knot winds. With quickscat supporting some 30-35 knot winds. Sab t shown 2.5=35 knots. There is little question that this system was at least a subtropical storm. But as of this morning, it has lossed most of its core convection. With only a strong band of convection south of the cyclone. A excluded front is on its northwestern quad, in which is what the northern band is. This frontal boundry should slowly push it eastward over the next few days. The latest satellite shows the convection trying to wrap around the core, so the system could be very close to a subtropical storm again.

The 300z shear maps shown very little shear over the cyclone. In which case the enviroment is very favorable...The system is centered with in a upper level system...Which go's well up into the 200-300 millibar level. In which is allowing for the low shear. But slow development can only be expected with these kinds of systems. This system also has formed a hole with in the subtropical flow above 700 millibars over the last day. In which allowed for a more northeastward track,,,while the flow is mostly south to north(As of 300z) at upper levels. It it likely the frontal system should move the system slowly eastward. Some of the older models also forecasted a southeastward track after 72-96 hour time frame. While the trough that is forming this whole is starting to lift out, and the high pressure is starting to form. Which is the reason this system is moving just slightly southward of east. There is also a trough moving out of eastern Canada...This system when it catchs this, will likely force this system northeastward or northward up its base. What is talked about above with a possible southeast movement is because some models do show that the high could build and stay in place over this system...While it is likely that our trough could catch it in 3-4 days. In which is what we will forecast right now. Also the hurricane Bams,bamd,bamm,lbar all show this. We are east of the sweet, because we believe that the ridge will build in for the next 2 days. Followed by the trough catching the system....

Low level shear should be expected through out the next 48 horus. Shear around 5-8 knots...After that time more upper level shear and the system should be moving over cooler waters, should stop any more development. We expect the convection to start forming over the core later today. With a subtropical storm once again with in 12 hours. We peak the system at 40 knots after 36 hours.,,,Followed by extratropical as it moves over colder waters after 60 hours.

0 36.1/46.2 30 knots
6 36.2/45.7 35 knots
12 36.4/45.1 35 knots
24 36.9/43.3 40 knots
36 37.5/42.4 40 knots
48 38.6/40.5 35 knots
72 45.5/37.4 30 knots extratropical



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.

[Matt-hurricanewatcher]

Tropical storm Jerry
Forecast 2#
9-23-2007
3:30pm pst/6:30pm est

...Jerry becomes a warm core system, while slowly moving northward...

The LLC has become more defined and convection has started to form from a warm core source over the last 6 hours. Even so the convection is north and northeast of the LLC. Data shows that the system has developed a warm core...So it has been upgraded to tropical. Quickcat data shown 35-40 knot winds...Which supports a soild tropical storm.

The shear over the system is 10-12 knots currently, which should not allow the system to become stacked. But is light enough for some slow strengthing over the next 12 hours. We will forecast the system to get to 45 knots by 12-24 hours. Afterwards cold water and increasing shear from the base of the trough should turn the system extratropical. This trough is already digging off Canada's east coast...In is at least 20 degrees away from the cyclone,,,A northward motion has already started...With the ridge to the north very weak,,,So a northward track should be expected with the cyclone...Followed with a more northeastward track after 24 hours. The hurricane models are all north followed by northeastward...In has been so far the last 3-4 runs.

0 37.0/46.4 40 knots
6 37.4/46.0 40 knots
12 38.2/45.5 45 knots
24 39.6/45.1 45 knots
36 41.5/43.2 40 knots becoming extratropical
48 48.5/39.5 35 knots extratropical



These forecast are made to test my skill of tropical cyclone forecasting. These our very unoffical. Only to enjoy and to go to for another option. please read the thing under the other forecast.