Author: Admin

Tropical Depression Lisa, Tropical Depression Fifteen, Ex-Julia

Post author By Admin
Post date 09/23/2010
No Comments on Tropical Depression Lisa, Tropical Depression Fifteen, Ex-Julia

Tropical Storm Lisa has been downgraded to a Tropical Depression. Although the deep convection has increased and has been better organized, and shear is still low – the dry air around Lisa is still a problem. Within 24-36 hours, Lisa should be in cooler SST’s along with an increase in shear. Lisa is forecast to continue the weakening trend and is forecast to be a post-tropical/remnant low in 120 hours.

ADDENDUM: as of the 5PM advisory from the NHC – Lisa has been upgraded to Tropical Storm Lisa.

visL — Visible Satellite image of Tropical Depression Lisa

A very bullish remnant low Julia has redeveloped but chances of it becoming anything tropical are very slim.

visJ — Visible Satellite image of remnant low Julia

Invest 95L which will probably be Tropical Depression Fifteen as I speak as the first recon report is finding 39 MPH winds at flight level but you have to adjust for the surface winds which is roughly 32 MPH. A special Advisory from the NHC will be issued at 2:00PM. By later today or early tomorrow I am sure Tropical Depression Fifteen will be upgraded to Tropical Storm Matthew. Where this storm will have landfall is a big question mark. Some models still want it to make landfall closer to Honduras or Belize or will the other models want it make landfall somewhere further north in the Yucatan. To complicate things even more there is a possibility a new system might develop east of TD Fifteen and might be a part of the same gyre only to confuse the models even further. For the next 48 hours most do believe a W to WNW track is forecast for TD Fifteen. This a system that needs to be watched by all in the western Caribbean and all those in the Gulf states and especially Florida.

ADDENDUM: As of the 5PM advisory Tropical Depression Fifteen has been upgraded to Tropical Storm Matthew.

95X — Visible Satellite image of TD Fifteen

vis95 — Visible Satellite image of TD Fifteen

12zgfs500mbstreamlinestropical216 — GFS Model 216 Hours

12zeurotropical500mbSLP192 — Euro Model 192 hours

Tags models

Tropical Weather

Tropical Storm Lisa & Invest 95L

Post author By Admin
Post date 09/22/2010
No Comments on Tropical Storm Lisa & Invest 95L

Tropical Storm Lisa way out in the Eastern Atlantic has been somewhat stationary or has drifted southeastward and the low-level center has been exposed. Tropical Storm Lisa is in an area of weak steering currents and is forecast to be drifting for the next 24-48 hours. Lisa is located within a COL which is an area between two high- and two low-pressure centers. After 48 hours a trough is expected to lift up northeastward and another ridge will build westward. This will allow Lisa to slowly move westward. At the moment shear over Lisa is light, but here is a lot of dry air around Lisa which is inhibiting or slowing further intensification. Since the shear is still low, there is the slight possibility of some intensification during the next 48 hours, but any intensification will be slow, if any. After the 48 hours, increasing shear is forecast. The forecast is for Lisa to weaken and there is the possibility it will just become an open wave.

Invest 95L is very disorganized and this will probably be this way until the system heads westward and gets to longitude 75W where there will be less interaction with South American coast. Shear will be light at that time and further development is forecast. There are two camps divided on where the system may head. A few models believe the Invest 95L will head due west and landfall will be near Nicaragua and possibly Honduras and dissipate. The other models like the Euro and the GFS believe 95L will slowdown and head WNW to NW and landfall will be around the Yucatan. With a strong trough coming down from the US this may pick this system up and the implications with that is this may be a strong tropical system that may head anywhere from Texas to the west coast of Florida. This is a system that needs to be watched carefully for the next 7 – 10 days. By then a much better forecast can be made.

12zgfs500mbstreamlinestropical228 — GFS Model 228 hour forecast

00zeurotropical500mbSLP168 — EURO Model 168 hour forecast

Tags COL, euro model, GFS, trough

Tropical Weather

Hurricane Igor, TS Lisa, Invest 95L, PGI47L

Post author By Admin
Post date 09/21/2010
No Comments on Hurricane Igor, TS Lisa, Invest 95L, PGI47L

Hurricane Igor after battering Bermuda with category one hurricane winds has left and now is expected to pass by southeastern NewFoundland. Igor is expected to to become extratropical within 24 hours.

visI — Visible Satellite image of Hurricane Igor

What was Tropical Depression Fourteen has been upgraded to Tropical Storm Lisa as of the 5:00am Advisory this morning by the NHC. Tropical Storm Lisa is headed directly north, but the motion now is in a weak steering current and in 24 hours Lisa will be begin to turn more NW due to a subtropical ridge from the north which will be building in. There is some disagreement within the models as to whether or not Lisa will be turned to the west because of the ridge amplifying or will there be a break in the ridge later on on the forecast period. The vertical shear will be very low for the next 48-72 hours so Lisa will have a chance to strengthen some but the mid level moisture envelope will be drying out and along with some cooler SST’s – strengthening will be limited.

avnL — AVN Satellite image of Tropical Storm Lisa

storm_94 — Models for Tropical Storm Lisa

PGI46L has now been designated as Invest 95L. For the next 24-36 hours, there is the possibility of some dry air wrapping into the system along with some northerly shear. This will limit some development. Beyond the forecast period, the environment will be conducive for development and most models want to keep 95L on a WNW path and eventually having landfall near Nicaragua but a possibility of of a more NW – to NNW and into Cuba/South Florida exists. Therefore, this system does need to be monitored carefully.

vis — Visible Satellite image of Invest 95L

PGI47L which is just off the African coast will probably not be threat in any way and most models believe this sytem will dissipate.

visPGI47 — Visible Satellite image of TS Lisa(left) & PGI47L(center and bottom)

Tags models

Tropical Weather

Hurricanes Igor, Julia & PGI45L, PGI46L, & New PGI47L

Post author By Admin
Post date 09/18/2010
No Comments on Hurricanes Igor, Julia & PGI45L, PGI46L, & New PGI47L

Hurricane Igor, now a category 2 storm is still a large and dangerous hurricane and the center is poised to either make landfall on the island of Bermuda or possibly just to the side of it. Conditions will start to deteriorate sometime tonight and there is the possibility that Igor may intensify and become a category 3 storm before landfall. Igor should start the transitional period of becoming extratropical in about 3 days
.

Tropical Storm Julia which has been assaulted for a day or two and now the strong northerly shear has displaced the deep convection and the low-level center is now exposed. Strong shear from the outflow from Hurricane Igor will to continue to weaken TS Julia and Julia should be a remnant low within 48-72 hours. Eventually, Julia will be absorbed by Hurricane Igor.

What was PGI45L has now been designated as Invest 94L. Environmental conditions are somewhat conducive for gradual development of Invest 94L. At least one model is forecasting that 94L will become a minimal tropical storm in about 5 days.

PGI46L has not developed in any way and there is the possibility it may dissipate. This is something that would still need to be monitored.

A new pre-invest system PGI47L that is still inland in Africa has some decent circulation but there is the chance that there might be dry air which might hinder development even though shear is forecast to be light. The very early forecast for PGI47L once it is in the Atlantic is to head WNW to NW and later NNW.

EUMETSAT_MSG_IR108Color-westernAfrica — IR Eumetsat Satellite image of PGI47L

Tropical Weather

Hurricanes Igor, Julia, Karl & PreInvest PGI45L

Post author By Admin
Post date 09/17/2010
No Comments on Hurricanes Igor, Julia, Karl & PreInvest PGI45L

Hurricane Igor still a threat to Bermuda with winds of 120MPH and is still a Category 3 storm. The inner eyewall of Igor has been broken on the west side, but there is still time for this to regenerate. Igor is an environment of very light shear and warm SST’s. Within 48 hours, Igor will start to feel the effects of cooler waters and some gradual increasing of south to southwesterly shear. The steering flow of a subtropical ridge will keep Igor on a NW – NNW for the next few days. After that forecast period, a series of strong short wave troughs that is located in the Northeastern US will turn Igor NE.

visSWTROUGH — Visible Satellite image of Igor, SW Troughs

Hurricane Julia is slowly decreasing in strength mostly due to an increasing N to NW shear from the large upper-level outflow from Hurricane Igor. The outflow is from top of the storm Igor and rotates clockwise. Continued weakening is forecast in two of the models and the Dynamical models are forecasting dissipation with Julia being absorbed within the circulation of Hurricane Igor.

visoutflow — Visible Satellite image of Igor & Julia with outflow

Dangerous Hurricane Karl is a Category 3 storm. The eye of Karl will be making landfall in Mexico within minutes, if not now. Karl will start to lose strength once the eye has made landfall due to the interaction with land and the high mountains in Mexico. Major flooding will be a problem.

ADDENDUM: The Eye of Hurricane Karl has made landfall just northwest of Veracruz, Mexico – just before 2PM EST.

Pre invest PGI45L is still a very series of thunderstorms associated with a broad low pressure system. Since this is the peak of the hurricane season and this area is in the Cape Verde Islands – this system has to be monitored. I feel any development, if any, will probably head NW and away from any land masses.

avnPGI45 — AVN Satellite image of PGI45L

Tags dynamic models, SST's

Tropical Weather

Hurricane Julia, Hurricane Igor, Invest 92L (now TS Karl), PGI45L

Post author By Admin
Post date 09/14/2010
2 Comments on Hurricane Julia, Hurricane Igor, Invest 92L (now TS Karl), PGI45L

Tropical Storm Julia had been upgraded to Hurricane Julia as of the 5:00am advisory. Julia is in an area with decent SST’s which will allow for some possible further intensification for at least another day or two. After that period, and even though Julia will still be in warm waters, Julia will be feeling the North to Northeasterly shear basically the outflow from Hurricane Igor. Julia is forecast to make a NW heading due to a mid to upper level trough for 24-48 hours, then a sub tropical ridge will cause Julia to return back on a WNW heading for a few days. Beyond that forecast, the models are in agreement on Julia turning NW then NNW as Julia will be along the Western periphery of at previously discussed ridge.

Dangerous Hurricane Igor has finally started to turn toward WNW then will make a turn toward the NW. A weakness in the sub tropical ridge will make Igor turn to the NW and later a NNW. Exactly when these turns will happen in unclear. The U.S. coast should have no problems except possible swells, but Bermuda might be right in Igor’s way. If Igor delays these turns then Bermuda may get the N and NE(strongest) side of the storm. If Igor starts the turns much earlier then Bermuda make get the weaker side of the storm or just possible Tropical Storm force winds. As Igor continues to gain latitude, Igor will begin to be in cooler waters and lose some of his strength – possibly a Category two or high Category one.

vis — Visible Satellite image of Hurricane Igor

avn — AVN Satellite image of Hurricane Igor

Invest 92L today seems the it is finally trying to get something together. Good convection has been present for several hours with the exception in the east and southeast quadrants. It does seem to have some very good, but not excellent cyclonic spin. If 92L can continue to do as well during the rest of the day, 92L may become a tropical depression. Tropical storm is not out of the question but I doubt it as 92L is running out of time before it comes ashore in the Yucatan.

ADDENDUM:
As of the 5:00pm Advisory Invest 92L has been upgraded to Tropical Storm Karl. TS Karl has maximum winds of 40 MPH but is the forecast is expected for Karl to strengthen slightly. Due to land interaction, any increase in strength should be gradual.

vis — Visible Satellite image of TS Karl

PGI45L is a system still over the African continent but will be coming off the coast soon. This a large system and will be monitored for further development.

EUMETSAT_MSG_IR039Color-westernAfrica — Eumetsat Satellite image of PGI45L

Tags Bermuda, SST's

Tropical Weather

Dangerous Hurricane Igor, & Tropical Storm Julia

Post author By Admin
Post date 09/13/2010
No Comments on Dangerous Hurricane Igor, & Tropical Storm Julia

Dangerous Hurricane Igor is now a Category 4 and there is a possibility it may attain Category 5 status. Igor will be going though a ERC, and during that time Igor will weaken slightly but will still be a major hurricane. Unfortunately, no one can tell when the ERC will start. Igor is still on a Westward track but within 24-48 hours, Igor should begin a WNW track due to a long wave trough in the Western Atlantic. There is some disagreement about the trough flattening out in about 3 days, which would bring Igor back on a westward track. This will have to be seen and the forecast discounts the possibility for the moment.

TD Twelve which is in the far Eastern Atlantic has been upgraded and is now Tropical Storm Julia as of the 11PM advisory. TS Julia is still having some moderate Easterly shear but this will be decreasing within 12-18 hours and is forecast to remain light for the next few days. TS Julia will be in very warm SST’s and this will allow steady strengthening so Julia is forecast to attain hurricane status. Thereafter, Julia will start to move into cooler SST’s and also will start in an area of increasing southwesterly shear. Julia will be on a WNW track and then later the storm is forecast to turn NW due to a weakness in a mid-level ridge.

A very large tropical disturbance still inside Africa will be rolling of the coast soon. This is another of the train of waves coming off Africa.

Tags ERC, mid-level ridge, SST's

Tropical Weather

Invest 92L, TS Igor

A wave in the eastern Caribbean, just south-southeast of the Windward Islands has become better organized and has been designated as Invest 92L. Once Invest 92L can move away from the South American coast, 92L will be in a position to strengthen and develop into a tropical cyclone. Most models are in agreement of 92L developing into a hurricane and the flow will be a W to WNW movement. An outlier model (the Canadian CMC) model has it closer to Cuba and possibly Florida. Shear will be very light and the environment will be conducive for further development. The pattern for this system will be for 92L to have landfall toward the Yucatan and if it follows a more WNW-NW flow it will get into the southern GOM and this might be another threat to Texas if it holds together.

vis92 — Visible Satellite image of Invest 92L

Tropical Storm Igor overnight and this morning was being assaulted by moderate easterly shear but as the day progressed the shear began to relax a little and this allowed deep convection within the center to form along with an expanding convective field. There was a weak low to the northeast of Igor but that has been absorbed by Igor. The shear will be relaxing over the next few days along with warm SST’s and a very moist envelope, Igor will be in an environment conducive for steady intensification. Both Statistical and Dynamical models are in agreement for Igor to be a hurricane with 2-3 days. Further intensification is also forecast. There is a mid-level ridge to the north of Igor and this will keep Igor on a W to WNW track along with a gradual increase of forward speed. On day 4 Igor will be be in the Central Atlantic and will be near a trough which should cause Igor to turn toward the NW. Exactly how much of a turn and when has caused the different models to slightly disagree. Some models tend to believe that Igor will follow a path similar to Danielle and therefore the will not affect Bermuda where as other models are taking a slower track and taking a path similar to Earl being between the coast of the SE U.S. and Bermuda.

Tags dynamic models, outlier, SST's, statistical models

Tropical Weather

Tropical Storm Igor

Invest 91L has been upgraded to Tropical Storm status as of the 11AM Advisory. TS Igor came off Africa and was very healthy right from the beginning. Even before the upgrade, Igor had very good convection and the cyclonic turning was getting better each hour. At the present there is some easterly shear over Igor but shear will lift up and in a day or two the shear will be will then be light for a few days. This will allow intensification for days 2-4 and models are in agreement on this scenario. On day 5 shear is forecast to strengthen some and slow down further intensification.

A mid-level ridge in the eastern Atlantic is forecast to strengthen and this will keep TS Igor on a westerly track. This will also increase the forward speed of Igor. After a fews, a trough that is over the central Atlantic may cause the ridge to weaken and this may allow a more NW track. Beyond 5 days, any forecast would be prone to major error.

Tags models, shear

Tropical Weather

Invest 91L and ex-Gaston

Ex-Gaston who seems to have been around forever has lost most of it’s cyclonic spin is now just under Puerto Rico and the last satellite imagery of Gaston was showing the best convection it has had in a long time. The only problem with Gaston is that he will soon be headed right into Hispaniola. The mountain range there can be very high and has many a time either disrupted a storm or killed it. If Gaston only clips the mountains, Gaston may survive and possibly may develop while in the the western Caribbean.

A tropical wave that has just come off Africa has been designated as Invest 91L. This tropical wave does have some decent cyclonic turning but there is some wind shear of about 20-30 knots just north and northwest of it. The shear will relax within the next 24-48 hours. Some on the models have just been initialized thus there may be errors or bias within them. Several models are suggesting this will be our next tropical cyclone.

Tags models