CybrTeddy's tropical weather blog

Tropical trouble in the Caribbean 5/31/11

By: CybrTeddy, 8:33 PM GMT on May 31, 2011

Good afternoon everyone and welcome for my blog update for Tuesday May 31st, 2011. I haven't posted a blog entry the last few days because nothing had really changed with our disturbance until today. As the models predicted the area of interest in the SW Caribbean has become better organized with near -80C cloud tops appearing in the system. Surface pressures are beginning to drop around the system, some indications of around 1006.8 in some places but we're missing one crucial thing - a surface circulation. At this time, all the rotation appears to only reflect in the mid-levels of the atmosphere instead of actually on the surface. The most recent ASCAT pass confirms this. There appears to be only a windshift and the surface and not really a circulation. Shear remains heavy over the system aswell with 20-40 knots right over the system. Its going to be a difficult one but this does have a chance to develop.


(system in the SW Caribbean 19:45 UTC - likely to be 93L soon)

As of the most recent runs here's what the models are indicating.

12z GFS indicates this system will remain quasi-stationary in the SW Caribbean through 114 hours, and by 172 hours the system begins to lift north out of the SW Caribbean to near Jamaica as a Tropical Storm ''Arlene'', ''Arlene'' gradually begins to spin out and becomes an open trough by 192 hours off Florida.

12z UKMET is similar in track to the GFS though features a stronger system, meanders in the SW Caribbean and begins to finally head northward and begins to strengthen to become ''Arlene'' by 120 hours.

12z CMC/GGEM has this system gradually developing but really close to the coast to the point of near dissipation but by Friday has it beginning to develop and just off the coast of Central America into ''Arlene'' with a 1001 mb low by 144 hours.

12z ECMWF has this system meandering in the SW Caribbean, gradually organizing and becomes ''Arlene'' by the end of the run with a 1001 mb low in the Caribbean.

12z NOGAPS is similar to the UKMET/ECWMF/GFS solutions - ''Arlene'' just south of Jamaica in 144 hours.

Basically in conclusion the models seem fairly in agreement that this system will attempt to become our first named storm of the season, Arlene, by the weekend and might actually have a chance to become a 50-60 mph Tropical Storm in the Caribbean before obviously being sheared to death in the Gulf. I highly, HIGHLY doubt that this system will make a run at hurricane strength and I think this system will be just a weak Tropical Storm with much beneficial rains for the Caribbean and maybe even Florida. I'd give this system in the SW Caribbean based on the current conditions and the strong model support a 30% chance of developing into a tropical cyclone.
(current shear)

Keep watching!

CybrTed

Mischief in the Caribbean appearing more likely 5/28/11

By: CybrTeddy, 3:45 PM GMT on May 28, 2011

Good morning everyone and welcome to my update for Saturday May 28th, 2011. Now time to dive into business. The tropics are starting to respond to the relative start of hurricane season, which officially begins on June 1st. All of the major forecasting models are all saying at least an area of low pressure will begin to develop in the Caribbean by June 1st.


Currently conditions in the Caribbean aren't very good for cyclone development however that appears to be about to change. A well established anti-cyclone is giving this area of interesting in the SW Caribbean decent ventilation, or breathing room, to begin to grow. As long as this anti-cyclone remains in place it is possible that this could be what the models are all indicating could become our first system of the year.


Summary of the model runs this morning as of each recent runs.

00z CMC is the most aggressive from what I can see. System begins to take shape by 72 hrs and develops into a tropical depression by the 1st of June. System is slow moving towards the north and gradually strengthens. By 144 hours the CMC has ''Arlene'' just to the south of Cuba and a strengthening ''Adrian'' in the EPAC.

06z GFS isn't very impressive. By Tuesday it shows a week area of low pressure ~1007 mb in the SW Caribbean moving rather stationary. GFS doesn't show an organized cyclone but it does show a large area of low pressures across the Caribbean through the 4th of June. This could prelude to cyclone development.

00z UKMET is only slightly stronger than the GFS, by the end of the run at 122 hrs the system is stationary with a 1007 mb low in the SW Caribbean.

00z ECMWF is sort of a mix between the CMC and GFS runs, an area of low pressure in the SW Caribbean by the 1st of June that's not impressive, however it keeps its identity as a single area of low pressure by the 4th of June just south of Jamaica and virtually dies by the next day.

00z NOGAPS is similar to the CMC. By the 1st of June there is an area of low pressure in the SW Caribbean that is gradually moving northward and by 144 hours ''Arlene'' is just to the west of Jamaica with an ''Adrian'' in the EPAC.

To conclude, all models indicate an area of low pressure will probably develop by the first day of Hurricane season. The NOGAPS and CMC indicate this area of low pressure will be able to beat off the high shear with the anti-cyclone and be drawn northward as a tropical storm. The as expected more conservative ECMWF, UKMET, and GFS indicate this area of low pressure will remain that with the GFS being the least impressive - only showing a broad area of lower pressures in the Caribbean. That could however if the case could lead to development in the Caribbean the 2nd week of June as well. Right now, I'd say its fairly possible we could see an invest in the Caribbean by 24-36 hours. If we do see a TD, it might happen as early as late-Wednesday. The models are showing the much-needed consistency but what we need to see also is the models showing more intensity to this system to be truly serious about ''Arlene'' by next week.

CybrTed

An early start to hurricane season? 5/27/11

By: CybrTeddy, 8:17 PM GMT on May 27, 2011

Good afternoon and welcome to my update for Friday (Happy Memorial weekend) May 27th, 2011. Today I want to focus on the growing chances of tropical development in the Caribbean. Now yesterday I made mention that all of the global models are indicating this possibility - they are still. Consistency is key, and we're starting to see that consistency for a system that could begin to develop a system by Wednesday, June 1st in the SW Caribbean. This is all indicated by the ECMWF, GFS, GGEM/CMC, UKMET, and NOGAPS though at this time all of them just show lower pressures from 1005 - 1009 mb. All of them agree that relative motion will be nearly stationary over the SW Caribbean, being drawn up northward some.


(GGEM/CMC is the most aggressive with this system)


(where to watch over the coming days)

Now, is this scenario of a 'June 1st surprise' have a good chance of actually occurring? I'd say maybe, given this is short range and last year as we witnessed when the models are consistently showing something on each run, unanimously, its very likely to occur. Now, where would this system go you ask? Generally, storms that form in the SW Caribbean head northward under the influence of late-season troughs that create weaknesses to draw it northwards. It is in my opinion that this 'Arlene' would probably take a similar path to its predecessor Arlene in 2005, Alberto in 2006, or maybe even Barry in 2007. This is an absolutely classic setup for a system in the first week of June, where you have ridging and troughs allowing a system to be drawn northward towards generally Florida. Florida is in much need right of rain, so this will defiantly benefit them.

As always, intensity is equally hard to predict as track. We're probably in all likelihood in the event this even develops not going to be looking at anymore than a 50 mph sheared Tropical Storm heading north-eastward to the Central GOMEX. After that its anyone's guess, it could suddenly pull an Alberto if shears good and nearly become a hurricane, or it could be like Barry and be a sheared system. Needless to say, I'll watch the situation carefully.

Finally, I wanted to tell you all in the US and everyone who is in harms way this year to please be ready for anything this season. I don't normally post gut feelings, but given the amount of extreme and serious natural disasters all across the world I think its warranted, but I have a really bad feeling about this season. The setup is similar to seasons like 2008 which featured destructive and deadly storms. Don't rush to the store right before a storm hits, I know from experience from 2003 that's a bad idea - generators run out quick and bottled water is essential. Be prepared, get ready and let the games begin.

CybrTed

Hurricane season about to begin - daily updates to resume. 5/26/11

By: CybrTeddy, 8:27 PM GMT on May 26, 2011

Good afternoon and welcome back everyone to my tropical blog! Like last season, I will be posting daily updates unless I have a personal emergency or I am on travel and will only post if a serious development that has potential to hurt people close to home. Anyways, its great to be back and providing updates for those who enjoy my blog! Periodically this year I have been posting updates and made my points about this season upcoming and they still hold true. Sea Surface Temperatures (SSTs) remain well above normal in the Gulf of Mexico (GOMEX) that and TCHP have skyrocketed to well above levels in the Caribbean, but do not appear to be as warm as they where last year out towards Africa. This in my opinion will mean 5 things.

1) Tropical Storms and Hurricanes will sprout closer to home this year, increasing the chance of landfalls.

2) Tropical Cyclones will be more active earlier this season, where as the last two seasons haven't been real active (though 2010 had the infamous Hurricane Alex in late-June)

3) Trough splits will be more common this year.

4) We will see less Cape Verde insanity unlike last year.

*5) Major factor - storms might pop up like Humberto and strike overnight. This is especially concerning in the GOMEX this year given that SST's are WAY higher in the GOMEX than they where in 2007. It is also interesting to note that since Humberto, every season has seen a storm go from TD to Hurricane in ~8 hours or so. (Lorenzo also in 2007, Gustav in 2008, Ida in 2009, Paula in 2010)

On that note I would like to point out that we have our first real signs of tropical mischief appearing on the models. A few days ago we had short-lived invest 92L which was very similar to 91L in terms of its fate - it was sheared like a sheep and casted out to sea. However, I'm starting to think we might see our first named storm next week. The GFS shows a disturbance in the Caribbean heading up towards the GOMEX in 162 hours (fig 1). The CMC is also showing lower pressures in the SW Caribbean (fig 2). NOGAPS is also showing this (fig 3) and the ECMWF (fig 4).

(fig 1 - GFS 12z)

(fig 2 - CMC 12z)

(fig 3 - NOGAPS 12z)

(fig 4 - ECMWF 12z)

This is a classic setup for an early-June system. This would be drawn north and probably head into the GOMEX, and would be a sheered system similar to Alberto and Barry from previous years. As always, we need to watch for model consistency and model support as this is fairly long range though its the first time the models are showing consistency on lower pressures in the SW Caribbean, maybe even a depression.

Game on.

CybrTed



The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.