Tropical Storm Ida a major flood threat for Nicaragua and Honduras
Tropical Storm Ida has arrived, the ninth named storm of the 2009 Atlantic hurricane season. Visible satellite loops show that Ida continues to steadily organize, with surface spiral banding and upper-level outflow now obvious over the northern portion of the storm. An Air Force hurricane hunter aircraft is in the storm, and found a large area of surface winds in the 45 - 50 mph range, with a smaller area of 60 mph winds, prompting NHC to upgrade the storm.
Figure 1. Afternoon satellite image of Ida.
Ida is currently under low wind shear, 5 - 10 knots, and shear is expected to remain in the low to moderate range in the Western Caribbean for the remainder of the week. Sea Surface Temperatures (SSTs) are 29°C and the Tropical Cyclone Heat Potential is about 40 kJ/cm^2, which is enough energy for a hurricane to form, if the center remains over water long enough. The Western Caribbean is plenty moist, and dry air is not an issue for Ida. Ida is currently too small to be affected by tropical disturbance (Invest 96E) 500 miles to its west, over the Eastern Pacific.
The forecast for Ida
The 1 - 3 day forecast for Ida has come into better focus now that the storm has formed, and models have come into better agreement. The current west to northwesterly motion of Ida should carry it inland over northeastern Nicaragua early Thursday morning. Ida is too small to tap the Pacific as a source of moisture, and it is just the northeastern portions of Nicaragua and Honduras that need to be concerned with heavy rains and mudslides. With Ida expected to spend a full two days over land, rainfall amounts of 10 - 15 inches over northeastern Nicaragua and Honduras will likely make Ida the deadliest storm of the 2009 Atlantic hurricane season. There is a medium chance (30 - 50%) that Ida will dissipate while over land. If Ida survives the crossing and emerges into the Western Caribbean on Saturday, low to moderate wind shear and warm waters await it, and strengthening is likely. An extratropical storm is forecast by GFS and ECMWF models to form in the Gulf of Mexico's Bay of Campeche on Saturday, and the counter-clockwise flow of air around this storm may propel Ida northwards into the Gulf of Mexico by Monday. However, both of these models show a high pressure ridge building in and forcing Ida southwards, back into the Caribbean, by the middle of next week. The long term fate of Ida, should it survive the crossing of Nicaragua and Honduras, remains murky.
Jeff Masters
Reader Comments
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No readings there above 10 knots...(at least none that are collected and displayed on that graphic)
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)
12Z Dynamic Models (More sophisticated models)
Surely agree with you there, this one's got a mean streak.
Posted by: JeffMasters, 9:46 AM EDT on October 23, 2009
There's only good news to report in the tropics today. The tropical disturbance in the Western Caribbean has weakened and shrunk, and has little prospect of developing into a tropical depression for at least the next three days. None of the computer models is forecasting tropical cyclone development in the Atlantic over the next seven days. Hurricane season is not over yet, though, and we will still need to keep a watchful eye on the Western Caribbean. Wind shear is expected to remain low there for most of the next two weeks, according to recent forecast runs of the GFS model. I expect I'll be talking about "Invest 95L" in the Western Caribbean sometime in the next two weeks.
Jeff Masters
Updated: 10:10 AM EDT on October 19, 2009
A Western Caribbean tropical storm coming?
In the Atlantic, an area of disturbed weather has developed in the Western Caribbean from Costa Rica to the Cayman Islands, in association with the remains of a cold front, a tropical wave, and a broad 1010 mb low pressure region that has developed over the extreme southwestern Caribbean off the coast of Costa Rica. Last night's QuikSCAT pass showed that the low off the coast of Costa Rica had a broad and disorganized surface circulation. The thunderstorm activity associated with this large and complicated area of disturbed weather is disorganized and under 10 - 30 knots of wind shear, and any development over the next three days will be slow. However, by Friday, wind shear over the Western Caribbean is expected to drop significantly, and development of a tropical depression in the Western Caribbean becomes a more real possibility. Numerous runs over the past few days of all of our reliable global forecast models have shown a tropical depression developing in the Western Caribbean by early next week. The timing, location, and track of such a such a storm are all pretty hazy, but I think there is a 60% chance of a named storm forming in the Western Caribbean sometime in the next 10 days. The regions most likely to be affected by such a storm would be Honduras, Nicaragua, and the Cayman Islands, and it is possible that such a storm may stay trapped in the Western Caribbean for many days (as predicted by the GFS model). Alternatively, the storm could move steadily northwards after formation, affecting western Cuba, the Cayman Islands, Jamaica, South Florida, and the Bahamas. This is the solution preferred by the ECMWF model. In either case, a long period of disturbed weather is likely for the Western Caribbean. Heavy rains will affect northeast Honduras, eastern Nicaragua, and the Cayman Islands this week, and could spread to adjacent countries as the area of disturbed weather evolves.
Not everything van be quantified,..this isnt a courtroom,..there arent many sidebars neither,..LOL
Question, anybody -- Are we allowed to bet, those who lose donate to Portlight? Or is that considered on-line betting and against the law (and shame on me). I call dibs on the ECMWF's being closest in what, a week? $20 to Portlight if I lose and a big "L" on my forehead (counting on beginner's luck). Please don't flag, I'm just asking. Iggy button is there for you to use. :)
This storm might never survive, and people have to consider that
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