Monday, July 04, 2005

Tropical Depression Four ...FOURTH TROPICAL DEPRESSION OF THE SEASON DEVELOPS OVER THE SOUTHEASTERN CARIBBEAN SEA... At 11 PM EDT the center of newly formed Tropical Depression Four was near 12.5 North 63.1 West, 100 miles west-southwest of Grenada.  Movement is to the west-northwest at 17 mph.  Maximum winds are set at 30  mph and pressure is 1010 millibars (29.83"). Tropical Depression Four Advisory Number 1 The initial intensity is based on a combination of an observation from the island of St Lucia and estimates based on satellite imagery.  The models agree strongly through the first 72 hours of the forecast (bringing the system to southeast Cuba) and diverge therafter.  The system looks very nice on satellite.  Intensity forecast is a bit less agressive than what their models are going with... the official forecast brings the system to hurricane strength in three days. Tropical Depression Four Discussion Number 1 As I posted earlier the 12Z model runs more or less concurred on this system affecting Florida in some fashion.  Their solutions remain dynamic, however.  The 18Z run of the GFS model shifted to the storm to the west... instead of bringing it to the Keys on a northbound path, it slid the storm around Key West on more of a northwestern trajectory.    I'll probably stay up tonight and watch the model outputs as they come in with commentary to follow. 2005 Hurricane Season, Weather comment []11:19:34 PM   trackback []

Tropical Depression Three Update 050300Z At 10 PM CDT the center of Tropical Depression Three was located at 23.9 North 89.7 West, 360 miles south of the Mississippi River.  Movement is to the north-northwest at 13 miles per hour.  Maximum sustained winds and minimum central pressure are unchanged at 35 mph and 1009 milllibars, respectively. Tropical Depression Three Advisory Number 6 While the storm's appearance has improved at the edges, the center of the storm doesn't show any signs of improvement in the past few hours.  Forecast track is shifted to the right slightly.  Despite low shear and warm sea surface temperatures their is not much intensification forecast due to the presence of dry air to the west of the depression. Tropical Depression Three Discussion Number 6 I've no comments to make until we see what the hurricane hunters find.  Right now I am skeptical of the strength of this system as it seems to be based only on a couple of scattered observations.  The $64 question is whether the recon team finds a closed center of circulation.  Right now there is nothing to indicate that their is one. 2005 Hurricane Season, Weather comment []11:05:31 PM   trackback []

Coming soon to a theater near you... Tropical Depression Four The FNMOC tropical cyclone page indicates that the system I posted about this afternoon is internally being referred to as Tropical Depression Four (and will be classified as such by the National Hurricane Center at 11 PM EDT). 2005 Hurricane Season, Weather comment []9:15:49 PM   trackback []

Tropical Depression Three Update 050000Z At 7 PM CDT the center of Tropical Depression Three was at 23.3N 89.5W, 395 miles south of the Mississippi River and moving to the north-northwest at 13 mph.  Winds are 35 mph and pressure is down to 1009 mb (29.80").  Tropical Depression Three Intermediate Advisory 5A At about the time the last advisory package went out, the system's appearance on satellite improved significantly and it looked its best since going ashore last night.  Tropical Storm watches remain up for Louisana and probably will be upgraded to warnings in the next advisory package (at 10 PM CDT). 2005 Hurricane Season, Weather comment []8:05:49 PM   trackback []

Tropical Depression Three Update 042100Z At 4 PM CDT the poorly defined center of Tropical Depression Three was near 22.8N 89.2W, 435 miles south of the Mississippi River, moving to the north-northwest at 12 mph. Maximum sustained winds are 35 mph and minimum central pressure is 1010 millibars (29.83"). A Tropical Storm Watch is in place for the Louisiana coast from the mouth of the Missippi River to Sabine Pass. Tropical Depression Three Advisory Number Five Hurricane hunters were unable to find a closed center of low pressure. The forecaster is assuming that the center is being reformed, so the classification as a tropical depression is being kept for the time being. The system's northward reformation gives it less favorable conditions for development.   Tropical Depression Three Discussion Number Five So, by the book, this isn't a tropical depression (it doesn't have a closed center of low pressure, but rather an open trough). Unless conditions change somewhat sharply in the next few hours, this could be the last advisory on the system. At this moment, the propensity of the models yesterday to not develop this system are being justified, much to the surprise of nearly everyone. 2005 Hurricane Season, Weather comment []4:59:33 PM   trackback []

Tropics Watch 0704 Another day, another system of interest.  This is how the afternoon Tropical Weather Discussion describes it: A STRONG TROPICAL WAVE LIES ACROSS THE LESSER ANTILLES WITH A WEAK 1012 MB LOW PRESSURE CENTER IN THE SOUTHERN WINDWARD ISLANDS W 15-20 KT. PRESSURES CONTINUE TO FALL IN THE AREA WITH SLY WINDS NOTED IN THE WINDWARDS S OF GRENADA AND ELY WINDS AT BARBADOS. THERE ARE BANDING FEATURES ESPECIALLY IN THE E SEMICIRCLE WITH ANTICYCLONIC FLOW ALOFT PROVIDING AN ENVIRONMENT CONDUCIVE TO FURTHER DEVELOPMENT. SCATTERED SHOWERS AND A FEW TSTMS ARE S OF 15N BETWEEN 56W-65W WITH WIDELY SCATTERED MODERATE CONVECTION FROM 15N-19N BETWEEN 54W-60W APPROACHING THE LEEWARD ISLAND. COMPUTER MODELS SUGGEST THIS WAVE HAS THE POTENTIAL TO EVENTUALLY DEVELOP INTO A TROPICAL CYCLONE AS WIND SHEAR IS FORECAST TO REMAIN WEAK DURING ITS TREKS WESTWARD THRU THE CARIBBEAN. REGARDLESS OF DEVELOPMENT... HEAVY RAIN IS LIKELY ACROSS THE LESSER ANTILLES ESPECIALLY IN THE WINDWARD ISLANDS FOR THE NEXT COUPLE DAYS WITH INCREASED MOISTURE NOTED S OF 15N W OF 50W. The computer models have been suggesting that this system is Florida bound.  However, they are not doing so in a manner consistent with each other or themselves.  For example,the 00Z run of the Canadian model brought they system to the Big Bend of Florida in six days while the 12Z run has a rather different idea, bringing the system ashore in the Keys in three and a half days (i.e. Friday night).  The GFS model and European models have different ideas on timing and placement; both put it on the southeast coast, the GFS on Saturday morning, the European on Sunday.   While the situation is far from clear at the moment, this system should be watched carefully by residents of south Florida as it may be upon them sooner than one would think. 2005 Hurricane Season, Weather comment []3:24:36 PM   trackback []

Tropical Depression Three Update 041400Z It was a rough night for TD Three. The system is down to 30 mph winds and pressure is up to 1010 millibars.  It appears that a new center is forming north of the Yucatan Peninsula.  A hurricane hunter is currently on the scene.  Will report back on this system as data comes back from the recon plane. 2005 Hurricane Season, Weather comment []3:00:17 PM   trackback []