Tuesday, June 28, 2005

Tropical Storm Bret Update 0300Z At 10 PM CDT, the center of Tropical Storm Bret was located near 20.0N 95.9W, 60 miles north-northeast of Veracruz, Mexico. Winds are 40 mph and pressure is 1005 mb. Movement is to the west-northwest at nearly 5 mph. Tropical Storm Bret Advisory Number Two The trend of development seems to have stopped for the moment. Storms as small as this one tend to be fragile and vulnerable to oscillations in strength (sometimes wild). Movement appeared to have stopped for a little bit, but appears to have resumed again. Predicting exact timing and location of landfall is problematic. Tropical Storm Bret Discussion Number Two As I mentioned earlier, the global models weren't really picking this up in their 18Z runs. As the 00Z runs are only just now starting, that means that the forecasters had virtually nothing to work with in terms of dynamical guidance. A rare situation in this day and age. (Slightly) LATER Another challenge for the forecasters is that the situation is a bit different than it would be if Bret were further north (hugging the Texas coast). The coast there is relatively richly filled with observation stations, both official and unofficial. Also, there are a slew of buoys offshore. This would give forecasters an extra tool in gauging how the storm is moving. The distribution of observation stations in Mexico is sparser (and fully featured stations are rarer yet). The only offshore buoy in the region is not of use at this time (it was marginally useful this morning). Because of this and the complications with models, the forecasters are really going to have to bank on satellite observations; not the best of situations. 2005 Hurricane Season, Weather comment []10:45:22 PM   trackback []

Tropical Storm Bret Just two hours after classifying a tropical depression, the National Hurricane Center upgraded it to a tropical storm.  This is the first time since 1986 that two tropical storms formed in the month of June. At 8 PM CDT, the center of Bret was located at 19.9 North 95.8 West, 55 miles north-northeast of Veracruz, Mexico.  Maximum sustained winds are up to 40 mph and minimum central pressure is down to 1002 millibars (29.59"). Tropical Storm Bret Advisory Number 1A On a tropical weather message board a couple of weeks ago, I  voted that there would be a second tropical storm in June.  A few days ago I had all but ruled out that prediction verifying, but lo and behold it has.  There have certainly been times that hurricane hunters have gone out to investigate a system and declare it a tropical storm on the spot.  However, I do not recall an instance where a recon plane was on station to make it a tropical depression and remained on station as it became a tropical storm.  The storm continues to have an eye 3 nautical miles in diameter.  Overall the storm is incredibly compact with a very tight pressure gradient at the center.  Due to the small size, the computer models weren't picking it up as late as 18Z (1 PM CDT).  This really was a system that a forecaster would have missed had one not paid attention to observations. Fascinating stuff. 2005 Hurricane Season, Weather comment []9:14:13 PM   trackback []

Tropical Depression Two At 5 PM CDT, the center of newly formed Tropical Depression Two was near 19.9N 95.7W, 60 miles northeast of Veracruz, Mexico. Maximum sustained winds are 35 mph and minimum central pressure is 1004 mb (29.65"). Movement is to the west-northwest at 7 mph. Tropical Depression Two Advisory Number One The depression is near tropical storm strength and has a chance of making tropical storm before its imminent landfall. Tropical Depression Two Discussion Number One Remarkably, the hurricane hunter found a closed eye, three miles in diameter. Personally, I would be surprised if it gets classified as a tropical storm, but it isn't beyond reason either. 2005 Hurricane Season, Weather comment []6:12:32 PM   trackback []

Tropics Watch I've spent a fair amount of time this morning looking at what could be a tropical depression in the southwest Gulf of Mexico. The system is moving due west, so it won't have much time to develop further. Latest Tropical Weather Discussion describes it as follows A SURFACE TROUGH RUNS FROM THE NORTH CENTRAL GULF OF MEXICO NEAR 30N88W TO 26N93W INTO THE SOUTHWESTERN GULF OF MEXICO AND THE ISTHMUS OF TEHUANTEPEC NEAR 18N95W. THIS TROUGH HAS BEEN MOVING WESTWARD DURING THE LAST FEW DAYS...RUNNING FROM THE YUCATAN PENINSULA TO THE SOUTHEASTERN GULF OF MEXICO EARLIER THIS WEEK. A SURFACE LOW PRESSURE CENTER IS FORECAST TO DEVELOP IN THE SOUTHWESTERN GULF OF MEXICO DURING THE NEXT 24 HOURS...POSSIBLY BECOMING A TROPICAL CYCLONE. Elsewhere it is quiet, although an impressive looking tropical wave came off Africa last night. This is how NHC described it in its Tropical Weather Discussion at 0205 this morning TROPICAL WAVE IS INTRODUCED ALONG 16W/17W S OF 16N MOVING W 10-15 KT. STRONG WAVE COMING OFF THE AFRICAN COAST. SCATTERED MODERATE/STRONG CONVECTION IS INLAND AND WITHIN 75 NM ALONG THE COAST OF AFRICA FROM 9N-13N WITH A BROAD AREA OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 12N-18N E OF 19W TO WELL INLAND OVER AFRICA AND WITHIN 60 NM OF 9N FROM 13W-19W. The GFS model seems to be trying to develop this into a storm a few days from now. It is a bit too far out to tell if that is an accurate forecast, however. In the course of typing this, NHC announced a 'resource available' recon flight into the possible tropical depression. I'll report back in this spot when more data becomes available. LATER: Still waiting on obs from hurricane hunter, but NHC did put this into their 5:30 PM EDT Tropical Weather Outlook: PRELIMINARY INFORMATION FROM AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT INDICATES THAT THE AREA OF LOW PRESSURE ABOUT 50 MILES NORTH-NORTHEAST OF VERACRUZ MEXICO HAS DEVELOPED INTO A TROPICAL CYCLONE VERY NEAR TROPICAL STORM STRENGTH. ADVISORIES WILL LIKELY BE INITIATED UPON RECEIPT OF MORE COMPLETE INFORMATION FROM THE AIRCRAFT. DUE TO THE PROXIMITY OF THE SYSTEM TO THE COASTLINE...LITTLE ADDITIONAL DEVELOPMENT IS LIKELY BEFORE IT MOVES INLAND BETWEEN VERACRUZ AND TAMPICO OVERNIGHT. LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS WILL BE AFFECTING PORTIONS OF THE COAST OF MEXICO FROM TAMPICO TO VERACRUZ...AND TROPICAL STORM WARNINGS WILL LIKELY BE REQUIRED IN THIS AREA. 2005 Hurricane Season, Weather comment []2:38:19 PM   trackback []