Tag Archives: Tropical Wave

Possible Hurricane Formation Southwest of Mexico

Guidance from recent runs of the Global Forecasting System (GFS) model indicate that a tropical cyclone could form southwest of Mexico during the next few days.  A tropical wave will move into the Eastern North Pacific Ocean south of Mexico.  The wave will move over water where the Sea Surface Temperature is between 29°C and 30°C.  Vertical wind shear caused by an upper low near the west coast of Mexico will initially inhibit development of the wave.  The GFS model is forecasting that the tropical wave will move into a region where the upper level winds are light and there will not be much vertical wind shear.  If that scenario occurs then a tropical cyclone could develop during the weekend near latitude 10°N and longitude 105°W.

If a tropical cyclone forms, a ridge of high pressure to the north of the cyclone would likely steer it in a generally west-northwesterly direction which would move it away from Mexico.  The environment would be favorable for intensification.  Rapid intensification may be possible and the system could become a major hurricane next week.

The development of this tropical wave could also be a signal that the Eastern North Pacific is getting active.  Although it has been a bit of a slow start to the hurricane season in that basin, the formation of a hurricane during the next week or so would be consistent with the long term climatology for that region.

Possible Tropical Development

For the first time this hurricane season the Global System Forecast (GFS) Model is suggesting a classical development of a tropical cyclone east of the Lesser Antilles might occur and that resulting storm could effect the U.S.  A tropical wave is about 600 miles east of the Lesser Antilles and there may be a low pressure center near latitude 10°N and longitude 50°W.  Thunderstorm activity has increased with this system today as it moves westward.

The 0600 UTC run of the GFS model developed a tropical cyclone from this wave and moved it through the Caribbean Sea and into the Gulf of Mexico near Texas by a week from Friday.  The following (1200 UTC) run also developed a tropical cyclone and moved it into the northern Gulf of Mexico by a week from Wednesday evening.  At this time it is prudent to ask if these runs represent model false alarms or a possible depiction of future reality.  If the development of a tropical cyclone does occur, then it may be that a hurricane could approach the coast of the U.S. during the second half of next week.  The first indication that the GFS forecast might verify would be the development of tropical depression east of the Lesser Antilles.

This far out in advance the uncertainty of a track or intensity forecast is very high.  If there was a cone of uncertainty for the track, it might extend from Cancun to Cape Hatteras.  If a center of low pressure organizes, then the model guidance will improve and the uncertainty will decrease.

People along the coast of the U.S. should be aware of this system and maintain a cautious vigilance until we see if it does develop,