Monthly Archives: October 2014

Tropical Storm Watch Issued for Part of Baja California

Although Tropical Storm Simon is moving over cooler Sea Surface Temperatures (SSTs) its circulation is spinning down more slowly than originally anticipated.  As a result, the government of Mexico has issued a Tropical Storm Watch for the portion of the coast of Baja California that extends from Punta Abreojos to Punta Eugenia.

At 5:00 p.m. EDT the center of Tropical Storm Simon was located at latitude 25.8°N and longitude 117.4°W, which put it about 200 miles southwest of Punta Eugenia.  Simon was moving toward the north at 7 m.p.h.  The maximum sustained wind speed was 50 m.p.h. and the minimum surface pressure was 999 mb.  Winds to tropical storm force extended out 120 miles from the center of circulation, which placed them within 80 miles from the coast of Baja California.

Strong southwesterly winds in the upper levels are generating wind shear over the top of Simon.  In addition, it is over cooler SSTs.  The shear and cooler water will continue to weaken Simon.   There is slightly warmer water near the coast of Baja California, which could maintain the circulation long enough for it to make landfall.  Simon is expected to move northeastward toward Baja California and it could possible bring tropical storm force winds to some portions of the coast.  The moisture associated with Simon will also bring an enhanced chance for rain and some areas could get locally heavy rainfall.

 

Typhoon Vongfong Intensifying

Warm Sea Surface Temperatures and limited wind shear allowed Vongfong to intensify on Saturday and it is now a typhoon.  At 8:00 p.m. EDT on Saturday the center of Typhoon Vongfong was located near latitude 12.6°N and longitude 149.9°E which put it about 330 miles east-southeast of Guam.  Vongfong was moving toward the west-northwest at 21 m.p.h.  The maximum sustained wind speed was 80 m.p.h. and there were gusts to 100 m.p.h.

Clockwise flow around a subtropical high pressure system will keep Vongfong moving in a general west-northwesterly direction for several more days.  It could pass very near Guam during the next 24 hours.  Vongfong should remain in a favorable environment and further intensification is possible.

 

Typhoon Phanfone Approaching Japan

Typhoon Phanfone is approaching the southwestern part of Japan.  At 11:00 p.m. EDT the center of Phanfone was located at latitude 28.9°N and longitude 131.4°E which put it about 200 miles south of Miyazaki, Japan and about 670 miles southwest of Tokyo.  Phanfone was moving toward the north at 9 m.p.h.  The maximum sustained wind speed was 115 m.p.h. and there were gusts to 140 m.p.h.

Phanfone is already bringing rain and wind to parts of southwestern Japan.  It could bring gusty winds and locally heavy rainfall as it moves northeastward.  Phanfone is nearing the latitude of stronger upper level westerly winds.  Those winds will soon make Phanfone start to move toward the northeast.  Phanfone will move more quickly toward the northeast on Sunday afternoon and evening and it could be near Tokyo in about 24 hours.  The westerly winds will also increase the wind shear over Phanfone and create a weakening trend.  As more cooler air gets pulled into the circulation, Phanfone will begin a transition to an extratropical cyclone.

 

Simon Intensifies Into a Major Hurricane

Hurricane Simon intensified rapidly on Saturday and it is now a Major Hurricane.  At 5:00 p.m. EDT the center of Hurricane Simon was located at latitude 20.6°N and longitude 115.0°W which put it about 365 miles west-southwest of the southern tip of Baja California and about 495 miles south of Punta Eugenia, Mexico.  Simon was moving toward the west-northwest at 14 m.p.h.  The maximum sustained wind speed was 120 m.p.h. and the minimum surface pressure was 950 mb.

Simon is the 8th hurricane to reach Major Hurricane intensity over the Eastern North Pacific during 2014.  This ties the record for the most Major Hurricanes in one year in that basin, which was set previously in 1983, 1992 and 1993.

Simon is moving around the western edge of a ridge centered over northern Mexico.  It should turn more toward the north on Sunday.  As Simon moves farther north, it will eventually move toward the northeast.  It could approach Baja California by the middle of next week.

Simon may be on the threshold of an eyewall replacement cycle.  If it goes through one of those cycles, there will be some fluctuations in intensity.  When Simon moves west of Baja California it will move over cooler Sea Surface Temperatures and begin to weaken.  Simon is likely to be a weakening tropical cyclone when it nears Baja California.

 

Tropial Storm Simon Intensifying West of Mexico

At 5:00 p.m. EDT on Friday the center of Tropical Storm Simon was located at latitude 18.8°N and longitude 110.6°W which put it about 285 miles south of the southern tip of Baja California.  Simon was moving toward the west-northwest at 9 m.p.h.  The maximum sustained wind speed was 65 m.p.h. and the minimum surface pressure was estimated to be 993 mb.

Simon appears to be developing a tight inner core and there are indications on visible satellite imagery that an eye might be forming.  Upper level winds have lessened and Simon is over warm Sea Surface Temperatures.  So, further intensification is likely and Simon will probably become a hurricane during the weekend.

Simon is being steered to the west-northwest by a mid-level ridge over northern Mexico.  It will likely turn more toward the north as it reaches the western extent of that ridge.  Guidance from the numerical models suggests two possibilities once Simon moves west of Baja California.  Some models are suggesting that it will turn northeastward and make landfall near the central portion of the Baja peninsula.  Another group of models is suggesting that Simon will weaken and stall west of Baja California.  It is too early to be certain which scenario is more likely.

Simon is the 18th named tropical cyclone to form over the Eastern North Pacific during 2014.  This equals the number of named tropical storms that formed over that region in 2013.

 

Tropical Storm Vongfong Forms East of Guam

A new tropical storm has formed east of Guam.  At 2:00 p.m. EDT on Friday the center of Tropical Storm Vongfong was located at latitude 9.1°N and longitude 156.3°E which put it about 820 miles east-southeast of Saipan.  Vongfong was moving toward the west-northwest at 15 m.p.h.  The maximum sustained wind speed was 50 m.p.h. and there were gusts to 65 m.p.h.

Vongfong is being steered by the same subtropical high that is also steering Typhoon Phanfone.  Clockwise flow around the southern portion of the high should keep Vongfong moving toward the west-northwest for the next several days.

Vongfong is over warm Sea Surface Temperatures and it has well developed upper level outflow.  The favorable environment should allow Vongfong to intensify and it is likely to become a typhoon during the weekend.  The projected path of Vongfong would take it near or just to the north of Guam in about 48 to 72 hours.

 

Typhoon Phanfone Turns Northwards

Strong Typhoon Phanfone has reached the western edge of a subtropical high pressure system and it is making the expected turn toward the north.  At 11:00 a.m. EDT on Friday the center of Phanfone was located at latitude 24.0°N and longitude 134.0°E which put it about 870 miles south-southwest of Tokyo, Japan.  Phanfone was moving toward the northwest at 12 m.p.h.  The maximum sustained wind speed was 120 m.p.h. and there were gusts to 150 m.p.h.

Phanfone went through an eyewall replacement cycle on Thursday in which the small inner eye dissipated and a much larger eye became apparent on satellite imagery.  The eyewall replacement cycle kept the intensity of Phanfone relatively constant.  Now that the inner eye is gone, the outer eye is likely to contract.  Phanfone remains over warm Sea Surface Temperatures and it is a favorable atmospheric environment.  So, some further intensification is possible during the next 24 hours.  In 24 to 36 hours Phanfone will be far enough north to begin to be influenced by upper level westerly winds.  The stronger upper level winds will increase wind shear over Phanfone and start a weakening process.  A combination of stronger wind shear and colder air to the north of Phanfone will initiate a process whereby it is transformed from a tropical cyclone to an extratropical cyclone.  It is difficult to determine the exact timing of the extratropical transition and Phanfone will be a powerful extratropical cyclone as it moves across the North Pacific.

Phanfone should gradually turn more toward the north during the next 24 hours as it moves around the western edge of the subtropical high pressure system.  It is likely to take a sharper turn to the northeast later in the weekend when it encounters the upper level westerlies.  Phanfone is likely to approach southern Japan in 36 to 48 hours.  Some models are indicating that it could cross parts of Central Japan, while other models keep the center south of Japan.  In either case Phanfone has the potential to brig locally heavy rain and gusty winds to portions of Japan.

 

Tropical Depression 19E Forms West of Mexico

The active hurricane season over the Eastern North Pacific Ocean continues.  An area of thunderstorms west of Mexico developed a surface circulation and a core of convection near the center.  As a result it was classified as Tropical Depression Nineteen-E (TD19E).  At 11:00 p.m. EDT the center of TD19E was located at latitude 17.8°N and longitude 105.4°W which put it about 110 miles southwest of Manzanillo, Mexico and about 455 miles south of the southern tip of Baja California.  TD19E was moving toward the west-northwest at 10 m.p.h.  The maximum sustained wind speed was 35 m.p.h. and the minimum surface pressure was 1003 mb.

The same upper level ridge of high pressure over northern Mexico that has been in place during much of the hurricane season will steer TD19E toward the west-northwest during the next day or two.  As TD19E rounds the western edge of the ridge it will turn more toward the north and it could follow a path similar to the one taken by Hurricane Rachel.

The upper level ridge is producing some northeasterly winds and wind shear over TD19E.  The shear is forecast to weaken and some intensification of TD19E is likely while it remains over warm Sea Surface Temperatures.

 

Typhoon Phanfone Intensifying Rapidly

A very favorable environment of warm Sea Surface Temperatures and light upper level winds is allowing Typhoon Phanfone to intensify rapidly.  At 11:00 p.m. EDT on Wednesday the center of Phanfone was located at latitude 19.5°N and longitude 139.0°E which put it about 400 miles south-southwest of Iwo To.  Phanfone was moving toward the west-northwest at 17 m.p.h.  It had maximum sustained winds of 120 m.p.h. and gusts to 150 m.p.h.

Phanfone is moving around the western end of the subtropical high pressure system and its track should take a more northward turn.  When Phanfone gets to a higher latitude, it will encounter the upper level westerly flow which will turn it northeastward.  Guidance from numerical models suggest that Phanfone could be south of Japan in about 72 hours.

Phanfone will be in a favorable environment during the next 36 hours and further intensification is possible.  When Phanfone encounters the upper level westerly flow, wind shear will increase and it will start to weaken.  Phanfone will eventually make a transition to an extratropical cyclone as it moves northeastward over the North Pacific.