Tropical Storm Gil

Tropical Storm Gil Track 0800 Hours August 4 2019
Tropical Storm Gil Track 0800 Hours August 4 2019

Tropical Storm Gil Satellite 1400 Hours August 3 2019Tropical Storm Gil Forming (see Thursday video below) – NWS National Hurricane Center Miami FL 800 AM PDT Sun Aug 04, 2019

Shortly after 1200 UTC, Gil lost all of its central deep convection due to strong southwesterly to westerly shear and entrainment of dry air as per GOES-17 mid-level water vapor imagery. The cyclone now consists of a tight swirl of mainly low clouds, with the nearest convection located more than 150 nmi to the east of the center. The initial intensity has been lowered to 25 kt based on a Dvorak T-number of T1.5/25 kt. Gil is expected to continue to weaken due to the aforementioned adverse conditions, degenerating into a remnant low later today and dissipating by late Monday.

Gil has continued to move westward or 270/09 kt. The shallow cyclone is now embedded within the low-level easterly trade wind flow, and Gil is expected to maintain a general westward motion until dissipation occurs in 36-48 hours. The official track forecast is nearly on top of of the previous advisory track and lies close to a blend of the consensus model TVCE and the ECMWF model.

FORECAST POSITIONS AND MAX WINDS

INIT  04/1500Z 14.9N 125.3W   25 KT  30 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 12H  05/0000Z 14.9N 126.8W   25 KT  30 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 24H  05/1200Z 14.9N 128.9W   20 KT  25 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 36H  06/0000Z 14.9N 131.0W   20 KT  25 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 48H  06/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 200 AM PDT Sun Aug 04 2019

Strong northwesterly shear has continued to take a toll on Gil overnight with the low-level center of the cyclone becoming even more exposed. The main convective mass has also decreased in size with a new smaller burst of convection recently developing to the northeast of the center, however satellite imagery shows that the new burst is already beginning to shear away. A recent ASCAT overpass revealed peak winds of around 25 kt, so the initial intensity has been lowered somewhat conservatively to 30 kt. The strong shear over the cyclone is not expected to abate during the next 24 to 36 hours, and this, along with dry mid-level air, should continue to cause Gil to weaken over the next day or so. The global model unanimously show the cyclone degenerating into a the trough of low pressure within 48 hours, and so does the updated NHC forecast.

Gil is moving westward or 275/10 kt. There is no change to the track forecast reasoning. The cyclone should continue moving generally westward during the next day or so while a low- to mid-level ridge remains to its north. The official track forecast is again close to the previous advisory and the latest HFIP corrected model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 14.9N 124.4W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 12H  04/1800Z 15.1N 125.8W   25 KT  30 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 24H  05/0600Z 15.2N 127.8W   25 KT  30 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 36H  05/1800Z 15.1N 130.0W   20 KT  25 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 48H  06/0600Z...DISSIPATED

NWS National Hurricane Center Miami FL 800 PM PDT Sat Aug 03 2019

Gil remains a strongly sheared tropical cyclone, with the estimated low-level center located near the western edge of a ragged-looking convective mass. Based on a Dvorak classification from TAFB, the intensity estimate remains at 35 kt. The shear is being produced by large upper-level trough that lies near and to the north of the storm, and the dynamical guidance indicates that this shear will persist for the next couple of days. This, along with relatively dry mid-tropospheric air of relative humidities near 50 to 60 percent, should cause Gil to weaken and then dissipate within 72 hours. The official intensity forecast is similar to the previous one and close to the model consensus.

The motion is estimated to be westward or 280/10 kt. A low- to mid-level ridge should be maintained to the north of the cyclone over the next few days. This flow pattern should cause a continued westward or slightly south of westward track until dissipation. The official track prediction is very close to the previous NHC forecast and also close to the corrected model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  04/0300Z 14.9N 123.6W   35 KT  40 MPH - Tropical Storm (WSW Zihuatanejo, Mexico)
 12H  04/1200Z 15.1N 124.8W   35 KT  40 MPH - Tropical Storm (WSW Zihuatanejo, Mexico)
 24H  05/0000Z 15.3N 126.7W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 36H  05/1200Z 15.3N 128.5W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 48H  06/0000Z 15.0N 130.4W   25 KT  30 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 72H  07/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 200 PM PDT Sat Aug 03, 2019

Scatterometers are providing plenty of surprises today. ASCAT-B data at 1716 UTC showed that the cyclone not only still has a well-defined circulation, but also winds of 30-35 kt northeast of the low-level center. Given that the instrument likely under-sampled the strongest winds, the initial intensity has been increased to 35 kts, and the system is now designated as Tropical Storm Gil.

Despite the slight increase in winds, the long-term prospects for Gil have not improved. The tropical storm is strongly sheared due to an upper-level trough located just to the north, and the GFS and ECMWF forecast that the shear will remain high during the next few days. A marginally dry surrounding environment will also likely limit further strengthening. Given the higher initial winds of Gil, the new NHC forecast carries the cyclone as a low-end tropical storm for about a day, before showing gradual weakening. By 72 h, all of the dynamical guidance indicates that Gil will open into a trough of low pressure, and many of the models suggest it could happen well before that.

The initial motion estimate is 285/10 kt. The center position of Gil was adjusted slightly southward since the last advisory and the official forecast has been adjusted accordingly. That said, there is no change in the reasoning behind the forecast, and low-level easterly flow should cause Gill to move generally westward for the next couple of days at a steady pace.

FORECAST POSITIONS AND MAX WINDS

INIT  03/2100Z 15.0N 122.4W   35 KT  40 MPH - Tropical Storm (WSW Zihuatanejo, Mexico)
 12H  04/0600Z 15.2N 123.8W   35 KT  40 MPH - Tropical Storm (WSW Zihuatanejo, Mexico)
 24H  04/1800Z 15.5N 125.6W   35 KT  40 MPH - Tropical Storm (WSW Zihuatanejo, Mexico)
 36H  05/0600Z 15.6N 127.4W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 48H  05/1800Z 15.5N 129.2W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 72H  06/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 800 AM PDT Sat Aug 03 2019

First light visible satellite images indicate that the disturbance over the open eastern Pacific has developed a well-defined center just west of an area of concentrated deep convection. Based on this, advisories have been initiated for Tropical Depression Eight-E. An earlier scatterometer pass measured winds of about 30 kt, and this is the basis for the initial intensity.

Vertical shear of 20-25 kt that is currently displacing convection off to the east of the low-level center is forecast to continue for the next few days as the system moves under the base of a mid- to upper-level trough. This shear is expected to prevent any strengthening of the cyclone in the near term. In addition to the shear, the depression will move into a drier airmass and begin to move over more marginal SSTs in about 24 hours. This should result in weakening and the depression is expected to dissipate in a couple of days.

Although the depression is currently moving west-northwestward at about 9 kt, all of the global models forecast that it will turn westward later today, steered primarily by low-level easterly winds. The cyclone should then continue westward for the next day or two until it dissipates.

FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 14.7N 121.2W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 12H  04/0000Z 15.4N 122.6W   30 KT  35 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 24H  04/1200Z 15.7N 124.6W   25 KT  30 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 36H  05/0000Z 15.9N 126.7W   20 KT  25 MPH - Tropical Depression (WSW Zihuatanejo, Mexico)
 48H  05/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 500 PM PDT Thu Aug 1, 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, located in the far southwestern part of the basin.

1. A broad area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce disorganized showers and thunderstorms. While upper-level winds are not forecast to be particularly conducive for development, a short-lived tropical depression could still form during the next two days while the low moves west-northwestward at about 15 mph. After that time, strong upper-level winds are
expected to prevent additional development.

* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Thu Aug 1, 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, located about 1500 miles west-southwest of the southern tip of the Baja California peninsula.

1. A broad area of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce disorganized showers and thunderstorms. Upper-level winds are forecast to be marginally conducive for development during the next two to three days, and a tropical depression could form during that time while the low moves west-northwestward at about 15 mph. After that time, strong upper-level winds are expected to prevent additional development.

* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Thu Aug 1, 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, located more than 1400 miles west-southwest of the southern tip of the Baja California peninsula.

A broad area of low pressure located several hundred miles south of the southern tip of the Baja California peninsula continues to produce disorganized showers and thunderstorms. Upper-level winds are forecast to be marginally conducive for development, and a tropical depression could form over the weekend while the low moves west-northwestward at about 15 mph.

* Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium...50 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Wed Jul 31,  2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Hurricane Flossie, located more than a thousand miles west-southwest of the southern tip of the Baja California peninsula.

1. Showers and thunderstorms remain disorganized in association with a broad area of low pressure located several hundred miles south-southwest of Manzanillo, Mexico. Upper-level winds are forecast to become more conducive for development late this week, and a tropical depression could form over the weekend while the low moves westward or west-northwestward at about 15 mph.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium...50 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Tue Jul 30, 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, located about 1000 miles southwest of the southern tip of the Baja California Peninsula.

A tropical wave located a few hundred miles south-southeast of Manzanillo, Mexico, continues to produce a large but disorganized area of showers and thunderstorms. Some gradual development of this system is possible late this week or this weekend while the system moves westward, away from the coast of Mexico.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…20 percent.

NWS National Hurricane Center Miami FL 1100 AM PDT Tue Jul 30, 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, located about 1000 miles southwest of the southern tip of the Baja California Peninsula.

A tropical wave located a few hundred miles south-southeast of Manzanillo, Mexico, continues to produce a large but disorganized area of showers and thunderstorms. Some gradual development of this system is possible late this week or this weekend while the system moves westward, away from the coast of Mexico.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low...20 percent.

NWS National Hurricane Center Miami FL 500 AM PDT Tue Jul 30, 2019

For the eastern North Pacific…east of 140 degrees west longitude:

The National Hurricane Center is issuing advisories on Tropical Storm Flossie, located about 1000 miles southwest of the southern
tip of the Baja California Peninsula.

1. A broad area of disturbed weather is associated with a tropical wave located a few hundred miles south of Acapulco, Mexico. Some gradual development of this system is possible late this week while the system moves quickly westward, away from the coast of Mexico.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…20 percent.

If this storm system is named, it will be Tropical Storm Gil.

Article Resources:

Recent Tropical Cruise Weather:

Video: Tracking 2 tropical waves in the Caribbean, Atlantic Ocean

Please follow and like us: