Tag Archives: Tropical Storm Hilary

Tropical Storm Hilary Drops Heavy Rain on Southern California

Tropical Storm Hilary dropped heavy rain over parts of southern California on Sunday. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Hilary was located at latitude 31.3°N and longitude 116.1°W which put it about 115 miles (185 km) south-southeast of San Diego, California. Hilary was moving toward the north at 23 m.p.h. (37 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 990 mb.

A Tropical Storm Warning was in effect for the portion of the coast from the U.S. border with Mexico to the Point Mugu, California. The Tropical Storm Warning included San Diego. The Tropical Storm Warning also included Catalina Island. A Tropical Storm Warning was in effect for the portion of the coast from Punta Eugenia, Mexico to the border with the U.S. A Tropical Storm Warning was in effect for the portion of the coast from Bahia San Bautista to Guaymas, Mexico.

Former Hurricane Hilary weakened to a tropical storm as the center of Hilary moved over the northern part of Baja California. Bands in the northern part of Hilary’s circulation brought gusty winds to parts of southern California and Arizona. Winds to tropical storm force extended out 230 miles (370 km) from the center of Hilary’s circulation. A weather station at the Imperial, California airport reported a sustained wind speed of 40 m.p.h. (65 km/h) and a wind gust of 61 m.p.h. (98 km/h). A weather station in Yuma, Arizona reported at sustained wind speed of 45 m.p.h. (75 km/h) and a wind gust of 59 m.p.h. (95 km/h).

The circulation around the northern side of Tropical Storm Hilary interacted with an upper level low west of California to drop heavy rain over parts of southern California. Weather stations in Carlsbad, Ramona, Los Angeles, Riverside, Big Bear, Borrego, Palmdale, Edwards Air Force Base, and Gray Butte, California were all reporting heavy rain at 7:00 p.m. EDT.

The upper low west of California will pull Tropical Storm Hilary quickly to the north during the next 24 hours. The center of Hilary’s circulation will pass east of San Diego on Sunday evening. Tropical Storm Hilary continue to weaken as it moves inland over the Southwest U.S. The circulation of Hilary will move over Nevada on Monday. The upper and lower parts of Hilary’s circulation could decouple because of strong vertical wind shear. Tropical Storm Hilary will continue to produce gusty winds and locally heavy rain during the next 24 hours. The heaviest rain is likely to fall where the wind forces the air to rise over mountains. Heavy rain is likely to cause flash floods in some locations. Flood Watches have been issued for parts of southern California, southern Nevada, southern Utah and western Arizona. Hilary could also bring strong winds to mountains in southern Nevada, southern Utah and western Arizona.

Tropical Storm Hilary Forms South of Mexico

Tropical Storm Hilary formed over the Eastern North Pacific Ocean south of Mexico on Wednesday morning. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Hilary was located at latitude 12.4°N and longitude 102.6°W which put it about 470 miles (755 km) south-southeast of Manzanillo, Mexico. Hilary was moving toward the west-northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1002 mb.

A low pressure system over the Eastern North Pacific Ocean south of Mexico strengthened on Wednesday morning and the U.S. National Hurricane Center designated the system as Tropical Storm Hilary. The circulation around Tropical Storm Hilary was organizing quickly. Multiple bands of showers and thunderstorms were revolving around the center of Hilary’s circulation. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 200 miles (325 km) in the northeastern quadrant of Tropical Storm Hilary. Winds in the other parts of Hilary’s circulation were blowing at less than tropical storm force.

Tropical Storm Hilary will move through an environment very favorable for intensification during the next 24 hours. Hilary will move over water where the Sea Surface Temperatures are near 30°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Hilary will intensify during the next 24 hours. Hilary could intensify rapidly at times. Tropical Storm Hilary is likely to strengthen to a hurricane on Thursday.

Tropical Storm Hilary will move around the western part of a high pressure system over Mexico. The high pressure system will steer Hilary toward the west-northwest during the next 24 hours. On its anticipated track Tropical Storm Hilary will move parallel to the west coast of Mexico. Hilary will move more toward the north when it reaches the western end of the high pressure system during the weekend. Hilary could be near Baja California by Sunday.

Elsewhere, Tropical Storm Greg was spinning southeast of Hawaii and former Hurricane Fernanda weakened to a tropical storm. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Greg was located at latitude 11.8°N and longitude 151.1°W which put it about 605 miles (975 km) south-southeast of Hilo, Hawaii. Greg was moving toward the west at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 1000 mb.

At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Fernanda was located at latitude 17.1°N and longitude 126.8°W which put it about 1165 miles (1875 km) west-southwest of the southern tip of Baja California. Fernanda was moving toward the west at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 994 mb.

Tropical Storms Hilary and Irwin Interact As They Weaken

Tropical Storms Hilary and Irwin started to interact on Thursday as both storms began to weaken.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Hilary was located at latitude 18.3°N and longitude 117.3°W which put it about 575 miles (925 km) west-southwest of the southern tip of Baja California.  Hilary was moving toward the west-northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were gust to 85 m.p.h. (140 m.p.h.).  The minimum surface pressure was 992 mb.

At 11:00 p.m. EDT on Thursday the center of Tropical Storm Irwin was located at latitude 14.9°N and longitude 124.6°W which put it about 1105 miles (1780 km) west-southwest of the southern tip of Baja California.  Irwin was moving toward the west at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 1000 mb.

Hilary weakened below hurricane intensity on Thursday.  It appeared that the circulation drew in drier more stable air around the northwestern side of the circulation.  The drier air reduced the formation of showers and thunderstorms and the core of the circulation weakened.  At the same time upper level divergence from Tropical Storm Hilary increased the vertical wind shear over Tropical Storm Irwin.  Irwin was over water where the Sea Surface Temperature is near 28.5°C and it was able to extract enough energy from the ocean to maintain most of its intensity.

Tropical Storms Hilary and Irwin will move over water where the Sea Surface Temperature is near 28°C on Friday.  However, the combination of drier, more stable air and vertical wind shear is likely to keep both of the storms from strengthening.  Hilary and Irwin will move over cooler water during the weekend and both tropical storms are likely to weaken when that occurs.

Tropical Storm Hilary is being steering toward the west-northwest by a subtropical high pressure system to the north of the tropical storm.  Hilary is forecast to continue moving toward the west-northwest.  Tropical Storm Hilary is larger than Irwin.  Winds to tropical storm force extend out about 110 miles (180 km) in Tropical Storm Hilary.  Winds to tropical storm force extend out about 70 miles (110 km) in Tropical Storm Irwin.

The centers of the two tropical storms are only about 540 miles (870 km) apart.  When Tropical Storm Hilary passes north of Irwin, Tropical Storm Irwin is forecast to start to revolve around the larger Tropical Storm Hilary.  Irwin is expected to turn toward the north after Tropical Storm Hilary passes by.  Some models are forecasting the that the centers of the two tropical storms will approach each other and the larger Tropical Storm Hilary will eventually absorb Tropical Storm Irwin.

Tropical Storm Irwin Forms, Greg Gets Larger, Hilary Strengthens

Tropical Depression Ten-E intensified into Tropical Storm Irwin, the circulation of Tropical Storm Greg increased in size and Tropical Storm Hilary strengthened on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Irwin was located at latitude 14.9°N and longitude 116.6°W which put it about 705 miles (1135 km) southwest of the southern tip of Baja California.  Irwin was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1003 mb.

At 5:00 p.m. EDT on Sunday the center of Tropical Storm Greg was located at latitude 14.4°N and longitude 130.1°W which put it about 1445 miles (2325 km) west-southwest of the southern tip of Baja California.  Greg was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1001 mb.

At 5:00 p.m. EDT on Sunday the center of Tropical Storm Hilary was located at latitude 14.9°N and longitude 102.9°W which put it about 410 miles (660 km) south-southeast of Manzanillo, Mexico.  Hilary was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was was 999 mb.

A primary rainband wrapped around the western and southern sides of the center of circulation of Tropical Depression Ten-E and the National Hurricane Center upgraded the system to Tropical Storm Irwin.  Several other bands of showers and thunderstorms were developing over the southern half of the circulation.  There were fewer showers and thunderstorms in the northern half of the circulation.  Thunderstorms near the center of circulation were generating some upper level divergence.

Tropical Storm Irwin will move through an environment that will be somewhat favorable for intensification.  Irwin will move over water where the Sea Surface Temperature (SST) is near 28°C.  An upper level ridge northwest of Irwin are generating northeastern winds which are blowing toward the top of the circulation.  Those winds are generating moderate vertical wind shear and the shear may be the cause of the asymmetric distribution of showers and thunderstorms.  Tropical Storm Irwin could intensify during the next 24 to 48 hours.

The circulation of Tropical Storm Greg grew in size on Sunday.  However, Tropical Storm Greg will move into a less favorable environment during the next several days.  Tropical Storm Greg is over water where the SST is near 28°C, but it will move over cooler water in a day or two.  Greg could intensify in the short term, but it will weaken by midweek.

Tropical Storm Hilary is moving through a very favorable environment.  Hilary is moving over water where the SST is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Tropical Storm Hilary could be beginning a period of rapid intensification.  Hilary is forecast to become a hurricane on Monday and it could be a major hurricane later this week.

A subtropical ridge is steering all three tropical storms in a general west-northwesterly direction.  Tropical Storms Greg, Hilary and Irwin are likely to continue to move a little to the north of due west during the next three days.  On its anticipated track Tropical Storm Hilary is expected to remain west of the west coast of Mexico.

Tropical Storm Hilary Develops South of Acapulco

More thunderstorms formed near the center of Tropical Depression Nine-E and the National Hurricane Center upgraded the system to Tropical Storm Hilary.  At 11:00 p.m EDT on Saturday the center of Tropical Storm Hilary was located at latitude 11.5°N and longitude 100.2°W which put it about 375 miles (600 km) south of Acapulco, Mexico.  Hilary was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1005 mb.

The circulation of Tropical Depression Nine-E was not well organized during the past several days as the depression moved over the Eastern North Pacific Ocean.  Thunderstorms began to form close to the center of circulation late on Saturday.  The formation of a core of thunderstorms was evidence of a more organized circulation and the depression was upgraded to Tropical Storm Hilary.  Some bands of showers and thunderstorms also began to develop outside the core of the tropical storm.  The circulation is still somewhat asymmetrical.  More showers and thunderstorms were forming in the northern half of the circulation.  The thunderstorms near the center were starting to generate upper level divergence which is pumping out mass.

Tropical Storm Hilary will be moving through an environment that is favorable for intensification.  Hilary will move over water where the Sea Surface Temperature is near 30°C.  The tropical storm will move through an area where the upper level winds are weak and there will not be a lot of vertical wind shear.  Tropical Storm Hilary should strengthen and it could intensify rapidly if the core of the circulation develops an eye.  Tropical Storm Hilary is likely to become a hurricane and it strengthen into a major hurricane early next week.

Tropical Storm Hilary is moving south of a subtropical ridge which is steering the tropical storm toward the west-northwest.  A general west-northwesterly motion is expected to continue for several more days.  On its anticipated track Tropical Storm Hilary will pass west of the west coast of Mexico.