Ignacio, Jimena and Erika


Over the next couple of weeks, it’s possible that the U.S. East Coast, West Coast, and Hawaii will all be affected by weather from a triplet of tropical cyclones: Hurricane Ignacio and Tropical Storms Jimena and Erika. This would be a highly unusual event—perhaps even unprecedented—but at present it’s also fairly unlikely.
Hurricane Ignacio is currently chugging away east of Hawaii and heading west with sustained winds of 90 mph and gusts to 115 mph. Sea surface temperatures are warm and it may strengthen into a major hurricane over the next day or two. The Central Pacific Hurricane Center is forecasting that the center of Ignacio will be due north of Hilo on the island of Hawaii on Tuesday morning. Tropical storm conditions are expected there as early as Sunday night. A direct strike by Hurricane Ignacio is not expected, but hurricane paths are notoriously hard to predict.
Following behind Ignacio is Tropical Storm Jimena. It currently has sustained winds of 60 mph and is strengthening rapidly, and could become a hurricane later tonight or tomorrow. Although generally following the path of Ignacio, it is not expected to threaten the Hawaiian islands. Instead, the Global Forecast System (GFS) model has Jimena making a broad loop around the East Pacific High, and what’s left of it bringing needed rain to Northern California around September 12. Of course, numerical weather prediction models aren’t very accurate that far in advance, but it does make for an interesting scenario.
Finally we come to Tropical Storm Erika, now plowing its way through the Eastern Caribbean, near the Virgin Islands and Puerto Rico. Erika is a minimal tropical storm at present, with sustained winds of 45 mph, and will have a hard time maintaining strength as its circulation passes over the many islands of the Caribbean. If it does make it through intact, some models suggest that it could threaten the Atlantic coast of Florida as a hurricane around Monday or Tuesday of next week.
All in all, the tropics are heating up and the next couple of weeks should prove interesting.

“Pineapple Express” brings substantial winter weather to most of California and eastern Nevada

A vigorous late Fall/early Winter storm system has tapped a connection to subtropical moisture and is bringing substantial rain and mountain snow to much of California and eastern Nevada. Storms of this type are commonly referred to by the media as “Pineapple Express”, for their connection to the tropics, but Meteorologists generally refer to these moisture plumes as “Atmospheric Rivers”.

In advance of the storm, Incline Village registered a wind gust to 51 mph yesterday. Today, snowfall will be measured in feet in the Sierras. At lower elevations in northern California, rainfall has already exceeded 10 inches in some foothill locations in northern California.

In southern Califonia, rain totals early morning through noon have approached 4 inches in the LA County Mountains, and 1 to 2 inches totals are common across Orange, Riverside, and San Diego Counties.

Steady rain has ended across LA and Orange County and will be ending early in the afternoon across San Diego and Riverside Counties. The steady rain will be replaced by scattered showers and thunderstorms the remainder of the afternoon through Saturday morning.

There will be a break in the rain after Saturday, but computer forecast models are showing another system with the potential for significant rain could affect Califonia and western Nevada Wednesday and Thursday.

The Latest on The Pineapple Express Storm

Jim Purpura
Director, Forecast Operations

Where is Hurricane Odile headed?

Hurricane Odile is now weakening as it moves across the Baja on its eastern shores. Early Monday it made landfall with sustained winds of 115 mph, a category 3 hurricane. Waves up to 24 feet also accompanied the hurricane as it approached Los Cabos. Early reports indicate major damage to resort areas.

The next question is where does it go next? The National Hurricane Center indicates the hurricane will weaken to a tropical storm overnight (39 to 74 mph sustained winds), then to a tropical depression (winds under 39 mph) by Wednesday morning. See the graphic from the National Hurricane Center, below.

Even a weakening storm like this will have abundant rainfall. Rain totals of 6 to 12 inches with areas of 18 inches of rain are possible in the Baja the next several days.

The track will take the storm toward Arizona later in the week, so unfortunately look for a repeat of flash flooding in areas like Phoenix and Tucson as the tenants of Odile move their way.


Hawaii Braces

Tropical Storm Flossie is almost out of steam, but by tonight, looks to make a direct landfall somewhere on Maui, Oahu, or Kauai. Tropical storm warnings and flood warnings have been issued by the National Weather Service in Honolulu. The storm formed over the open waters of the Eastern Pacific on July 25, and never reached hurricane strength.

Thanks to wind shear and plenty of dry air in the region, Flossie has been weakening on its final approach to the islands, but still will be a threat for tropical storm force winds (sustained near 40 mph, with higher gusts), and torrential rainfall. Though the center of circulation should pass directly over one of the smaller islands, most of the remaining thunderstorm convection is hanging on the southern side of the circulation, so the entire Big Island is expecting heavy rain. Locally, cities and towns across the Hawaiian Islands should expect anywhere from 4-12 inches of rain from the system (with heavier amounts in the higher elevations). Flooding is likely with this system, especially in low-lying and particularly susceptible areas.

Visible satellite image over the Central Pacific, showing Tropical Storm Flossie ready to make landfall. The center of the circulation is actually north of the main core of convection, which looks to be just east of the Big Island (NOAA).

Water Vapor satellite image (same time as above) showing the dry air in the region. Some has been ingested by the storm, and is contributing to the weakening trend. However, the storm still has plenty of moisture associated with it, and will produce several inches of rain over the state (NOAA).

The projected path for Flossie, showing continued west-northwest movement and weakening as it enters the open waters west of Hawaii (The Weather Channel).

Hawaii is no a stranger to tropical cyclones, but a direct hit is rare when you compare the size of the land mass to the vast size of the Pacific Ocean. Direct hits and close calls are uncommon, but like many things in the state of Hawaii, they can happen in waves. Hurricane Iniki struck the island of Kauai head-on in September of 1992 as a Category 4 Hurricane, causing around 2 billion dollars in damage there. Low-grade Tropical Storm Flossie, while not ideal for vacationers, is quite a blessing when you compare it to Iniki and other far more intense storms in the past.

Stephen Bone