Updraft® - Minnesota Weather News

Rare Hawaiian hurricanes, State Fair week heat wave?

There's tropical trouble in paradise.

Rare twin hurricanes are closing in on Hawaii. Iselle and Julio continue to track in a general westward direction and both storms look to impact the Hawaiian Islands in the next five days.

Here's a look at the projected tracks of Iselle and Julio from the National Oceanic and Atmospheric Administration, via Weather Underground.

1806 wxu hawaii map
Weather Underground

Iselle flared in intensity on satellite loops Wednesday afternoon, and looks destined for a direct hit Thursday on Hawaii's Big Island.

1806 iselle sat 2
NOAA GOES floater IR image of Hurricane Iselle Wednesday afternoon.

Official forecasts still have Iselle in a weakening phase from 85 miles per hour sustained winds as it approaches the Big Island Thursday.

But hurricane intensity forecasts are notoriously fickle. Getting a handle on rapid short term intensity fluctuations remain one of the biggest challenges in hurricane forecasting.

A strong tropical storm or Category 1 hurricane is most likely at this point, but higher intensity can't be ruled out.

Hurricane warnings are flying for the Big Island of Hawaii.

HURRICANE ISELLE LOCAL STATEMENT

NATIONAL WEATHER SERVICE HONOLULU HI

1055 AM HST WED AUG 6 2014

...ISELLE MARCHING STEADILY TOWARD HAWAII AND HAS NOT WEAKENED...

.NEW INFORMATION...

A HURRICANE WARNING HAS BEEN ISSUED FOR BIG ISLAND AND SURROUNDING WATERS. A TROPICAL STORM WARNING HAS BEEN ISSUED FOR MAUI COUNTY AND SURROUNDING WATERS.

1806 iselle warm
NOAA

STORM INFORMATION...

AT 10 AM HST...THE CENTER OF HURRICANE ISELLE WAS LOCATED NEAR LATITUDE 17.2N...LONGITUDE 145.9W...OR ABOUT 625 MILES EAST-SOUTHEAST OF HILO HAWAII ABOUT 830 MILES EAST-SOUTHEAST OF

HONOLULU HAWAII. HURRICANE ISELLE IS MOVING WEST-NORTHWEST AT 16 MPH. MAXIMUM SUSTAINED WINDS ARE NEAR 90 MPH.

SITUATION OVERVIEW...

ISELLE IS EXPECTED TO BRING HEAVY RAINS...HIGH SURF AND DAMAGING WINDS. HURRICANE CONDITIONS ARE EXPECTED ON THE BIG ISLAND OF HAWAII ON THURSDAY. TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD

TO MAUI COUNTY THURSDAY NIGHT AND POSSIBLY TO OAHU ON FRIDAY. SWELLS GENERATED BY ISELLE ARE EXPECTED TO REACH THE MAIN HAWAIIAN ISLANDS TODAY...POSSIBLY BECOMING DAMAGING ALONG SOME COASTLINES

STARTING LATE TONIGHT OR THURSDAY. HIGH SURF IS EXPECTED TO REACH THE ISLANDS AHEAD OF THE HEAVY RAINS AND STRONG WINDS. THE HIGH SURF MAY BRING COASTAL FLOODING...PARTICULARLY WHEN COMBINED WITH

AFTERNOON ASTRONOMICAL HIGH TIDES.

WHILE THERE IS STILL SOME UNCERTAINTY IN THE EXACT TRACK AND STRENGTH OF ISELLE...THE BIG ISLAND AND MAUI ARE EXPECTED TO BE IMPACTED FIRST. THE REST OF THE STATE REMAINS AT RISK TO EXPERIENCE THE IMPACTS OF ISELLE.

If Iselle follows the projected track and the center passes just south of Hilo, that would put the more intense right side of the storm and highest surge into Hilo Bay late Thursday.

Damaging wind gusts to 80+ mph, damaging high surf, and heavy rains of 10 to 20 inches, triggering flash floods and mudslides are the biggest threats with Iselle. Here's a look at projected rainfall totals for the Islands.

1806 iselle rainfall
Predicted rainfall along the track of Hurricane Iselle from the 06Z (2 am EDT) Wednesday August 6, 2014 run of the HWRF model. The model forecasts that Iselle will be a weak Category 1 hurricane with 75 mph winds when it hits the Big Island Thursday evening. Widespread rains of 8 - 16" are predicted over the Big Island, with some regions seeing 16 - 24". This rainfall forecast will be too high if Iselle is considerably weaker, as the official CPHC forecast is predicting. Image credit: NOAA/EMC/NCEP/NWS via Weather Underground.

Julio next?

Julio is officially forecast to pass just north of the Hawaiian Islands this weekend. Still, any change in track or additional high surf and rainfall could add to problems from Iselle.

1806 Julio 3
NOAA

Rare Twin Hawaiian Hurricanes

Hurricanes in Hawaii are rare. Two in a week? Almost unheard of.

hawaii_hurricane_history
Tracks of all tropical cyclones (tropical depressions, tropical storms, and hurricanes) to pass within 100 miles of the Hawaiian Islands, 1949 - 2013. Hurricanes approaching from the east typically fall apart before they reach Hawaii due to the cool waters and dry air that lie to the east of the islands. Only one named storm approaching from the east has hit the islands since 1949, an unnamed 1958 tropical storm that hit the Big Island. Hurricanes approaching from the south represent the biggest danger to the islands, due to the warmer waters and more unstable air present to the south. The only two major hurricanes to have affected the islands since 1949, Hurricane Iniki of 1992 and Hurricane Dot of 1959, both came from the south. Image credit: NOAA/CSC via Weather Underground

Weather Underground hurricane expert Dr. Jeff Masters has a nice write up on just how rare this week's events are in Hawaii.

Hawaii's hurricane history
On average, between four and five tropical cyclones are observed in the Central Pacific every year. This number has ranged from zero, most recently as 1979, to as many as eleven in 1992 and 1994. August is the peak month, followed by July, then September. Tropical storms and hurricanes are rare in the Hawaiian Islands. Since 1949, the Hawaiian Islands have received a direct hit from just two hurricanes--Dot in 1959, and Iniki in 1992. Both hit the island of Kauai. Only one tropical storm has hit the islands since 1949--an unnamed 1958 storm that hit the Big Island. A brief summary of the three most significant hurricanes to affect Hawaii in modern times:

September 1992: Hurricane Iniki was the strongest, deadliest, and most damaging hurricane to affect Hawaii since records began. It hit the island of Kauai as a Category 4 on September 11, killing six and causing $2 billion in damage.

November 1982: Hurricane Iwa was one of Hawaii's most damaging hurricanes. Although it was only a Category 1 storm, it passed just miles west of Kauai, moving at a speed of nearly 50 miles per hour (80 km/h). Iwa killed one person and did $250 million in damage, making it the second most damaging hurricane to ever hit Hawaii. All the islands reported some surf damage along their southwest facing shores, and wind damage was widespread on Kauai.

August 1959: Hurricane Dot entered the Central Pacific as a Category 4 hurricane just south of Hawaii, but weakened to a Category 1 storm before making landfall on Kauai. Dot brought sustained winds of 81 mph with gusts to 103 mph to Kilauea Light. Damage was in excess of $6 million. No Dot-related deaths were recorded.

Coolest summer on record so far in Rochester?

Yes, it's been cool in Minnesota this summer. And no, that has absolutely no relation climate change trends. It's been the 3rd warmest year on record globally so far in 2014. For some odd reason, Minnesota and the Upper Midwest have been the coolest place on earth relative to average this year. The rest of earth continues to run a fever.

Rochester may be ground zero for the coolness this summer. So far the thermometer has only managed 86 degrees in Rochester this summer. If that stands, it would be the coolest summer maximum on record.

The story from NWS La Crosse.

[image]

Minnesota State Fair heat wave developing?

It seems predictable as clockwork. We muddle through a languid August. Then a heat wave hits just in time for the State Fair.

Will it happen again this year?

It's too early to say for sure, but the National Oceanic and Atmospheric Administration's Global Forecast System model seems to be latching on to a solution that could send a puff of hot stuffy air north into Minnesota sometime during State Fair week.

Here's an admittedly early look at the GFS 500 millibar upper air chart for Thursday Aug. 21.

1806 heat
A developing ridge of high pressure called the "Bermuda High" may bring heat to the Midwest sometime during State Fair opening week. Image: NOAA

The GFS 16-day output is cranking out some eye opening, even withering heat numbers. Several days in the 90s with temps as high as 98 degrees? Probably not that intense but worth keeping an eye on.

1806 16 2
NOAA via IPS Meteostar

Minnesota State fair time is legendary for sudden heat waves popping up as summer makes one last gasp.

As we say in the weather biz, stay tuned.