Aug 5, 2014

Tropical systems to threaten Hawaii..while Bertha threatens North Atlantic shipping lanes

Trop. Storm Julio
Tropical cyclone activity in the Pacific Ocean continues at above normal levels with the 10th named system, Tropical Storm Julio  located about 1145 miles to the SW of the Southern Tip of the Baja Peninsula. Julio is forecast to move toward the WNW over the next 5 days and slowly intensify to hurricane strength. Winds are currently near 60 mph this early Tuesday morning and are forecast to increase to near 85 mph by Friday morning then weaken to near 75 mph by Sunday morning.

NHC forecast track for Julio
Currently sea surface temperatures are very warm along the forecast path of Julio which has the storm located to the ENE of the Big Island of Hawaii by Sunday morning.

Major Pacific Hurricane Iselle
 Of greater concern for the Hawaiian Islands is MAJOR Hurricane Iselle. Early this morning Iselle was located about 1055 miles to the ESE of Hilo, Hawaii, moving toward the West at 9 mph. Iselle is a Category 3 hurricane (it was a CAT 4 storm yesterday) with maximum winds of 125 mph. Iselle is expected to weaken very slowly over the next 24 hours with a slight turn toward the WNW. It is possible that tropical weather watches may be required for (parts of) the Hawaiian Islands later today or tonight; for sure ALL interests in the Hawaiian Islands are advised to monitor the progress of Iselle. The forecast track for Iselle is fairly straightforward with the system expected to affect the Hawaiian Island during Thursday through Friday. The uncertainty is in how strong will it be when it does impact the Islands' weather.
Forecast track of Iselle

For now the potential for Iselle to be a strong tropical storm (with winds of 55-73mph) when it affects Hawaii is estimated to be about 70%; there is about a 20% chance that it could be a weaker tropical storm and a bout a 10% chance that it could still be a minimal hurricane.

Over in the Atlantic the second named tropical cyclone of the season continues to churn toward the north-northeast and out to sea away from the U.S. mainland  at a speed of near 22 mph. It is also weakening as increasing wind shear aloft continue to push the strongest convection toward the northeast, away from the lower-level circulation. Loop of Tropical Storm Bertha . The forecast track of Bertha calls for acceleration and continued weakening over the next 36 hours. After this time Bertha is expected to become a post-tropical or extratropical cyclone that will rapidly accelerate toward the east or east-northeast and perhaps affect Western Europe (Iberian Peninsula) and/or  the British Isles by Sunday.
Forecast track for Bertha