At 11 a.m. HST Friday, Hurricane Lowell's center sat near 13.2 north, 160.7 west, about 615 miles south of Lihue and 590 miles south-southwest of Honolulu, moving west-southwest at 7 mph with maximum sustained winds of 150 mph and a central pressure of 926 mb. [1] It is a Category 4 hurricane. There are no coastal watches or warnings in effect. "Watches could be required for portions of the westernmost Hawaiian Islands on Saturday." [1]
Thursday's file held Category 4 at 140 mph, no watches, a wide-error north turn, and a swell that can kill a swimmer now. Friday does not write the landfall. It writes 150, a Category 5 door left open, and a Saturday watch the National Hurricane Center has forecast and not posted.
The morning was a staircase, not a second storm. At 5 a.m. HST, Advisory 33 still had Lowell at 125 mph, a Category 3, with a pressure of 947 mb and no watches. [4] At 8 a.m., Air Force Reserve Hurricane Hunters found winds near 150 mph and a pressure of 936 mb. A special advisory was to follow. [3] By the 11 a.m. package, dropsonde data put the pressure near 926 mb. Peak winds around 130 knots. The eye had become larger and more distinct, with mesovortices on satellite and an eye temperature near 20 C. Eyewall convection was more symmetric than it had been at dawn. [2] Do not treat the 5 a.m. dip as a separate story. Thursday was 140. Friday midday is 150.
Some additional intensification is possible. Lowell could regain Category 5 strength later Friday or Friday night if the inner core stays symmetric in conducive conditions. [1] [2] A pronounced increase in southerly or southwesterly shear and cooler water should then start a weakening trend in a couple of days. Confidence is high that Lowell will be weakening as it nears the western islands. Confidence is also high that it will still be at or close to major hurricane strength. [2] Hurricane-force winds now extend up to 60 miles from the center. Tropical-storm-force winds extend up to 160 miles. [1] That is a larger wind field than Thursday's 40 and 140. The land hazard NHC named first is still the one already in the water. Swells are likely to cause life-threatening surf and rip currents across many of the islands for several days, and those swells are likely to increase early next week. [1] [2]
The track is the sentence weather accounts will rewrite. A general west-southwest motion with a gradual decrease in forward speed is expected for about a day, then a sharp turn north or north-northeast on Sunday. [1] That turn is supposed to bring the system close to the westernmost Hawaiian Islands on Monday and Monday night. [2] Predicting where and how sharply Lowell turns, the discussion said, depends on the location and amplitude of a mid- to upper-level low relative to the hurricane. The official track is close to the previous one and in good agreement with the Google DeepMind ensemble mean and the simple consensus. [2] Spaghetti is not a watch.
Rainfall is a later hazard, not today's posted product. Lowell is expected to produce 3 to 6 inches on Kauai and the Big Island, with isolated totals exceeding 10 inches. Maui is 2 to 4 inches, isolated 8. The remaining islands are 1 to 2 inches, isolated 4. Flash flooding and mudslides are possible in steep terrain. [1] Heavy rain is forecast to begin Sunday afternoon. [2] Kauai County is named for storm-surge and wind risk early next week. [2] Named risk is not a posted watch.
Key message one is the gap. Lowell is forecast to be near major hurricane strength when it moves close to the western islands late Monday and Monday night. "Watches will likely be issued on Saturday." Residents should have a hurricane plan in place. [2] Friday's public advisory still reads: there are no coastal watches or warnings in effect. [1] Weather X will file Iniki 2.0 from a north turn and a Kauai rainfall line. NHC's Friday record is 150 mph, still no watches, and a likely Saturday watch it has not posted. Those are two different sentences. Only one of them is on Advisory 35.
-- DARA OSEI, London