You’ll be hearing quite a bit about Pacific hurricane Guillermo over the next several days. The track forecast suggests that it could impact Hawaii sometime next week but that is not a certainty, not by any means.
Right now, Guillermo is a category one hurricane with 90 mph winds. Overall, the environment looks favorable for additional intensification and it could become a major hurricane over the weekend.
Water temperatures around Hawaii are running above the long term average due to a spike in northern Pacific sea surface temps this year. However, warm water alone is not enough to bring a hurricane in to Hawaii. The NHC notes on their most recent forecast discussion that upper level winds are likely to be less favorable in the latter part of the forecast period, causing the hurricane to weaken quite a bit before reaching Hawaii. This weakening would also have an impact on steering as well.
If Guillermo weakens and loses a lot of its deep convection, then it is prone to bending back to the west more with time, steered by lower level winds. If this happens sooner rather than later, there is a good chance that Hawaii is only grazed by a passing tropical storm to the south. Obviously, this can change and it really depends on how strong the shearing winds are and when they begin to adversely affect the hurricane. For now, interests in Hawaii should simply be monitoring the progress of Guillermo as it tracks over open water.
Meanwhile, in the Atlantic Basin, all is quiet. The NHC has lowered the chance for development of invest area 94L to 10% over the next several days. None of the global models show the tropical wave surviving the hostile environment of the tropical Atlantic. There is still way too much African dust and drier more stable air in place for anything to have a chance out that way.
Looking down the forecast road, it appears that while several tropical waves emerge from Africa as we begin August, none ever make it past about 40 degrees west longitude before being eaten up by shear or dry air. This is almost exactly what was expected to happen this hurricane season though it is hard to imagine that nothing will ever develop in the deep tropics. Sooner or later, a small window of opportunity will open, even if only for a few days, and we’ll see one or two Atlantic hurricanes. For now, such is not the case and is likely to remain that way for the next several days.
I’ll have more here over the weekend concerning Guillermo in the Pacific.
M. Sudduth 1:40 PM ET July 31