Hermine In Focus

Hermine made landfall in northern Florida last night as a category 1 hurricane, the first to hit that state since Wilma tore across south Florida back in 2005. As Hermine continues it’s journey northeast bound, through Georgia, South Carolina and North Carolina, wind, heavy rain and isolated tornadoes will continue to plague those areas.  By midday Saturday, Hermine comes off the Carolina coastline, moves northeast and then stalls out. Where it stalls out, for how long and what’s it next move, are questions that are important to our long range forecast. Below is the 5am update from the National Hurricane Center. Notice how the cone becomes a circle?  It essentially expresses uncertainty in the track by Tuesday and Wednesday.

While there’s uncertainly in the long range, we can look at what the pattern suggests the set-up be, and what the most likely impacts are through the weekend. The chart below shows different models and their thoughts on Hermine. That cluster off the mid-Atlantic coastline and south of New England suggests good agreement on Hermine stalling out close enough to have some impact to our forecast.

As some non-tropical factors influence Hermine later this weekend, the opportunity for a rain/wind shield expanding some Sunday and Monday is there, before contracting again Tuesday/Wednesday. What that means to our forecast is that the expanding wind field likely increases the breeze here Sunday, and by Sunday afternoon/Sunday night, gusts past 40mph are likely across the Cape and Islands, especially over the Islands.  For the rest of us, 25-35mph gusts are possible, with the strongest along the coast.  The gusty wind on Sunday is in part due to the strong high pressure banked to our north too. The big difference from high to low pressure creates gusty winds. Although the breeze picks up Sunday, most of the showers hold off until Sunday night and Monday (although some afternoon showers are possible for the Cape/Islands Sunday). Showers and a gusty wind are likely Monday, with gusts Monday around 25-40mph, strongest near the coast.  With all this said….If the track is closer, wind/rain threat goes up. If the track is farther away, less wind and rain.

Beyond Monday, the wind field and rain field likely contract again as Hermine becomes more tropical again.  That could pull back the rain/wind chance here. The caveat to that forecast is where does Hermine track on those days?  If by mid-week, Hermine makes a closer pass to New England, then the rain/wind threat, especially near the south coast of New England, will still be there.  Certainly plenty to watch the next several days!

While we do have lower astronomical high tides early next week, with such a powerful storm to our south, and one that lingers for days, minor coastal flooding and beach erosion is possible. The more significant beach erosion will likely be on the south and east facing sides of the Islands, Rhode Island.  Coastal flooding and erosion could be a major problem for Long Island, New Jersey and much of the mid-Atlantic as they’re most exposed to the surge and waves from this storm.