September summer; Florence takes shaky aim

Hobbits might call this week “second summer” in Minnesota. Our breezy to windy, warm, and slightly humid air mass lingers this week. Highs in the mid-80s are more typical of late July or early August. Augtember indeed.

One thing all Minnesotans know? It won’t last forever. A fall-like air mass is ready to push south into Minnesota next week.

Temperatures do a face-plant next week.

National Oceanic and Atmospheric Administration, via Weather Bell

Florence takes shaky aim

Steering currents and forecast models are in close agreement with the track of Hurricane Florence for the next 24-48 hours. By late Thursday, the storm rakes the Carolina coast with hurricane-force winds.

After that, the air currents steering Florence collapse. Wide forecast model variations emerge in the ensuing chaos of erratically weak upper winds.

Here’s the official National Hurricane Center forecast track.

Scary scenarios

It’s important to use the official NHC forecast track. These are the most seasoned group of hurricane forecasters on the planet. But I think it’s important to talk about some of the range of model solutions we’re seeing now.

The truth is there are some scary solutions for landfall scenarios along the Carolina coast Friday. Here are two widely divergent models forecasts.

European model

The usually trusty European Centre for Medium-Range Weather Forecasts model continues to be the left track outlier. Today’s Euro run brings the hurricane to near Wilmington, N.C., then skips it southwest along the coast toward Myrtle Beach and Charleston in South Carolina, before a turn inland to near Atlanta.

That would be an extended horror show of surge and wind damage along the coast. Again, this is just one model. But…

ECMWF model from Sept. 12 to Sept. 17, via tropical tidbits

Canadian model

Other models like the Canadian paint a more northerly scenario of a hurricane stalled for 2-3 days near the Outer Banks. This scenario would be a devastating blow to North Carolina’s Outer Banks with possible overwash from the Atlantic and sound directions.

Canadian GEM model via tropical tidbits

The point in showing these two different scenarios is this. Everyone in the hurricane zone needs to prepare as if they will get a direct hit. Model consensus deteriorates quickly at landfall. Don’t focus on any one model solution, especially on this storm.

Flooding rains

One of the biggest threats with this storm will be torrential flooding inland rainfall. Some models project potential Harvey-level rainfalls of 30 to 40-inches.

Costliest storm ever?

Core Logic is out today with an early estimate of 170-billion in damages from Florence given current track scenarios.

As Hurricane Florence bears down on the southeastern United States, nearly 759,000 homes are in the storm’s path, and a worst-case rebuilding scenario could cost more than $170 billion, according to an estimate from real estate data provider CoreLogic.

CoreLogic calculated the reconstruction cost value, which is the total expense of completely rebuilding a property in case of 100% destruction, for 12 metro areas in the Carolinas and Virginia.

If Florence damage reaches that level is would surpass Hurricane Katrina as the costliest in U.S. history.

Stay tuned.