Matthew’s Track Moves West Again

October 6th, 2016

The track for Matthew has again moved west. Coastal Glynn County is now at the very edge of the hurricane-force wind field. Our NWS forecast now predicts that we will receive sustained winds of 55 MPH with gusts up to 75 mph. The winds are predicted to peak from about 9 PM Friday and last until 4 AM Saturday. There is currently a flood watch from now until Saturday, and a hurricane warning in effect for an unknown time.

In the overall weather picture, our winds, now 13 MPH, will begin to increase after noon tomorrow, peaking at the above speeds and times mentioned above. Then, as the storm passes, the wind will gradually wind down to about 20 MPH at 2 PM Saturday afternoon. The rain amount forecast hasn’t really changed, except that there is, unsurprisingly, a 100 percent chance of rain for a longer period.

The voluntary evacuation orders issued by Glynn County are still in effect. So far, no mandatory orders have been issued.

Having written all that, I’d like to point out that we are seeing a unique meteorological event. There is a second tropical weather pattern in the Atlantic named Tropical Storm Nicole (60 MPH winds). Matthew and Nicole are both influencing each others tracks in a big way. Because of this interaction, Matthew is now predicted to make a loop of around 1000 miles, and hit us again next week, as early as Monday. Everybody I talk with or read is expressing the same thing – variations on “Wow,” “Um,” “OMG,” “WTF.” And so on. I’ve seen storms loop from time to time, and I’ve even seen, as late as last year’s season, storms merge, but I’ve never seen anything like this before.

Remember that all these are predictions. And predictions change.

Glynn County Severe Weather PSA Page

October 5th, 2016

I’ve just become aware that Glynn County has a page on their web site devoted to severe weather, tropical storm and hurricane announcements. Here it is:

Severe Weather /TS/ Hurricane Updates

The announcements are issued both on the web page as PDF files and are sent out by e-mail. Here is an excerpt from the current announcement regarding the voluntary evacuation:

Glynn County Board of Commissioners has called for a voluntary evacuation for the islands (St. Simons, Jekyll Island, Sea Island, and Little St. Simons Island), low lying areas, and mobile homes that is effective immediately. At this time, an evacuation of the mainland is not anticipated. There are no plans to close {the] FJ Torras causeway at any time during the storm unless it is physically impossible to cross the causeway due to water. However, should conditions warrant a closure, emergency services will no longer be available to island residents and evacuation will not be possible.

h/t Jacinda Creech

Start Of Tropical Storm Force Winds

October 5th, 2016

I’ve just become aware of an error in local media claiming that tropical storm force winds will start for the Golden Isles as early as tomorrow. I’m not saying it won’t happen, but it’s extremely unlikely to happen. Hurricane Matthew hasn’t even passed Cuba yet, and it outlying cloud cover is only now due east of southern Florida. In addition to that, our own forecast from the NWS is that winds will cross the 35 MPH threshold after 6 PM Friday night. I simply don’t see how it is possible for us to have tropical storm force winds that early.

On the other hand, the headline and story could be referring to the eastern coast of Florida south of Melbourne. Melbourne is forecast to have winds of 36 MPH at 10 PM Thursday night.

Five AM Update on Hurricane Matthew – it might loop?

October 5th, 2016

It is my pleasure to announce that the predicted track for Hurricane Matthew has moved back towards the east. It is almost as far east as it was yesterday at 5 AM. As of today’s 5 AM forecast, the storm’s center will make its closest approach between 2 AM and 5 AM Saturday morning at a distance between 60 and 80 miles.

As time moves forward, our weather forecast is beginning to anticipate the actual weather we will experience. From now until 5 PM Friday, our winds will be around 20 MPH with gusts to 30. At 5 PM Friday, the winds will gradually increase until 2 AM Saturday (passage) when they will peak at 45 to 50 MPH with gusts to near 70 MPH. Rainfall amounts are hard to predict, but anticipate 8 inches or more. That’s in addition to the foot of rain we’ve already had from Hermione and Julia.

The six-hour rain forecasts break down like this, from 8 PM Thursday to 2 PM Saturday.
8 PM – 0.18 inches
2 AM – 0.25 inches (Friday)
8 AM – 0.80 inches
2 PM – 2.07 inches
8 PM – 2.60 inches
2 AM – 1.70 inches (Saturday)
8 AM – 0.19 inches
And it falls off after that.

The track of Matthew is looking kind of strange. The NHC is now predicting that Matthew will make a sharp turn towards the northeast then east within a few hours after passing Glynn County. It will miss Savannah, Georgia by over 150 miles. The end of the track looks like it might begin a loop. I’m less than convinced that the front that passing us now will steer the storm away from the coast by that much. Getting the current NHC update on Matthew is doubly important, because the track could change back towards the west just as radically as it did from last night to this morning.

Passage Of TS Julia at 5 AM

September 14th, 2016

The last thing I ever expected is that Invest 93L would organize over land into a tropical storm. But, that’s what happened last night. Starting at 11 PM last night, the NHC began issuing advisories to TS Julia, just as the storm was passing Saint Mary’s, Georgia. The storm was and still is, moving very slowly to the north.

The center of TS Julia passed Saint Simons at around 5 AM this morning, as signified by the low pressure of 1011 MB. All of Julia’s rain activity seems to be in the northeast quadrant of Julia, and radar shows that has passed north of us. The clouds in general are in the eastern half of the storm, so those will be with us for a while.

As far as total rainfall, the weather station at McKinnon Airport (KSSI) is reporting a total of 6.47 inches since yesterday morning at 9 AM. Top winds were recorded at around 2 AM, with a speed of 28 MPH and gusts of 38 MPH. More often than not, after 2 AM winds have been measured above 20 MPH.

Landfall of Hurricane Hermione Soon

September 1st, 2016

As of the 11 PM advisory, Hurricane Hermione had winds of 80 MPH and a central pressure of 983 MB. The storm continues to move towards the NNE at 14 mph. The center of Hermione is expected to make landfall in a few hours.

Hermione’s closest approach to coastal Glynn is estimated at around 65 miles to the west in a little less than twelve hours. We are already under a large rain band that will rotate out in about six hours, but by then the central part of the storm should be close enough for us to be under another band. In other words, we might be under continuous rain clouds for the next eighteen hours.

Keeping in mind that the NWS forecast almost always over-estimates threats, the coming hours will bring us high winds, steady medium and heavy rainfall, and possible tornadoes. The key word in my previous statement is “almost.” It could turn out as bad as predicted but it’s hard to know for sure. Still, it’s wise to be prepared without being alarmist.

Starting at around 3 AM our winds will begin to rise from their current 18 MPH to a peak of around 50 MPH with 67 MPH gusts at around 7 AM. The winds are forecast to stay peaked until 11 AM when they will gradually fall back to the 15-20 MPH range by 4 PM. Rainfall will be in the order of 3-1/2 to 4-1/2 inches by nightfall. Tropical storm Dolly dumped almost six inches of rain on us four years ago, so Hermione’s rain will not be outside our experience.

At the moment, there is a tornado watch until 8 AM and a flood watch through tomorrow evening.

What I’ll be watching for more than anything else is the barometric pressure. It’s falling very slowly as the storm approaches, and when it starts rising again, I’ll know that the center has passed. There will still be high winds and a lot of rain to fall after that, but at least I’ll know the storm will end.

Update: a very useful feature from Georgia Power called “the Outage Map” shows that 433 people are without power on the Island.

Tropical Depressions 08 and 09

August 30th, 2016

Over the next five days our weather will be influenced by, not one, but two tropical depressions.

Just south of TD 08 is a large area of water vapor and storms extending down the South Carolina, Georgia and Florida coasts. This area of moisture is flowing from the Atlantic and is helping to steer TD 08 away from land. Our weather is already being affected, with the thick cloud cover and rip tide warnings being the most visible results. There is a 50 to 60 percent chance of rain because of this moisture through tomorrow night. The NWS is forecasting at least an inch of rain over the next 48 hours. As usual with rain forecasts, we will probably wind up a bit short of that.

Starting Thursday morning, TD 09 will begin to affect our weather in a big way. The chances of rain increase to 70 to 80 percent, and the wind and rainfall forecasts both increase to tropical storm levels. The rain forecast from 7 AM Thursday to 7 PM Friday tops three inches and the winds are expected to peak at around 2 AM Friday with 50 MPH winds and 65 MPH gusts.

As of the 11 AM tracks of Tropical Depression 09, the storm will be passing over Jacksonville, Florida at 7 PM, Thursday evening. This is also the storm’s closet approach to Glynn County. The tracks have remained remarkably consistent over the last twenty-four hours, so at this point I feel safe in saying that Thursday and Friday’s weather forecast from the NWS is fairly accurate in timing if not in magnitude.

As I wrote above, the NWS has, far more often than not, over-estimated the winds and rain from a passing tropical system. Even so, be prepared for anything, including high winds, blinding rain, rip tides, and tornadoes.

Passage Of TS Colin

June 7th, 2016

Tropical Storm Colin made its closest passage to Coastal Georgia at around 4 AM, as evidenced by a low pressure of 1003.1 millibars. The wind peaked at midnight at 15 MPH. The total rainfall was just shy of three inches. Overall, not a bad result of the passage of a tropical storm.

TS Colin is a diminishing threat to the coast. By this time tomorrow, the storm will be well out at sea.

Tropical Storm Warning

June 6th, 2016

Coastal Glynn County has been placed under an open ended tropical storm warning. The rain will continue to worsen until 1 AM as the center passes, then gradually lighten until tomorrow evening. A total of more than two inches is expected. The wind is forecast to stay steady until around 10 PM when it will climb to 40 MPH with 55 MPH gusts. The winds will gradually die down to about 10 MPH after that. There is also a flood watch until 7 AM tomorrow.

As of the 5 AM advisory TS Colin had winds of 50 MPH and a central pressure of 1005 MB. The storm is moving towards the north-northeast at 14 MPH. Landfall is forecast at around 8 PM tonight and the center is now predicted to re-emerge over the ocean just north of Jacksonville, Florida.

Tropical Storm Watch

June 5th, 2016

As of the 5 PM advisory, the NHC has declared the coast from the Altamaha River in Georgia to Flagler Beach, Florida to be under a tropical storm watch. This is an open-ended watch, presumably ending Tuesday night.

As of the 5 PM advisory, TD3 had winds of 35 MPH and a central pressure of 1005 MB. The landfall and exit have been moved a few hours, but the exit point is still at Glynn County at around 1 AM Tuesday night. The winds are forecast to be 40 MPH with gusts to 56 MPH.