It’s that time of the year again when the peak of the Atlantic hurricane season is almost upon us. September 10th marks the annual peak and with that being said we are seeing numerous waves lining up across Africa that will have their day once they cross into the Atlantic.
The wave leading the pack is Hurricane Fred which is currently crossing over the Cape Verde Islands. Fred has the dubious distinction of being not only the easternmost hurricane ever, but also the only hurricane to ever cross directly over the Cape Verde Islands. Usually it takes these waves a bit more time to develop, but Fred was an early bloomer. Fred won’t have much left after it passes the Cape Verde Islands and should degenerate into a depression and then tropical wave by the end of the week.
Then you have to come all the way to the other side of the Atlantic to find the next system of note, and that would be the remnants of TS Erika which is parked off the southwest coast of Florida. It now appears that the remnants aren’t going to have as much of an impact on Florida and the Southeast as first feared. Parts of Florida will still see significant rains, but the flooding should be minimal. Here in Georgia any heavy rain from Erika will be confined to South Georgia. You can see from the RPM model that only scattered showers will develop in North Georgia on Wednesday while pockets of heavier rain will barely make it above the Florida-Georgia line on Wednesday, with most of the activity offshore of the Georgia Coast on Thursday.
So what seemed like a wet week here in North Georgia now looks to be a mainly dry week with just a few showers from time to time. Looking back on August that is probably not such a bad thing as we ended the month well above normal on our rainfall total.
So what is in store for the month of September? All indications point to a dry and warm month due to the continued presence of the strong El Nino. As you can see temperatures for much of the eastern half of the nation will be well above normal for September.
Dry weather is expected for much of the Northeast, Mid Atlantic and Southeast states as well as the lower Mississippi Valley and Texas. Above normal rainfall can be expected from the Desert Southwest to the Rockies and into the Central and Northern Plains.
So far the Hurricane Season of 2015 which began on June 1st and end November 30th, has been an extremely quiet one with only 3 named storms in the first two months. The first tropical storm Ana, began as Subtropical Storm on May 8th and eventually was classified a Tropical Storm on May 10th near Myrtle Beach, SC. The second storm Bill formed in the western Gulf of Mexico on June 16th and proceeded to move make landfall in Texas on the same day. Claudette formed off the coast of Nantucket, MA on July 13th and proceeded to head into the open waters of the Atlantic. Since then only a few investigative lows have formed, but nothing getting close to developing into a depression or storm.
Can we expect an active back half to the season? Probably not. Reason being there is a very strong El Nino taking place that looks like its going to be around a while. The El Nino is a warming of the equatorial waters in the central and east-central Pacific and this vastly influences the upper level wind patterns downstream.
You can see from the map above that there is an expensive area of pink and magenta colors representing temperatures at or above 30 degrees Celsius (86 degrees Fahrenheit). The warm sea surface temperatures lend themselves to an increase in hurricane activity in the Pacific, but the upper level flow downstream tends to be too strong to allow for development in the Atlantic.
We also have to look to where the storms form this time of year in the Atlantic, and that is off the west coast of Africa. So far this year there has been a fair share of dust coming off of the Sahara that can help to suppress the t-storm development needed to form tropical waves as they move west into the Atlantic. The air has been very dry as well.
In the image above from the University of Wisconsin you can see that the area of dust right now is quite small but the air is very dry especially just north of a few developing waves of t-storms. In the animation below from NASA notice how the dust is forecast to spread farther into the Atlantic by next week. This along with a large area of dry air does not bode well for tropical development.
Just remember that even though the forecast is for fewer storms to develop, we could still have a major hurricane develop and affect the East Coast or Gulf Coast for that matter.
Showers and t-showers will increase Wednesday through Friday as a cold front along with a more active upper level pattern start to move through. Of course today we have seen little if any development thanks in part to high pressure sitting overhead, and dry air mixing in from aloft. In fact between noon and 2pm the dew point temperature dropped 10 degrees. Too bad the actual air temperature didn’t drop as well. So far we have been up to 95 which would tie us for the hottest day so far this summer. If the showers and t-showers develop early enough on Thursday and Friday then there is a chance that temperatures will stay in the 80s!
By the weekend the front should push to our south giving us slightly less humid conditions, and less of a chance of rain. Since it is still August don’t look for any log term cooling to take place. Highs will still hit the 90 degree mark through the weekend and into next week.
In other weather news we have an area of low pressure along the Carolina coast that is being monitored by the National Hurricane Center. This is the same low that formed over the Gulf Of Mexico and brought extensive flooding to the Tampa area.
Although the low will probably never develop into a tropical depression or storm, it will still bring lots of heavy rain and wind to the coast of North Carolina. If it does turn into a tropical depression or storm, computer models take it quickly out into the open waters of the Atlantic which is good news for residents along the coast.
In keeping with the trend so far this summer it would appear that August is going to be a hotter than normal month. In the near term the forecast from the Climate Prediction Center calls for above normal temperatures to continue here in the Southeast through the 16th of August. Since El Nino is locked in and the medium range models are in agreement I see no reason for this not to happen.
As for precipitation, parts of the Southeast will see above normal rainfall, but here in North Georgia near normal rainfall looks likely. This is not to say that a localized t-storm or two couldn’t produce above normal rainfall for any one given spot.
Now the outlook for the entire month paints a slightly different picture. The temperature outlook is basically the same with above normal temperatures expected across all of the deep south.
What differs is the precipitation forecast. The forecast calls for dry conditions across the Southeast and much of the rest of the south which I would tend to lean toward more toward.
So all in all get ready for what will more than likely be a hot, dry month of August her in North Georgia.