Wednesday, December 30, 2009

Updated New Year's Forecast

The two major models continue to differ in the short-term forecast guidance. The NAM forecast model suggests a drier frontal passage while the GFS shows more moisture and greater precipitation. The NAM seems to be too dry and the GFS looks more likely but because of the disparity between the two solutions I am guessing we will experience a hybrid of them.

A slight risk of rain will exist today (12/30) but the greater chance will exist tomorrow as the bulk of the low-level moisture enters the area. Throughout the day on Thursday, there will be a chance of rain showers and as the day progresses, chances of precipitation will rise. By 10PM (12/31), the front will enter eastern Georgia and the last of the precipitation will exist the coast by early Friday morning.

Temperatures around the area will reach approximately 58°F on Thursday. Friday morning, the low will drop to about 52°F on the islands and 49°F inland. During the day Friday, 59°F will be the high temperature and winds will pick up to around 15 - 20mph from the West.

Expect cold temperatures, even on the islands, this weekend and early next week with lows possibly creeping down to 25°F on Tuesday morning.

Happy New Year!

Monday, December 28, 2009

Is it going to rain for the New Year's Festivities?

Rain could move into the area by New Year's Eve and stay in the area overnight into the first day of the new year however I believe the precipitation will be isolated. It is unlikely that we will see a steady rain. At most, we should see decent weather for Thursday, with sporadic rain showers moving into the area by 9PM and that chance of on-and-off rain will continue through the night. The precipitation chances should shrink to close to zero by 12PM on Friday as colder, much colder air in fact, moves into the area. The New Year's weekend looks to become one of the coldest thus far.

New Year's Forecasts

BOTTOM LINE - Temperatures will be cool but not cold on New Year's Eve and Day; precipitation chances will be greatest Thursday (12/31) night and early Friday (1/1/10) morning. However any rain that develops will likely be light dropping little accumulating rain. Probability of Precipitation - 50% inland; 35% along coast.

First few days of the New Year - Very cold and temperatures in Savannah could drop to sub-freezing temperatures for several hours in the mornings (mainly 1/2 - 1/5); along the coast, temperatures could very well drop below 32°F which is highly unusual.

Thurs., December 31, 2009 - High around 54°F and Low approaching 45°F (thought that may occur just after midnight and rise steadily as the morning progresses). Precipitation develops after 6AM ET and chances continue to increase as day progresses. Can't rule out showers moving inland from ocean, as moisture is pulled into frontal zone. Any precipitation will bring little accumulation.

Fri., January 1, 2010 - High reaching around 53°F (but again, this will probably be reached in the early morning) and lows around 42°F (likely reached during last evening hours). Rain chances will diminish drastically by 9AM.

The Quantitative Precipitation Forecast shows little precipitation accumulation for Wednesday and Thursday (from 12/30 7PM ET to 12/31 7PM ET, respectively) and keeps that same pattern of relatively small amounts of precipitation for the area, including Skidaway Island. The first image below is the forecast and note how the high amounts of precipitation have not fallen over the Savannah area, they remain to the west. The same holds true for the second images, which shows precipitation accumulation from 12Z 12/31/09 until 12Z 1/2/10 of around a tenth of an inch.



Two major models, the GFS (18Z) and the NAM (0Z 12/29), both paint different pictures for this upcoming week. The GFS continues to keep moisture in the area much more so by Thursday night, while temperatures throughout the first part of the week remain cool and warm gradually as rain chances increase. The NAM keeps the area drier and cooler, giving the Savannah area a relatively calm weather day on Thursday night and Friday morning.

As for the blizzard that could impact parts of the Northeast around the first of January, the models are essentially guessing haphazardly how strong the storm will be in terms of pressure, whether the storm will have a more easterly or westerly component, and if the precipitation line will be far enough south to impact the ball drop in Times Square. I believe the chances are slim for snow or frozen precipitation on New Year's Eve and the early morning hours of New Year's Day. Most all the models remain in agreement that some type of low pressure system will impact the East Coast and the rain/snow line continues to be located incredibly near the New York City metro area. So this certainly points to the fact that could potential be some mixed precipitation in the general area--but I would not put much faith in that possibility.

On another note, a Freeze Warning is in effect from this evening until 9AM ET tomorrow morning (12/29/09). This event will bring the coldest temperatures of the season to coastal locations, including Halfmoon Landing, Fort McAllister, and Darien.

Stay Warm!

Ways to Communicate with the Skidaway Island Weather Center

Take a quick look at the Social Media websites the Skidaway Island Weather Center is utilizing to communicate with others in our community.

Saturday, December 26, 2009

New Year's Day Storm for the Northeast

Times Square for the New Year's celebration could be snowy and cold, according to current trends and forecasting data. It's too early to begin stating in a definite way that it will snow in New York's Times Square when the ball drops to bring in the new year; but most of the forecast models and the weather parameters have begun to elude to low pressure development and propagation up the East Coast.

The GFS forecast model showed a massive low pressure system moving into the northeast on the 6Z run but that later disappeared on the subsequent ones. The North Atlantic Oscillation values have turned extremely negative, and typically when you see this, there is a higher than normal likelihood of weather system development along or just east of the Continental United States. At one point on the 6Z run, the model showed heavy frozen precipitation in the Southeast, even in eastern Georgia and South Carolina. That's very unlikely, but it points to the fact that the GFS has picked up on something that could develop for the new year.

The DGEX model, on the other hand, forecasts a slightly weaker system but that it will move off the coast faster and will not affect as much of the mainland as the GFS model. The NAM model, while only showing the next 84 hours, shows the low pressure system developing in the Gulf of Mexico that could move through the Southeast and then move off the coast. At that point, the low would either turn toward the United States or move off the coast as a weaker system.

What's even more interesting--there's another storm that the GFS is showing the long-range that could be even stronger and more potent that this one.

It's a difficult situation to forecast. We'll keep you updated. I hope everyone had a wonder Christmas and a happy holiday.

Thursday, December 24, 2009

Christmas Day Rain & New Year's Forecast

Hi everyone. Unfortunately, it looks like Savannah, the Skidaway Island area, and most of southeastern Georgia will see rain on Christmas Day. However, temperatures in the area will be slightly above seasonal levels, given the warm air flowing from the Gulf of Mexico ahead of a cold front that will impact us tomorrow.

This chance of rain has been caused by a relatively strong low pressure system centered near Missouri, propagating northeastward and the resulting cold front moving through the southeastern United States. The front has already spawned several tornadoes in Eastern Texas and parts of Louisiana. It does though look as if we will not have to endure the brunt of the severe weather in our area, even though the Storm Prediction Center has put our area under a slight risk for severe thunderstorms tomorrow (Christmas Day). http://2.ly/dym

Severe weather parameters for the area are marginal and I feel that the potential for tornadoes, the main threat throughout today with the front, will be rather limited. High winds from thunderstorms will be the greatest threat in the area. But again, the potential threat for severe weather will remain low.

Looking at the long-range models, I have seen that the GFS forecast model has begun to show a massive blizzard impacting the northeast states starting New Year's Eve and continuing through New Year's Day. This is extremely unlikely, as the model--at the same time as the blizzard in the Northeast--shows flurries in eastern Georgia and southern South Carolina. Interestingly enough though, I was reading an intriguing article written by Joe Bastardi, a senior meteorologist at Accuweather, who believes that the United States could see the "coldest 10-day opening to January" in nearly twenty-five years. I found this particularly interesting given the level of cold air the same model showing the massive blizzard in the Northeast shows in the long-range.

Whatever the case, cold air will be widespread in the United States during the new year. It is less likely though that this cold air will be in our area. More than likely, we will see seasonable or slightly cooler temperatures in January. As would be expected, the areas that will be most affected by this cold air will be the Plains states, who are at the present experiencing near-blizzard conditions.

Merry Christmas and Happy Holidays! Enjoy the new year!