Today is Candlemas Day, the second of February, when the Groundhog is supposed to predict the likelihood of an early Spring. While Pennsylvania’s Punxsutawney Phil is probably the best nationally known prognosticator of the weather, many others of the species Marmota monax are weighing in as well.

In Shubenacadie, Nova Scotia Sam the woodchuck failed to see his shadow in the rain this morning, foretelling an early Spring. Another Canadian groundhog, Ontario’s Wiarton Willie, concurred. In New York, Staten Island Chuck is also calling for an early Spring, although I suspect many New Yorkers would at least like to see some snow before that happens. Ohio’s Buckeye Chuck predicted an early spring in Marion. He’s been making forecasts since 1979. And in Woodstock, Illinois, where the movie Groundhog Day was filmed, Woodstock Willie opined that an early spring was on the way as well.

Punxsutawney Phil might say these five are amateurs. at Gobbler’s Knob, where people began lining up at 3 AM in anticipation of his prediction, Phil saw his shadow just before 7:30 AM, and predicted six more weeks of winter. But here in Georgia, General Beauregard Lee awoke from his sleep at the Yellow River Game Ranch and did not see his shadow, making it six marmots to one in favor of an early spring.

Of course, we won’t know which prediction is correct for another two months. However, the National Weather Service, which is a bit more scientific in its predictions is calling for a good chance of warmer than normal weather for most of the eastern half of the United States in February, so maybe the groundhogs will be right.

It looks like things could get fairly nasty Wednesday Night and into Thursday for much of the Atlanta area north of Interstate 20, and especially for the northeast counties, including Gwinnett.  An incoming low pressure system in the Gulf of Mexico will bring precipitation to Georgia beginning Wednesday morning.  Meanwhile, the high currently over the eastern part of Kentucky will move northeast, running into the Appalachians, and causing a ‘wedge’, or cold air damming to affect northeast Georgia.

What happens is that the colder air gets trapped on the western edge of the mountains, and the approaching lower pressure, warmer air slides above the colder, heavier air. You can tell when we’re in a CAD situation when the wind comes from the east, and it doesn’t warm up much during the day.

The presence of warm air above cooler closer to the ground tends to favor the formation of sleet or freezing rain, since the warm air layer will melt any snow as it passes through, while the cold air close to the ground will either re-freeze the precipitation, or cause freezing when the water hits the surface.

In the last day, forecasters have increased the total amount of expected precipitation from the storm to almost an inch, while dropping the low temperature Wednesday night, especially in the northeast counties most affected by the wedge.

(more…)

For fans of changing weather, January so far has been right on target. After starting the year with temperatures well below normal, last week brought high temperatures 15 to 20 degrees above normal.   This week, the pattern will change again, and  bring the possibility of some  sort of frozen precipitation to  North Georgia.

A cold front will move through Georgia today, although it won’t bring any sort of precipitation. After the front passes, look for skies to clear, and temperatures to return to normal or slightly cooler than normal.

Things begin to get interesting on Wednesday, as a low pressure system develops in the Gulf of Mexico, and moves northeast into Georgia, bringing gulf moisture and a chance of precipitation by Wednesday night.  Meanwhile, high pressure out of Canada will force the jet stream southward, bring colder air to the region.  Exactly where these two systems meet will determine what type of precipitation we get.

Right now, forecasters are calling for half an inch of precipitation from the system, with lows Wednesday night just below freezing.  If the storm sticks around long enough, lows will be in the upper 20s Thursday night after daytime temperatures only in the 40s.  It’s possible we could get snow, freezing rain, or sleet, and south of Interstate 20, it will probably be all rain.

The forecast is still long range with plenty of possible outcomes, so I wouldn’t go and get the  sleds out yet.  But, it’s worth keeping an eye on.

The Atlanta Journal-Constitution today ended its Christmas editorial with a wish that it would just precipitate. 2007 had the possibility of going into the record books as the driest year on record, which is currently held by the year 1931, with 29.14 inches of total rainfall. As of this morning, Atlanta saw 28.69 inches of rain, and today Hartsfield-Jackson airport recorded 58 inches of rain. bringing the total to 29.27 inches. Most of today’s rain stayed to the western half of the state, so Gwinnett county recorded much less, but it’s Hartsfield that counts.

But, the situation could get even better. The most current precipitation forecast from NOAA’s Hydrometeorological Prediction Center calls for between three and four inches of rain in North Georgia between now and Sunday night, December 30th. You can see their predictions in the map to the right.

Accuweather.com says that we should get more than 3.1 inches of rain in the next five days. Of course, we’ve seen these precipitation forecasts become busts more often than we’d like. Despite many optimistic forecasts, you would have to go back to November 2006 to see more than 2 1/2 inches of rain in a five day period, and back to July, 2005 to see 3 1/2 inches of rain in five days.

But, it’s the holiday season; a time of goodwill and wishes coming true. Like the AJC, I wish for rainfall, and hope that you and yours enjoyed the best Christmas ever.

Depending on where you were, you may have been disappointed with the Thanksgiving Day rainfall totals. Here in Lawrenceville, I recorded .15 inches for the storm, which is less than many other areas did. Looking at the radar as the storm passed over the Atlanta metro area, most of the rainfall seemed to be to the north of Georgia 316, and that’s borne out by some of the precipitation reports:

Athens: 1.17 inches (they really needed it)
Gainesville: .46 inches
Johns Creek: .93 inches
Alpharetta: 1.09 inches
Rome: .87 inches
Atlanta: .16 inches

The good news is that we’re due for some more rain before the month ends, and then at the beginning of December. Cooler air is beginning to filter into the state from northwest to southeast, and Friday should be a sunny, if cool, day for shopping or golf. (Someone told me that the day after Thanksgiving is one of the biggest days for golf - the ladies go shopping and the men to golfing.)

(more…)