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.)

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A change in the weather pattern is going to bring a good chance of precipitation to much of the southeast starting just as people are heading out to their Thanksgiving destinations, and continuing through the first weekend in December. First, however we will enjoy pleasant weather through Wednesday, when an approaching cold front could bring half an inch of rain to North Georgia before it passes over late Thursday or Friday morning.

If you’re traveling to the Midwest, there’s a chance of showers, while thunderstorms are in order for Alabama and Mississippi.  There’s a small chance of rain in Florida and the Carolinas.  And, travel could be complicated along the line of an approaching cold front, which should be affecting a line between Oklahoma and Ohio during the early travel period.  There will be rain in front of the front, and snow behind it.  Here’s a map of expected weather conditions around the country on Thursday morning:

Once the front passes through, it should be fairly quiet in the Southeast US through the first part of the weekend.  The big difference is that instead of the upper level air flow being dry out of the northwest, it will come from the southeast, allowing gulf moisture and higher dewpoints than we’ve seen for the past few weeks.  That will give the next front something to work with when it comes through on Sunday.

There are additional chances for rain in the Southeast, with the GFS model calling for a low pressure system to bring rain from Tuesday the 27th through Thursday the 29th, and another storm the first weekend in December.

Even if all the precipitation comes through as promised, we’ll still have less than normal rain for November. So far this month, Atlanta has had only .14 inches of rainfall.  Here in Lawrenceville, I’ve recorded .36 inches.  That’s a long way from the 4.1 inches we would expect for the entire month.

Today ended up being a big day for releasing weather data and forecasts, so let’s take a look at the news:

First of all, the Weather Service issued its final Winter 2007-08 forecast. Because of the strengthening La Nina in the Pacific, the revised forecast slightly extends the boundaries of the wet/dry warm/cold areas it predicted in it’s preliminary October forecast. If conditions go according to the forecast, it’s going to be wetter than normal in the Pacific Northwest and in the Ohio/Tennessee Valleys, and drier than normal for much of the southern half of the country, including virtually all of Georgia. It’s also going to be warmer than normal for most of the country, except the Pacific Northwest, with the heart of the heat in the Plains States.

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