In what could be the first of three pre-Christmas winter events, Gwinnett County is waking up this morning to an ice storm. Originally predicted to stay north of our area, temperatures dropped enough prior to the onset of rain to create a hazardous situation once the rain began to fall.

The Weather Service gave up shortly after midnight and issued a winter storm warning for Gwinnett County and Northeast Georgia until 6 PM on Thursday. Peering outside, light ice has formed on the trees. Several areas are without power, including parts of Lilburn and Duluth, although the situation so far doesn’t seem too serious.

Here, temperatures dropped as low as 30.9 degrees around 1 AM before starting to rise slightly, although the thermometer hasn’t gone above the present 32.5 degrees. Once day breaks, the question is how fast and far the temperatures will go up. For areas to the south and west, we’re likely to see above freezing temperatures after sunrise. North and east may see temperatures hover in the 32 degree range until afternoon. Both areas will see up to a quarter of an inch of precipitation before things slow down this afternoon.

Forecasters were slightly caught by surprise this morning by the extent of the cold weather’s reach. Atlanta is on the edge of two frontal systems - a high pressure system centered over New England bringing in cold, dry air in from the east, and a low pressure system bringing in the rain from the southwest. This mixture caused a wedge of cold air to get stuck over the north Georgia mountains. Yesterday was expected to make it into the low 40s in northeast Atlanta, with temperatures staying above the freezing mark overnight.

Instead, the wedge was stronger than expected, reaching farther south. the temperature here hit a high of 38 degrees shortly after noon before beginning to fall slightly. By the time the rain arrived in the early evening, the thermometer began to drop even more as dewpoints began to rise.

Even if we manage to dodge the bullet today, there are two more chances of winter weather in the next week - on Sunday, and again on Tuesday or Wednesday. I’ll post more on these possibilities later.

As of noon Saturday, temperatures were hovering around 29 degrees, up from an overnight low of 26°. We had a high of 31° shortly after 7 PM, still below the freezing mark. There is a possibility of additional precipitation this evening, with an upper wave rotating into Georgia. The National Weather Service extended its Winter Storm Warning until 1 AM, citing the lack of improvement in the weather conditions.

It looks like much of the precipitation overnight on Friday night was sleet, with about 1/2 inch on the ground, and less than 1/4 inch of ice on the trees. Later on during the day Saturday, this changed to mixed rain and sleet, which built up the ice on exposed objects to about 3/8 inch, and made driving difficult. The Weather Channel was reporting an inch of sleet as of late afternoon in metro Atlanta. By Saturday night, you could hear the trees crackling as the wind blew, and over 100,000 Georgia customers had lost power due to the storm. The good news is that by 10 AM on Sunday, temperatures will begin to warm up, with a high on Sunday of 44.

To the right is a picture of ice-laden dogwood trees backlit by the neighborhood streetlight on Saturday evening. Click here to view additional pictures of the effects of the weather in our area.

That’s what the forecaster at the National Weather Service called this weekend’s weather in North Georgia. After a brief round of sleet around sunset, the second wave of wet weather arrived in mid evening as far south as Americus, and moved northward, with significant icing across much of North Georgia.

Temperatures continued to drop as the wet weather arrived, caused by evaporational cooling. In metro Atlanta, temps were in the mid 20s at 5 AM, with freezing weather as far south as middle Georgia. At this point, temps are not expected to go above freezing until sometime Sunday morning. Freezing rain, and possibly some snow will continue throughout the period, with the heaviest icing in the metro Atlanta area. After 7 PM, the chance of freezing rain drops overnight.

The winter storm warning remains in effect until 4 PM. Travel isn’t recommended, with I-85 closed in the Hamilton Mill area. Looking out my window, I can see what looks to be about a quarter inch of snow/sleet on the ground, not only in grassy areas, but also on the street. I’ll try to get out once it gets light to get some pictures. Some folks have posted their experiences from earlier last evening in the ‘comments’ area of the post below. Please tell us what you see using the Comments link.

The National Weather Service forecast map for today shows the wide-ranging effects of the storm. While we’re getting freezing rain, heavy snow is possible in an boomerang shaped area from eastern Illinois, to West Virginia, and on south through eastern Tennessee. The freezing rain will move up through North Carolina and Virginia.

It’s beginning to look like the area of freezing rain predicted for this weekend is being extended south and west of where it was estimated to be on Tuesday.
As you can see in the image at the left, light rain moves into Gwinnett county by 10 PM on Friday, and turns into freezing rain by 4 AM on Saturday. The area of freezing rain moves eastward and becomes more widespread by 10 AM, and should be all rain by 4 PM. The freezing rain should stay north Interstate 20.

Temperatures should drop below freezing around midnight Friday, and could reach 28 degrees just before sunrise Saturday, and will probably rise above freezing around noon. Of course, all of this is still two days away, and the forecast could change, but it might be a good idea to get your errands out of the way today and tomorrow.

Although the threat of freezing rain ends as things warm up Saturday afternoon, we’ll still see cloudy, wet weather typical of a wedge situation until Tuesday, when high pressure moves into the area. We’ll probably see a total of about 1/2 inch of precipitation throughout the period.

January is likely to end up being a dry month. We should normally have just over four inches of rain by the end of January; I’ve only recorded 1.14 inches of rain so far, with most of that recorded on January 14th. Hartsfield Airport has had 1.57 inches. Even if we get half an inch over the weekend, we will end the month with two fewer inches of rain than normal.

It looks like Gwinnett County could be in the middle of a battle between two weather fronts, and the result could be some freezing rain on Saturday.

After pleasant weather today and tomorrow, with highs around 60 degrees, a front approaching from the north will bring colder, dry air into our area on Thursday and Friday. By Friday, high temperatures will only be in the mid 40s.
Meanwhile, a second front is approaching from the southwest. As it travels through Texas and the gulf states, it will pick up moisture from the Gulf of Mexico and bring rain into Mississippi and Alabama on Friday, and into south Georgia on Friday.

By Saturday, things get interesting as the warm moist southern front overtakes the cold air over north Georgia. As you can see on the map to the left, freezing rain is currently expected to occur north and east of Gwinnett County. However, at this point it is really too early to tell exactly where we will have rain, and where we will have freezing rain. Stay Tuned.