Lawrenceville Weather Blog

Now, I Wouldn’t Mind Seeing This

2008-08-19T23:28:04Z

Fay continues to strengthen as she moves towards the Florida coast. At 7 PM, she was located 45 miles south-southwest of Melbourne. In their major 5 PM update, the National Hurricane Center didn’t make any major adjustments to the official forecast track, which is predicting Fay will move out into the Atlantic and then make landfall (again) as a hurricane south of Jacksonville, then follow a path along the Georgia-Florida border, and into Alabama. A hurricane watch has been issued from Flagler Beach, Florida north to Brunswick, Georgia.

While the Hurricane Center still thinks that strong upper level high pressure to the north will keep Fay from having much effect on the Atlanta area, Accuweather still predicts that the path will track further north. That’s in line with a few models, including the GFDL, which takes Fay on a path from Brunswick to Chattanooga. Here’s a map of what the GFDL thinks precipitation will be for the six hour period from Saturday at 2 PM:

The white dot represents the approximate location of Gwinnett County. If this model is right, we could have between 3 and 4 inches of rain in that six hour stretch, and of course that doesn’t include what would fall before and after. That would top the 24 hour rainfall of 4.57 inches I recorded back on September 16, 2004 when Hurricane Ivan passed to our west.

Whether the GFDL or another model has correctly pictured the upcoming weather, we’re probably not going to get a better idea until tomorrow night or Thursday, when Fay starts to curve back west. I talked to a friend living in Sarasota, Florida today. She said that although school was cancelled due to the possibility of Fay coming through, she didn’t get any rain at all.

Fay Not Weakening As She Travels Through Florida

2008-08-19T18:48:30Z

At 2 PM, Tropical Storm Fay was located near Lakeport, Florida, about 25 miles southwest of Lake Okeechobee. The storm made landfall near Cape Romano, 55 miles south of Fort Myers around 5 this morning, and has been moving northeast across the Sunshine state. She is expected to move back out into the Atlantic sometime overnight. Here’s a satellite image of Fay taken at 10:15 this morning, with a distinctive eye feature:

The interesting thing is that contrary to forecasters’ predictions, Fay is gaining in strength and intensity as she moves across land. Estimated winds have increased from 60 to 65 MPH, and minimum pressure has dropped from 29.21 inches to 29.12 inches of mercury. These two indicators, plus the presence of an eyewall show there might be more to Fay than was originally thought, and that despite the morning forecast track taking her along the Georgia-Florida border into Alabama, there might be enough strength to keep her out to sea longer, and make an approach closer to the Atlanta area.

We’ll have to see what happens to the intensity of the storm as it continues to move north, and if the predicted path changes again at the next update, due around 5 PM.

Fay Update

2008-08-18T22:43:06Z

Forecasters are having a difficult time predicting the ultimate path and speed of Fay, with the forecast track changing with each six hour update. Sunday at this time, the storm was expected to track through southeast Georgia, exiting into South Carolina near Augusta, and ending up Friday evening near the Kentucky/Virgina/West Virginia border. By this morning, the storm was going to travel roughly the same path, but end up near Asheville, NC. Midday today, the storm was going to move further east into South Carolina. And today’s late afternoon forecast has it as a tropical depression over Brunswick by Thursday afternoon, over Statesboro by Friday afternoon, and close to Atlanta by Saturday afternoon.

You can watch an animation of the 5 day forecast maps here.

Forecasters have slowed Fay down and moved it more towards the heart of Georgia primarily because of developing upper level high pressure to the north that will slow the tropical system down and ultimately push her to the west. That puts is in the scenario outlined by the Peachtree City weather office I mentioned in last night’s post.

The meteorologist who prepared this afternoon’s Peachtree City forecast admitted he was following the Hurricane Center’s guidance on Fay’s path, primarily because the models continue to offer different possible outcomes to the storm. Since the latest update from the Hurricane Center was released after his forecast was, there still isn’t much mention of possible rain. We’ll have to see what tomorrow’s forecast brings.

Fay Could Bring Needed Rainfall to Georgia

2008-08-17T22:46:57Z

Over the weekend, Tropical Storm Fay has made her way across the Dominican Republic and Western Cuba, and is expected to turn north and cross the island overnight. Because of the proximity of Cuba to the storm’s path, she hasn’t been able to intensify very much. I’ve been watching the models and the National Hurricane Center’s estimates of Fay’s path, which earlier in the weekend took the path further east, but now seem to be bringing Fay west again.

This morning’s official track had Fay moving through southeast Georgia and exiting into South Carolina near Savannah. If that is the path she ultimately takes, there won’t be that much of an effect on the Atlanta area. However, this afternoon’s forecast track is a bit further west, with the storm crossing into South Carolina closer to Augusta. In addition, the storm is kept off the coast of Florida until it reaches the panhandle, allowing for development into a hurricane before making landfall. Here is a look at some of the latest modeling:

The white colored track is the official forecast, but as you can see, the models disagree on the forecast path once the storm crosses Cuba. For this reason, at this point confidence in the forecast path remains fairly low. However, this afternoon’s discussion from the weather forecast office in Peachtree City outlines what would be a good scenario as far as the north Georgia drought is concerned:

The real concern arises once the system moves into east GA/SC and what occurs thereafter. The 12Z run of the GFS has returned to the rather ominous theme advertised by yesterday’s 12Z run…namely to track Fay into SE/EC GA…then slowly retrograde the remnants westward across central and into W GA/E AL underneath the building mid-Atlantic upper ridge. The upper ridge is then forecast to build SW into GA…with the remnants of Fay being trapped over the CWA for 3-4 days [...]

This scenario would result in grave flooding concerns for much of the CWA…even more so than indicated yesterday. Any time a tropical system…albeit weak… remains stalled over an area for several days…the flooding threat is very real and serious.

Translating a bit of weatherspeak, the GFS is the main computer model used by the Weather Service to help make forecasts, and the CWA is the ‘county warning area’ that the weather office serves. 12Z is universal time for 8AM EDT. If this is indeed what happens, it will not only provide some short term relief for the lack of rainfall much of the area has seen this month, but it will also allow some recharging of groundwater, and improve stream flows, both major components of the hydrological drought conditions that have plagued the area for the last two years.

If all this does come to pass, it would start sometime on Wednesday and continue through the weekend. But, as I pointed out earlier there is still a lot of uncertainty to the forecast, although I think we’ll have a better picture of what will happen by this time tomorrow.

Fay is Named, Could Affect Georgia Next Week

2008-08-15T21:18:10Z

Tropical Storm Fay was officially named by the Hurricane Center this afternoon. She is located near the Dominican Republic, with winds of 40 MPH and moving west at 14 MPH. The official forecast track takes the storm across Cuba, and making landfall in Florida near Venice sometime Tuesday afternoon, and by Wednesday afternoon, the storm should be approaching South Georgia.

The forecast models for this storm have been steadily moving Fay’s track further and further to the west. Here are the latest models:

A lot can change over the next few days, especially if Fay doesn’t make landfall in the Florida peninsula. However, North Georgia could be feeling Fay’s effects sometime late next week.

Water Wars Continue

2008-08-15T02:08:23Z

You may have had heard two pieces of news regarding the drought, and the Atlanta area’s ability to take water from Lake Lanier. The first bit of news is that the metro area has managed to reduce its water use by 20% in June, compared to June 2007. In Gwinnett, recent usage amounts to 77 million gallons per day, compared to 88 MGD a year ago.

While the reduced use probably mostly comes from the outdoor watering ban imposed last fall and modified this spring, it’s still remarkable that Georgians have responded to the crisis as well as they have. Another article I read says that it took residents of Cary, NC 11 years to reduce consumption by 15% in 11 years, and Tampa Bay reduced consumption by 26% in 12 years.

Realistically, though, a more or less total watering ban isn’t going to be a long-term solution to conserving water, unless we want to sacrifice the quality of life afforded by trees, grass and landscaping. More efficient toilets and appliances, less waste through leaky pipes and other techniques will need to be employed to reduce consumption while allowing conservative outdoor use, and that indeed could take years to complete.

The other major story in the news is a promise by a Federal judge that he will decide if Georgia (and the Atlanta area in particular) has the right to withdraw water from Lake Lanier. He views that question as central to coming up with answers to the ongoing water wars between Alabama, Florida and Georgia.

Many people, upon hearing of this think, “What are we going to do, go without water, since we can’t get it from the lake?” Actually, the reality is different. The real question is whether Atlanta has the right to use Lake Lanier as a storage area for future withdrawals from the Chattahoochee river. Atlanta, like many other cities along the Chattahoochee, has the right to take water from the river, and that’s not being questioned. The issue is whether Lake Lanier can be used as a reservoir to supply sufficient water in times of drought.

The argument is that Congress authorized the construction of Buford Dam and the lake for purposes of flood control, hydroelectric power generation from Buford Dam and maintaining a navigable waterway along the lower Chattahoochee. Because water supply wasn’t mentioned in the authorization, the Atlanta area has no right to control how much water is released. (Of course one could wonder how Alabama’s interest in releasing more water in order to support paper mills and power plants in their state would stand up to the same argument).

If you live in Gwinnett, Hall or Forsyth counties, though, this becomes a tougher question. These counties (or cities within them) take water directly from the lake, not the river. I had the opportunity today to talk with a senior official within the Gwinnett Department of Water Resources who said that the department believes that it has a permit to take water from the lake that will meet county needs until at least 2030. This person also said that if the court decides that the lake can’t be used to provide drinking water they weren’t sure what would happen.

Congress could solve this problem by passing a law authorizing the use of Lake Lanier for water supply to the Atlanta area. While passing such a law would be sure to cause a catfight between representatives of the southeastern states, it may be the only way to solve this problem permanently.

Of course, an easier way to fix the problem, at least in the short term, would be to end the drought and get the lake back to its full pool. And, it looks like there might be a chance of this coming up next week. I’ve maintained for a while that tropical weather will be needed to get us out of drought conditions, and right now there’s a developing system headed towards the Bahamas that could develop into a hurricane aimed towards Georgia. The National Hurricane Center issued a Tropical Disturbance Statement this afternoon, and expects that a tropical depression or storm could develop in the next day or so.

Models indicate the storm could develop into a category 3 hurricane near Jacksonville by Tuesday. If the storm were to make landfall and move into Georgia, we could see enough rain to start bringing stream flows back to normal and reverse the drought’s effects. It’s still too far away to know the exact path (much less to start evacuating coastal areas), but it’s definitely something to keep an eye on.

Rain Mostly a Bust

2008-08-13T23:42:34Z

Well, it looks like those predictions for all that rain this week didn’t exactly come true. Despite predictions of one to two inches made as late as Monday, most of the Atlanta area received less than an inch of rain from the storm.

The official rain gauge in Atlanta recorded .53 inches of precipitation as of 8 this morning. Other locations include Chamblee with .28 inches, Marietta with .24 inches, Macon with .69 inches and Athens with .35 inches. Isolated areas got soaked, though. Brunswick reported 1.6 inches, Cordele had an inch and a half, Plains had 2.37 inches and it looks like West Point got the day’s highest rainfall, with 2.97 inches. However, a few miles away in Columbus, then had .7 inches, so the possibility of ‘isolated heavy rainfall’ did come true in a few locations.

I guess you could say that in the battle of pressures, the high pressure won out. The dry air and the very nice weather we had over the weekend had to be forced out in order to get the moist rain producing tropical air into the northern half of the state. As late as 4 PM, the dew point hadn’t gone above 60, and we had a case of cold air damming–unusual in the summer–where the high pressure was being forced up against the mountains, giving the low pressure nowhere to go.

All of this could result in another typical winter phenomenon, a Nor’Easter running up the Atlantic coast, bringing heavy precipitation to the mid-Atlantic and New England. The low will seek its escape out into the Atlantic and keep moving north, bringing unneeded rain to the northeast. Between the CAD (which because it was summer, wasn’t really that cold) and the Nor’Easter, this storm was more typical of what you would see in the winter, instead of the middle of August.

Of course, Fall is rapidly approaching. We’ve finally started lowering both the daily average high and low temperatures, and we’ve lost almost an hour of daylight since the beginning of summer two months ago. Due to the drought the leaves on my trees are dropping, making it look more like mid-October than mid-August, but that’s not due to the cooler weather.

The best hope for drought relief remains tropical weather, and it looks like we may see some activity beginnining this weekend. A tropical wave east of Cuba is drawing attention, and could develop into a tropical storm by the weekend. Some models have it crossing Florida into the gulf, while others keep it along the Atlantic. The northeast quadrant of a storm is the one that tends to get the most rain, so for really beneficial rainfall in north Georgia, we really need to see something come from the gulf, rather than from the Atlantic. If this wave doesn’t do the trick, however, there will likely be others behind it.

Rainy Weather Ahead

2008-08-11T23:36:44Z

It may not be a tropical storm, but Georgia is going to have its best chance for significant rainfall on Tuesday and Wednesday as a low pressure system brings tropical moisture up from the Gulf coast. There could be over two inches of rain in some parts of central Georgia:

Unlike the storms we’ve had recently, this front is approaching from the southwest, and is going to be fairly slow moving–more typical of what Georgia sees in the winter rather then the summer. The big question is how far north the bulk of the rain is going to go. Forecasters with the weather service are predicting most of the rain will stay south of and along the I-85 corridor, but the models are varying somewhat in how far north the front will go before it gets stalled. I’m hoping for a good soaking, since most of the recent rain has been north of I-85, and my part of Gwinnett has seen little to no rain in the last two weeks.

While the rain will be welcome, I’m going to miss the delightful weather we’ve had over the weekend. With dew points down around 50 degrees, nighttime temperatures have dropped, and even the daytime is bearable, especially compared to last year, when we were at the end of the first week of temperatures in the upper 90s to low 100s. With the change in the weather tomorrow, we’re going to enter a more typical summertime weather pattern, with a decent chance of rain from thunderstorms for the next week or so.

Next week could also bring increased chances of increased tropical activity. While the storms so far this year have had no effect on Georgia’s weather two low pressure systems that are likely to develop into tropical storms later this week are more likely to affect Florida and possibly Georgia as well. Stay tuned.

Warmest Day So Far This Year / Updated Hurricane Forecast

2008-08-06T21:58:44Z

The August heat wave looks like it will go on through Thursday, but at least here at my house, today was the warmest day so far in 2008. It got up to 99 degrees (well, 98.7) at 2:10 PM, topping the 97.1 reached on both June 8 and July 10. It could have been worse though: with the dew point in the low 60s, the heat index was only 102 degrees.

Temperatures reached the century mark today in Augusta, Milledgeville, Savannah, Athens and Vidalia. For whatever reason, it stayed a bit cooler in Atlanta today, with highs only in the low 90s. Tomorrow, the humidity goes back up, and by tomorrow afternoon, the approaching front will bring a chance of rainfall, and at least a temporary end to the excessive heat we’ve been seeing recently.

Hurricane Forecast Update

We’re about ready to get into the strongest part of the hurricane season, from mid-August through the end of October. The folks at Colorado State University have updated their tropical forecast and are now calling for more storms than they predicted back in April and repeated in June.

Instead of 15 named storms, the predicted total has been upped to 17, with nine hurricanes, instead of eight. Five of those should be intense, compared to four predicted previously. Part of the reason for upping the predictions is the number of storms we’ve seen through July, with four named storms, two hurricanes and one intense hurricane. That doesn’t count Edouard, which was the first storm in August. According to the forecast, only 2005 (the year of Katrina) and 1916 have had more active pre-August tropical activity.

There’s a 2/3 chance of a major hurricane making landfall somewhere in the US during the rest of the season, with a better than 40% chance of a storm striking either the east coast or the gulf coast. Overall, the forecasters are predicting a tropical season that is 190% as active than the average season from 1950-2000.

In addition to providing forecasts for the rest of the season, the Dr. Gray and his team are providing a forecast for August tropical activity. If they are right, we will have four storms, three of which will become hurricanes, and one intense hurricane this month. With Edouard already occuring, that’s the non-hurricane storm, if their forecast is correct. They will also issue forecasts for September and October at the beginning of those months.

The Temperature’s Rising, but the Rain isn’t Falling

2008-08-05T00:25:55Z

We’re here at the beginning of the last week of Dog Days, the warmest part of the year, and the temperatures haven’t been disappointing. Highs over the last few days have been in the mid 90s, five or six degrees above normal. Both June and July saw 97 degrees, though, which we haven’t seen in August. Be glad we aren’t in Texas, where temperatures have been over 100 degrees for the last three or four days.

At least Texas is going to get a bit of a break with Tropical Storm Edouard getting ready to bring plenty of rain to much of the Bluebonnet state. I wish the same could be said for here, where I’ve had less than two tenths of an inch of precipitation in the last two weeks. Most of my plants are wilting, and it’s a challenge to try to use my little bit of watering time to apply first aid to the plants that are showing stress the most. As I said in my last post, other areas have had no problem with rainfall, but the thunderstorm gods haven’t decided to visit my corner of Gwinnett county.

Rain chances may increase on Wednesday or Thursday, though. Models indicate that a cold front could pass through midweek. The problem is that typically Georgia doesn’t get cold fronts in the dog days of summer–they usually don’t have enough energy to get this far south. Accuweather is optimistic, though, calling for over an inch of rain before Friday. I hope they’re right.