Update #2 – 8:17 AM ET 2/9/2011
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Just a quick update … I wont be changing anything, not even my call map [ snow prediction map ] seen below in the original post. I think it is a pretty good representation of what will go down. If I were to change anything, it would be for the northern most part of Georgia. I would bump up the snow potential just a tad to around 1.5 to 2 inches of accumulation. Still .. I think that will be pushing it as I don’t think the moisture will be available that far north. One other thing I might change .. there may be more freezing rain / sleet in the southern counties than expected. Probably not enough to cause a problem though.
Here is a graph showing the current Winter Storm Warnings and Winter Weather Advisories in my general area. Like other weather events, I find it funny / strange how the weather stops at the Alabama / Georgia state line.
I will mention that the system will move through quicker than I had anticipated. This could change. There are also some difference between models as to the liquid to snow amounts. My forecast is based off of a 10:1 ratio. That being for 1 inch of rain 10 inches of snow. I have viewed some of these ratios as high as 20:1.
It is now down to a now-cast as to what will happen. At this time models pretty much become useless. Some of the short-range models still provide a little insight, but radar is now your friend.
My next update will come as the storm enters the area sometime this evening or late tonight. I will post some observations form my area. That is of course unless something really wild happens like a Blizzard Warning or a Tornado. Maybe even some Thundersnow.
Update #1 – 7:53 PM ET 2/8/2011
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Well .. it appears the winter storm system is materializing as I had thought it would, mentioned in my first post below. Everything is coming into place for what I believe to be more snow than the local and even the national mets are calling for at this time, but likely what I showed, also in my first post. Here is what has happened since my previous post —
I was watching to see if the initializations are getting stronger, or if we see the 5400m heights at 500mb start appearing on the initializations. This will tell us if we have a significantly stronger system than modeled since none of the global models have this. And guess what; They are and did.
Here is the 500mb showing a 5460m height above our S/L. The system is getting stronger.
Here is the MSL[ Mean sea level ] pressure and surface wind chart. It shows our surface low at 998mb, and on top of that .. its a closed low. Which means it could get even stronger. As far as I could see early on, this wasn’t supposed to happen. But I did have a suspicion from sampling many models and maps earlier.
Here is the latest projected track of the Low. It even shows a minimum pressure of 1002mb. It is supposed to become just a blob of LP at 1012 in about 12-16 hrs as it traverses the Gulf.
And for your viewing pleasure … the 18z GFS at hour 36 showing precip/mean sea level/temp.
Notice the low at 1012mb and the 850mb 540 line, the blue line. Notice how far south it is. I tend to think that most areas north of it by 50 miles would have a surface temp right around freezing or below. Still .. the 540 line is usually a good indicator of where snow. ice or freezing rain will appear if moisture is available.
And at hour 48
And here is the 72 hour precip forecast total for this winter storm. Well .. for the part of it that will impact my area of Georgia.
Now you may see why I’m predicting more snow for middle GA than north GA. The temps are there and ample precip is available too. In my area if it all fell as snow at a 10 to 1 ratio, I’d be looking at 2.5 to 5 inches of snow. Hence my forecast of 1-3 inches seen below in my first call map, in my original post.
Thats it for now, and likely tonight. Check back tomorrow for updates as the storm approaches even closer. I hope this verifies but as stated before, forecasting snow in the deep south is a fine line. Things will change.
I wont go into much detail. I will say though from what I’m seeing, which isn’t what the professionals see, someone will be getting a surprise in the deep south. I personally think at this time from what models and maps I’ve looked at, combined with observations, the storm will track deeper, stronger and slower. I think central and southern GA will see more snow than the pro’s forecast. Temps are trending colder. Now that I’ve jinxed this by posting what I think, I wont see anything in my area.
Heres what the pros [http://www.srh.noaa.gov/ffc/]currently think-
Move everything farther south and you have my thoughts. I know, wishcasting for my backyard.
Things can and will change. Still 36 hours out.