New short rage models just in indicate a stronger system than before.
Some parts of north Georgia will be looking at 10"-12" of snow. Here
in Gwinnett, I would not be surprised to see 8"-10".
From the meteorologist that I trust:
"Overall it has a little more factors that point to this being a
little more than the run of the mill 80's storm, making it a vicious
storm for some areas. If the NAM is right, there will be tree damage
and power outages for some areas, probably N. GA and the Upstate maybe
southern NC, just from the snow, and beyond that whatever ice
accumulates. This is quickly escalating into a much bigger deal than
just a nice 4 to 6" snowfall. "
Sunday, January 9, 2011
Winter Storm
Here we go!
When winter weather is in the forecast, it's funny watching the
meteorologists and weather enthusiasts when the new models come out.
It makes the oldest person become a kid again, everyone is very
anxious and gets excited (or depressed) as soon as they hear the
results. I know you must remember the feeling as a kid on the night
before Christmas, this is the adult version of that.
The models are still good to us this morning, and we apparently have
their blessing. Here's where we stand right now.
We are colder this morning than forecasted, not just at my weather
station, but about 4 degrees colder across a very wide area. If we can
carry this trend through the day we will be in good shape. At the time
of this writing, it's 14.7 degrees, so we now have a frozen surface
for precipitation to fall on unlike the Christmas snowfall.
I still believe the precipitation will begin around the midnight time
frame and continue through the day tomorrow and probably into Tuesday.
The trailing end of the precipitation will be freezing rain and at
this point that looks like a given. We could see up to .25" of
freezing rain on top of the snow and this will be very important to
watch. What will happen after the majority of the snow falls, is that
the very cold lower level of the atmosphere is shallow and has warm
air over running the top of it. That warm level will get lower and
lower which doesn't give the warm precipitation much cold air to fall
though. So it falls into the shallow layer of below freezing air where
it freezes on contact. This will make a glaze of ice on top of the
already heavy snowfall. The big concern is how much freezing rain/
drizzle will fall. Even .25" of ice is extremely dangerous and I do
expect to see power outages in the metro area. Of particular concern
are those areas south of Atlanta, this will be a devastating ice
storm, not just in Georgia but over the entire southeast.
We will begin as snow and should remain all snow until the end when we
transition to freezing rain. I haven't made any predictions until this
point and still very reluctant to do so due to the number of unknown
variables still out there, but based on the trends, I would say we're
looking at a 7"+ snowfall in Gwinnett. I wouldn't expect it to be much
lower on the low end but could go to 10"+ in isolated areas if a
strong band happens to cross our area. It's possible a deformation
zone could setup as the moisture is lifted rapidly by multiple methods
over the cold air. Isentropic lift, the normal rise due to the
mountains to the north, and forcing by upper level winds all can help
to fuel this intense band of snow, and in this zone snow can
accumulate rapidly. Something to watch for.
Another thing that can affect the amount of moisture we receive...
enhanced convection in the Gulf of Mexico can sometimes cut off the
moisture transport to our area which would greatly reduce the amount
of snow we receive. I believe that the convection will decrease before
that will become an issue but this is also something else to be
watched today.
I'm providing some links that I think will be informative today,
1. Deep South Google NEXRAD Radar - This radar loop covers the entire
southeast US and loads 36 actual NWS radar sites. It's a little slow
to load so please be patient. Once you get it loaded, you can just let
it run all day, it updates and refreshes automatically.
http://www.daculaweather.com/ridge_southeast_wide_master.php
2. GRLevel3 Atlanta NEXRAD - This radar loop runs from custom software
that takes higher level data from the National Weather Service to give
you a more detailed image and considerably more information that a
regular loop. From this you can see temperatures, wind, and reported
precip. I have 5 of these running today, Jackson MS, Birmingham AL,
Robins AFB GA, Greenville SC, as well as the Atlanta loop. Please
visit my website for all of the links and other radar products.
This is Atlanta - http://www.daculaweather.com/grlevel3/ffc_284.php
3. I also have a nice Weather Underground interactive Wunder Map
http://www.daculaweather.com/wu_wunder_map_new.php
I will keep you updated throughout the day as things develop, at this
point the we can almost throw the models out the window and rely on
observations and radar to determine the actual course of events. This
will be very interesting to watch as it evolves today, just know
you're about to experience a once in a quarter of a century weather
event!
When winter weather is in the forecast, it's funny watching the
meteorologists and weather enthusiasts when the new models come out.
It makes the oldest person become a kid again, everyone is very
anxious and gets excited (or depressed) as soon as they hear the
results. I know you must remember the feeling as a kid on the night
before Christmas, this is the adult version of that.
The models are still good to us this morning, and we apparently have
their blessing. Here's where we stand right now.
We are colder this morning than forecasted, not just at my weather
station, but about 4 degrees colder across a very wide area. If we can
carry this trend through the day we will be in good shape. At the time
of this writing, it's 14.7 degrees, so we now have a frozen surface
for precipitation to fall on unlike the Christmas snowfall.
I still believe the precipitation will begin around the midnight time
frame and continue through the day tomorrow and probably into Tuesday.
The trailing end of the precipitation will be freezing rain and at
this point that looks like a given. We could see up to .25" of
freezing rain on top of the snow and this will be very important to
watch. What will happen after the majority of the snow falls, is that
the very cold lower level of the atmosphere is shallow and has warm
air over running the top of it. That warm level will get lower and
lower which doesn't give the warm precipitation much cold air to fall
though. So it falls into the shallow layer of below freezing air where
it freezes on contact. This will make a glaze of ice on top of the
already heavy snowfall. The big concern is how much freezing rain/
drizzle will fall. Even .25" of ice is extremely dangerous and I do
expect to see power outages in the metro area. Of particular concern
are those areas south of Atlanta, this will be a devastating ice
storm, not just in Georgia but over the entire southeast.
We will begin as snow and should remain all snow until the end when we
transition to freezing rain. I haven't made any predictions until this
point and still very reluctant to do so due to the number of unknown
variables still out there, but based on the trends, I would say we're
looking at a 7"+ snowfall in Gwinnett. I wouldn't expect it to be much
lower on the low end but could go to 10"+ in isolated areas if a
strong band happens to cross our area. It's possible a deformation
zone could setup as the moisture is lifted rapidly by multiple methods
over the cold air. Isentropic lift, the normal rise due to the
mountains to the north, and forcing by upper level winds all can help
to fuel this intense band of snow, and in this zone snow can
accumulate rapidly. Something to watch for.
Another thing that can affect the amount of moisture we receive...
enhanced convection in the Gulf of Mexico can sometimes cut off the
moisture transport to our area which would greatly reduce the amount
of snow we receive. I believe that the convection will decrease before
that will become an issue but this is also something else to be
watched today.
I'm providing some links that I think will be informative today,
1. Deep South Google NEXRAD Radar - This radar loop covers the entire
southeast US and loads 36 actual NWS radar sites. It's a little slow
to load so please be patient. Once you get it loaded, you can just let
it run all day, it updates and refreshes automatically.
http://www.daculaweather.com/ridge_southeast_wide_master.php
2. GRLevel3 Atlanta NEXRAD - This radar loop runs from custom software
that takes higher level data from the National Weather Service to give
you a more detailed image and considerably more information that a
regular loop. From this you can see temperatures, wind, and reported
precip. I have 5 of these running today, Jackson MS, Birmingham AL,
Robins AFB GA, Greenville SC, as well as the Atlanta loop. Please
visit my website for all of the links and other radar products.
This is Atlanta - http://www.daculaweather.com/grlevel3/ffc_284.php
3. I also have a nice Weather Underground interactive Wunder Map
http://www.daculaweather.com/wu_wunder_map_new.php
I will keep you updated throughout the day as things develop, at this
point the we can almost throw the models out the window and rely on
observations and radar to determine the actual course of events. This
will be very interesting to watch as it evolves today, just know
you're about to experience a once in a quarter of a century weather
event!
Friday, January 7, 2011
Winter Storm Update
Last night the Euro and GFS weakened the low pressure that is expected
to bring us winter precipitation on Sunday/Monday. It was discouraging
for some folks. But at this point, the NAM and GFS are the computer
models to be watching, and we're just now entering the NAM's sweet
area for forecasting.
So with that...
This morning, the NAM and new GFS runs have actually strengthened the
low to the point to where those of us in North Georgia are in a
bullseye of snow. Take a look at this snow accumulation loop from the
NAM this morning and watch the last two frames. The times are UTC
times but the last frame is approximately 1 pm on Monday.
http://www.daculaweather.com/nam_se_snow_06.php
Folks, according to this model run (and this is no prediction yet)
we're looking at possibly 10"+ of snow here in Gwinnett County. That's
some serious snow.
Right now what we're focused on is the timing and strength of the low
and exactly where the freezing line will fall. What we do know is that
many people in the south will have a considerable amount of frozen
precipitation no matter what happens. This mornings forecast
discussion from the National Weather Service here in Atlanta alludes
to Watches/Warnings being posted, possibly as early as this evening.
We'll keep you posted.
to bring us winter precipitation on Sunday/Monday. It was discouraging
for some folks. But at this point, the NAM and GFS are the computer
models to be watching, and we're just now entering the NAM's sweet
area for forecasting.
So with that...
This morning, the NAM and new GFS runs have actually strengthened the
low to the point to where those of us in North Georgia are in a
bullseye of snow. Take a look at this snow accumulation loop from the
NAM this morning and watch the last two frames. The times are UTC
times but the last frame is approximately 1 pm on Monday.
http://www.daculaweather.com/nam_se_snow_06.php
Folks, according to this model run (and this is no prediction yet)
we're looking at possibly 10"+ of snow here in Gwinnett County. That's
some serious snow.
Right now what we're focused on is the timing and strength of the low
and exactly where the freezing line will fall. What we do know is that
many people in the south will have a considerable amount of frozen
precipitation no matter what happens. This mornings forecast
discussion from the National Weather Service here in Atlanta alludes
to Watches/Warnings being posted, possibly as early as this evening.
We'll keep you posted.
Thursday, January 6, 2011
Winter Storm Update
First...
Possibly some very light snow or most likely, just flurries for us
tonight. A little clipper type system is flying through, there's not
much in the way of moisture to work with so I wouldn't expect too much
out of it.
Here's what's happened overnight.
The models are still showing a major winter storm in the south. There
are some differences between these latest runs and the runs from
yesterday and this is to be expected over the next three days as the
models get a better handle on the storm. The low is still off of the
California coast and won't be onshore for another 24-48 hours.
The differences are:
1. The low pressure system that will be responsible for the
precipitation is now looking stronger, and stronger means more
precipitation. Some of the QPF amounts are in the 1"- 2" range (for
someone, not everyone) of liquid precipitation. It also means warmer
air so there is a trade-off for someone in the south. If you were
looking at a pure snow event, we could possibly see 10" - 15" of snow
from that liquid amount, but some of the moisture might fall as sleet,
and in some areas, freezing rain. Here's the real problem. The
freezing line has moved closer to the Atlanta area with the increase
in storm strength, a freezing rain event of this magnitude would be
devastating and crippling for many people and a very dangerous
situation that needs to be watched very closely. A quarter of an inch
of ice is dangerous but an inch or more and we all lose power for an
extended amount of time. Top that off with temperatures that might not
hit 20 on Tuesday and Wednesday, you begin to see the how important
tracking the exact track storm is going to be.
2. The storm appears to be modeled to move a little slower. This could
be one reason for the higher precipitation amounts. Needless to say,
once the frozen precipitation starts, it should be a lengthy event. It
could snow for as long as 24 hours straight. Or sleet. Or freezing
rain. You get the picture.
It will still be a few days, probably sometime on Saturday, before the
models have a good handle on the exact track of the storm. And even
then, +-50 miles is all the difference it makes here in the south.
However this ends up playing out, I would begin making preparations
for a large southeast winter storm. And most of all, be prepared for
an ice storm, I'm NOT saying that's going to happen for us, just know
the potential is there.
Possibly some very light snow or most likely, just flurries for us
tonight. A little clipper type system is flying through, there's not
much in the way of moisture to work with so I wouldn't expect too much
out of it.
Here's what's happened overnight.
The models are still showing a major winter storm in the south. There
are some differences between these latest runs and the runs from
yesterday and this is to be expected over the next three days as the
models get a better handle on the storm. The low is still off of the
California coast and won't be onshore for another 24-48 hours.
The differences are:
1. The low pressure system that will be responsible for the
precipitation is now looking stronger, and stronger means more
precipitation. Some of the QPF amounts are in the 1"- 2" range (for
someone, not everyone) of liquid precipitation. It also means warmer
air so there is a trade-off for someone in the south. If you were
looking at a pure snow event, we could possibly see 10" - 15" of snow
from that liquid amount, but some of the moisture might fall as sleet,
and in some areas, freezing rain. Here's the real problem. The
freezing line has moved closer to the Atlanta area with the increase
in storm strength, a freezing rain event of this magnitude would be
devastating and crippling for many people and a very dangerous
situation that needs to be watched very closely. A quarter of an inch
of ice is dangerous but an inch or more and we all lose power for an
extended amount of time. Top that off with temperatures that might not
hit 20 on Tuesday and Wednesday, you begin to see the how important
tracking the exact track storm is going to be.
2. The storm appears to be modeled to move a little slower. This could
be one reason for the higher precipitation amounts. Needless to say,
once the frozen precipitation starts, it should be a lengthy event. It
could snow for as long as 24 hours straight. Or sleet. Or freezing
rain. You get the picture.
It will still be a few days, probably sometime on Saturday, before the
models have a good handle on the exact track of the storm. And even
then, +-50 miles is all the difference it makes here in the south.
However this ends up playing out, I would begin making preparations
for a large southeast winter storm. And most of all, be prepared for
an ice storm, I'm NOT saying that's going to happen for us, just know
the potential is there.
Wednesday, January 5, 2011
Winter Weather Update
First, no concern for us today.
Here is an update after last night’s model runs.
The main issue right off the bat is that this is still pretty far out in the model world (around 5 days or so away) so the models have been having a hard time converging on a specific solution. This problem is exacerbated when you are in a strongly blocking regime, one of which is very unusual during the La Nina pattern. In essence, the models have been everywhere.
But now a nice trend is shaping up with a potential southeast snowstorm for late this weekend. There are two models with a similar forecast that is carrying some weight since one of them is the EURO with several consecutive consistent runs inside five days now. Add to this mix the NAM at hour 84 showing something similar and now the 06z GFS trending toward the same idea, it’s plausible to start getting excited. It will still take a few more days to nail down the exact
details, but things in the model world are starting to fall in line with the pattern that is evolving. We'll see how the EURO does on the next run today, if we get three consecutive consistent runs the confidence factor will go up considerably. The main thing now is to
getting the pattern to fall into place (which it appears is happening)and the details will follow. Hopefully everyone in the SE can get some white carpet laid down and make the future long cold snap more enjoyable. Just to tease you, some models are showing anywhere from 2"to 10", possibly more (or less) for this area depending on the track of the low and the location of the cold air. It's still too far out to know anything definite though.
Some of the models are showing highs for a few days next week in the teens for our area, so expect some bitterly cold air to plunge south at the start of the week. Not only that, it's not forecasted to go anywhere anytime soon and will probably make this the coldest January in almost 25 years. Throw in multiple chances for frozen precipitation next week and we might start to look like it does up north!
We will probably send these emails out daily for the next few days to keep you updated with what's going on. Things are rapidly changing and need to be watched closely.
Stay tuned!
Here is an update after last night’s model runs.
The main issue right off the bat is that this is still pretty far out in the model world (around 5 days or so away) so the models have been having a hard time converging on a specific solution. This problem is exacerbated when you are in a strongly blocking regime, one of which is very unusual during the La Nina pattern. In essence, the models have been everywhere.
But now a nice trend is shaping up with a potential southeast snowstorm for late this weekend. There are two models with a similar forecast that is carrying some weight since one of them is the EURO with several consecutive consistent runs inside five days now. Add to this mix the NAM at hour 84 showing something similar and now the 06z GFS trending toward the same idea, it’s plausible to start getting excited. It will still take a few more days to nail down the exact
details, but things in the model world are starting to fall in line with the pattern that is evolving. We'll see how the EURO does on the next run today, if we get three consecutive consistent runs the confidence factor will go up considerably. The main thing now is to
getting the pattern to fall into place (which it appears is happening)and the details will follow. Hopefully everyone in the SE can get some white carpet laid down and make the future long cold snap more enjoyable. Just to tease you, some models are showing anywhere from 2"to 10", possibly more (or less) for this area depending on the track of the low and the location of the cold air. It's still too far out to know anything definite though.
Some of the models are showing highs for a few days next week in the teens for our area, so expect some bitterly cold air to plunge south at the start of the week. Not only that, it's not forecasted to go anywhere anytime soon and will probably make this the coldest January in almost 25 years. Throw in multiple chances for frozen precipitation next week and we might start to look like it does up north!
We will probably send these emails out daily for the next few days to keep you updated with what's going on. Things are rapidly changing and need to be watched closely.
Stay tuned!
Sunday, January 2, 2011
January 2010 Weather
Happy New Year!
Now that the holidays are over it's time to get winter kicked off in
ernest, and what better way than with some snow! The upcoming weeks are going to be very interesting in the southern part of the United States with a major pattern change on the way.
The GFS (and the Euro to some degree) have one incredible historic
pattern coming up in our near future. It's still pretty far out and
can't be fully bought into yet, but its trending more and more that
way with each run. The pattern is very similar to the late February/
March pattern of 1960 in which it snowed, then snowed some more, and then snowed some more... well, you get the picture. For about four weeks in 1960 that pattern caused a series of snow events across the south and southeast that just kept coming.
Just an example from Roanoke VA and a study that was done about the record snowfalls:
http://www.easternsnow.org/esc/proceedings/2006/perry_and_konrad.pdf
Feb 13 - 15"
Feb 18 - 8"
Feb 25 - 4"
Mar 2/3 - 17"
Mar 09 - 6"
Mar 16 - 5"
The weather pattern that caused that snow is the same basic pattern
that the models are currently projecting to fall into place beginning
in the 7 - 10 day time frame. Of course, that doesn't mean we will
have the same results as Roanoke, but if you like snow and winter
weather, this is an amazingly good pattern that is brewing and will
most certainly increase our chances for snow dramatically, at least
once and perhaps multiple times over the next 3-4 weeks.
So enjoy the relatively mild (but perfectly normal for January)
weather this week. There is a small chance of rain on Wednesday and
that will be the only weather to speak of until we get closer to the
weekend. We will know much more as the week progresses and as soon as the models can come to some agreement about the upcoming changes, we will let you know, just don't put away the sleds just yet!
Now that the holidays are over it's time to get winter kicked off in
ernest, and what better way than with some snow! The upcoming weeks are going to be very interesting in the southern part of the United States with a major pattern change on the way.
The GFS (and the Euro to some degree) have one incredible historic
pattern coming up in our near future. It's still pretty far out and
can't be fully bought into yet, but its trending more and more that
way with each run. The pattern is very similar to the late February/
March pattern of 1960 in which it snowed, then snowed some more, and then snowed some more... well, you get the picture. For about four weeks in 1960 that pattern caused a series of snow events across the south and southeast that just kept coming.
Just an example from Roanoke VA and a study that was done about the record snowfalls:
http://www.easternsnow.org/esc/proceedings/2006/perry_and_konrad.pdf
Feb 13 - 15"
Feb 18 - 8"
Feb 25 - 4"
Mar 2/3 - 17"
Mar 09 - 6"
Mar 16 - 5"
The weather pattern that caused that snow is the same basic pattern
that the models are currently projecting to fall into place beginning
in the 7 - 10 day time frame. Of course, that doesn't mean we will
have the same results as Roanoke, but if you like snow and winter
weather, this is an amazingly good pattern that is brewing and will
most certainly increase our chances for snow dramatically, at least
once and perhaps multiple times over the next 3-4 weeks.
So enjoy the relatively mild (but perfectly normal for January)
weather this week. There is a small chance of rain on Wednesday and
that will be the only weather to speak of until we get closer to the
weekend. We will know much more as the week progresses and as soon as the models can come to some agreement about the upcoming changes, we will let you know, just don't put away the sleds just yet!
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