more on the SE CONUS RIDGE FROM HELL?
I was going to issue a final call with regard to be developing system moving through the Midwest and southern New England but after looking over the latest data and Seeing that the main event is still 24 plus hours away I'll think all hold off until early this evening.
I've noticed looking at some of the weather boards is quite of the dismay and concern and disbelief that the warm air is going to surge as far north into New York State and southern new england as the models are showing. However the problem here is not whether one wants to arse kiss the NAM/WRF or the op GFS or even the SREF for that matter.
The problem is that synoptically there is Not a lot of support for the idea of keeping the Low level cold air in place over lower New England . There is little if any Eastern neck or extension of the Arctic HIGH now over the Upper Plains on the short range models and this makes sense synoptically.
As a result even as the LOW begins to develop the Ageostrophic circulation over Lower New England there is NOT a lot of cold air to pull south. Moreover when the 850 low is tracking too far to the north NOT to erode the cold air. When your 850 Low tracks that far to the north -- N of Cleveland and over or North of BUF and BGM you are going to have real problems keeping the cold air which is only marginal to begin with in place over Low New England.
Of course the cold air does not get into the East coast until after the Low passes off the New England coast on Monday.
I'm sure that the last few runs out some of theMR odels have caused quite a bit of consternation for those who want to see when to return to the eastern US. I was going to post on its Saturday but I want to see how things were going to play out before overreacting to what appeared to be a series of significant is handling so the features on some of the MR models.
Obviously the cold air is in place across the eastern US from the 16th into the 19th. The problem is that some of the models have been taking the next piece of energy coming in on the Pacific Jet from the far northeastern Pacific / western Canada and dropping it into the western US. This causes the Southeast Ridge to re assert itself and keeps the eastern US not nearly as cold as it might be of the otherwise. http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_120s.gif
However there is big difference SYNOPITCALLY this time around. Over the last several weeks we have had a strong Ridge over the Southeast or just off the Southeast coast there is been no vortex over Northern were eastern Canada to counter the power of the Ridge. As result the warm air gets to run across the eastern half of the US with no check or balancing factors. This time around even IF the operational GFS is correct we do have a large vortex sitting over eastern Canada which does keep the Southeast Ridge somewhat suppressed at least allow temperatures to remain close to seasonal normals over the eastern third of the US. That its you "BUY" the last few runs of the Op GFS.
which I dont.
Most of the other Medium range models are taking this energy that's dropping into the western US and closing off a 500 low over California and then retrogrades out into the immediate Pacific off the California coast. This results in a rex block configuration.... the 500 closed cutoff Low off the s california coast and the RIDGE over Alaska. The 0z euro shwos this nicely
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f120.gif
And because you have a rex configuration here the Ridge is forced North which in turn forceds the trough over the eastern US deeper as well as a deeper PV... and drops a lot more Arctic air in the the eastern US .. and of course in this pattern there is no hint of a Southeast Ridge whatsoever.
OK... now that we have analyzed the Synoptic problem lets try and figure out which of these of these two solutions/ or possible scenarios is correct one.???
Here is the 0z GFS Jan 14 ensembles. As you can see the top row far left mao is the OP - GFS... and of course you can see that it has the Ridge over the Southeast and no close cutoff low over the Southwest. But as you can see about half the models in fact you have a 500 MB configuration that is much closer to the operational European.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f144.html
The latest runs out the UKMET also strongly support the operational European with the closed 500 low off the California coast and rex block setting up which drives the Ridge over Alaska actually eastward into western Canada. And we can also see us on the latest run all the0z op
http://www.meteo.psu.edu/~gadomski/UKHEMI_12z/f144.gif
OZ CMC DAY 6
http://weatheroffice.ec.gc.ca/data/model_forecast/hdd_50.gif
As we go further out in time we can see other problems develop with the operational GFS not only against the other medium range models but versus its own ensembles. Because the model screws things up at D6 and D7... the d9 and D10 solutions also model outliers and by considerable margin. Notice we can see the operational GFS here at day 10 is vastly different that what almost all the members are showing which is a huge trough over eastern US and a lot of very cold and place along with the potential for some sort significant storminess in around January 23 --24
Here's a comparison between the operational European day 8-10 500 MB mean heights on the LEFT vs the OP GFS day 8-10 on the right ... and you can see vast differences between the two. One of the reasons why the European weekly ensembles are showing such a cold blast coming into the eastern third of the US especially the Northeast in the last week of January & the first week of February is because the Ridge which is now over the Gulf Alaska is not really a +PNA configuration at all. But the development of the 500 Low off the California coast that retrogrades into the eastern Pacific and sets of the rex block results in the Ridge from the Gulf of Alaska being forced into western Canada and that DOES set up a +PNA which also finally gets rid of the Southeast Ridge once and for all.
Moreover the operational European is really developing the Ridge in the Central Atlantic Ocean and trying to drive it towards Greenland... which would be a significant development if the model is correct. The operational GFS just shows the strong Southeast Ridge now displaced a little bit into the Southwest Atlantic Ocean but it has no hint of any sort of ridging in the North Atlantic trying to drive towards Greenland Iceland.
In addition the operational GFS to showing a much weaker vortex and a much weaker northern branch....
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html
As you can see the top row far left mao is the OP - GFS... and all you have to do is quickly scan through the different members to see a much deeper cloth over the eastern US.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f240.html
You can also compare the operational run of the GFS to the other members on this link and see that the white lines which represent the operational run are not nearly as deep as the vast majority of the GFS ensembles
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_0z/f240.html
Therefore based upon all that I have seen so far it's pretty clear that the operational European at D10 is running far superior to the operational GFS. It should be noted that a D10 the operational Canadian has a significant snowstorm for the East coast and European is also showing some sort system coming out of the Southwest low and thee is t least some cold air in place over the Northeast that results in a possible winter threat as well but not nearly as impressive as what the operational Canadian showing. Even in the operational GFS does eventually get out to showing a couple threats and these are showing up on both the operational 0z and 6z runs... at around 240 and 300 hrs.
JAN24 6Z
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_252.shtml
JAN 24 OZ OP GFS
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_240.shtml
6Z and 0z at 300 hrs
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_300.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_312.shtml
I've noticed looking at some of the weather boards is quite of the dismay and concern and disbelief that the warm air is going to surge as far north into New York State and southern new england as the models are showing. However the problem here is not whether one wants to arse kiss the NAM/WRF or the op GFS or even the SREF for that matter.
The problem is that synoptically there is Not a lot of support for the idea of keeping the Low level cold air in place over lower New England . There is little if any Eastern neck or extension of the Arctic HIGH now over the Upper Plains on the short range models and this makes sense synoptically.
As a result even as the LOW begins to develop the Ageostrophic circulation over Lower New England there is NOT a lot of cold air to pull south. Moreover when the 850 low is tracking too far to the north NOT to erode the cold air. When your 850 Low tracks that far to the north -- N of Cleveland and over or North of BUF and BGM you are going to have real problems keeping the cold air which is only marginal to begin with in place over Low New England.
Of course the cold air does not get into the East coast until after the Low passes off the New England coast on Monday.
I'm sure that the last few runs out some of theMR odels have caused quite a bit of consternation for those who want to see when to return to the eastern US. I was going to post on its Saturday but I want to see how things were going to play out before overreacting to what appeared to be a series of significant is handling so the features on some of the MR models.
Obviously the cold air is in place across the eastern US from the 16th into the 19th. The problem is that some of the models have been taking the next piece of energy coming in on the Pacific Jet from the far northeastern Pacific / western Canada and dropping it into the western US. This causes the Southeast Ridge to re assert itself and keeps the eastern US not nearly as cold as it might be of the otherwise. http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/images/gfs_500_120s.gif
However there is big difference SYNOPITCALLY this time around. Over the last several weeks we have had a strong Ridge over the Southeast or just off the Southeast coast there is been no vortex over Northern were eastern Canada to counter the power of the Ridge. As result the warm air gets to run across the eastern half of the US with no check or balancing factors. This time around even IF the operational GFS is correct we do have a large vortex sitting over eastern Canada which does keep the Southeast Ridge somewhat suppressed at least allow temperatures to remain close to seasonal normals over the eastern third of the US. That its you "BUY" the last few runs of the Op GFS.
which I dont.
Most of the other Medium range models are taking this energy that's dropping into the western US and closing off a 500 low over California and then retrogrades out into the immediate Pacific off the California coast. This results in a rex block configuration.... the 500 closed cutoff Low off the s california coast and the RIDGE over Alaska. The 0z euro shwos this nicely
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/f120.gif
And because you have a rex configuration here the Ridge is forced North which in turn forceds the trough over the eastern US deeper as well as a deeper PV... and drops a lot more Arctic air in the the eastern US .. and of course in this pattern there is no hint of a Southeast Ridge whatsoever.
OK... now that we have analyzed the Synoptic problem lets try and figure out which of these of these two solutions/ or possible scenarios is correct one.???
Here is the 0z GFS Jan 14 ensembles. As you can see the top row far left mao is the OP - GFS... and of course you can see that it has the Ridge over the Southeast and no close cutoff low over the Southwest. But as you can see about half the models in fact you have a 500 MB configuration that is much closer to the operational European.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f144.html
The latest runs out the UKMET also strongly support the operational European with the closed 500 low off the California coast and rex block setting up which drives the Ridge over Alaska actually eastward into western Canada. And we can also see us on the latest run all the0z op
http://www.meteo.psu.edu/~gadomski/UKHEMI_12z/f144.gif
OZ CMC DAY 6
http://weatheroffice.ec.gc.ca/data/model_forecast/hdd_50.gif
As we go further out in time we can see other problems develop with the operational GFS not only against the other medium range models but versus its own ensembles. Because the model screws things up at D6 and D7... the d9 and D10 solutions also model outliers and by considerable margin. Notice we can see the operational GFS here at day 10 is vastly different that what almost all the members are showing which is a huge trough over eastern US and a lot of very cold and place along with the potential for some sort significant storminess in around January 23 --24
Here's a comparison between the operational European day 8-10 500 MB mean heights on the LEFT vs the OP GFS day 8-10 on the right ... and you can see vast differences between the two. One of the reasons why the European weekly ensembles are showing such a cold blast coming into the eastern third of the US especially the Northeast in the last week of January & the first week of February is because the Ridge which is now over the Gulf Alaska is not really a +PNA configuration at all. But the development of the 500 Low off the California coast that retrogrades into the eastern Pacific and sets of the rex block results in the Ridge from the Gulf of Alaska being forced into western Canada and that DOES set up a +PNA which also finally gets rid of the Southeast Ridge once and for all.
Moreover the operational European is really developing the Ridge in the Central Atlantic Ocean and trying to drive it towards Greenland... which would be a significant development if the model is correct. The operational GFS just shows the strong Southeast Ridge now displaced a little bit into the Southwest Atlantic Ocean but it has no hint of any sort of ridging in the North Atlantic trying to drive towards Greenland Iceland.
In addition the operational GFS to showing a much weaker vortex and a much weaker northern branch....
http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html
As you can see the top row far left mao is the OP - GFS... and all you have to do is quickly scan through the different members to see a much deeper cloth over the eastern US.
http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/f240.html
You can also compare the operational run of the GFS to the other members on this link and see that the white lines which represent the operational run are not nearly as deep as the vast majority of the GFS ensembles
http://www.meteo.psu.edu/~gadomski/ENSHGTAVGNH_0z/f240.html
Therefore based upon all that I have seen so far it's pretty clear that the operational European at D10 is running far superior to the operational GFS. It should be noted that a D10 the operational Canadian has a significant snowstorm for the East coast and European is also showing some sort system coming out of the Southwest low and thee is t least some cold air in place over the Northeast that results in a possible winter threat as well but not nearly as impressive as what the operational Canadian showing. Even in the operational GFS does eventually get out to showing a couple threats and these are showing up on both the operational 0z and 6z runs... at around 240 and 300 hrs.
JAN24 6Z
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_252.shtml
JAN 24 OZ OP GFS
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_240.shtml
6Z and 0z at 300 hrs
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/06/fp0_300.shtml
http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/00/fp0_312.shtml
posted by DT @ 1/14/2007 09:53:00 AM
1 Comments:
At 7:38 PM,
Anonymous said…
DT - Thanks for the analysis once again.
I doubt you'll want to post this, and it's not intended in that fashion - but I know of no other venue to ask -
So here goes:
This time of year, you understandably concentarte on weather in the NE and upper south; however, every once in a couple years south GA and real N Fla can get slammed with cold, and occasionally some frozen precip. Other times, like this year, we bake, and only hope. A week ago models gave some hope, but that has one away.
So, here's my request - even though we are outside your Zone Map, can you (please) once and in a while let us poor southerners know if we have a chance for anything, and for educational purposes, tell us why not when it isn't going to happen, especially when the 10 to 15 day model runs show a chance?
Maybe too much to ask, but it would sure be appreciated!
Take care - I've been reading you now for 4 years and have learned alot - not a met, but just someone who is and has been for most of his 51 years very interested in the science of weather.
Thanks!
pcbjr
Post a Comment
<< Home