End of January/early February storm potential part 2

[buckeye]

At least for us it would be lol. A full blown bomb would almost surely be rain for you and me.

no no...im not asking what the best scenario is for us, (i know that). Im asking would you agree that 2 is the most likely taking seasonal trends into account so far. We haven't had any big early phasers nor have we had many that just quietly escaped southeast either.

[OHweather]

Looking at the global models, most of the 12z runs were in good agreement with the placement of the polar vortex at hour 120. The UKMET appears to be a bit farther north and weaker than the other models with it, however.

GFS:

ECM:

CMC:

UKMET:

NOGAPS:

GFS ensembles:

ECM ensembles:

With all the models so close on the placement on the polar vortex, what determines if we see the Pacific shortwave amplify/possibly phase or shear out likely is how the models handle the Pacific shortwave. So like Baro's been saying I have a feeling it's the juiced up Pacific that is giving the models trouble. We might not see a true consensus until the shortwave is moving onshore and sampled, which probably won't occur for a few more runs.

Anyways looking at the models, here is the piece of energy that breaks free of the Pacific jet and moves into the southwestern US over the next few days and potentially causes our storm, for anyone curious:

[dilly84]

euro's not perfect, and has been just as bad as most mos beyond 96 hrs. But once inside that timeframe it has done well with the overall solution, not talking about details and small waffles, but i'm talking about the bigger solution. It never waivered from the idea of a digging low making the turn and becoming an eastcoast low, with this last storm, it just had the usual strength issues and minor track waffling. The gfs was doing that silly miller B scenario til it finally got a clue.

As far as this past one, jma did best. Euro wasn't horrible but I can't forget that 1.55 it showed for me and nearly 2" for pburgh. Heck central pa barely got anything. So that's pretty significant waffling.

[dilly84]

I guess ec tv mets and fox and twc already hyping another ec bomb for wednesday lol

[buckeye]

As far as this past one, jma did best. Euro wasn't horrible but I can't forget that 1.55 it showed for me and nearly 2" for pburgh. Heck central pa barely got anything. So that's pretty significant waffling.

yes i remember that too...but that was, i think, outside 96 hrs if i remember correctly.

120hr timeframe is the window in which models are diverging on the phasing issue.

I suspect that tomorrows 12z euro will begin to paint a clearer pic of what will unfold.

[Organizing Low]

2 big "IF's" here--one the cyclone and how it eventually develops. If you look at the spread on the GEFS spaghetti plot at 48 hours--it is unusually large as a result with the placement of the cyclone off the coast. Right now it is a ripple on the Pacific Jet--so a lot has to happen there. Second question is how the first wave/occlusion interacts with the northern stream at 36-42 hours and how much of a "phase" occurs there. The GFS has consistently been more bullish and "initiates" CAA and development of the northern vortex/trough into the plains much earlier than other guidance. All these "interactions" and developments occur within the next 36-48 hours--I would like to believe things will be straightened out quite a bit by the 0Z run of the 29th--about 36 hours from now. We should have a much clearer picture of who gets what. I do think it is becoming obvious regions across the south will certainly be seeing some action though.

thanks Baro

gives at least some sense of hope.

[OHweather]

Hmmmmmmm. The Euro is actually quite a bit different than the GFS at least on how it handles the big PAC energy. While the GFS cuts off most of it, the Euro brings the whole thing out. Just doesn't line up right.

Ya, it's how the models handle the PAC energy that seems to be throwing them. It's odd how the GFS is cutting the energy while the ECM brings it out, normally it's the other way around if anything. Anyhow, the GFS, despite being similar to most of the other models with the location of the PV, is still stronger than most with the amount of cold over the east, which should be taken into consideration:

vs.

[dilly84]

yes i remember that too...but that was, i think, outside 96 hrs if i remember correctly.

120hr timeframe is the window in which models are diverging on the phasing issue.

I suspect that tomorrows 12z euro will begin to paint a clearer pic of what will unfold.

Posted 21 January 2011 - 01:35 AM

ZZV 1.55

CMH .61

CLE .25

PIT 1.78

LEX 1.44

Me and pa and steve will take our 15-20" lol too bad it'll never verify

so it'd have been the 0z run of Jan 21st so 4 days out.

[buckeye]

Posted 21 January 2011 - 01:35 AM

ZZV 1.55

CMH .61

CLE .25

PIT 1.78

LEX 1.44

Me and pa and steve will take our 15-20" lol too bad it'll never verify

so it'd have been the 0z run of Jan 21st so 4 days out.

good catch...lol...riding the 96 hr rail. In fact i believe it was the next run 12z where it made the major shift southeast.

point taken, I'll wait til the run following the 96 hr solution

[dilly84]

good catch...lol...riding the 96 hr rail. In fact i believe it was the next run 12z where it made the major shift southeast.

point taken, I'll wait til the run following the 96 hr solution

Yea the 12z run after it gave nothing lmao.. But anyways.. It had a similar track, but was still of on how far back the snow would make it. It was still showing a decent shot for central pa and nada.. like 2"

Im getting hammered right now... By virga lol.. Clipper giving you anything?

[buckeye]

Yea the 12z run after it gave nothing lmao.. But anyways.. It had a similar track, but was still of on how far back the snow would make it. It was still showing a decent shot for central pa and nada.. like 2"

Im getting hammered right now... By virga lol.. Clipper giving you anything?

quick peek at the street light...that's an affirmative to flurries

[dilly84]

quick peek at the street light...that's an affirmative to flurries

haha. same thing I do. Look out the window at the street light lmao. I bet everyone does.. Place sure gets boring between model runs lol

[Hoosier]

Posted 21 January 2011 - 01:35 AM

ZZV 1.55

CMH .61

CLE .25

PIT 1.78

LEX 1.44

Me and pa and steve will take our 15-20" lol too bad it'll never verify

so it'd have been the 0z run of Jan 21st so 4 days out.

In the Euro's defense, that's a huge gradient across a relatively small distance. I'd be really weary of any solution to accurately nail down a gradient like that especially that far out.

[snowstormcanuck]

haha. same thing I do. Look out the window at the street light lmao. I bet everyone does.. Place sure gets boring between model runs lol

I have a flood light right in my front lawn. Technically it's just for Christmas but I leave it out until April as my night time snowvision.

[Organizing Low]

It happens to all the models. The Euro has not been too hot lately--op and ensembles. But all the models have had their good and bad moments. It is a good reminder though that models are models--not reality--and even the Euro can stink it up bad sometimes. The forecaster should never think one model will always be right--and I think some operational forecasters rely on certain guidance too much without any particular reasoning. In reality--the GFS has really closed the door on the Euro's overall lead--and the ECMWF is no longer as "supreme" as it may have been 10 years ago when it kicked all other global models respective tails.

baro

since most of the action has been on the coast, i think many people have missed just how well the GFS has been performing this season, defintely as well or even more stable than the euro in handling big events.

anyways, im not about to get into a pissing match about the models, but the reality is the GFS has been much better this year since the upgrade, in terms of sensible wx.

it seems the upgrade has been a big step in the right direction for the GFS.

ive already mentioned that im not in unless the GFS is in.......something i never would have said in years past!

now for that matter, i hope the Ukie verifies!

[Organizing Low]

and i do think the OV makes out well in this event, regardless of how the models play out.....unless its totally junk energy.

should be a miss up here barring a phase job....and toronto will be touch and go, barring a phase job.

[snowstormcanuck]

21z SREFS going for at least a partial phase at 87

[Organizing Low]

21z SREFS going for at least a partial phase at 87

yeah that looks decent, very nice height amplification in process there.

[prinsburg_wx]

21z SREFS going for at least a partial phase at 87

21z sref members 500 at 87

[snowstormcanuck]

21z sref members 500 at 87

Pretty good sign. I don't see a single member that's similar to the GFS. All are further west and more amplified with the northern vort. But they are the SREFS at their maximum range, so TIFWIW.

[OhioValleyWx]

This is my take on the storm. It does not mean some areas get pulverized just a general statement of what I think could occur plus a little explanation of a few things.

I am taking the road less traveled by but I just do not think models

can sense two energy waves coming out at the same time frame before we

get inside 48 hours. They either want to push everything out way too

quickly and it goes east and we get light stuff or nothing or the models

want to bring one piece out too fast before the second piece can be

realized so that second piece is hung out to dry waiting for another

kicker. The tired phrase of, too much in front and not enough back

scenario I am beating into the ground over and over and over again,

shows up very well on the models. The H5 is too flat (Rich A mentioned

it earlier with positive tilt) and the streaming energy wants to rush

towards a heat weakness so zoom, out it goes. This is where the

southern branch becomes the bully and grabs it all and whisks it out.

Then on another model run the northern branch becomes dominant and the

northern energy gets the idea to rush to the heat source and it gets

whisked out because the H5 is too flat and the southern branch gets left

in the dust so we have energy hanging out to the SW. Being 4.5 to 5.5

days out models do not know how to cordially invite both streams to

merge together or at least work in tandem fashion to move more

accordingly to the law of baroclinicity (find the difference in pressure

gradients and march one by one until a balanced is reached). We all

know weather is never in balance but that is why storms keep coming over

and over to try to get to a steady medium.

This is why the two part scenario I have been trying to detail is on the

table. This does not mean I will be correct but the way the pattern is

evolving makes sense that something like this can happen. Clipper 1,

tonight into tomorrow, sends a little heat to build the high pressure

off to the east. Up goes the heights a bit. That is why Clipper 2

rounds the bend a bit north. Clipper 2 sends a little more heat into

the ridge and the heights rise a bit again. As the higher heights off

to the east are being created the atmosphere will start to counter that

with deeper low pressure. Then upstream the deeper low pressure will

start to set up a stronger high to form a balance. The tighter these

gradients become the stronger the low pressure will become. What I

believe happens is the first low gets caught in the geostrophic wind

field and takes off at the first sign of weakness. However, it does not

have time to mature and gather all its energy. Remember a low likes to

find the path of least resistance. Since there should be a cranking

Arctic High to the NW of us, some of the heat will go towards that high.

Well we tighten the gradient again, low #2 is sitting and festering

and grabbing all the energy it can to obtain some balance. That High

and low will work in tandem and out comes the second piece with all the

dynamics and as the high slides down from the NW to the SE, that low

will move NE in tandem with the high to create an equilibrium. As the

High continues to grab heat from the low it will intensify to a point

until the low is far enough north to run out of the heat source and then

move out.

With all that being said, Low 1 will be the jack rabbit and cut fast to

find more heat to become stronger but low 2 will sit and become stronger

working off low 1 and the Arctic high. So what should happen is like a

traffic light. Low 1 goes, Low 2 comes in and waits for the high to

come in and then the battle results and Low 2 becomes stronger and fuels

the high to push it northeast until it runs out of heat. That is why I

do not see an East darter because that high will create a great

baroclinic zone and force NE movement for a time. The track could be a

Houston, TX to Huntsville, AL to Hagerstown, WV before it runs out of

warm air and darts east and a coastal low pops. The key for us in an

over running situation is with so much deep low and wide open gulf once

that low gets east of us on a south trajectory the cold comes in and we

go to snow. So basically once east of Huntsville the cold air comes in

and it is snow city.

Josh

[buckeye]

This is my take on the storm. It does not mean some areas get pulverized just a general statement of what I think could occur plus a little explanation of a few things.

I am taking the road less traveled by but I just do not think models

can sense two energy waves coming out at the same time frame before we

get inside 48 hours. They either want to push everything out way too

quickly and it goes east and we get light stuff or nothing or the models

want to bring one piece out too fast before the second piece can be

realized so that second piece is hung out to dry waiting for another

kicker. The tired phrase of, too much in front and not enough back

scenario I am beating into the ground over and over and over again,

shows up very well on the models. The H5 is too flat (Rich A mentioned

it earlier with positive tilt) and the streaming energy wants to rush

towards a heat weakness so zoom, out it goes. This is where the

southern branch becomes the bully and grabs it all and whisks it out.

Then on another model run the northern branch becomes dominant and the

northern energy gets the idea to rush to the heat source and it gets

whisked out because the H5 is too flat and the southern branch gets left

in the dust so we have energy hanging out to the SW. Being 4.5 to 5.5

days out models do not know how to cordially invite both streams to

merge together or at least work in tandem fashion to move more

accordingly to the law of baroclinicity (find the difference in pressure

gradients and march one by one until a balanced is reached). We all

know weather is never in balance but that is why storms keep coming over

and over to try to get to a steady medium.

This is why the two part scenario I have been trying to detail is on the

table. This does not mean I will be correct but the way the pattern is

evolving makes sense that something like this can happen. Clipper 1,

tonight into tomorrow, sends a little heat to build the high pressure

off to the east. Up goes the heights a bit. That is why Clipper 2

rounds the bend a bit north. Clipper 2 sends a little more heat into

the ridge and the heights rise a bit again. As the higher heights off

to the east are being created the atmosphere will start to counter that

with deeper low pressure. Then upstream the deeper low pressure will

start to set up a stronger high to form a balance. The tighter these

gradients become the stronger the low pressure will become. What I

believe happens is the first low gets caught in the geostrophic wind

field and takes off at the first sign of weakness. However, it does not

have time to mature and gather all its energy. Remember a low likes to

find the path of least resistance. Since there should be a cranking

Arctic High to the NW of us, some of the heat will go towards that high.

Well we tighten the gradient again, low #2 is sitting and festering

and grabbing all the energy it can to obtain some balance. That High

and low will work in tandem and out comes the second piece with all the

dynamics and as the high slides down from the NW to the SE, that low

will move NE in tandem with the high to create an equilibrium. As the

High continues to grab heat from the low it will intensify to a point

until the low is far enough north to run out of the heat source and then

move out.

With all that being said, Low 1 will be the jack rabbit and cut fast to

find more heat to become stronger but low 2 will sit and become stronger

working off low 1 and the Arctic high. So what should happen is like a

traffic light. Low 1 goes, Low 2 comes in and waits for the high to

come in and then the battle results and Low 2 becomes stronger and fuels

the high to push it northeast until it runs out of heat. That is why I

do not see an East darter because that high will create a great

baroclinic zone and force NE movement for a time. The track could be a

Houston, TX to Huntsville, AL to Hagerstown, WV before it runs out of

warm air and darts east and a coastal low pops. The key for us in an

over running situation is with so much deep low and wide open gulf once

that low gets east of us on a south trajectory the cold comes in and we

go to snow. So basically once east of Huntsville the cold air comes in

and it is snow city.

Josh

blah blah blah....whatever. So is it gonna snow in my backyard?

j/k...great write up. Hope it pans out

[baroclinic_instability]

Ya, it's how the models handle the PAC energy that seems to be throwing them. It's odd how the GFS is cutting the energy while the ECM brings it out, normally it's the other way around if anything. Anyhow, the GFS, despite being similar to most of the other models with the location of the PV, is still stronger than most with the amount of cold over the east, which should be taken into consideration:

vs.

Both your analyses are spot on I think. Of course there are always a ton of considerations to make--but there are certain things we can key in on for the overall synoptic evolution.

[baroclinic_instability]

This is my take on the storm. It does not mean some areas get pulverized just a general statement of what I think could occur plus a little explanation of a few things.

I am taking the road less traveled by but I just do not think models

can sense two energy waves coming out at the same time frame before we

get inside 48 hours. They either want to push everything out way too

quickly and it goes east and we get light stuff or nothing or the models

want to bring one piece out too fast before the second piece can be

realized so that second piece is hung out to dry waiting for another

kicker. The tired phrase of, too much in front and not enough back

scenario I am beating into the ground over and over and over again,

shows up very well on the models. The H5 is too flat (Rich A mentioned

it earlier with positive tilt) and the streaming energy wants to rush

towards a heat weakness so zoom, out it goes. This is where the

southern branch becomes the bully and grabs it all and whisks it out.

Then on another model run the northern branch becomes dominant and the

northern energy gets the idea to rush to the heat source and it gets

whisked out because the H5 is too flat and the southern branch gets left

in the dust so we have energy hanging out to the SW. Being 4.5 to 5.5

days out models do not know how to cordially invite both streams to

merge together or at least work in tandem fashion to move more

accordingly to the law of baroclinicity (find the difference in pressure

gradients and march one by one until a balanced is reached). We all

know weather is never in balance but that is why storms keep coming over

and over to try to get to a steady medium.

This is why the two part scenario I have been trying to detail is on the

table. This does not mean I will be correct but the way the pattern is

evolving makes sense that something like this can happen. Clipper 1,

tonight into tomorrow, sends a little heat to build the high pressure

off to the east. Up goes the heights a bit. That is why Clipper 2

rounds the bend a bit north. Clipper 2 sends a little more heat into

the ridge and the heights rise a bit again. As the higher heights off

to the east are being created the atmosphere will start to counter that

with deeper low pressure. Then upstream the deeper low pressure will

start to set up a stronger high to form a balance. The tighter these

gradients become the stronger the low pressure will become. What I

believe happens is the first low gets caught in the geostrophic wind

field and takes off at the first sign of weakness. However, it does not

have time to mature and gather all its energy. Remember a low likes to

find the path of least resistance. Since there should be a cranking

Arctic High to the NW of us, some of the heat will go towards that high.

Well we tighten the gradient again, low #2 is sitting and festering

and grabbing all the energy it can to obtain some balance. That High

and low will work in tandem and out comes the second piece with all the

dynamics and as the high slides down from the NW to the SE, that low

will move NE in tandem with the high to create an equilibrium. As the

High continues to grab heat from the low it will intensify to a point

until the low is far enough north to run out of the heat source and then

move out.

With all that being said, Low 1 will be the jack rabbit and cut fast to

find more heat to become stronger but low 2 will sit and become stronger

working off low 1 and the Arctic high. So what should happen is like a

traffic light. Low 1 goes, Low 2 comes in and waits for the high to

come in and then the battle results and Low 2 becomes stronger and fuels

the high to push it northeast until it runs out of heat. That is why I

do not see an East darter because that high will create a great

baroclinic zone and force NE movement for a time. The track could be a

Houston, TX to Huntsville, AL to Hagerstown, WV before it runs out of

warm air and darts east and a coastal low pops. The key for us in an

over running situation is with so much deep low and wide open gulf once

that low gets east of us on a south trajectory the cold comes in and we

go to snow. So basically once east of Huntsville the cold air comes in

and it is snow city.

Josh

Everyone has their own thoughts and opinions--but the atmospheric motions all happen for a physical reasoning through the thermodynamic and dynamical equations of motion. I guess I don't catch on exactly to all the "zooming" and "heat" you keep referencing as well as disturbances filling holes and the models not catching on to two waves, etc. I can see where you are trying to go--but perhaps some images would help in your explanation since you have a lot of different things going on here.

[kab2791]

Through HR 57, 00Z NAM has better phase potential than the 18Z NAM

[baroclinic_instability]

baro

since most of the action has been on the coast, i think many people have missed just how well the GFS has been performing this season, defintely as well or even more stable than the euro in handling big events.

anyways, im not about to get into a pissing match about the models, but the reality is the GFS has been much better this year since the upgrade, in terms of sensible wx.

it seems the upgrade has been a big step in the right direction for the GFS.

ive already mentioned that im not in unless the GFS is in.......something i never would have said in years past!

now for that matter, i hope the Ukie verifies!

Yeah I agree--it still has some verifiable weaknesses, and models are models--they are a bunch of discretized equations and parametrizations with incomplete initial conditions. They will be limited in what they can do. That said--folks bash the GFS for the wrong reasons--and honestly the Euro has the same issues. Models are not to be taken verbatim but as a piece of guidance. Too many times models are judged on their verbatim solution without seeing the big picture. I don't think non-mets should be expected to know that--but I sure hope regular mets do--and I think most do.

[patrick7032]

Both your analyses are spot on I think. Of course there are always a ton of considerations to make--but there are certain things we can key in on for the overall synoptic evolution.

Is one of getting in the RAOB network (had to say it) ? I agree with you baro....and with what they said. One thing that is worth keeping an eye on is the energy and associated strong jet energy with the vort diving SE off of the "tail energy" from the Aleutians low....which is moving fast enough (the diving vort) to overtake and merge/strengthen the strong vort moving towards Vancover Island. The GFS model does not even show this vort diving SE which is clearly evident on WV imagery of the North Pacific.

[Hoosier]

Through HR 57, 00Z NAM has better phase potential than the 18Z NAM

It's not going to be worse at least.

[OhioValleyWx]

blah blah blah....whatever. So is it gonna snow in my backyard?

j/k...great write up. Hope it pans out

LOL yeah a little verbose and to some a repeat of certain elements but thought I would be informative today.

Josh

[baroclinic_instability]

Is one of getting in the RAOB network (had to say it) ? I agree with you baro....and with what they said. One thing that is worth keeping an eye on is the energy and associated strong jet energy with the vort diving SE off of the "tail energy" from the Aleutians low....which is moving fast enough (the diving vort) to overtake and merge/strengthen the strong vort moving towards Vancover Island. The GFS model does not even show this vort diving SE which is clearly evident on WV imagery of the North Pacific.

I think I see your point--and yeah I definitely agree. The way that cyclone develops is where much of the "spread" is amongst the ensembles--and how rapidly and exectly when that thing begins cyclogenesis will have massive implications on the overall forecast. I agree--the evolution is key and there will be continued spread up till that point.

I posted this earlier too--and not to spam my weather blog--but I talk about how these non-linear processes in the Pacific can result in rapid changes.

http://jasonahsenmac...rodynamic-flow/