Potential for a Bomb Late This Week?

[Robert Dewey]

It looks like the medium range models are coming together in showing a strong storm system developing as early as FH84-96. While the energy is in the US at that time, it doesn't really develop until later in the week...

The 12Z ECMWF and 12Z UKMET are VERY strong with this system, on the order of 975MB tracking through the Ohio Valley towards CLE. The latest 00Z GFS is much further northwest and phased than the old 12Z run, which is much more in line with the Euro models, and bombs the system out towards the southeast PA (with a WIDE area of +30KNT winds). FWIW, the Canadian GEM is also jumping in... Not nearly as strong, but it has made a trend toward a further northwest and more phased system. Either way, ALL models agree that there will be significant upper level energy and support... Pretty amazing this far out.

Not much more to say except there is decent agreement and model support for a potential bomb/monster cyclone later this week. I seem to remember such good agreement also existed with other intense storms (Blizzard of 1999, 1996 East Coast Blizzard, and even the "Storm of the Century" March 1993)... But, I'm sure there were many other cases that pooped out... LOL

 

[Jonathan Whitehead]

Im preparring my fallout shelter and have air raid siren in hand. Army fatigues...check.

ok maybe i shouldnt be making light of that.

 

[Joel Wright]

Looks like yet another "non-event" to me.


Yawn.

 

[Robert Dewey]

06Z GFS jumped on board with a "bomb" as well... Deepening the system to < 980MB. The 12Z NAM shows more energy at 500MB than what the GFS was showing... With phasing, there should be plenty of cold air for this system to work with.

I guess the only question is... Where will it "explode"? If it DOES in fact phase and bomb out, this could easily be another "Blizzard of 1996" - quite likely stronger than the "Blizzard of 1999" which only featured a 994MB low. If the system DOESN'T bomb out, then the storm will likely track much farther south and ride the East Coast, but it won't be nearly as deep.

But... The 00Z UKMET and ECMWF are now back to a split system... It appears the only two models showing any phasing as of now are the GFS and NAM, with a trend toward phasing seen in the GEM.

Don't jinx it so soon Joel (which is probably what I am doing) :lol:

 

[Angie Norris]

Looks like it may be quite the rain/snow machine for the upper Midwest, the southeast and up the coast...but it is the GFS and it is 4-5 days out...
Definitely worth keeping an eye on...

Angie

 

[brody_clifton]

Looks like a severe potential may exist with this sytem from far eastern TX east along the gulf coast. 84hr NAM and GFS both indicating southerly surface flow ahead of the trough from near the TX/LA line on east, below an exiting 50+ kt southwesterly LLJ. Right now, the shortwave looks like it will arrive early Friday, as the 96hr GFS indicates an 80+ kt 500mb streak nosing in to northeast TX, from mostly due west. The 84 hour runs of the NAM and GFS have the 500mb streak in the same general area of northwest tx, with that it appears possible the next NAM run for 500mb may look similar to the current 96GFS. Upper 60s temps, low 60s dewpoints forecast for SE tx Thursday evening, with that airmass moving into western LA overnight and into Friday morning. Moisture at 850, however, looks marginal on both models (<10 Td) at least compared to the 1/2/06 event, but this could be underforecast, will have to wait and look at surface Tds later in the week in the NW gulf.

 

[nickgrillo]

Looks pretty decent to me... Just browsing through the GFS and NAM, and it shows a shortwave amplifying as it moves into OK/TX by the late evening -- with moderate moisture ahead of the deepening surface cyclone (yielding weak SBCAPE of at least 500 j/kg). I wish this system would pull a bit further west... To help this drought. At any rate, things likely will not initiate until late (ascent doesn't reach the warm sector til afterdark).

Originally posted by brody_clifton
Looks like a severe potential may exist with this sytem from far eastern TX east along the gulf coast. 84hr NAM and GFS both indicating southerly surface flow ahead of the trough from near the TX/LA line on east, below an exiting 50+ kt southwesterly LLJ. Right now, the shortwave looks like it will arrive early Friday, as the 96hr GFS indicates an 80+ kt 500mb streak nosing in to northeast TX, from mostly due west. The 84 hour runs of the NAM and GFS have the 500mb streak in the same general area of northwest tx, with that it appears possible the next NAM run for 500mb may look similar to the current 96GFS. Upper 60s temps, low 60s dewpoints forecast for SE tx Thursday evening, with that airmass moving into western LA overnight and into Friday morning. Moisture at 850, however, looks marginal on both models (<10 Td) at least compared to the 1/2/06 event, but this could be underforecast, will have to wait and look at surface Tds later in the week in the NW gulf.

 

[Jeff Snyder]

*** EDIT: I'm referring to the south-central US low tonight and tomorrow. This probably isn't the best place for my comments, but I don't want to open a new thread just for this yet.

I'm just having fun reading the AFDs out of OUN and TSA from the past few days. The horrible model-to-model and run-to-run consistency over the past 3-4 days has been interesting to read play out in AFDs -- for example, "will insert rain chances", "will remove rain chances", "will increase pops", "not looking as good for precip, so will decrease pops", "surprise! time for a snow advisory in OK!". Will we have a closed low or a fast-moving wave? LOL.

I also can't help but notice that the snow advisory from OUN extends through OKC, but does not include Norman (Cleveland county)... It always seems like these winter events extend right up to I44 or as close to Norman as possible while still leaving OUN in cold rain.

 

[Joel Wright]

Originally posted by Joel Wright
Looks like yet another "non-event" to me.


Yawn.

I guess I should add definitely not a non-event out east. Here in the midwest though the storm looks like it'll still be in it's infant stages. By the time the storm really gets revved up it will be well east of the midwest.

It looks like a hell of a bomb though along the east coast, with a band of heavy snow probably in the eastern great lakes, again.

Enjoy it guys, it should be fun to watch.

 

[Robert Dewey]

I'm just keeping an eye on it...

Agreement between the models seems pretty bad... The GFS is the only model showing such a strong system. though it's supported by most of the ensembles. The previous Euro models also showed a bombogenesis solution, but they are now back to the cutoff low near the GoM that weakly affects the Gulf and no one else. I would bet that a solution in between the more progressive GFS and the stalled out Euro models will prevail.

Either way, just look at the Absolute Vorticity fields on ALL of the models... That's ALOT of energy! If all of that energy were to consolidate into a main mid level wave, we could easily be looking at a sub 970MB-975MB sfc low somewhere east of the MS River. But, the models definitely aren't showing that as of now.

 

[Fred Gossage]

The 18Z model runs are generally in now..... and the NAM seems to have the same general idea as the GFS on this run (for as far as the NAM can go out at least).

I'm starting to see a decent severe weather pattern on the front side of this system Friday for MS/AL/TN/KY......

 

[nickgrillo]

Originally posted by Fred Gossage
The 18Z model runs are generally in now..... and the NAM seems to have the same general idea as the GFS on this run (for as far as the NAM can go out at least).

I'm starting to see a decent severe weather pattern on the front side of this system Friday for MS/AL/TN/KY......

I could see this...

The 50F sfc isodrosotherm pushes up into northern Illinois and Indiana by the afternoon on FRI (with deeper moisture further south into KY and points southward) with strong flow at all levels (with a favorable moist/sheared boundary layer for strong/severe storms). Maybe I'll make a Maproom thread a little later...

 

[Scott Weberpal]

I'll be driving from WI to Chattnooga, TN on Friday to visit my girlfriend, but may leave Thursday night if the GFS solution comes to pass. Not to say my excitement level for chasing in TN is too high, but any convection may do for me right now. Understandably moisture is still forecast to be relatively shallow, but there's a lot of climatology that goes into the GFS. I'll be keeping a close eye on the system.

 

[Robert Dewey]

The 06Z NAM is kind of interesting... It's a bit further south with the shortwave, and looks like it wants to develop someting around MO/AR beyond FH84. That would support significant cyclogenesis as 500MB shortwave rounds the base of the trough with the 110KNT upper level jet phasing with the 90KNT subtropical jet... This is in contrast with the GFS solution, which is MUCH further north and weaker with cyclogenesis until things hit the East Coast.

The 06Z NAM would support a better severe weather threat in the south and a winter storm threat in the north with significant cyclogenesis...

On the other hand, the ECMWF is still very far south and closes things off quickly... While the UKMET is now somewhat further north - but still closes off the 500MB shortwave. The 06Z DGEX is along the lines of the ECMWF, and rides a 965-970MB low up the East Coast. The 00Z GEM is back north like the GFS...

There are so many different possibilities as of now... We will likely have to wait until tomorrow's 00Z THU run or possibly the 12Z THU run so the system can be completely sampled by the upper air network...

I'm really crossing my fingers that we can get something in between the GFS and the DGEX... A system further southeast than the GFS, but further northwest of the DGEX.

 

[Robert Dewey]

Well, the latest GFS really looks like crap. It doesn't even keep a closed height contour at 850MB and is already through the Great Lakes by FH72. In other words, it's ALOT more progressive and much weaker. The NAM is also trending towards the more open wave/weaker system. This doesn't look good for strong cyclogenesis and associated severe weather / winter potential... On top of that, there is no high pressure north of the system - one ingredient usually present in winter storms.

EDIT: 12Z GEM also in line with the GFS/NAM with a much weaker system... 12Z UKMET out to 72HR is deeper with the 500MB trough and would support a strong solution. My bet is the ECMWF will look more like the UKMET... So now we have two different "camps" - the weak GFS/NAM/GEM versus the stronger UKMET/ECMWF models. NCEP/HPC discussions will be interesting later today.

If this trend continues, we may be looking at just a plain ol' trough swinging through with little action.

Looks like another one might bite the dust....