December 24-25 Snowstorm

[hawkeye_wx]

This system would have to take a leap north or south for me to not get at least a solid 3 or 4 inches, so I'm feeling pretty good. I do agree with some others that this GFS run looked a bit odd. Who knows... should be fun to watch it evolve.

[buckeye]

its amazing how the ggem dries up between the hrs of 108 and 120. literally its a precip bomb in the lower midwest at 108 and as soon as it hits IN it practically dries up.

[The_Global_Warmer]

HAHAHA GGEM is way south........

108 HR... RELOAD if it's the old one (Should be 12z Fri)

Gem is awesome....weakens fast but is awesome.

[baroclinic_instability]

HAHAHA GGEM is way south........

108 HR... RELOAD if it's the old one (Should be 12z Fri)

Hmm, at 96 hrs they both have the shortwave over OK, doesn't seem too different.

[JoMo]

GFS Ens mean.

[buckeye]

Hmm, at 96 hrs they both have the shortwave over OK, doesn't seem too different.

looks like it transfers to the southeast and heads up the coast. The 'drying up' it's showing over the OV must be due to that transfer because I can't see any reason why it would do that so dramatically.

[buckeye]

looks like it transfers to the southeast and heads up the coast. The 'drying up' it's showing over the OV must be due to that transfer because I can't see any reason why it would do that so dramatically.

I might have to bump my morning "screw zone map" ....looks like the ggem nailed it

[csnavywx]

Hmm, at 96 hrs they both have the shortwave over OK, doesn't seem too different.

Yeah, only the 00Z run manages to park the SLP under the 500 trough axis over AR. If I didn't have a surface map, I'd place it over Wrn TN/KY. Odd indeed.

[Harry]

S/W at 500 isn't closed. It may appear that way, but the actual wind circulation isn't closed off, it's still an open wave, and the jet would support the low where it is. At the moment, it appears to carry a steady-state SLP across the Plains while slowly strengthening the 850-500 upper wave. This is the non-phased scenario, which as I mentioned before, still produces a decent storm for the Midwest, and a further south track eastward. The GFS, being a lower-res global, may not be giving the strengthening the storm will likely experience over the Plains in this scenario, so even with this run, I would expect it to track a bit slower and further north.

The 00Z NAM is suffering from the "phase shift" problem (very obvious from early in the run), and is complete and utter garbage. It is not to be used for any serious discussion on this storm.

Something about that whole picture ( which even DT mentioned ) at 102hrs/108hrs seems suspect thoughwith how everything progresses.

Note even the flow at 102hrs.. Keep in mind where the surface reflect is in W.MO. That does not scream a move ese to N.AR at 108hrs especially with that closed 540 in se IA.

As for that feature in IA at 108hrs. Again look at 102hrs and you can see what the model is attempting to do there which it sorta does 108hrs. Thus again something is not totally right with this run. If it was to indeed close off as the model did hint at then i am 99.9% certain that surface low does not go from W.MO to N.AR and or ese.

IF i had to venture a early guess i think what we may see is a bowling ball type low tracking from the plains to the eascoast.

[JoMo]

Hmm, at 96 hrs they both have the shortwave over OK, doesn't seem too different.

I think the difference is that the GGEM pushes it east or ENE and not NE like the GFS.

108 color just updated. Energy over SW MO on the GGEM

Up over Iowa at same time on GFS:

[buckeye]

i feel like clark griswold after he just opened his xmas bonus....membership to jelly of the club month If that ain't a kick in the.......

[Harry]

Something about that whole picture ( which even DT mentioned ) at 102hrs/108hrs seems suspect thoughwith how everything progresses.

Note even the flow at 102hrs.. Keep in mind where the surface reflect is in W.MO. That does not scream a move ese to N.AR at 108hrs especially with that closed 540 in se IA.

As for that feature in IA at 108hrs. Again look at 102hrs and you can see what the model is attempting to do there which it sorta does 108hrs. Thus again something is not totally right with this run. If it was to indeed close off as the model did hint at then i am 99.9% certain that surface low does not go from W.MO to N.AR and or ese.

IF i had to venture a early guess i think what we may see is a bowling ball type low tracking from the plains to the eascoast.

The euro ensembles have been hinting at that sort of thing as well. with track a low almost due east from the plains to the eastcoast. Main difference is some track across KY while the others are along i70.

[Stevo6899]

That ec storm is still there at hours 100 on the GGEM. Its weaker but still windy on the east coast. perhaps thats why the weakening?

[dilly84]

i feel like clark griswold after he just opened his xmas bonus....membership to jelly of the club month If that ain't a kick in the.......

I have a feeling, Euro is going to throw the wrench tonight. Just a gut feeling. Hope I am wrong.

[WxMidwest]

Hey, I was Reading Piers Corbyn's Website, Predicted an East Coast Blockbuster for Christmas on Dec 6th.

[baroclinic_instability]

its amazing how the ggem dries up between the hrs of 108 and 120. literally its a precip bomb in the lower midwest at 108 and as soon as it hits IN it practically dries up.

With a non-phase solution, what the models are trying to prog is rapid cyclogenesis. Without doing a PV analysis but just looking at 500 hpa vorticity alone, it seems the models are suggesting a rather deep PV anomaly. From a cyclogenesis standpoint, a deep PV anomaly "ejecting" directly over a moist baroclinic zone like that will incite rapid and tropospheric deep cyclogenesis and a ton of latent heat release. However, being un-phased with the northern stream, that potential energy is used up quick and the rapid latent heat release and heavy qpf through the depth of the column further warms and weakens the system as the baroclinic zone in the low/mid levels is processed. If it were a phased solution, this drying wouldn't occur so quickly.

Latent heat release is an important process in early cyclogenesis and in stronger phased solutions a system will "dryslot" and occlude but continue strengthening even though the low level baro zone has been sufficiently "processed".

[buckeye]

I have a feeling, Euro is going to throw the wrench tonight. Just a gut feeling. Hope I am wrong.

what direction is the wrench going? north or south

[Harry]

i feel like clark griswold after he just opened his xmas bonus....membership to jelly of the club month If that ain't a kick in the.......

Time to go give some congrats to Ji..

[buckeye]

With a non-phase solution, what the models are trying to prog is rapid cyclogenesis. Without doing a PV analysis but just looking at 500 hpa vorticity alone, it seems the models are suggesting a rather deep PV anomaly. From a cyclogenesis standpoint, a deep PV anomaly "ejecting" directly over a moist baroclinic zone like that will incite rapid and tropospheric deep cyclogenesis and a ton of latent heat release. However, being un-phased with the northern stream, that potential energy is used up quick and the rapid latent heat release and heavy qpf through the depth of the column further warms and weakens the system as the baroclinic zone in the low/mid levels is processed. If it were a phased solution, this drying wouldn't occur so quickly.

i guess that makes sense. Would we, (further east folks), have a better shot if this sucker closed at 500 and just bowled?

[buckeye]

Time to go give some congrats to Ji..

we'll see. I think the euro is still holding it's cards.....gonna play them in the next 24 hrs.

[Thundersnow12]

i feel like clark griswold after he just opened his xmas bonus....membership to jelly of the club month If that ain't a kick in the.......

"Clark, thats the gift that keeps on givin the whole year....that it is edward, that it is indeed."

[baroclinic_instability]

i guess that makes sense. Would we, (further east folks), have a better shot if this sucker closed at 500 and just bowled?

Yeah, something along the 12Z GFS would be quite ideal.

All guidance is pretty suggestive of a nearly cutoff "migratory" deep PV over the plains. If not sufficiently phased with the northern stream, it will undergo that rapid cyclogenesis I mentioned over the plains and weaken heading east. You want a phase, even if it results in a bowling ball and potential dry slot.

[buckeye]

"Clark, thats the gift that keeps on givin the whole year....that it is edward, that it is indeed."

lol...yea that's how i feel about this damn pattern, the gift that keeps on giving....heartbreak

I'm so damn sick of watching these threats literally dry up as they come east.....hell look at tomorrow/tuesday, same damn thing.

...excuse my vent

[csnavywx]

Something about that whole picture ( which even DT mentioned ) at 102hrs/108hrs seems suspect thoughwith how everything progresses.

Note even the flow at 102hrs.. Keep in mind where the surface reflect is in W.MO. That does not scream a move ese to N.AR at 108hrs especially with that closed 540 in se IA.

As for that feature in IA at 108hrs. Again look at 102hrs and you can see what the model is attempting to do there which it sorta does 108hrs. Thus again something is not totally right with this run. If it was to indeed close off as the model did hint at then i am 99.9% certain that surface low does not go from W.MO to N.AR and or ese.

IF i had to venture a early guess i think what we may see is a bowling ball type low tracking from the plains to the eascoast.

Sorry.. should have said 850 low is where it should be. Progged SLP turns out to be kind of irrelevant in these types of situations at this lead time... i.e. where cold air is entrenched east of the Rockies, as this can lead to an inverted trough type situation, and make it seem like the SLP track is flopping every run.

If you look at the 850mb level and up, it doesn't really change that much. Take a look at the 102 hr frame on the 00z run vs the 108 hr frame on the 18z run. A little stronger (and thus a tad slower) on the more phased 18Z, which makes sense, but otherwise, very little change there.

[Stebo]

I don't think anyone should really be making drastic calls on this yet, its still 6 days out, with a system still in front of it. The fact that the ensembles are all over the place should tell you not to write it off one way or another. Too many do that too soon in the game.

[jhamps10]

I don't think anyone should really be making drastic calls on this yet, its still 6 days out, with a system still in front of it. The fact that the ensembles are all over the place should tell you not to write it off one way or another. Too many do that too soon in the game.

agreed...

[baroclinic_instability]

Yeah, only the 00Z run manages to park the SLP under the 500 trough axis over AR. If I didn't have a surface map, I'd place it over Wrn TN/KY. Odd indeed.

On the GFS or CMC?

[JoMo]

120 UKMET has a low over N Alabama @ 120. (from main model thread)

[baroclinic_instability]

Yeah, only the 00Z run manages to park the SLP under the 500 trough axis over AR. If I didn't have a surface map, I'd place it over Wrn TN/KY. Odd indeed.

I guess, in terms of either solution, given the depth of the PV and the moist baro zone, the nearly stacked nature of the migrating PV would suggest cyclogenesis would be nearly stacked with little tilt, hence the rapid weakening in the non-phased solution.

[michsnowfreak]

"Clark, thats the gift that keeps on givin the whole year....that it is edward, that it is indeed."

There are 5 days til this storm. Does EVERYONE know how many ups and downs are on the way. GUARENTEED. So everyone just relax. And lets just press on, and have the hap, hap, happiest Christmas since Bing Crosby tapdanced with Danny F**kin Kaye.