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Dec 9th Winter Threat

ORH_wxman

By ORH_wxman,
in New England

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Tropopause_Fold

Tropopause_Fold

Posted
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It had bigger QPF when this was back in the middle range...  I think part of the problem here is that the baroclinic axis is pressed out so far SE of the v-max track, so much so that it is stressing the vertical structure of the cyclone.  The q- vector forcing is a bit too askew of the low and mid level frontal slopes (in the GFS), such that UVM is weaker.   Less UVM --> less restoring jets -->  less cyclogen.  And we notice that not only is the QPF trending lower, the primary low is trending weaker and more open.  

 

Who knows if that is the way it will go down, but what I'm looking at is a v-max over Milwaukee WI, at 96 hours, and leading up to that, the frontal structures are very amorphous, and also the thermal packing is way down over the Gulf states -- systems don't usually engineer that way; they need to have mid level jet entrance regions to pass over lower lvl baroclinicity, and this whole structure on this thing is way way too tilted. 

yeah and there is also virtually no 5h vorticity east of the region (WI) you mention...it rides the periphery of the ridge. if you go back several GFS runs to early in the week (and i know at least 1 euro run)...when this event was a week out...it was punching the mid-level energy into the OV and E GL. 

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CoastalWx

CoastalWx

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yeah and there is also virtually no 5h vorticity east of the region (WI) you mention...it rides the periphery of the ridge. if you go back several GFS runs to early in the week (and i know at least 1 euro run)...when this event was a week out...it was punching the mid-level energy into the OV and E GL. 

 

Yeah the lack of s/w forcing isn't good..it's straight WAA, Seems like euro is more robust with WAA.

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ORH_wxman

ORH_wxman

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As long as you have some pretty strong SW flow with moisture running into that type of arctic high, you'll get some moderate precip. The energy being well west though tells us not to expect a 12/16/07 when we were pounding out 0.15" of qpf per hour.

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Typhoon Tip

Typhoon Tip

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yeah and there is also virtually no 5h vorticity east of the region (WI) you mention...it rides the periphery of the ridge. if you go back several GFS runs to early in the week (and i know at least 1 euro run)...when this event was a week out...it was punching the mid-level energy into the OV and E GL. 

 

I remember that... right.   Also, not the first time a western Atlantic ridge was dismantled too fast -- but we'll see what ultimately verifies of all this.  Still a chance however fleeting and low, that it rides a bit east -- nah.  

 

Folks, perhaps more of a banter topic, but one that I think is plausibly a correction that could be applied to this system   ... I step back and looking at a nice -EPO domain, and a -PNA tendency that wants to have heights be high over Florida, and it dawns on me that all this is, is one giant cluster -f of a L/W interference pattern.  Sparing a big technical, eyes-glazing run-down,  ... -EPO is good for cold loading, but we need something else in the general circulation to be cyclone-friendly, or you end up with these ana headaches and/or shred jobs.  It would be nice if the NAO would ease off the positive throttle, because it might offer suppression in the SE ... but therein creates another problem of too much gradient.  (Will was all over that aspect last week...)   

 

I know it is cold, and that is good for winter enthusiasm (don't get me wrong!  once winter is here, I am apart of that ilk...), and I suppose beggers can't be choosers and we get what we get for systems... but, this is somewhat of waste quite frankly.  Having large scale fields interfering with storm production when we have so much deep cold loading near-by is rather unfortunate. 

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CoastalWx

CoastalWx

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As long as you have some pretty strong SW flow with moisture running into that type of arctic high, you'll get some moderate precip. The energy being well west though tells us not to expect a 12/16/07 when we were pounding out 0.15" of qpf per hour.

 

That's what I was saying at work...I mean I don't expect to be ripping S+...but I don't see how the GFS is so light with QPF. That's a good thermal push trying to move north. Bit of a red flag it's doing it for successive runs..but seems a little too dry.

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ORH_wxman

ORH_wxman

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That's what I was saying at work...I mean I don't expect to be ripping S+...but I don't see how the GFS is so light with QPF. That's a good thermal push trying to move north. Bit of a red flag it's doing it for successive runs..but seems a little too dry.

 

 

GGEM is a nice look...probably a low end advisory snow, but it takes it time...probably like a nice picturesque snow for 6-8 hours that accumulates 2-4" before changing over.

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Typhoon Tip

Typhoon Tip

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Keeping in mind... the discussion above was pertaining to specifically the GFS....   I really have no idea what will actually happen, but seeing as we are inside D4, I think it would be unwise to go against the Euro -- I think, in fact, it would be unwise to even go half way between the GFS and Euro.  

 

I'd go with the Euro, and then consider the GFS as an afterthought, and wait for the rare day that the GFS wins a model battle for a system that's a 96 hours lead.  The Euro is that good in these nearer time frames.   

 

I like your idea, Scott, of a giant WAA thing...  In fact, I actually was just ruminating that it's like the whole thing is just big warm front.  But there is enough ...albeit modifying arctic air over the Lakes region, poised to roll back in here by next Wednesday I just didn't mention it.  

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SnowGoose69

SnowGoose69

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Keeping in mind... the discussion above was pertaining to specifically the GFS....   I really have no idea what will actually happen, but seeing as we are inside D4, I think it would be unwise to go against the Euro -- I think, in fact, it would be unwise to even go half way between the GFS and Euro.  

 

I'd go with the Euro, and then consider the GFS as an afterthought, and wait for the rare day that the GFS wins a model battle for a system that's a 96 hours lead.  The Euro is that good in these nearer time frames.   

 

I like your idea, Scott, of a giant WAA thing...  In fact, I actually was just ruminating that it's like the whole thing is just big warm front.  But there is enough ...albeit modifying arctic air over the Lakes region, poised to roll back in here by next Wednesday I just didn't mention it.  

 

 

Looking at the packing of the height lines and the flow nearly perpendicular to them from 700-850 I don't see anyway there is not a massive outbreak of precipitation possibly as early as 18-20Z across SNE down through MA....The GFS seemed fine through 78-84 hours then just looked wrong....the 850 temps warm from -7C over Central NJ at 00Z to above 0C by 08Z...thats relatively strong WAA yet no precip is really generated or it seems to "hit a wall" the thing is the GFS nor any model rarely if ever can see mid or low level dry air as a reason for eating up its precipitation shield usually at this range the models generate precip anyhow regardless of whether that is going to be a factor...so to me the GFS is seeing some other reason the precip dies advancing from SNJ up through NYC into SNE...what the reason is I don't know but IMO its not good enough to see a 800-900mb dry nose as the reason why.

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Typhoon Tip

Typhoon Tip

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Looking at the packing of the height lines and the flow nearly perpendicular to them from 700-850 I don't see anyway there is not a massive outbreak of precipitation possibly as early as 18-20Z across SNE down through MA....The GFS seemed fine through 78-84 hours then just looked wrong....the 850 temps warm from -7C over Central NJ at 00Z to above 0C by 08Z...thats relatively strong WAA yet no precip is really generated or it seems to "hit a wall" the thing is the GFS nor any model rarely if ever can see mid or low level dry air as a reason for eating up its precipitation shield usually at this range the models generate precip anyhow regardless of whether that is going to be a factor...so to me the GFS is seeing some other reason the precip dies advancing from SNJ up through NYC into SNE...what the reason is I don't know but IMO its not good enough to see a 800-900mb dry nose as the reason why.

 

I think the other reason is that the model sucks ?    haha, j/k   Yeah, agreed... the 850mb panel at 96 hours off this 12z GFS oper. run has nearly 50kts of wind flow plowing normally into the temperature gradient over SNE (early for MA/NYC ...etc).  And, as KTAN has noted, given the source region of the air being foisted over that frontal slope is 3 SD above PWAT norm, you'd think at least SOME potency would have to take place.  

 

Could be a classic IB band in there ...

 

Any early risers on the Euro ?   ...My hunch is that it holds.

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ORH_wxman

ORH_wxman

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Shows you what type of system we are dealing with when a half inch or more QPF is considered really wet, haha.

Out in lala range this thing first started with what looked like a solid 0.5-1.25" type QPF event.

 

 

Almost impossible to get an inch of QPF when the big PVA is as far west as it is in this setup. But given the utter strength of the SE ridge, its probably a good thing and what helps us stay pretty cold.

 

I'll take 0.5" of qpf mostly/all frozen vs 1.25" where half of it is heavy rain. :lol:

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Typhoon Tip

Typhoon Tip

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no kidding, huh? check out some of the obs in the front-range this afternoon. pretty LOL-tastic. 

 

Yeah, guys, check out these SD obs from 12pm -- sick!


LOCATION	TIME[cst]	WEATHER	TEMP	DEWPT	HUMIDITY	WIND	PRESSURE
Aberdeen, SD	11:53	Fair and Breezy	        -0ºF	-9ºF	65%	W 23 G 28 mph	30.21 in
Pierre, SD	11:53	A Few Clouds and Breezy	 2ºF	-6ºF	69%	NW 22 G 28 mph	30.29 in
Watertown, SD	11:53	Overcast and Breezy	-0ºF	-6ºF	76%	W 22 G 26 mph	30.13 in
Mobridge, SD	11:52	Fair and Breezy	        -0ºF   -10ºF	62%	W 23 G 28 mph	30.20 in
Sisseton, SD	11:56	Breezy	                 4ºF	-4ºF	69%	NW 21 G 31 mph	30.12 in
Wheaton, MN	12:34	Partly Cloudy and Breezy 7ºF	-0ºF	72%	W 25 G 30 mph	30.15 in
Ortonville, MN	12:33	Fair	                 3ºF	-4ºF	72%	W 18 mph	30.15 in
Huron, SD	11:55	Fair and Breezy	         3ºF	-6ºF	66%	W 23 G 31 mph	30.25 in
Brookings, SD			                  ºF	  ºF	%	 mph	 in
Hettinger, ND	11:53	Fair and Breezy	        -7ºF   -15ºF	68%	W 22 G 29 mph	30.17 in
Philip, SD	11:55	Fair	                 3ºF 	-9ºF	57%	NW 18 G 31 mph	30.29 in
Faith, SD	11:56	Breezy	                -4ºF   -13ºF	65%	W 24 G 28 mph	30.21 in
Chamberlain, SD	11:52	NA	                 4ºF	-8ºF	57%	NW 18 G 28 mph	30.29 in
Winner, SD	11:53	Fair and Breezy	         4ºF	-8ºF	57%	NW 22 mph	30.27 in
Morris, MN	12:23	Partly Cloudy with Haze and Breezy	3ºF	-2ºF	78%	W 23 G 31 mph	30.11 in
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ravensrule

ravensrule

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Yeah, guys, check out these SD obs from 12pm -- sick!


LOCATION	TIME[cst]	WEATHER	TEMP	DEWPT	HUMIDITY	WIND	PRESSURE
Aberdeen, SD	11:53	Fair and Breezy	-0ºF	-9ºF	65%	W 23 G 28 mph	30.21 in
Pierre, SD	11:53	A Few Clouds and Breezy	2ºF	-6ºF	69%	NW 22 G 28 mph	30.29 in
Watertown, SD	11:53	Overcast and Breezy	-0ºF	-6ºF	76%	W 22 G 26 mph	30.13 in
Mobridge, SD	11:52	Fair and Breezy	-0ºF	-10ºF	62%	W 23 G 28 mph	30.20 in
Sisseton, SD	11:56	Breezy	4ºF	-4ºF	69%	NW 21 G 31 mph	30.12 in
Wheaton, MN	12:34	Partly Cloudy and Breezy	7ºF	-0ºF	72%	W 25 G 30 mph	30.15 in
Ortonville, MN	12:33	Fair	3ºF	-4ºF	72%	W 18 mph	30.15 in
Huron, SD	11:55	Fair and Breezy	3ºF	-6ºF	66%	W 23 G 31 mph	30.25 in
Brookings, SD			ºF	ºF	%	 mph	 in
Hettinger, ND	11:53	Fair and Breezy	-7ºF	-15ºF	68%	W 22 G 29 mph	30.17 in
Philip, SD	11:55	Fair	3ºF	-9ºF	57%	NW 18 G 31 mph	30.29 in
Faith, SD	11:56	Breezy	-4ºF	-13ºF	65%	W 24 G 28 mph	30.21 in
Chamberlain, SD	11:52	NA	4ºF	-8ºF	57%	NW 18 G 28 mph	30.29 in
Winner, SD	11:53	Fair and Breezy	4ºF	-8ºF	57%	NW 22 mph	30.27 in
Morris, MN	12:23	Partly Cloudy with Haze and Breezy	3ºF	-2ºF	78%	W 23 G 31 mph	30.11 in

I would have no faith living there, damn that is cold.

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