swimmatte Posted November 24, 2012 Share Posted November 24, 2012 18Z NAM looking stronger FWIW Link to comment Share on other sites More sharing options...
BristowWx Posted November 24, 2012 Share Posted November 24, 2012 Nam just went off on precip... And went off in general. Mother of God....NAM would be a real treat...but it's the NAM Link to comment Share on other sites More sharing options...
tombo82685 Posted November 24, 2012 Share Posted November 24, 2012 Mother of God....NAM would be a real treat...but it's the NAM Make sure you look at the whole column and not just 850 and up. In reality the nam is pretty warm in the bl from 900mb on down to surface. Link to comment Share on other sites More sharing options...
BristowWx Posted November 24, 2012 Share Posted November 24, 2012 Make sure you loofact at the whole column and not just 850 and up. In reality the nam is pretty warm in the bl from 900mb on down to surface. Yes..I just got ahead of myself for a moment..The fact that it is after sunset had me for a mintue. Link to comment Share on other sites More sharing options...
wxmeddler Posted November 24, 2012 Share Posted November 24, 2012 I was looking at the 12z Euro on the accuwx pay site that we subscribe to here at school. The cut off line for snow is the fall line. If your NW of that it's 1-3". If your northwest of the Carrol co./ S York co. hills then it's 3-6" Make sure you look at the whole column and not just 850 and up. In reality the nam is pretty warm in the bl from 900mb on down to surface. Yep, BWI/DCA is stuck in the mid-upper 30's. You have to be north of the fall line in order to get snow. Interesting note also, the nam is slower bringing in precip almost 12 hours later. Link to comment Share on other sites More sharing options...
mitchnick Posted November 24, 2012 Share Posted November 24, 2012 Make sure you look at the whole column and not just 850 and up. In reality the nam is pretty warm in the bl from 900mb on down to surface. strange too since thicknesses are below 540 and drop during the event well, even if we miss this one, it's nice to see this kind of system so early in the season Link to comment Share on other sites More sharing options...
MN Transplant Posted November 24, 2012 Share Posted November 24, 2012 No skin in the game, since I'll be out of town. DCA sounding from the 18z NAM. - maybe a new thread for the Tuesday threat? Starting to get inside of the mid-range. Link to comment Share on other sites More sharing options...
tombo82685 Posted November 24, 2012 Share Posted November 24, 2012 strange too since thicknesses are below 540 and drop during the event well, even if we miss this one, it's nice to see this kind of system so early in the season The issue is in the 925-850mb layers on the models. the wind backs from the south, and thats deadly if you want a snowstorm. Also the 925 and 850mb lows, which seen below tracks overhead, you want to be north of that. Link to comment Share on other sites More sharing options...
Ian Posted November 24, 2012 Share Posted November 24, 2012 vort is in a decent spot on the nam.. nam. meh. probably wrong. Link to comment Share on other sites More sharing options...
tombo82685 Posted November 24, 2012 Share Posted November 24, 2012 vort is in a decent spot on the nam.. nam. meh. probably wrong. I wouldn't give the nam much consideration outside of 48 hrs. Once inside of that timeframe start paying attention to it. For you and us up here yoiu need that euro track maybe a hair further south or stronger to drag the colder air down increasing precip rates. Link to comment Share on other sites More sharing options...
winterymix Posted November 24, 2012 Share Posted November 24, 2012 I-81 special Link to comment Share on other sites More sharing options...
mitchnick Posted November 24, 2012 Share Posted November 24, 2012 The issue is in the 925-850mb layers on the models. the wind backs from the south, and thats deadly if you want a snowstorm. Also the 925 and 850mb lows, which seen below tracks overhead, you want to be north of that. agreed but that one map is for 81 hrs and at 84 hrs there is still precip overhead in central MD no doubt, as currently modeled, the big cities won't see accum snow, but there's plenty of time if we can take another couple of steps in the right direction, which is where I'm going....especially considering the 5H low placement maybe the lower levels will be adjusted as time goes on (or some other weenie magic!) Link to comment Share on other sites More sharing options...
tombo82685 Posted November 24, 2012 Share Posted November 24, 2012 agreed but that map is for 81 hrs and at 84 hrs there is still precip overhead in central MD no doubt, as currently modeled, the big cities won't see accum snow, but there's plenty of time if we can take another couple of steps in the right direction, which is where I'm going....especially considering the 5H low placement maybe the lower levels will be adjusted as time goes on (or some other weenie magic!) Yea, like i said to Ian, i wouldnt give the nam consideration until inside 48hrs. Link to comment Share on other sites More sharing options...
Ian Posted November 24, 2012 Share Posted November 24, 2012 If we get a decent track etc I would bet this event ends up colder than forecast. Prime season for that once you get precip going. air mass isnt super by any means but there's cold enough air around with reinforcements coming in with the storm. Link to comment Share on other sites More sharing options...
Ian Posted November 24, 2012 Share Posted November 24, 2012 Yea, like i said to Ian, i wouldnt give the nam consideration until inside 48hrs. you're the one that pulled out the twister data maps. Link to comment Share on other sites More sharing options...
tombo82685 Posted November 24, 2012 Share Posted November 24, 2012 If we get a decent track etc I would bet this event ends up colder than forecast. Prime season for that once you get precip going. air mass isnt super by any means but there's cold enough air around with reinforcements coming in with the storm. heavy precip rates will help, just ask nj and nyc 2 weeks ago. Link to comment Share on other sites More sharing options...
tombo82685 Posted November 24, 2012 Share Posted November 24, 2012 you're the one that pulled out the twister data maps. Lol i was just illustrating a point. All the models are showing the southerly wind carnage to some degree or other. Link to comment Share on other sites More sharing options...
Ian Posted November 24, 2012 Share Posted November 24, 2012 Lol i was just illustrating a point. All the models are showing the southerly wind carnage to some degree or other. yeah it's an uphill battle particularly without elevation but that's standard early season. Link to comment Share on other sites More sharing options...
Amped Posted November 25, 2012 Share Posted November 25, 2012 GFS almost pulls a PDI day 7 something to watch. Big warmup after that. Link to comment Share on other sites More sharing options...
Deck Pic Posted November 25, 2012 Share Posted November 25, 2012 GFS almost pulls a PDI day 7 something to watch. Big warmup after that. Link to comment Share on other sites More sharing options...
midatlanticweather Posted November 25, 2012 Share Posted November 25, 2012 Larry Cosgrove stating something big may be coming Dec 7 - 9 time frame Link to comment Share on other sites More sharing options...
eurojosh Posted November 25, 2012 Share Posted November 25, 2012 I have to say, it's much more fun to be sitting in the last week of November and seeing this than to be in the last week of February and knowing it's the last chance... Link to comment Share on other sites More sharing options...
Ian Posted November 25, 2012 Share Posted November 25, 2012 Larry Cosgrove stating something big may be coming Dec 7 - 9 time frame Lol Link to comment Share on other sites More sharing options...
Amped Posted November 25, 2012 Share Posted November 25, 2012 Larry Cosgrove stating something big may be coming Dec 7 - 9 time frame We'll see, the pattern gets a better after day 12. Dec 5-10 typically brings a first winter threat. I would never call for something big in DCA at that range. Link to comment Share on other sites More sharing options...
CAPE Posted November 25, 2012 Share Posted November 25, 2012 We'll see, the pattern gets a better after day 12. Dec 5-10 typically brings a first winter threat. I would never call for something big in DCA at that range. Not sure the pattern is going to be better. Yeah the AO is going pretty strongly negative per most models, But that big ass ridge west of Alaska isnt budging. That means cold for parts of AK and western Canada and maybe Pac NW at times, but the PNA is negative which means downstream ridging and generally mild over central/eastern US. And the NAO doesnt look to be persistently negative. See the latest CFS monthly temp anomalies for Dec. Looks quite toasty. Need that ridge to retrograde. Link to comment Share on other sites More sharing options...
Deck Pic Posted November 25, 2012 Share Posted November 25, 2012 Not sure the pattern is going to be better. Yeah the AO is going pretty strongly negative per most models, But that big ass ridge west of Alaska isnt budging. That means cold for parts of AK and western Canada and maybe Pac NW at times, but the PNA is negative which means downstream ridging and generally mild over central/eastern US. And the NAO doesnt look to be persistently negative. See the latest CFS monthly temp anomalies for Dec. Looks quite toasty. Need that ridge to retrograde. we may see a -EPO/+PNA/-NAO pattern develop after the 5th....probably would be transient, but we could maybe eek out a mixy event then....LC may be on to something...too far out now, but I'd say 60-40 we average -departures in the 12/7-12/12 range..December will start out warm Link to comment Share on other sites More sharing options...
usedtobe Posted November 25, 2012 Share Posted November 25, 2012 we may see a -EPO/+PNA/-NAO pattern develop after the 5th....probably would be transient, but we could maybe eek out a mixy event then....LC may be on to something...too far out now, but I'd say 60-40 we average -departures in the 12/7-12/12 range..December will start out warm Matt, I think that is too early to get the positive PNA. To me the pattern looks warmer than normal with a crappy PNA through the 9th. The CPC superensemble has a strongly negative ao but has a really crappy look to it. one that lets lots of warm air flood the conus as lots of pac air crashes into coast. I composited the analog dates to make sure their 500h looked similar to the center mean. They did, then I looked at the temp anomalies for date of the centered mean from the anomalies and got this warm look. Based on the 500h anomaly pattern, I think this temp anomaly look is reasonable for that dec 5th or 6th. I then composited the 500h for 3 days beyond the centered man and got this composite which still holds onto the neg pna and positive heights across the east despite the neg ao look. That;s still a warm look overall for us. My guess is that the temps for the dec 4-9 period will be warmer than normal and that any snow chances will have to wait. That said, I'm relying on a mean model pattern and have little skill past day 4 or 5 so I could be totally wrong. Link to comment Share on other sites More sharing options...
Ian Posted November 25, 2012 Share Posted November 25, 2012 writing's on the wall. snowy winter casts are gonna bust. Link to comment Share on other sites More sharing options...
Deck Pic Posted November 25, 2012 Share Posted November 25, 2012 Matt, I think that is too early to get the positive PNA. To me the pattern looks warmer than normal with a crappy PNA through the 9th. The CPC superensemble has a strongly negative ao but has a really crappy look to it. one that lets lots of warm air flood the conus as lots of pac air crashes into coast. I composited the analog dates to make sure their 500h looked similar to the center mean. They did, then I looked at the temp anomalies for date of the centered mean from the anomalies and got this warm look. Based on the 500h anomaly pattern, I think this temp anomaly look is reasonable for that dec 5th or 6th. I then composited the 500h for 3 days beyond the centered man and got this composite which still holds onto the neg pna and positive heights across the east despite the neg ao look. That;s still a warm look overall for us. My guess is that the temps for the dec 4-9 period will be warmer than normal and that any snow chances will have to wait. That said, I'm relying on a mean model pattern and have little skill past day 4 or 5 so I could be totally wrong. thanks for the info...maybe we have to wait until a few days later if it even happens?...I though there were some indications a decent pattern might pop up the 8th or 9th but maybe not...I don't mind punting the 1st 10 days of december when climo is bad if we get a better one the 2nd half...I never thought much of December this winter...others went cold....I like where I stand as far as the outlook Link to comment Share on other sites More sharing options...
Deck Pic Posted November 25, 2012 Share Posted November 25, 2012 writing's on the wall. snowy winter casts are gonna bust. I always thought we would be backloaded, but maybe Dec 15-30 could be decent... Link to comment Share on other sites More sharing options...
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