snowstormcanuck Posted January 7, 2011 Share Posted January 7, 2011 Cold bias didn't play a role in this...the mean was affected by the 4-5 ensemble members developing a coastal low which took the whole mean and shifted it NW. I was talking about the individual members. Almost all the members were further NW with the QPF shield advancing through the OV in comparison with the OP. Even the members with a more OTS coastal sfc low, had more precip further northwest, west of the Apps. Seems to be caused by a sharper ul trough that doesn't dampen out so readily. Link to comment Share on other sites More sharing options...
buckeye Posted January 7, 2011 Share Posted January 7, 2011 When you look at that map, then yes, it looks good. I glanced at the members, and they have huge discrepancies with the southern migratory wave and its placement. As a result of the speed differences, the mean height field dampens it out completely and makes it look like it isn't there. Right now SREF prolly isn't a good guide simply because the mesoscale models will have more difficulty in handling the southern wave than the globals will. would it be correct to say if that vort over se canada moves far enough east it will give room for the ridge to pop in the east and could translate into a more western solution? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 I was talking about the individual members. Almost all the members were further NW with the QPF shield advancing through the OV in comparison with the OP. Even the members with a more OTS coastal sfc low, had more precip further northwest, west of the Apps. Seems to be caused by a sharper ul trough. Sorry my mistake, thought you were referencing the mean. That southern wave is our key player here. Watch that little pecker wave and how it trends because that will influence the amount of warm advection/height ridging is possible ahead of the secondary wave ejecting into the plains and how far the trough tracks N. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 would it be correct to say if that vort over se canada moves far enough east it will give room for the ridge to pop in the east and could translate into a more western solution? If that pecker southern stream wave didn't exist, then yes. 3-4 days ago it looked like that southern wave would be well ahead of this incoming western trough. Remember the way the ECM dampened the developing trough with that weird vortex over the lakes? The models have sinced relaxed the suppression over the Lakes, but now they slowed down the cutoff low and also develop it farther into the GOM. This little vort is killing the moisture feed and warm air advection pattern ahead of the trough, therefore heights aren't rising sufficiently to take the storm farther NW. Watch the southern vort and the answer to the rest of the forecast becomes clear. The reason for the slowdown? It is farther S, and as a result, the southern vort weakens due to diabatic heating and height rises with the weak open wave closing off and crapping out. Link to comment Share on other sites More sharing options...
buckeye Posted January 7, 2011 Share Posted January 7, 2011 If that pecker southern stream wave didn't exist, then yes. 3-4 days ago it looked like that southern wave would be well ahead of this incoming western trough. Remember the nway the ECM dampened the developing trough with that weird vortex over the lakes? The models have sinced relaxed the suppression over the Lakes, but now they slowed down the cutoff low and also develop it farther into the GOM. This little vort is killing the moisture feed and warm air advection pattern ahead of the trough, therefore heights aren't rising sufficiently to take the storm farther NW. Watch the southern vort and the answer to the rest of the forecast becomes clear. so basically, those rooting for a nw trend want that southern vort weak and the hell out of there fast Link to comment Share on other sites More sharing options...
snowstormcanuck Posted January 7, 2011 Share Posted January 7, 2011 Sorry my mistake, thought you were referencing the mean. That southern wave is our key player here. Watch that little pecker wave and how it trends because that will influence the amount of warm advection/height ridging is possible ahead of the secondary wave ejecting into the plains and how far the trough tracks N. It's no problem. I should have specified. Models have been pretty steadfast with that lead southern wave, which is why I'm not expecting much. Mostly straw grasping at this point on my part. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 so basically, those rooting for a nw trend want that southern vort weak and the hell out of there fast Yeah pretty much. Root for that to head E faster and/or stay farther N of the GOM so it doesn't sit there and rot as it precipitates itself out. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 so basically, those rooting for a nw trend want that southern vort weak and the hell out of there fast Here is my simplistic explanation, but easy to understand. The southern wave and its associated surface low (green line). Note the circled area--the GOM is closed for business, and this both weakens the baroclinic zone ahead of the incoming western trough, but very importantly for development of the secondary trough ejecting into the plains, it cuts the moisture feed off and the storm can't amplify and intensify nearly as fast. Also look at all that convection...there will be a lot of precipitation/thunderstorms with that system unless it tracks elsewhere. Why does the GOM being closed off matter? Warm air advection. The height rises are dynamically induced via low level WAA. Heights aloft are the result, and as most now know, that is why mets talk about height rises ahead of a trough so much. This storm overall is actually being suppressed by that pathetic, weak looking migratory wave. It is a terrific example of how tiny errors can have massive impacts in time. Link to comment Share on other sites More sharing options...
buckeye Posted January 7, 2011 Share Posted January 7, 2011 Here is my simplistic explanation, but easy to understand. The southern wave and its associated surface low (green line). Note the circled area--the GOM is closed for business, and this both weakens the baroclinic zone ahead of the incoming western trough, but very importantly for development of the secondary trough ejecting into the plains, it cuts the moisture feed off and the storm can't amplify and intensify nearly as fast. Also look at all that convection...there will be a lot of precipitation/thunderstorms with that system unless it tracks elsewhere. Why does the GOM being closed off matter? Warm air advection. The height rises are dynamically induced via low level WAA. Heights aloft are the result, and as most now know, that is why mets talk about height rises ahead of a trough so much. This storm overall is actually being suppressed by that pathetic, weak looking migratory wave. It is a terrific example of how tiny errors can have massive impacts in time. ok, i understand what you're saying. Link to comment Share on other sites More sharing options...
buckeye Posted January 7, 2011 Share Posted January 7, 2011 well fwiw....the 00z nam compared to the 18z nam shows a bit of a weaker southern wave and a stronger and slower northern wave. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 N Kansas/S Nebraska gets crippled per latest NAM. Even with frontal banding, some of those QPF values seem a bit overdone though. Congrats to our lone member down in that area Omahawx. Link to comment Share on other sites More sharing options...
dilly84 Posted January 7, 2011 Share Posted January 7, 2011 N Kansas/S Nebraska gets crippled per latest NAM. Even with frontal banding, some of those QPF values seem a bit overdone though. Congrats to our lone member down in that area Omahawx. a little soon for congratulatories lol.. Although, they seem to be in a good spot regardless. Link to comment Share on other sites More sharing options...
prinsburg_wx Posted January 7, 2011 Share Posted January 7, 2011 N Kansas/S Nebraska gets crippled per latest NAM. Even with frontal banding, some of those QPF values seem a bit overdone though. Congrats to our lone member down in that area Omahawx. also "jcwxguy" from the Lincoln, NE area...they get crushed...wonder what the snow ratio would be? Link to comment Share on other sites More sharing options...
Stebo Posted January 7, 2011 Share Posted January 7, 2011 Given that Nebraska has been jobbed all winter I'll pass out some congrats to them they deserve one, and we can cross one off the list of places needing a big one this winter too Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted January 7, 2011 Share Posted January 7, 2011 Nam looks a bit stronger out west.probably will give us a decent dry snow here. I an putting down 3-6 for STL..and 4.5 inches for my backyard when its all over. Link to comment Share on other sites More sharing options...
JoMo Posted January 7, 2011 Share Posted January 7, 2011 Still got a few runs to go before it ends up in Minnesota like usual. Link to comment Share on other sites More sharing options...
michsnowfreak Posted January 7, 2011 Share Posted January 7, 2011 Given that Nebraska has been jobbed all winter I'll pass out some congrats to them they deserve one, and we can cross one off the list of places needing a big one this winter too I agree they deserve some snow, but I wouldnt be crossing anything off so fast just because of the 84-hour nam. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 also "jcwxguy" from the Lincoln, NE area...they get crushed...wonder what the snow ratio would be? A good question that always needs to be considered. It depends on where the main frontogenesis response is. Looks like much of this event will be occurring through frontogenesis from 850-700 hpa. Soundings show the inversion not topping out much past 700, and most of the higher level forced ascent associated with DPVA will be relegated farther S and W. Forcing will be relegated just outside of the DGZ, but still noteworthy snow amounts are possible were NAM to verify as is. Link to comment Share on other sites More sharing options...
buckeye Posted January 7, 2011 Share Posted January 7, 2011 Nam looks a bit stronger out west.probably will give us a decent dry snow here. I an putting down 3-6 for STL..and 4.5 inches for my backyard when its all over. stronger and slower out west.....southern wave a little weaker. Those are probably good things. But I wont extrapolate the nam beyond 84hrs lol Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 I agree they deserve some snow, but I wouldnt be crossing anything off so fast just because of the 84-hour nam. In this storm case, the NAM gets consideration because of its ability to handle longwave troughs better than fast moving shortwaves. Also, the NAM does well with modeling mesoscale events such as frontogenesis, and this event across that region will be dominated by it. Agree though, not marking it in stone, but the NAM to my eye has a decent handle and representation of the overall synoptic pattern wrt to globals at the same time frame. Link to comment Share on other sites More sharing options...
Chicago WX Posted January 7, 2011 Share Posted January 7, 2011 Nam looks a bit stronger out west.probably will give us a decent dry snow here. I an putting down 3-6 for STL..and 4.5 inches for my backyard when its all over. Bold. Hope it works out for you. Still got a few runs to go before it ends up in Minnesota like usual. -5% chance. Link to comment Share on other sites More sharing options...
Stebo Posted January 7, 2011 Share Posted January 7, 2011 Still got a few runs to go before it ends up in Minnesota like usual. I don't see this one heading toward Minnesota. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted January 7, 2011 Share Posted January 7, 2011 also "jcwxguy" from the Lincoln, NE area...they get crushed...wonder what the snow ratio would be? he seems to be around more during svr wx season, met up with him for a short time on the cap bust on 6/6/09 in sw IA. NAM showing a good area of snow at 84hrs, would be curious if that expands to the east, when looping the H5 vort maps you can see a good deal of energy about to come around the base of the trof and kick out. also, the 850mb low moving quite slow, 72 hours on the CO/NM border to north of AMA at 84 hours Link to comment Share on other sites More sharing options...
Moneyman Posted January 7, 2011 Share Posted January 7, 2011 Looks like a pretty good snowstorm for Neb. according to the GFS, through hr 87. Link to comment Share on other sites More sharing options...
Stebo Posted January 7, 2011 Share Posted January 7, 2011 GFS not budging on having this southern low track across the gulf, even with the vort max pulling away and weakening. Link to comment Share on other sites More sharing options...
FarmerRick Posted January 7, 2011 Share Posted January 7, 2011 N Kansas/S Nebraska gets crippled per latest NAM. Even with frontal banding, some of those QPF values seem a bit overdone though. Congrats to our lone member down in that area Omahawx. Lone member in the area? It's kinda hard to get a word in edgewise with 90% of those in these threads being from OHIO. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted January 7, 2011 Share Posted January 7, 2011 Lone member in the area? It's kinda hard to get a word in edgewise with 90% of those in these threads being from OHIO. I hope your joking.. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted January 7, 2011 Share Posted January 7, 2011 Looks like a pretty good snowstorm for Neb. according to the GFS, through hr 87. KS gets rick rolled pretty good. Link to comment Share on other sites More sharing options...
Stebo Posted January 7, 2011 Share Posted January 7, 2011 Man the GFS is lol worthy tonight. Link to comment Share on other sites More sharing options...
Moneyman Posted January 7, 2011 Share Posted January 7, 2011 When is it not? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.