Baroclinic Zone Posted March 1, 2019 Share Posted March 1, 2019 3km NAM is a bit more robust a solution then the 12km NAM. Warning criteria snows in SE MA down to the Cape. Link to comment Share on other sites More sharing options...
TalcottWx Posted March 1, 2019 Share Posted March 1, 2019 I'd have 3-6" Boston at this time frame. There is a solid chance this becomes 6-10" if things break right. Link to comment Share on other sites More sharing options...
ORH_wxman Posted March 1, 2019 Share Posted March 1, 2019 1 minute ago, wxsniss said: Don't think it's just chasing the convective blob here... you can see differences already by 14 hrs, vorticity is spread out more east and so later does not wrap in Not an unrealistic solution, eSNE widespread 4-8" instead of 8-12"+ It definitely chases the convection once it gets going...it may have started off a tick east, but it gets exacerbated as we go into the run. You can actually see a couple little bullseye of vorticity south of the benchmark by 18 hours. Regardless, the lack of a compact vortmax is definitely an issue for a really wrapped up solution. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted March 1, 2019 Share Posted March 1, 2019 Just now, sbos_wx said: I'd have 3-6" Boston at this time frame. There is a solid chance this becomes 6-10" if things break right. Yep, I'm going 7-14" down in SE MA given the proximity to SLP and some ML deformation. Wait and see on 12z runs. Link to comment Share on other sites More sharing options...
USCAPEWEATHERAF Posted March 1, 2019 Author Share Posted March 1, 2019 Just now, wxsniss said: Don't think it's just chasing the convective blob here... you can see differences already by 14 hrs, vorticity is spread out more east and a so later does not wrap in Not an unrealistic solution, eSNE widespread 4-8" instead of 8-12"+ The reason it is unreasonable is the vorticity is developed through the convection the model develops offshore. The vorticity looks to develop due to the convection, not due to the upper level energy within the shortwave. Water vapor imagery is a great tool to use in this case. The MO shortwave is phasing in with the Gulf shortwave, you can see this taking place as the shortwave begins to pivot in place. I will show you an image of what I mean. Image below shows the developing storm system, with the strong baroclinic leaf in the southeast, the dry slot developing to the west of the low is where our disturbance has phased together with the top of the storm now taking shape. Link to comment Share on other sites More sharing options...
Tiktock Posted March 1, 2019 Share Posted March 1, 2019 3 minutes ago, USCAPEWEATHERAF said: The reason it is unreasonable is the vorticity is developed through the convection the model develops offshore. The vorticity looks to develop due to the convection, not due to the upper level energy within the shortwave. Water vapor imagery is a great tool to use in this case. The MO shortwave is phasing in with the Gulf shortwave, you can see this taking place as the shortwave begins to pivot in place. I will show you an image of what I mean. Image below shows the developing storm system, with the strong baroclinic leaf in the southeast, the dry slot developing to the west of the low is where our disturbance has phased together with the top of the storm now taking shape. That looks really.....elongated. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted March 1, 2019 Share Posted March 1, 2019 These more robust solutions are definitely due in part to the MLs closing off. The 3KM NAM manages to still do that Link to comment Share on other sites More sharing options...
dendrite Posted March 1, 2019 Share Posted March 1, 2019 Just now, Tiktock said: That looks really.....elongated. Looks like it needs a little blue pill. 2 Link to comment Share on other sites More sharing options...
Hoth Posted March 1, 2019 Share Posted March 1, 2019 I'm gonna dust off the old "latent heat release will pump the heights more than modeled and draw this in closer" chestnut. Rightly or wrongly. Link to comment Share on other sites More sharing options...
WinterWolf Posted March 1, 2019 Share Posted March 1, 2019 Would we put more weight on the GFS currently, or the NAM??? I'd go with the GFS at the moment. If the GFS goes to a more NAM like solution at 12z...then that's a horse of a different color for sure. Link to comment Share on other sites More sharing options...
ORH_wxman Posted March 1, 2019 Share Posted March 1, 2019 The water vapor shot that jimmy posted is actually pretty impressive. Makes it hard to envision a mere scrape. 1 Link to comment Share on other sites More sharing options...
USCAPEWEATHERAF Posted March 1, 2019 Author Share Posted March 1, 2019 1 minute ago, Tiktock said: That looks really.....elongated. Lol, my drawing needs a little work, water vapor shows a much better-developed system Link to comment Share on other sites More sharing options...
weatherwiz Posted March 1, 2019 Share Posted March 1, 2019 1 minute ago, dendrite said: Looks like it needs a little blue pill. It's pretty close to Miami too...wonder if it makes a quick stop. Maybe that's why some models go QPF happy. 2 Link to comment Share on other sites More sharing options...
WinterWolf Posted March 1, 2019 Share Posted March 1, 2019 Just now, ORH_wxman said: The water vapor shot that jimmy posted is actually pretty impressive. Makes it hard to envision a mere scrape. I thought the same thing...but wasn't sure if I was looking at it right lol. Link to comment Share on other sites More sharing options...
USCAPEWEATHERAF Posted March 1, 2019 Author Share Posted March 1, 2019 Just now, ORH_wxman said: The water vapor shot that jimmy posted is actually pretty impressive. Makes it hard to envision a mere scrape. Will, I think the models are mishandling the phase of the Great Lakes shortwave because the NAM, for instance, is too far east with the shortwave in the southern stream, with this phase between the MO disturbance and the GULF disturbance, this system will grow in size and allow the phased shortwave to slow down and grow in size and intensity. Link to comment Share on other sites More sharing options...
TalcottWx Posted March 1, 2019 Share Posted March 1, 2019 3 minutes ago, dendrite said: Looks like it needs a little blue pill. Definitely tucked Link to comment Share on other sites More sharing options...
wxsniss Posted March 1, 2019 Share Posted March 1, 2019 3 minutes ago, ORH_wxman said: It definitely chases the convection once it gets going...it may have started off a tick east, but it gets exacerbated as we go into the run. You can actually see a couple little bullseye of vorticity south of the benchmark by 18 hours. Regardless, the lack of a compact vortmax is definitely an issue for a really wrapped up solution. Agree, and there is definitely a little chicken-egg feedback going on as you commented. 3k 12z NAM also has a buckshot diffuse vorticity. Jimmy's shortwave image is actually useful in favor of a more consolidated vortmax, so despite what guidance is showing, that would argue for a more consolidated and tucked low. Link to comment Share on other sites More sharing options...
Baroclinic Zone Posted March 1, 2019 Share Posted March 1, 2019 1 minute ago, WinterWolf said: Would we put more weight on the GFS currently, or the NAM??? I'd go with the GFS at the moment. If the GFS goes to a more NAM like solution at 12z...then that's a horse of a different color for sure. I would tend to agree with this premise, seeing as the Euro, is a pretty solid model and normally great with with coastals. The GFS also agrees with it. Tough to argue against that unholy alliance. Let's see what the rest of 12z guidance shows though before passing judgement. 1 Link to comment Share on other sites More sharing options...
dendrite Posted March 1, 2019 Share Posted March 1, 2019 1 minute ago, weatherwiz said: It's pretty close to Miami too...wonder if it makes a quick stop. Maybe that's why some models go QPF happy. Looks like convection is trying to rub and tug it. If that happens someone will get a shaft. Link to comment Share on other sites More sharing options...
ORH_wxman Posted March 1, 2019 Share Posted March 1, 2019 1 minute ago, USCAPEWEATHERAF said: Will, I think the models are mishandling the phase of the Great Lakes shortwave because the NAM, for instance, is too far east with the shortwave in the southern stream, with this phase between the MO disturbance and the GULF disturbance, this system will grow in size and allow the phased shortwave to slow down and grow in size and intensity. I'm not that concerned with the lakes shortwave....it's really how tucked in the system is against our main shortwave riding up through the TN valley and into the mid-atlantic. The lakes shortwave does interact with it some, and it will affect this system, but much more of the variance is due to how the vorticity is being handled....it's not strong which is giving the models fits on where to focus the conveyors. Link to comment Share on other sites More sharing options...
NeonPeon Posted March 1, 2019 Share Posted March 1, 2019 The NAM has been reasonably accurate in the last two garbage systems, and seems entirely plausible. I wish I could feel comfortable ignoring it, because its says I am on the outside looking in. Box's conservative approach seems to have been quite reasonable. I'm sure more adjustments will come, but it won't be oversteer. What a headache if the GFS/Euro are obstinate. Link to comment Share on other sites More sharing options...
OSUmetstud Posted March 1, 2019 Share Posted March 1, 2019 1 minute ago, dendrite said: Looks like convection is trying to rub and tug it. If that happens someone will get a shaft. "The Kraft" 1 1 Link to comment Share on other sites More sharing options...
TalcottWx Posted March 1, 2019 Share Posted March 1, 2019 2 minutes ago, dendrite said: Looks like convection is trying to rub and tug it. If that happens someone will get a shaft. Winter Storm LuLu 1 Link to comment Share on other sites More sharing options...
USCAPEWEATHERAF Posted March 1, 2019 Author Share Posted March 1, 2019 Just now, ORH_wxman said: I'm not that concerned with the lakes shortwave....it's really how tucked in the system is against our main shortwave riding up through the TN valley and into the mid-atlantic. The lakes shortwave does interact with it some, and it will affect this system, but much more of the variance is due to how the vorticity is being handled....it's not strong which is giving the models fits on where to focus the conveyors. Will what I believe argues against the premise of a weaker shortwave and low, is that the precipitation shield is beginning to show rotation as it moves northeastward and the amount of energy in the GULF states with lightning everywhere. Including the energy needed to produce a squall line. Link to comment Share on other sites More sharing options...
DomNH Posted March 1, 2019 Share Posted March 1, 2019 The HRRR is really not feeling it. That model mostly sucks but highlights the disconnect between the mesos and globals. I'm going to guess the GFS doesn't go thermonuclear at 12z and cans the warning snows to CON but who knows. Link to comment Share on other sites More sharing options...
ORH_wxman Posted March 1, 2019 Share Posted March 1, 2019 RPM is in the meso camp...no surprise since its a meso model....has a low end warning event for most of SE MA, RI, and S CT. 1 Link to comment Share on other sites More sharing options...
Hoth Posted March 1, 2019 Share Posted March 1, 2019 Just now, DomNH said: The HRRR is really not feeling it. That model mostly sucks but highlights the disconnect between the mesos and globals. I'm going to guess the GFS doesn't go thermonuclear at 12z and cans the warning snows to CON but who knows. Isn't it a bit early to break that out? Link to comment Share on other sites More sharing options...
TalcottWx Posted March 1, 2019 Share Posted March 1, 2019 Just now, DomNH said: The HRRR is really not feeling it. That model mostly sucks but highlights the disconnect between the mesos and globals. I'm going to guess the GFS doesn't go thermonuclear at 12z and cans the warning snows to CON but who knows. I am perhaps one of the few sickos who uses that model a lot within 24hr.... I honestly don't even look at it until about 12 hours before the event... Pretty much worthless at this time frame Link to comment Share on other sites More sharing options...
TalcottWx Posted March 1, 2019 Share Posted March 1, 2019 Just now, ORH_wxman said: RPM is in the meso camp...no surprise since its a meso model....has a low end warning event for most of SE MA, RI, and S CT. This is honestly my snow map. Exactly what I think. Link to comment Share on other sites More sharing options...
PowderBeard Posted March 1, 2019 Share Posted March 1, 2019 5 minutes ago, NeonPeon said: The NAM has been reasonably accurate in the last two garbage systems, and seems entirely plausible. I wish I could feel comfortable ignoring it, because its says I am on the outside looking in. Box's conservative approach seems to have been quite reasonable. I'm sure more adjustments will come, but it won't be oversteer. What a headache if the GFS/Euro are obstinate. When temps and terrain matter or its a simple clipper, I like the NAM. However, systems still developing, tons of variables and pieces of energy at play, I don't trust it. I was kind of laughing at the high numbers getting thrown around but the flaccid water vapor image makes me think the GFS is on this one. 1 Link to comment Share on other sites More sharing options...
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