MID ATLANTIC NY PA NJ DE MD DC MID ATLANTIC NY PA NJ DE MD DC

Hi guys, I'm back

Discussion started by John Manetta 2 years ago

Hi everyone, it's John Manetta, or John M. as some of you know me.  To those that don't know me, I look forward to having some great discussions with you.  I've been absent for some time, which is a long story, but I'm glad to be back.

 

There is a threat of a warning criteria event in the 8/9/10th time frame, (likely the latter part).  At this point there is a fairly wide range of possible outcomes.  I am currently using the ECMWF and GFS for guidance into this period, (of course with a close look at the UKMET, EPS and other ensembles etc.).  Both models, (at this time), are predicting a situation that would be favorable for significant cold air damming during the event.  This means that the cold air at the low levels will likely remain cold while warm air floods the mid levels as waves of low pressure enter the region and finally a coastal develops and locks the surface cold in.  This would favor a significant period of freezing rain for a portion of the region. 

Of course, the global models have not yet had a good sampling of data to ingest into their initialization because the systems have not yet reached the the upper air network, (the weather balloons that are launched from around the world to collect data are very sparse over the oceans).  This is why 00z and 12z predictions are usually more accurate, because the balloons are launched twice per day and the data is used at those times, (sometimes more in exceptional circumstances). 

 

As we can get a handle on this in the coming days, I will get more specific.  At this point I suspect that the high pressure system will be in an optimal position for a while, but with the Atlantic not helping with a -NAO it's going to be close.  The timing of the second wave and where the high is before and during the development of the coastal means everything from significant snow, to an icing event to a mix, (I'm confident about the coastal development, but it's placement and the column temperatures are debatable at this time).

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John Manetta
John Manetta
The guidance continues the Southward shift which was expected. As was discussed a couple of days ago, the low level cold will probably not be completely eroded at the surface. In addition the warm air advection will not be as impressive as it was with the last system. This being said, the icing threat that I talked about when this blog was written almost 3 days ago is becoming more and more likely for parts of the region. It should also be mentioned that the amount of precipitation is dependent on where the surface low tracks. As I've been saying, even when the models had it going over or North of us, I believe that it will track South of us, but how far South is very important.
2 years ago
ajb
ajb
Central New Jersey has only received a total of about 8 inches of snow this season so far. I don't know too much about weather forecasting, I follow these blogs because I find the science of forecasting and the interpretation of the different models interesting and I also like snowstorms. That being said the little that I do know gives me the gut feeling that we'll get something very substantial before February ends or the winter in general finishes...
2 years ago
John Manetta
John Manetta
I haven't done this since last year when I did it a lot but the 2/14-2/21 period may be our chance to make up for the snow deficit....I'll zero in on a 3 or 4 day period after another day or two at checking some stuff out.
2 years ago
John Manetta
John Manetta
Well, the 00Z GFS came back South a little with the surface low track...the 00Z ECMWF continued to adjust South of its last run. The NAM is still lost as usual but adjusted Southward also. My thinking is that the surface low will track South of us. I also think that the low level cold from the cold air damming is slowly being incorporated into guidance, but is still underestimated. The coastal that develops will make a big difference for our weather if it is East of Virginia rather than New Jersey. So for tonight, I think the models are still off but are slowly run to run coming to something nearing a consensus...As I mentioned very early yesterday morning, there is a real threat of icing for portions Southeast PA.
2 years ago
John Manetta
John Manetta
That should say "this year" not "yeah"...for some reason I am having trouble trying to edit that post.
2 years ago
John Manetta
John Manetta
Yeah, thanks. Last year was so, so easy to forecast. I mean you could just pick things out from pretty far off and the events, in the days before were not so much in question compared to this year. This yeah this area is getting "climo"-like systems with mixing issues etc. But on the longer range I really believe we'll make up for the snow deficit with one major storm.
2 years ago
ajb
ajb
Welcome back John M! I remember you from years gone by...I hope all is well...
2 years ago
John Manetta
John Manetta
Here's a quick guidance update, I will give my own thoughts later on tonight. The ECMWF at midday made some Southward adjustments and was colder over-all. It's ensembles agreed. The 18Z GFS nudged a little North of 12Z but it is an off run trying to predict unsampled weather systems so I think that 00Z will be more useful, (and I suspect that it will come in colder). I of course am discounting the horribly unreliable NAM.
2 years ago
John Manetta
John Manetta
The ECMWF will be in soon, but the other morning and midday guidance has made some Southward adjustments keeping parts of the region in a position where a significant problem with sleet/icing could occur, as mentioned very early yesterday.
2 years ago
John Manetta
John Manetta
Thanks. Hopefully we can get a good discussion going regarding tonight's runs. Though obviously much will change in coming days, it's the tracking that's a big part of the fun.
2 years ago
ActionPhilosopher
ActionPhilosopher
Welcome back John!!
2 years ago
John Manetta
John Manetta
Thank you it's great to be back, I'll se what we have going and let you know in an hour.
2 years ago
John Manetta
John Manetta
Sure enough the models that I am weighting for insight into the upcoming event, at midday today made some Northward adjustment and sets up an opportunity for a significant freezing rain event and have the coastal where expected based on current information. This being said, the shortwaves have still not been sampled by the upper air network, so time will tell.
2 years ago
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