Wednesday / Thursday Storm (Wednesday Afternoon Update)

First and foremost, our storm is really taking a toll in the Southeastern US. Snows and ice are really hitting an area hard that is not normally accustomed to this. I can only hope everyone down there follows their forecasts and have plans done accordingly.

For our area up here, we are about 10 hours away from the start of our storm. As you can see, we are dealing with a very large storm. We can see a direct influence from the Gulf Of Mexico feeding directly into our low pressure. This will be a very intense and large storm. This will also probably be our longest duration event for the year.

My going thinking has been 4-8" for the area and then a switch over to a mix and possibly rain. I do think we switch back to snow as the CCB (Cold Conveyor Belt) swings through the area. The CCB is the back end of the "comma" head of the storm. As the storm pushes through, this will swing over the area. How much additional will that add? Well, like everything else with this storm, it depends.

I will say, the models have been all over the place with this very large and complex storm. My 4-8" is my best guess trying to make sense and from experience with these types of storms from prior years. Growing up in NJ, most of the large intense storms bring a period of a transition to a mix or rain. As the storm moves east of the area, we go back to snow till the end of the storm. While the model guidance has been less than stellar, I do hold out hope for the short range models, the HRRR and the RUC models which will be in their range later on tonight.

While my call is 4-8" with a transition, the confidence of that is low to medium. I think we are going to see some very impressive snowfall rates through the area. We have a storm that is going to dump between 1-2" of precipitation. The question is going to be figuring out, how much of that is snow, mix, rain. If it were all snow, we would be looking at 12"+ easily. Now, how fast do we transition? Do we transition? does it stay as sleet? freezing rain? rain? Do we go back to snow? What kind of precipitation rates do we have? These questions will all be answered starting in 10 hours. Until then, I am going with the 4-8" as my conservative estimate, with a strong feeling that the totals may end up higher than that.

So, while those are the accumulation questions, there will be other questions that will also need to be answered. I said that we are dealing with a very large and dynamic storm. Even if warm air moves in, and the surface temps get above freezing, if we have a period of very heavy precipitation, we can remain snow if the upper atmosphere is still below freezing. This will all have to be tracked as well with the storm. Obviously, if the rates are not that impressive, or the upper atmosphere and surface are above freezing, we will have rain. Speaking of dynamic......I fully expect there to be a good number of reports of thundersnow tomorrow. Maybe even as early as the early morning hours.

So, the specifics.

Snow moves in around midnight to 2am. It will snow very heavily in the early morning hours, with the possibility of thundersnow. Accumulations by the time we wake up will be 3-6". I expect to pick up another inch or two and then a transition to a mix will occur as the storm moves closer and some warmer air floods the upper atmosphere. I do think though we will remain sleet for a while. During the afternoon, precipitation may actually stop or become very drizzly. To the evening hours, I expect the CCB to intensify and move through dropping more intense snowfall before ending towards midnight. Exactly how much will depend on how the low pressure bombs out, and how much moisture can be thrown back over the area.

Anyways, those are my thoughts and concerns as of now. As always, I will be posting on facebook and twitter throughout the day and night.

Stay Safe!

February 5th Event (Monday PM Update)

As we wind down from our storm today, we can now turn out attention to the upcoming threat on Wednesday. Last week I made a post about a very active pattern unfolding over the area, and that seems to be the case. Yes, we have a lot of threats, and yes, we have some shots at snow. I will however, take it one storm at a time. I spoke of the change in any variable from a previous storm having an impact on storms following. Case in point, the next storm up, Wednesday.

Two days ago, this was looking like a washout. Now, with some fresh snowcover down, there is talk of a couple inches of snow and then a switch over to a mix and then to rain. Places now in NW NJ and NE PA could get a whole lot of snow and never transition over now. So, I am going to be curious to see how the models interpret this tonight and tomorrow. I have a sneaking suspicion that we could be in for a ice event, especially from Trenton north. 

As of now, Snow moves in late tomorrow night and will accumulate. Precipitation will transition over to a mix from south to north. It will make it to about rt 80 where north of there is out best bet to remain all snow. In addition, the mix will also change over to rain from south to north, and how far up that goes will be the question. This will be another quick moving storm, and will probably be out of here again by the late afternoon Wednesday. More to come on this storm. 

Wednesday 2/13/2013 Morning Update

Look for precipitation to break out around 7pm. Surface temperatures today will be quite warm, so that is going to limit the amount that accumulates on paved surfaces. This will be more of a nuisance event, especially since there will be little accumulation on pavement. Precipitation moves out around midnight, so its a quick hitter. General accumulations from 2-4" across the area, mostly on grassy surfaces. Once you get north and west of Route 80, precipitation really cuts down. 

Still keeping an eye on the weekend, as the potential is still there. Nothing of substance is really showing up, but it will be monitored. 

Monday February 11, 2013 Morning Discussion

Some areas this morning had icy conditions. Areas from Central Jersey south have transitioned to all rain as temperatures have risen well above freezing. A frontal boundary is moving through with a low pressure to our west. With that setup, we get flooded with warmer air aloft and eventually down to the surface. Areas further north that have a substantial amount of snow will stay with the freezing rain a little longer due to the fact that your surface temperatures are colder due to the snow. Eventually, all areas will transition to plain rain.

A lot going on this week. First, for the period Wednesday and Thursday we have a potential coastal storm development. Most models have some sort of storm (although they get here through different tracks) for our area. The usual questions remain; track, intensity etc. Biggest question for me right now is surface temperatures. As it looks now, would more than likely be a mix to snow for Central Jersey and snow north and west. Coastal areas would be rain and some backside snows possibly. Hopefully over the next day we can nail this down.

Then to the weekend. This would be the period from Saturday Night through Sunday Night. We have another modeled storm that could be a bit more substantial. A lot to work out with this storm, and I am going to focus on the Wednesday - Thursday storm first. There is potential though for another coastal storm. We have had a number of storms affect our area during the Presidents weekend time frame, and this could be another case.

12/28/2012 Evening Update

Well, what a turn of events on the weather modeling regarding tomorrows storm. Yesterday, we were looking at a storm that was tracking east of us far enough where there was no issues with precipitation type. We were getting snow, end of story. Today, things have changed. Each model run has brought a solution closer and closer to the coast, and also transferring energy and phasing energy sooner. All this leaves us in a position where we may actually have to worry about a changeover to a mix, or worse, rain.

Models have been showing this all day, and each run is more precipitation and further west (bringing in warmer air). I am kinda hoping there is a correction back a bit to the east on tonights runs, but not overly enthusiastic that happens. Tomorrow, it is very possible as of now, that coastal areas get a brief period of snow before a direct change to rain. That rain/snow line will then march northward and to what extent is unknown, it will just have to be watched in a nowcasting situation tomorrow. It will more than likely setup shop somewhere around interstate 95.

More to come.