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!

January 2-3, 2014 Storm (Wednesday Noon Update)

First, HAPPY NEW YEAR!

Well, here we are once again with a very challenging forecast which will more than likely go down to another nowcasting event. There are a number of moving parts to this storm, and the overall strength will not be known for some time. We have an interaction that will occur between the subtropical jet (currently the precipitation along the Gulf States and the Polar jet (currently the precipitation through the midwest into Detroit). As seen here:

As the storm progresses, we will see an interaction occur. When, and how quickly these parts interact and eventually phase, that will determine how much snow we are looking at. The NAM model paints an earlier phase and a bigger storm for our area, and the GFS model paints a later phase, and as a result, a bigger storm over New England. In any case, the GFS model still paints a plowable event for our area.

GFS model- Showing a quick intesification for our area, but moves out rather quickly in the next frame and hits NE.

1am Friday:

 Friday 7am: (notice brunt of the precip off shore and over eastern NE

NAM MODEL

Quicker phase, really hammers our area

 Still has moderate to heavy snow over our area at 7am Friday (notice our area has the brunt of the precip):

So, the big question will be when does this phase occur. And unfortunately, it will have to be now casted tomorrow night. Either case, we are looking at a storm which will drop a couple inches. Here is where I am now, if we get that earlier phase, I think our area would be looking at 6-10" of snow. If we get that later phase, I think we will be looking at 2-4 (SNJ) to 3-6 (CNJ-NNJ). Its going to be another thread the needle event, with another tough forecast. Don't be surprised to hear amounts going up and down by the media stations. I do believe that Watches and or Warnings will be issued for MT Holly's forecast area this afternoon. In addition, Areas just to our north, we may actually have the B word watches issued. Winds will definitely be a factor, and if they can get high enough, we may meet that criteria ("Blizzard conditions" technically occur when strong winds (at least 35 mph) combine with either falling snow or snow on the ground to reduce visibilities to 1/4 mile or less for at least three hours.)

The other dangerous part of this storm will be the temperatures. We are dealing with a polar airmass with this, so even though the morning tomorrow will be cool, temperatures will plummet tomorrow night and it could infact get down to the teens and be snowing, 20's all the way down to the coast. The danger with that, is #1, its cold and #2, salt does not work as well in much colder temperatures. #3, snow ratios will be higher (usually 1" water = 10" of snow). We could be looking at 15:1, 20:1 or higher! In any case, I am tuned and am looking forward to seeing this come together!

March 6th and 7th Update 3/4/13 Afternoon

I talked about model chicken going on earlier, and it appears a consensus is growing. While there is still a long road to go until the final outcome, indications today are the mighty EURO is caving and moving towards the GFS. Major models, excluding the Canadian, moved north today. NAM and GFS both are big hits for DC-Boston. Euro has moved further north and is on NYC's doorstep. The Euro now puts appreciable precipitation into the Central and Southern NJ area. The 20 million dollar question now becomes temperatures. We look to have appreciable precipitation moving in, but our temperatures are going to be MARGINAL at best for snow. In fact  the low pressure tracking to our south will bring an easterly wind to our area and bring air in off the ocean which is above freezing. Easterly winds and snow do not mix. Precipitation is also going to be coming in during the daytime hours and the sun angle is higher in March which will have a profound effect on accumulations on pavement. The caveat is that this could be a prolonged event and precipitation will last through the night (as modeled now). When the sun sets, if we can get temperatures cold enough for snow, we could see accumulations then.

Coastal areas are going to get hit again. I hate saying this, but an inch of water, winds 40-50mph and high seas are going to really hurt and hamper recovery efforts. There is little doubt that the shore areas will be hit hard regardless of what happens inland. Please make preparations down da shore if you own property down there.

Still a long way to go here, and a lot can happen. I am going to remain a little more conservative here until there is more compelling evidence one way or the other. I am increasingly more interested in this storm though because regardless, it has been a wild two days from nothing to a moderate to major threat for the area.

Anyways, here are some pics with the representation of events from the different models. (NOT FORECASTS, JUST SINGLE MODEL RUNS)

GFS Evening:

Surface low pressure:

Snowfall:

NAM Evening snowfall:

EURO Midday Snowfall:

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. 

Tuesday 2/12/2013 Morning Update

Increasingly more confident of measurable snows moving into the area for Wednesday Night into Thursday. Over the past 24 hours, models have kept the measurable precipitation SOUTH of areas just bombarded (CT, NYC etc). For those areas a coating to 1" can be expected. From NYC South to Trenton 1-2" looks good. From the Trenton area south towards Philly 2-4" is my call, and areas south of that, while seeing more precipitation, you will have serious surface temperature issues preventing a lot of accumulation 1-3" down there. In any case, this looks to be a quick hitter. precipitation moves in between 6pm and 8pm and is out by 7am.

For the weekend there still remains a lot of questions. Most major models are not showing anything resembling a monster storm. The UKMET is probably the closest, but for now remaining cautiously optimistic about the event. More to come on this.

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.