Monday, December 29, 2014

Some Statistics For You...

Let's do another recap comparing last winter to this winter so far up to December 29th.

Winter 2013- 2014

Season snowfall:        15.9"
Days below freezing:  22
Days of snow cover:   24
Coldest reading:          11.3 degrees

Winter 2014-2015

Season snowfall:        11.6"
Days below freezing:  11
Days of snow cover:   13
Coldest reading:          13.7 degrees

While last year we were similar in the snow department, it's clear that we aren't seeing the cold temperatures that we saw last year. This year we had our cold come even earlier than last year and November brought over 10" across the area. This time last year there was no snow on the ground and the cold really got cranking in January.

Last January about 16" of snow fell, which is about the normal snowfall for the area. However in February nearly 40" fell which I believe will our snowiest month this year once the -QBO begins to weaken and allows the strong Pacific jet to weaken as well.

It was clear to me that this year wouldn't be as cold as last year, and that could even be found in my winter forecast (http://meteomaddness.blogspot.com/2014/11/winter-forecast-2014-2015.html). I also mentioned about an elevated risk of major snowstorms, which I still believe is a strong possibility. Last season we had a lot of events that added up to 72" for a season total, but this year the events could be cut in half but provide more precipitation and still give us a snowier than normal winter.

The pattern seems to be changing a bit and with cold air moving in the snow isn't to far behind. I see potential for storms in January but I want to give it a few more model runs before I open the flood gates of hype.



Wednesday, December 24, 2014

Let's run the numbers...

Adding to my post yesterday, I'm going to look further into the QBO signal and try to confirm or dismiss any rumor that "winter is over".


Here are the winters with a similar QBO Phase:


Here is how much snow fell in NYC those winters. We need to figure out what year matches up best with this year and what in the world happened in 2005-2006.

So right away I took a look at the ENSO phase. (Basically was it an El Nino, La Nina, El Nada?) Interestingly enough there is no consistency with ENSO phase and -QBO as seen below, but there is one year that's pretty similar. This year (so far) and 1979-1980 both feature a weak El Nino. The very snowy season of 2005-2006 was a neutral phase while the rest were La Nina.


Then I decided to look at the PDO, NAO, AO, AMO, and EPO which all gave me charts looking like the one below. Basically there is no link between these years and those indices. This could mean something else over powered the other indices or basically these winters only have the -QBO in similarity and it doesn't mean much for the winter pattern. Let's keep digging.


I finally looked at the PNA and saw that the trend was there, but nothing to impressive. How ever I had a difficult time finding this years line on the chart.

It was nearly over lapped by 1979-1980. That winter is linking up again with this one. This makes 79-80 a strong candidate for a matching analog winter.  


During most these years the PNA started off positive and went negative at times during the mid to late winter when I also noted NYC saw it's snowiest months, which is not expected. The data is conflicting and points to another force at play here. 

What ever happened in 2005-2006 is not happening this year (so far) in the data. As I could find nothing to match it up with. The 79-80 winter however linked up a little better but still has much that isn't in common with the numbers this year so far. The other 70's winters, had no signs of any linkage. The strong -QBO events of this past decade have way more in common when we start looking at long trend terms and patterns. 

My conclusion, the strong -QBO has minor influence on our winters and is only a percentages of the larger picture in a winter forecast. It alone cannot be used to determine how winter will behave. I made this decision after seeing very little in the way of linkage between this winter and the other winters with similar QBO indices. A strong -QBO can produce both snowy/snow less winters as seen in the data. I would love to use the majority of the 1970's winters as evidence but there are a few multi-decadal oscillations that are in totally opposite regimes today than 30+ years ago. Going off the data from this last decade it looks like we still have a strong possibility for a snowy winter though not at cold as last, which is still in line with my winter forecast. 

 I would love to hear some feedback from this. Any opinions and ideas are welcome. Thanks for reading!

Tuesday, December 23, 2014

Where is the cold?

Where is the cold air? It seems like its coming next week, but always seems to keep getting delayed. The problem, a strong Pacific jet as seen below in the left portion of the loop. This is aiding in keeping the cold arctic air locked up over the polar region and when it does make its way into the lower 48 it quickly gets swept away. 



The model are showing much colder air on the way but it could be short lived if this Pacific jet doesn't start to weaken. It's simply not allowing for a more winter like pattern to set up over the country and keeping the NAO and AO in positive phases. Another thing we look for to indicate cold and snowy weather is stratospheric warming events in the higher latitudes, and it looked a few weeks ago that it was occurring but the warm regime has collapsed as seen below.


So what's the cause of this persistent jet? Another meteorologist (DT from Wxrisk, a great guy to follow on Facebook) pointed out it could have to deal with the strong intensity of the QBO. The QBO is an upper level wind pattern over the equator that actually switches direction every year or so. So I looked up the past years with a a similar QBO pattern going into the winter months and highlighted them in yellow, red dots are no match.


The years with a match are pretty few and far between. What really interests me is that 2007-2008 is a close match and had an extremely strong -QBO. Some of the other years that match up are 1979-1980, 1974-1975, and 1970-1971. Here is a run down of how much snow fell in NYC those years and which month was the snowiest.

*07-08  11.9" (Feb 9.0")
*79-80  12.8" (Mar 4.6")
*74-75  13.1" (Feb 10.6")
*70-71  15.5" (Jan 11.4")

Each of the years season snow totals were about half of New York City's average snowfall. That is not a good sign. Interesting enough as the QBO began to weaken in the middle and late winter it finally allowed for bigger snow storms and colder weather. I take this as a sign that our snowiest month is yet to come in NJ. Just remember these are New York's averages and we get about double the snowfall per season so this is just to get an idea of what the trend is. 

I need to do some more research on this. If what I'm seeing here has any merit this winter is not going to be a very memorable one... I need to figure out if the other years had signals that match up with this season, if that's the case my winter forecast is a bust.


Sunday, December 21, 2014

A quick meteorology lesson...

Right now the southern portion of NJ is seeing the coldest temperatures. Why? Clear skies there have allowed for heat to escape while up north the cloudy conditions act like a blanket trapping the warmer air. Some places in South Jersey saw 40 degrees for highs and are currently at 23 degrees while Netcong saw a high of 30 and is currently at 28 during the same time frame. Now that's why I love meteorology!


Thursday, December 18, 2014

Will we have a white Christmas?

My last post talked about a potential storm for this weekend that the Euro was catching onto. This storm however will not effect us here in New Jersey. The Euro was wrong this time around and yes the GFS model was correct the entire time. I find that odd considering it's been the complete opposite this season.

Below is the map for the "storm" this Sunday off the Euro. Significant change!


So will we be able to get snow on the ground for Christmas? Our next system could clip the eastern seaboard on Tuesday but temperatures look marginal at best, and even if we did squeeze out the 1" necessary for a "white Christmas" I highly doubt it would make it till the 25th. 


On Christmas Eve it looks like it will be miserable outside. A good night to just stay home and watch a good movie with the family. The rain will even be falling as far north as Vermont and Maine.


The probability of a white Christmas looks very low, unless by chance the tail end of this system could put down a quick inch. I would say chances are below 20%.

Now, will it ever snow? The system to watch right now is for December 26th. The set up looks much better for a northeast snow event and plenty of cold air should be in place by then. After this storm system temperatures really start to take a plunge and it looks like winter really gets cranking. 





Sunday, December 14, 2014

"Winter" So Far

I say "Winter" because it hasn't even started yet! Let's recap where we are at right now and compare to the epic season we had last year.

As of December 15th:

Last Year:

Snowfall:                      13.4"
Days of snow cover:        17
Days below freezing:       15

This Year:

Snowfall:                       11.6"
Days of snow cover:         13
Days below freezing:          8


So as of today we are currently behind where we were last year. Last year mid December was cold and snowy, how ever this year it's been more moderate (it hasn't been "warm") with more in the way of rain. By the time we hit Christmas Day last year we had no snow on the ground and winter didn't really get cranking again until mid January. I think we are going to play a game of catch up now...

I have been persistent in saying that this season will NOT be as cold as last season, so we won't catch up with the days of below freezing high temperatures. I'm very confident though that we will surpass last years snow fall total and days of snow cover comparing it to last year by January 15th. You can quote me on this.

The European model already has it's eyes on a major winter storm THIS COMING WEEKEND. Right now the other models are bullish on the idea, but they will all come into agreement over the next couple ideas. This storm system will make the turn up the coast and is capable of dumping double digit snow totals.

I hate to get ahead of myself but the rest of this month from this weekend on looks perfect for winter weather lovers and January doesn't look to disappoint either. You better believe I'm in storm watch mode so keep checking back. If you want a good forecast that is.... :)


Tuesday, December 9, 2014

Update**

The precipitation this morning never really started as snow for most across the area, instead the upper air warmed way to fast. When the precip started it was actually rain at 32 degrees, but in the image below the rain caused the surface air to cool down to 27 degrees with heavy freezing rain here in Netcong. The blue circle is the clear indication of when the rain started and cooled the column. We didn't rise above freezing till 12:00 noon.


This storm is very different from others. Normally the jet stream would take this storm north and spin it up into Canada, but this is a cut off low pressure system meaning the main jet is way up north and a piece broke off and is just trapping this system over the northeast. The image below helps to illustrate. 


This system could still be around in northern New England till Saturday and Sunday! This storm was born here, intensified here, and will essentially die here until it exhausts all it's energy and the atmosphere stabilizes. 

The system will have some slight re-strengthening and keep spiraling bands down over the region. The tricky part is that these bands will essentially sit over the same areas with little movement and produce accumulating snow. Question is where do they set up? My snow map is a complete shot in the dark and depends on where and if these bands move over New Jersey. 

Don't be shocked to see some surprise snow totals across the the higher terrain and also don't be surprised if your area gets nothing! Okay, I'm ready for the next storm...



Monday, December 8, 2014

Complex Nor' Easter Coming...

This storm is one of the most difficult I've ever had to forecast. Looks like we will see ALL forms of precipitation and lots of wind. Let's start off with EURO surface maps and sounding combos. Early tomorrow morning around 6:00 AM the snow will start and continue for a couple hours. This could accumulate to up one inch in spots but it will quickly change over.


Next we can see the warmer air has won out (just barely). The surface is still around freezing but the mid levels are a couple degrees above. A slight shift could keep the wintry precip over NW NJ longer than expected but this still seems like primarily rain for most. 

As the storm pulls away the colder air can start to make a return, at the surface. There is now a strong mid level inversion late afternoon tomorrow and sleet and freezing could now be an issue after the rain. Yes, we have gone from snow, to rain, sleet and freezing rain, and now the wind is really kicking up.

A few models show a significant shot of snow on the backside of the storm Wednesday morning. (Yeah, now back to snow.) This is where things could get interesting and potentially give us several inches of snow. The whole situation is so complicated and this part of the event depends on how the storm intensifies, and this thing hasn't even formed yet. 

This storm can have an effect on us till Thursday and has many phases:

1. Starts off as snow tomorrow morning (up to 1")
2. Snow changes to a cold rain (temps struggle to break 32)
3. The warm air wins out at mid levels but surface temps are below 32 (freezing rain)
4. Sleet can start to mix in with the freezing rain Tuesday night
5. The winds will get strong tomorrow night
6. The wintry mix now changes to back to snow (accumulation possible)

Tomorrow night I'm going to post a snow map for the end of the event. Doing it now would be setting myself up for failure because the models are all over the place. This storm needs to actually form first before I make a forecast on the "wrap around" snow which rarely actually happens in NJ. 

Sunday, December 7, 2014

Update**

I have no changes to map I issued yesterday. Tomorrow I'll start looking into accumulation amounts but most of us will see little if any. There is just a lack of cold air with this system from about 850mb to the surface. Check back tomorrow.

Saturday, December 6, 2014

Outlook Map For Next Week

Just a preliminary map for next weeks storm. As of right now there are no models showing NJ having a major snow event. Instead it crushes us with flooding rains on the order of several inches with lots of wind. The models do show snow to start but the low retrogrades inland right over Long Island, which is too close for an NJ snowstorm. Perhaps ending as a little snow as it pulls away. Now a shift of 50 miles east could bring that significant snow line over NE PA into our neighborhood (6+ inches). Let's keep an eye on the exact track of this system....




Thursday, December 4, 2014

Snow Outlook

Start off by saying our warm air advection event Tuesday ended up having a lot of dry air for NW Jersey. The precipitation shield split in two with the heaviest being over the Poconos and central Jersey. By the time steadier precip rates made it to our area the column was too warm, which was a worry of mine. Still some places were able to pick up a nice coating before the change over.
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I want to talk about a potential Nor' Easter for early next week. And this looks to be just BARELY cold enough for snow, but I have to admit it's setups like this one that create historical events.

The GEM model really goes all out on this system. With a lack of cold air in place this causes record breaking flooding across the region. How ever this is still too far out to make any judgement, the point of showing this map is that this storm is on the maps.



The UKMET also shows this system but intensifying further north over New England.

 

I hate the JMA, but it shows it...


The EURO gives us a major winter storm and a blizzard over New England.


And the GFS is out in La La Land....


The GFS, NOGAPS, and extended NAM (all American models) say the storm is a no go. Yet all the other models out there say yes, and given the track record of the American models I can confidently they are garbage runs and to ignore them. In a few days they will start to catch on slowly but there WILL be a storm, question is how far close to NJ does it form and how much cold air will be available. There is nothing more I can say or do except wait for more runs to come in to track this storms path and intensity. 

Check back this weekend. Things could get pretty interesting...

Monday, December 1, 2014

Wintry Weather For Tuesday

The image below shows the start of the event for tomorrow afternoon. Plenty of cold air in this sounding and it's snowing pretty hard. Note the red line is the freezing line and the blue line is temperature.


Just three hours later we start to see the warmer air around 850 this will be the change over to sleet. So we have about a 3 to 4 hour window of snow get the accumulations. After that it's a done deal.




Just another three hours goes by and the warmer air is winning out between 950mb and 800mb. At the surface temperatures are still below freezing. This sounding shows freezing rain which will linger the longest in valley locations where the cold air gets trapped. 


Yet another three hours later the warm air has won out at all levels and it ends as rain for everyone. 



This is a very difficult event to forecast accumulations. It really depends how much snow can fall in the first several hours of the system. If it comes down heavy at an inch an hour we could get a nice surprise. Now if the storm starts off slow with dry air we may have issues getting the ground covered. This map is my best guess but confidence very low. Check back daily for updates.