Sunday, November 30, 2014

More Wintry Weather On It's Way...

While things look to be moderating going into December we will have just enough cold air around for more accumulating snow for Tuesday night into Wednesday. When warmer air over rides the colder air things can get interesting. In most cases these systems start off as snow, then to prolonged period of sleet, and then to freezing rain (especially in the valley locations). By the end of the event most areas end as rain but not long enough to wash the snow away. The key with this system is how much moisture does it bring and how quickly does the snow accumulate before the change over. Once again higher elevations will get the most and your position north. As of right now it doesn't seem to be a big deal and a few areas could get a couple inches at most. More updates tomorrow.



What a little snow cover can do...

We live in such a small state, but we can have vast differences over the 168 miles from Cape May to High Point. Here is my point, near 60's in South Jersey while areas north with snow are stuck in the 30's.

Saturday, November 29, 2014

How was my forecast on this past storm?

Title says it all. Did I forecast well? Am I even worth listening to, or just another social media hype, gloom, and doom attention seeker?

Let's find out! Here is my first initial map issued on Sunday when a lot of meteorologists were still saying the storm system would go out to sea. My significant snow area outlined was near 100% accuracy keeping the major cities just miles out of the storms reach. Go ahead, match up the lines with what fell, I'll wait.

Top Map: My outlook on Sunday
Bottom Map: What actually fell


This isn't a "Northeast US" blog so how did I do with the New Jersey higher resolution map. I pretty much nailed the forecast for south Jersey and for north and west. However I did go a little over board with the snowfall for Hudson, eastern Union, eastern Bergen, and Essex counties by 1"-2". In my final forecast I did note that urban areas would see the lower end of the contour values and the highest terrain would see the highest contour values. My highest amount forecast was for 12" TOPS in the state, and the highest total was in Wantage at 11.7". Accuracy was near 85%, not bad for predicting the future.

I do need to point out that I did say most areas N&W would be all snow yet for about an hour it started as rain. Only High Point started as all snow. I did over look the warmer air at the surface and I need to keep this in mind for future events.

Top Map: My forecast issued Tuesday
Bottom Map: What actually fell

I did learn a few things from this storm from my mistakes. It's not easy to get accumulating in the eastern sections this time of year and starting off with a lack of cold air in place. Also, when the precipitation get's lighter in intensity it allows the return of warmer air at the surface and cause a change over very quickly.

This blog wasn't intended to gloat or brag about how I did, but to point out my mistakes and what I did correct and try to improve the forecast for the next storm. I'm going to try to do this for every major event regardless of the result. 

Keep checking back for updates about what's in store for December!

Thursday, November 27, 2014

Interesting Statz

Just some weather statz for your turkey day. First off this November is the snowiest in our lifetimes with 8"-14" of snow across NW Jersey. Occurring just three years after the snowiest October on record in 2011 when 6"-18" fell (elevation dependent). On top of that in 2010 around 50" fell in February alone. This decade will definitely be remembered as a snowy one.

Since 2004 this is how many of the holidays were white:

-Halloween ..........................2
(2011, 2008)

-Thanksgiving......................4
(2014, 2013, 2010, 2005)

-Christmas............................3
(2012, 2009, 2007)

Yes, in the last decade we had more white Thanksgivings than on Christmas. And I really stretched out that 2007 where a coating was on the ground, barely. Not something you would like to hear but currently we have had 5X times the amount of snow than this time last year...


Tuesday, November 25, 2014

Final Call Map

My final map for the storm. Surface temperatures are going to be a struggle in eastern areas for a good part of the storm, however the higher terrain will be seeing accumulation from pretty much the beginning of the event. Urban areas that radiate slower are going to see the lower end of the forecast snow contours and accumulations will be limited to colder surfaces. The 9" - 12" range is only for the highest terrain of the NW counties and a few of these areas will see double digit totals. Start time of the event will be during the height of morning rush, that gives me a couple hour cushion 

Monday, November 24, 2014

Preliminary Snow Map

I'm going to start right off with the snow map then explain my reasoning. Please note, this is a preliminary map and the final forecast one will be issued tomorrow night.


I'm being very conservative in the urban areas and very generous in the northwestern corner of the state, and I have very good reasons for that. The above map has three points displayed on it. EWR  is Newark Airport (5 feet above seas level), MMU is Morristown Airport(180 feet above seas level), and 12N is Andover airport (600 feet above seas level) .

Now let's take those points on the map and look at a vertical slice of the atmosphere.

**Also note that in these soundings there is no warm air inversions. It's either raining, snowing, or both. Sleet and freezing rain will not be a concern.


Newark Airport (KEWR):

The two blue lines represent temperature and moisture in the air. When they come together the air is saturated and could be used to identify a cloud deck or if it's precipitating. Obviously here precipitation is hitting the surface in Newark, but if you look in the red circle the temperature during the height of the storm is well above the freezing line or 0 Celsius line at the surface. This is going to make it hard for the SNOW that is falling in this sounding to accumulate. So while it will snow here most of it will melt on contact. 


Morristown Airport (KMMU):

Now we are getting closer. The temperature in Morristown is just above freezing here and snow is probably sticking to colder surfaces and the temperature drops off dramatically with altitude so nearby hill tops are already seeing accumulations on most surfaces. 

Andover Airport (K12N):


At no point during this storm does Andover show a temperature exceeding the freezing mark. Snow at 32 degrees will stick to all surfaces and this is why I expect 6" snowfall here. This airport is only at 600 feet on the western side of the highlands. Areas above 1,000 feet will be in the upper 20's during the event and be able to get higher snowfall totals.


I hope all this helps to explain my ideas. I don't just issue a map with pretty colors without seriously looking at the situation honestly and without bias (even though I do live in the bulls eye). Check back tomorrow for my final map. 


Sunday, November 23, 2014

MAJOR EAST COAST STORM?

Here is my first guess for the storm system that WILL be riding up the eastern seaboard Wednesday into early Thursday. Question is how close to the coast does it travel? A shift of just 30 miles is significant and could mean the difference between NYC seeing a rain event or an all snow event. Tomorrow I'll issue a preliminary snow map and try to narrow down on specific totals.


Thursday, November 20, 2014

Forecast for the rest of November

With the latest cold blast starting to lose it's grip on the continental US it's time to look forward and see what the long range says for the end of the month. Let's start by looking at the forecast map for tomorrow. 

Friday will be the last day of the arctic assault as warmer air is building to the west. Temperatures should range between 28 at the highest elevations for highs and the middle 30's toward eastern sections. Yet another day of the lake effect snow machine adding another 1 to 3 feet just south of center of Buffalo. 

The following map is off the new parallel GFS which seems to be doing a fantastic job with longer range forecasting. Much better than the current version of the GFS.

Monday looks to be the warmest day with temperatures in the early morning approaching 60 degrees ahead of the low pressure system. Once the front goes through temperatures will drop and back in the fridge we go, though not as cold as this last arctic blast. 


Thanksgiving looks to be a chilly day with temperatures in the 30's, and perhaps even more lake effect for western New York. The rest of the month looks questionable as the new GFS shows moderation in the temperatures but the EURO tells the complete opposite. Should be interesting to see in the coming days which model ends up being correct. 

(EURO model NOV 30th)
(Parallel GFS NOV 30th)



Check back for updates and let's see if the new GFS is going to be able to top the highly praised EURO. 


Monday, November 10, 2014

Winter Forecast 2014-2015

The follow winter forecast is based on current observations and historical data and will only forecast temperatures departures for average, snowfall percent of average, precipitation percent of average and some added forecast comments.

Here is the outline for the forecast:

A. Last winter compared to my forecast

B. Big Picture (driving mechanisms)
1. Arctic Sea Ice & Siberian Snow cover
2. ENSO phase
3. NAO & AO & EPO
4. PDO & AMO
5. QBO

C. The Checklist

D. Final Forecast
1. Temperature anomalies
2. Liquid Equivalent percent of average
3. Snowfall compared to average

------------------------------------------------------------------------------------------------------
A. Last winter

Here are some statistics:

-Total snowfall 71.2"
-94 days of snow cover
-66 days below freezing high temperatures
-Deepest snow pack was 33.6" on February 13th
-61 consecutive days of snow cover Mid-Jan through Mid-March
-Coldest daytime high was 2.1 degrees on January 7th
-Biggest snowfall was 17.1" on February 13th
-Earliest snowfall was November 12th with 0.5"
-Latest snowfall was April 15th with 1.0"


Now let's take a look at some charts:

DAYS NOT EXCEEDING FREEZING
SNOW DEPTH LAST SEASON

AVE SNOW BY MONTH VS. LAST YEAR

SEASON SNOW TOTAL LAST 10 YEARS

When I look at the above statistics from last winter I see a very cold winter overall with above average snowfall. The cold is what made last winter stand out since the snow that fell never got a chance to melt before the next storm and so on. The cold came early and lasted through a good portion of the winter and even right into the summer months. The 71.2" of snow that fell is above the 10 year average of 51" but it was nothing extreme or record breaking. If it wasn't for the February 13th storm that dropped 15" - 20" then seasonal snowfall would have been at average.

Now was my forecast from last year correct? And should you believe anything I have to say this year? Let's find out. (http://meteomaddness.blogspot.com/2013/12/winter-forecast-2013-2014.html)

Last year I was expecting the coldest and snowiest weather (with respect to average) just to our west since I was forecasting the AO and NAO phases to stay mainly positive almost all winter. I was correct on the phase prediction, in fact it's safe to say I did a very good job with that. However, I over looked something that shifted my thinking just to our west by few hundred miles. The Eastern Pacific Oscillation was something I didn't take into consideration and it seems to have been the cause of the extreme cold since the other forcing mechanisms pointed in another direction. 

The image below pretty much sums up what happened last winter if we could shift the core of the cold a little more east. This will play another role this winter and honestly I see very similar conditions shaping up for this winter, but that's for part B.





B. The Big Picture 

When forecasting for the season you must look at EVERYTHING. Some people will look at just one or two aspects, compare it to winter 1995-1996 (1978, 2003, 2010...) and then the forecast is a bust. I've found out through research of the Arctic Oscillation that in New Jersey it only has a correlation coefficient of 14%-21% with respect to cold and snowy conditions, which means that yes it's significant BUT only a piece of the puzzle. If one piece of the meteorological puzzle is missing the picture it makes could be altered. 

1. Arctic Sea Ice & Siberian Snow Cover

Every single forecast I've seen on this winter has covered the above average snow cover over Siberia and what it means for us. Statistically whenever this occurs it generally ends up in a cold snowy winter over North America and some even relate it to negative Arctic Oscillation patterns. In my opinion statistics are great and can tell us a lot but there have been years where above average snow cover in Siberia has NOT been in favor for a cold snowy winter. I'll put extra consideration about this into my forecast but I won't let this dictate my overall product.

The images below show the sea ice and snow cover up till November 5th of this year and last year on the same day. The sea ice is about the same in area but as you can see the northern hemisphere snow cover is SIGNIFICANTLY ahead of last year. Will the cold come earlier this year than last year? Chances look favorable.





2. ENSO Phase

The El Nino Southern Oscillation can have huge effects on the weather in north America and is a household name to many. I can go for a very long time about this but I will make this short and sweet. A weak phase of El Nino is in the forecast for the winter months and unlike last year when we had a weak phase of La Nina (complete opposite). Perhaps this could throw more moisture into the mix for this winter which is why I would predict a boost in overall precipitation amounts than the average. When it comes to temperatures I don't believe it will have a warming effect on us like the extreme event that happened in 1998. 


3. NAO & AO & EPO

The NAO and AO are blocking patterns in the atmosphere that vary by day, week, and months with no real forecast tools to predict more than a week out accurately. Generally negative phases in both mean cold and snowy weather. Certainly will be this winters wild card and when they tank expect increase chances for harsh weather.



The EPO is similar to the NAO but is centered over the northern Pacific and influenced by the ocean itself. Last winter saw this went negative and caused arctic air to be displaced from Alaska to center of the continent. 



4. PDO, AMO

The PDO has seen a flip in the last few months. It went negative back in 2007 and seemed to have went postive earlier this year. Whether it's just visiting the positive end or made its official switch it looks like increased precipitation this year with better forcing for Alaskan ridging assuming it stays in place. 

The AMO on the other hand is still in it's warm phase which will dominate the rest of this decade. This generally means more precipitation and warmer temperatures in the northern hemisphere. Not a end all for our winter because we have had plenty of rough winters while this phase has been in the red zone. However yet another clue points toward more precipitation.



5. QBO

 Last winter a huge concern for me was the QBO phase (an up level oscillation that can effect NAO and AO values). It went positive which meant the AO and NAO would be primarily positive during the winter. Was I right? Answer is yes. The chart below shows both phases last season staying mostly positive.




QBO 2012 till Present:
This season looks much more favorable for the NAO and AO to be negative. Primarily negative this time around. Another sign this winter is going to be rough.




C. The Checklist

(red= bad for snow lovers / blue= bad for snow haters / black= equal chances

-AMO (warm phase)

-QBO (easterly-negative)
-NAO (negative influence by QBO)
-AO (negative influence by QBO)
-PDO (warm phase=Alaska Ridge)
-Weak El Nino (add moisture)
-Arctic Sea Ice Extent (large increase)
-Siberian Snow Extent (well above average)

D. The Final Forecast

I have not included everything I researched for this winter forecast into this write up. In fact only about half made here for you to see. I still could not find a single item to put into the checklist that could indicate a mild and dry winter pattern. If there was ever a perfect set up this is it, and it seems quite obvious. 

1. Temperature Anomalies

The easterly QBO and it's influence on NAO and AO, the artic sea ice, the Siberian snow extent, PDO forcing an Alaskan ridge all point toward cooler weather. How ever a weak El Nino could help to serve some slight warming effect but not enough to alter this forecast. I can't find a single piece of evidence that would point toward a warmer than average, but I don't think it will be as cold as last winter when we had weak La Nina conditions.

Overall forecast for winter temperature anomalies is BELOW average



2. Liquid Equivalent Percent of Average 
All indices I've looked at suggests increased precipitation amounts for the eastern US. More precipitation could mean more intense storm systems than last year and increases the likelihood for a block bluster snow event measured in feet rather than inches. Also could mean heavier rain events as well on the warm side of a low pressure system. Unfortunately for the south west I don't see much in the way of relief for the record breaking drought.  

Overall Precipitation for New Jersey is ABOVE average




3. Snowfall Percent of Average
North Jersey has a wide range of seasonal snowfall totals. From around 24" near the city to as much as 55" in places like Highland Lakes and West Milford. My personal 10 year average for Netcong comes out to about 51" how ever areas with lower elevation just minutes away may only average about 40". Still the state as a whole does not see that much snow and just one event could make or break a seasonal forecast. One storm could bring Newark's seasonal average and could miss another portion of the state entirely and end up with below average snow. 

This season looks to bring above average precipitation which increases the likely hood of above average snowfall overall. Even if half of the events fall as rain, the other half could still bring average to above snowfall. With temperatures expected to be below average in combination with more precipitation chances look likely for MUCH ABOVE average snowfall.


This sums up the winter forecast and all we can do now is ride it out and see if the prediction hold true. There are sure to be times of extreme cold events and even times where it could feel spring like. The overall averages however will show that winter 2014-2015 is going to be remembered as a cold and snowy one.