Friday, September 25, 2009

My 2009-2010 Winter Forecast

By John Ruggiano

October 1, 2009

From December 1, 2009 Through March 31, 2010 (Dec, Jan, Feb, and Mar)

A Weak to Moderate El Nino Signal, along with an active STJ (Subtropical Jet), will bring stormy conditions across much of the Southern US, & a good part of the Eastern 1/3rd of the Nation.

This upcoming 2009-2010 winter season, will be quite a switch from the last 2 winter seasons. For the most part, during last year the heaviest snow and coldest temperatures were concentrated over the Northern 1/3 rd of the country. This was mainly due too, weak to moderate La Nina conditions. This year things will change, as the main storm track will likely be much further south, as weak to moderate El Nino conditions prevail. In addition, a more active subtropical jet can be expected.

The mean storm track for the 2009-2010 Winter Season will extend from the Southern Rockies, eastward to the SE States, and then mainly along and east of the Apps, through the M/A States and SE New England. Overrunning events will be quite common from the Tenn/Ohio Valley into the M/A States. This will also raise the flag for possible Moderate to Severe Ice Storms, from the Southern Plains into the interior SE, and lower M/A States. This is something to be aware of this winter season. I expect plenty of this for the month of January into mid February.

Clipper type systems and Strong cold fronts riding with the Polar Jet (P/J) and Arctic Jet (A/J) will be less common, than the last couple of years. Sure, we’ll still have a fair amount of activity with the Northern branch, but most of the energy this year will come from the STJ and effects of the ENSO El Nino, with more southern storm systems. Some of these Southern systems will get a chance to phase with the Northern branch energy, so I expect several good east coast storms, mainly in January and February !

This year I'm forecasting "Above Normal Snowfall" to be concentrated in two general areas: One area will be over the Southern Rockies into the Southern/Central Plains. The second area will be from the Tenn/Ohio Valley's, The interior SE, all of the M/A States, and into SE New England. All other areas will be "Near Normal Snowfall", with the exception of the NW PAC, The Northern Rockies, and Northern Plains, were I'm forecasting "Below Normal Snowfall". (See Snowfall Map)

The NAO (North Atlantic Oscillation) And other key Teleconnections.

The NAO/AO couplet that I mentioned in my prelim winter forecast back in mid August, continue to flow in very similar wavelengths, and I expect this couplet to continue into the fall and winter months. During the Fall months, I expect both the NAO and AO to be mainly near neutral overall, then continue to maintain a near Neutral Index for much of the winter season. But at the specified times I've listed below, mainly during January and February, the NAO/AO couplet will go NEG. The best chance for a slightly POS NAO index will come in both December and March.

Click to enlarge:

This NAO/AO couplet will be one of the key players this winter for the Southern and Eastern US. Unlike the past several winter's the NAO has been mainly in a Neutral to Positive state, with the exception of last year, being more Neutral to slightly NEG, as I forecasted this quite well last year. I’ve also commented there's some strong indications that a long term switch to a Negative NAO decadal cycle, is starting to take place.

These factors I've mentioned, along with a more favorable ENSO State, will allow for "Above Normal Snowfall", and "Near to Below Normal Temps" to occur for much of The M/A Region and the SE States. The only exception being, Northern New England, and Upper Midwest Region, where "Near to Slightly Above Normal Temps", and "Near Normal Snowfall" can be expected.

Here's my forecast for the NAO signal, with Monthly breakdowns. Dec, Jan, Feb, and Mar)

December: Neutral to Slightly POS.

January: Neutral to Slightly NEG.

February: Neutral to NEG.

March: Neutral to POS

During December I expect variable conditions with the signal being mainly neutral to slightly POS. Both January and February is where I'm forecasting the coldest and stormiest (snowiest) month's to occur. Both months will be mainly Neutral to NEG. Overall, temps will be “Slightly Below Avg.” during January, and “Below Avg. during February, with a continued active pattern, producing both Rain and Snow, along with some big Ice threats in the areas I've outlined earlier. During March, a switch to a POS NAO signal will occur, and close out the 2009-2010 winter season, with Slightly Milder than normal temps, with a less active and drier pattern.

With a Weak to Moderate El Nino Signal, the PNA signal will likely be Neutral to POS for much of the winter. This will allow for more Ridging over the NW PAC States into the Northern Rockies and Plains states, so expect milder and drier conditions for much of the winter in these areas.

The AO (Arctic Oscillation) will be Neutral to at times NEG, this will allow for a rather active Northern and Arctic branch to evolve and nose into the Central and Eastern US, causing some phasing and overrunning to occur from the Mid section east to the M/A coast.

So, Will the Delaware Valley & The M/A States see a big snowstorm or two this winter ? I'll have to say: YES

My best estimated time-frame for any Snowstorms of 6" or greater, will be between January 5th and 15th, and an even better chance in late January and early February, between Jan 25th and February 15th. During both of these time frames, the NAO signal will be going into a NEG phase. With an active sub-tropical jet stream and a mean Southern storm track, It's during these time-frames that Miller A, and East coast storms are most likely to develop.

So once again the best chance for a SECS/MECS, for the M/A and NE States, will be between Jan 5th-15th and also between Jan 25th-Feb 15th. In the M/A States, both December and March we'll only see minor snow events for the I-95 Corridor from RIC to NYC, but The interior M/A States, SE New England and Boston, will see good snow events during December and March.


In this segment I've attached all my maps, to summarize my overall Winter Outlook. Please see the (4) maps below: Temperature, Precipitation, Snowfall, and Overall Storm Track's. These maps best illustrate my outlook for the month's of: December, January, February, and March.

These maps indicate the overall Anomalies for both "Temperatures" and "Precipitation" for the 4 month period.

In addition I have included a “Total Snowfall Map”, relative to normal and a “Mean Storm Tracks Map”, to show the type of pattern I‘m forecasting for the winter months.

TEMPERATURE MAP: (Click map to enlarge)

PRECIPITATION MAP: (Click map to enlarge)

SNOWFALL MAP: (Click map to enlarge)

MAIN STORM TRACK MAP: (Click map to enlarge)

My Forecast for Philadelphia, PA. (PHL)
(Including extreme SE PA, Interior Southern NJ, and Northern DE.)
Dec 1, 2008 - Mar 31, 2009 (Dec, Jan, Feb, and Mar)

Mean Temperature: -0.5 F
(Slightly Below Avg.)

Mean Temp Range: 0.0 to -2.0 F

(Near to Slightly Below Avg)

Total Snowfall Range: 26" to 32"
(Above Normal)

Target Snowfall Prediction: 29"

Total Precipitation: Above Normal

The Monthly Breakdown for PHL (Philadelphia, PA:

December: + 1.0 F
Mean Temp Range: 0.0 to +2.0 (Near to Slightly Above Avg.)
Snowfall: 2" to 4" or (Near Avg.)

January: - 1.5 F
Mean Temp Range: -1.0 to -3.0 (Slightly Below Above)
Snowfall: 10" to 12" or (Above Avg.)

February: - 3.0 F
Mean Temp Range: -2.0 to -4.0 (Below Above)
Snowfall: 10" to 12" or (Above Avg.)

March: + 1.5 F
Mean Temp Range: +1.0 to +3.0 (Slightly Above Avg.)
Snowfall: 2" to 4" or (Near Avg.)

Selected I-95 Corridor Cities:
(Dec, Jan, Feb, and Mar)

BOS (Boston, MA)
Temps: 0.0 to -2.0 F (Near to Slightly Below Avg.)
Total Snowfall: 44" to 50" (Above Normal)
Overall Forecast: Temps: -0.7 F / Snowfall: 47"

NYC (New York City, NY)

Temps: 0.0 to -2.0 F (Near to Slightly Below Avg.)
Total Snowfall: 26" to 32" (Above Normal)
Overall Forecast: Temps: -0.5 F / Snowfall: 31"

BWI (Baltimore, MD)

Temps: 0.0 to -2.0 F (Near to Slightly Below Avg.)
Total Snowfall: 22" to 28" (Above Normal)
Overall Forecast: Temps: -1.0 F / Snowfall: 26"

DCA (Washington DC)

Temps: 0.0 to -2.0 F (Near to Slightly Below Avg.)
Total Snowfall: 18" to 24" (Above Normal)
Overall Forecast: Temps: -1.0 F / Snowfall: 21"

RIC (Richmond, VA)

Temps: -2.0 to -4.0 F (Below Avg.)
Total Snowfall: 14" to 20" (Above Normal)
Overall Forecast: Temps: -2.3 F / Snowfall: 17"

For additional weather discussion and comments on this Winter Forecast and upcoming winter weather events, please register and sign up today !

Ruggie Weather Forum:

My Google Webpage Doc Link to this Winter Forecast:

Take Care,




Hi Beau, How's it going ?

You're welcome, good luck out there in the lower Midwest, I'm going about slightly colder than normal temps and near to above average snowfall in your neck of the woods.

Good Luck buddy and enjoy the fall and winter !


DESteve said...

Wow.. great synopsis.. nice to see a enthusiast for the DE area.. dont see much DE local overviews but your probably the closest Ive seen. Im located near Odessa DE.. have been more involved in Hurricane and Severe weather for quite sometime.. thanks alot !



Hi Steve in DE and thanks for the feedback and compliments on the winter forecast !

DE will do well this year as will much of the M/A States. I'm most concerned with Ice just as much as snow, as folks in the central and lower M/A States will more than likely have problems with some icestorms.

I think DE to Central VA and points south will be on that fine line.


Anonymous said...

Love your forecast!! How will southeast new York do this winter???


Gastonwxman said...

Very interesting forecast you have there. I'm impressed with how you covered all of the factors that affect the different regions of the U.S. for the winter season. This is probably one of, if not, the best forecast I've read about. Hoping for several opportunities of snowy weather here in the Piedmont of NC (I live in Gastonia btw). Thanks for posting. :)


So you live near Charlotte NC !
I know exactly where Gastonia is located, as I live in Charlotte for about a year. A nice city, but not for me. The Climate, traffic, and congestion are a huge thumbs down.

Yeah thanks for the comments and feedback ! I think you guys will do pretty good this winter and yes well overdue for a better than average winter in your parts.

Icestorms could be one of the bigger concerns for you guys, but you'll have your snow chances as well. Good luck.


RaleighSnow said...

Great forecast! What are your thought on cold air damming events for central NC? CAD usually brings winter wx to this area.


Hi and thanks !
CAD setups will be quite common with the pattern this winter. I'm thinking the mean High Pressure belt will extend from the Upper Midwest to SE Canada and Northern New England. So this will help set the stage for CAD situations over much of the M/A and parts of the SE States. A southern storm track will also be in your favor.

Good luck and enjoy the winter season !


Anonymous said...

We live in Wilmington NC and it always snows west of I 40. And always when the local folks predict white stuff we never get it.
Why is that


Wilmington NC, Isn't the best place in the world to get snow. It takes the perfect setup to get snow there and that's not often. Your on the coast and Ocean temps are mild even in the winter, with the gulf stream not far offshore. The slightest wind off the ocean, even with a cold airmass in place and you guys are cooked for snow chances.


Cassie said...

Hi! So I think I'm liking the forecast. I am hoping for LOTS of snow in Central/Northern Jersey, more exact the Cranford area. What do you think? Will my wish come true this winter? And of course, the colder the better for me :) Let me know! Thanks!



Hi Cassey, from Cranford NJ.

I'd say a good 32" to 40" for you just west of Newark. Slightly below normal temps and expect a few 6"+ Plus snowstorms this year.

Enjoy ;-)

Unknown said...

Hey great site and a heck of alot easier than the NOAA site. I live in Jackson and deliver mail in the North part of Ocean Co.
Just how bad do you think it will get in this area?
Thanks, Marc


Hi Marc from Jackson, NJ and thanks for the compliments and feedback. Good ole Central NJ where the battles can be won, Lol ! I think you guys do well this winter, my best estimate would be between 30" to 36" could top near 40" for the season in your area. More snow events than Ice, but an Icestorm or two across the Del.Valley region is a good bet as well. Enjoy and check back for any updates and my winter storm calls.

Take Care,

Vonnyj said...

Hi I'm Vonny from Washington,DC

I am a snow lover & I would like to know if we are going to have lots of snow this winter?

Also, I really enjoyed all of the snow we received during the "Blizzard of 1996" so will we have a winter similar to that one or at least more snow than the last two winters?


Hi Vonny,
I don't see a 95-96 winter season but much better than the past couple of years in the DC area.

20"-26" is a good bet, but could even be more and close to the 02-03 winter season,if things work out better than I expect. So 30"-35" is not out of the question if things work out to the best scenerio. Enjoy !



Make sure you check out my new message board. Sign up and join for great weather discussion throughout the fall and winter seasons.

Ruggie Weather Forum:


Ella said...

Hello Im from Dayton ohio and was wondering if you see much snow for us? I love the snow but not so much the ice but can deal ok with either. thanks for sharing such great information it helps plan alittle ahead for how much winter items we need to have around incase of a big snow or ice storm. thanks again .


Hi Ella,
I'm forecasting near to slightly above normal snowfall for Dayton OH, so my best estimate would be 28" to 36". I don't see any major Ice storms for your area. But some minor ice events are possible. I'm thinking the setup for ice will be much further south. I think you guys will be missed by many East coast storms (too far west) and much of you snow will be from overrunning events and clippers.


AshandWes said...

Hi John! I'm actually looking forward to your SE states winter forecast! I live in the extreme NE corner of Mississippi, and it has been a WHILE since we have had a 'nice' winter. To see the beautiful white powder fall from wintery skies, will be a breathtaking sight. It will also put big smiles on the faces of many children! Now, Mother Nature just needs to make it all happen! Thanks for all the hard work you do! Have a blessed day!



Hi Anna !
Oh Boy, NE Mississippi is in pretty good shape to see 1 or even 2 good snowfalls this winter.

I know the past few winters haven't been good for much of the SE and Deep South, but this winter is the breaker, for a better than Avg winter.

I also have your region in a high risk for mod/severe Icestorm threat, so this could be a problem this winter with the Icestorms. I hope I'm wrong on that part for your sake.

But nevertheless, I see a couple good snow events for Northern MS. Good luck and enjoy the winter season !

God Bless,

Ella said...

Thanks Ruggie I appreciate your answering my questions very much. The snow will be great its fun to play with the dogs in and they love it, Thanks again for the udate on ohio. God bless to you and your family

Thanks again.

Anonymous said...

Hi Ruggie!

Im from Easton,Maryland on the Eastern Shore of MD and I'd like to know what the forecast snowfall you think for our area. It does snow each yr but it isnt enough.. I love the snow and I wish that the Chesapeake bay was as big as the Great lakes to get those Lake Effect snow. I can't wait to look forward on this coming winter!



Hi Danny from Easton MD

My best estimate would be 18-24" of snowfall for your area. Also could see some ice events. Overall a great winter for the M/A which has been quite snow starved over the past few years relative to normal values.


Anonymous said...

Just stumbled upon your site, and I think it is great! I am in central NJ, and really like the focus of your sight, on NJ and ME states.

I will definitely keep this site in my favorites!


Jordan said...

Hi i came across this sight and it is cool and i love the weather and hope to be a meteorologist someday cause rite now im only 13 and i live in southern Illinois and the weather here can be pretty unpredictable here and i was wondering how much snow do u think we will get here? I live just about 30 miles south of I-64 in a small town called Pinckneyville,IL

Michael Spagnolo said...

Hey! I'm 14 and live north of Richmond. Always wanted to be a meteorologist. Anyway, A lot of the forcasts have been the same. More snow! The snowstorm last year was the first in several years. There have been lots of NOr Easters this year, and already saw some snow last weekend. It seems like twice a week we are getting a coastal storm, with another wed. and this weekend. (Snow and Ice mabye) Are these storms just going along the Jet Stream? And what Does all of that data mean in the middle? All the Neutral NES and Nuetral POS, ENSO, NAO index, and AO index? What is that stuff and how does if factor to everything? Just curious. Thanks!

Michael Spagnolo said...

Hey! I'm 14 and live north of Richmond. Always wanted to be a meteorologist. Anyway, A lot of the forcasts have been the same. More snow! The snowstorm last year was the first in several years. There have been lots of NOr Easters this year, and already saw some snow last weekend. It seems like twice a week we are getting a coastal storm, with another wed. and this weekend. (Snow and Ice mabye) Are these storms just going along the Jet Stream? And what Does all of that data mean in the middle? All the Neutral NES and Nuetral POS, ENSO, NAO index, and AO index? What is that stuff and how does if factor to everything? Just curious. Thanks!

Unknown said...

I was wondering if you could give me any detailed info about your forecast for far Western KY. You nailed it last year for us on the ice storm! I work for a Home Health Agency and it would be helpful if we had some kind of idea ahead of time to be more prepared to help our patients. Do you expect us to get ice again this year? Thanks for your help and keep up the GREAT work!

Anonymous said...

Your blog keeps getting better and better! Your older articles are not as good as newer ones you have a lot more creativity and originality now keep it up!


Thanks for the feedback on my blog updates. I'd like to update more on a daily basis, but time does not allow me, as this is my passion and hobby, but work and other daily life factors often prevent that. Ahh I can only do my best with the time I have in 24 hours of the day, LOL. ;-)

Take Care

Cassie said...

Ruggie, what is going on with this mild January weather??? Ughh!!! I can't take it anymore! I want the cold and snow back! I live in Cranford, NJ and the winter started out nice but this is just strange for January. Please tell me winter is not over! I am still waiting for all that "above average" snowfall but the way things are going, it's looking very grim for me :( When will the cold and snow come back or will it???


Hi Cassie,
Don't you worry about this 2 week January thaw, as it's about to end soon. A Pattern change to colder and snow reverts back between Jan 27th-Feb 3rd and we should do very well in February.

I know January was a big Dud for snow, but February will make up for it and March is looking good as well. Winter comes back quite strong. In 5 great matching Analog El Nino seasons, just about all January's had little snow. February and March rocked in most of these Analogs, and a couple had good hits in December, just like we did this year. I'm already above normal snowfall with 26" to date < 1/20/10

We're only at the half way point, so be patient, winter returns very soon.


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Ellen said...

Hi Ruggie,

What's the rest of the winter going to be in the Ossining, NY (Westchester) area?
When can we expect Spring?

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Cassie said...

Hey Ruggie,

Cassie from Cranford, NJ again :) Thanks again for the excellent winter forecast! I got lots of snow so I couldn't be happier. Please tell me winter is not completely over yet! Can we expect anymore snow before we're done?? I wish winter could last forever! lol :) Thanks!

sonnyaccurateweather said...

Hey I was just wanting to know when you would get your 2010/2011 winter maps up?