2008-2009 Winter Forecast for the Southeast
Let's face it; if you like cold and snow in the southeast the last 6 years have been very inconsistent to say the least. We have had bouts of very cold weather only to be interrupted by very mild weather for weeks on end in the December-March time frame. With the exception of the 2004 winter where we had a major snowfall in February the winters since 2000 have lacked major snowstorms. Most of the snow has been thanks to "long range lake effect" along with northwest flow snows. This has been beneficially to the Virginia, Maryland and West Virginia resorts, but has done little for the North Carolina Mountains. Northwest flow snows are the primary source of snow for the southern Appalachian Mountains and recurring events help bring cold and snow to most of the southeast ski resorts. These events usually bring small amount of snows but are great for snowmaking operations and creating bases on the slopes.
Locations of snow when we have northwest cold and moist flow during the winter
Well after the past few years with La Nina and weak El Niño's in the equatorial Pacific Ocean there are many climate signals for a colder winter then the past 6 winters. Snowfall will be below the long term averages but a huge improvement over last year is very likely. It would appear that the Eastern United States may get back to a more typical winter, the kind that people around here often lament about when, "we use to have real winters"
Of course what is average snowfall? Let's looks at nationally then locally for the southeast using these average snowfall maps that follow.
U.S. average Snowfall
Southeast Snowfall Averages
The number of winter events either ice or snow in an average winter season
Total number of snow events per season below
Last year's forecast re-cap
Before we look forward it's always nice to look back. Last year's forecast panned out almost as good as I could expect for the Virginias with lots of snow and cold. The North Carolinas resorts I had a worse forecast, especially temperatures. While I nailed the December cold the January into February thaw was a killer. Snow forecast verification in West Virginia last season was around 83% but a measly 60% for the Carolinas. The one big highlight for me was my forecast of the December 7-10 cold and snow which I forecasted more than a month in advance. The actual storm started on the 9th but was a nice start to the season.
Snapshot from last year's Winter Forecast! This was posted Nov 6th 2007.
I hit the March storm and came close to February storm but overall not bad, but it can better and I will try again this year!
The Forecast tools, things I base the forecast on!
There will be 5 indicators that I use to base my December 2008 through March 2009 winter forecast on. Let's remember we are just now coming out of a drought in the southeast and coming out of a moderate La Nina within the past 12 months.
#1 La Nina / El Nino a.k.a. ENSO
ENSO is currently in a neutral phase after a strong La Nina last year which meant dry and warm weather for the southeast. Now El Nino would be better for snow fans but ENSO neutral is a huge improvement over last year and means cold for the east coast. ENSO neutral years are usually an anything goes kind of winter, but neutral is better than the strong La Nina we saw last year.
Current ENSO Phase
What La Nina and El Nino usually mean weather-wise in the U.S.
So with a neutral ENSO and a slight lean towards LA Nina things are looking cooler than last year, but any indication in the next few months of a return to La Nina would spell warm and dry for the southeast. The good news is that we have seen a reversal of the strong La Nina of last year and already this year has been much cooler than average for the whole.
#2 North Atlantic Oscillation a.k.a NAO
For my money this might be the best and most closely correlated oscillation for cold and snowy winters on the east coast. When the NAO is in the negative phase the east coast is snowy and cold, when it's positive it's warm and dry. A good example of who this works is the period from the winter of 1979-1980 until the winter of 94-95 the NAO stayed positive except for 1984/85 and 1985/86. What we would like to see is a winter similar to the very strong negative phase of the winters of 1995-99 when we had a east coast snow storm just about once a week.
Here is an historical look back at NAO during the winter months notice the negative phase from 1995-1999 compares to recent winters since 02.
The forecast for the NAO is going negative for the month of end of November and early December meaning cold weather for the East coast. Notice already we are seeing a forecast of negative for the end of the November into December.
#3 The Arctic Oscillation a.k.a AO
This oscillation is correlated closely with the NAO and it too goes negative when cold air is building in the Arctic and is likely to spill south and east into the East coast of the U.S.
It's important to note that these oscillations...well they oscillate but the more negative they go and the more frequent they persist negative the colder and usually snowier it is on the east coast.
# 4 Sunspot activity
I talked about this last year that we were going into a solar minimum and that the amount of solar activity continues to be lower than average. This continues this year and the forecast is for the solar minimum to continue. The weaker the sun the less heat the earth absorbs and the cooler we will get
# 5 Arctic Ice Coverage
Last year the arctic ice recovered from a record low which is amazing. The problem for the southeast was all the cold air was working in the arctic to re-freeze that ice pack and not moving south to cool off the southeast. This year that has changed dramatically, the ice coverage is back big time. Contrary to some erroneous media reports the ice coverage is increasing at record rates in October and is on the verge of being the biggest extend of ice to date since 2002. This means larges domes of cold air can and have been building in the polar regions of the Northern Hemisphere.
Images from a year ago to this week show a much bigger and deeper snow and ice pack in the Northern Hemisphere. These leads to an early cold air mass building over the arctic region.
To back this up Alaska had a near record cold summer and the 4th coldest October on record, setting the stage for lots of cold air to build early this fall in northwest Canada and Alaska the source region of most of our cold air outbreaks. You can read about the cold more at this article.
Needless to say our source region for cold air up north is in the best shape it's seen in several years.
Conclusion and forecast for Winter 2008-2009 in the Southeast United States
All signals point to a better winter for skiers than the past winter, but natural snow maybe hard to come by further south. While I do see colder temperatures building in Canada and the arctic this fall into the winter the storm track appears to want to set up similar to last winters. This means Northern plains to Ohio valley then a New England storm track. This will bring heavy snow for the Virginia and West Virginia resorts. Snowshoe should have another bumper year with lots of cold and snow. This storm track will bring Northwest flows snows and cold further south into the Carolina resorts but big natural snow in the southern Appalachians come from the Gulf of Mexico as low pressure systems move to the Carolina coast. This would be a favorable storm track for the Carolinas. We see these tracks typically during El Nino winters. This kind of storm track has been noticeable absent in the last 6 winters. Though one or even two per winter are possible just about any winter, we just haven't seen the persistent storm track from Texas to north Florida to the Outer banks. These dump snow on the North Carolina Mountains. The one saving grace is that temperatures should remain colder then the past few winters especially in December, February and March with our usually January thaw.
In the short term I already see the cold air and snow for this weekend Nov 15-16 and even better cold air and a major storm possible next week Nov 21-23. This weekend it's just a very cold air mass and front that will bring 1-2" of northwest flow snows to the whole Appalachian chain with 4-6" possible at Snowshoe. It appears to be a very cold pattern next week which could allow numerous resorts to open very early.
This weekend's storm below
Next weekend the models point to an awesome set-up for big snows in the North Carolina Mountains and the kind of pattern I'd like to see all winter. You get both the cold air and the moisture in place for major snows next weekend!
Next weekend's storm
In the model chart the purple line in the snow line and the colored contours are precipitation.
So on my scale of winter forecast I'll split the southeast into two distinct regions because the weather truly is different in these 2 areas. Looks pretty good early on and I think that will be the case this late November and all of December cold and snowy
Forecast for the Southeast
Temperatures DEC 08 - Mar 09
Snowfall DEC 08 - Mar 09
We need to split the area into two parts the "Northern South East Resorts" Snowshoe, Wisp, Canaan Valley and Winter Place.
Area #1 Virginia, West Virginia and Maryland resorts
Temperatures forecast colder than average (scale warm-cold 1-10)
Snow forecast near average with potential for above average ( scale light-heavy 1-10)
Area #2 North Carolina Resorts the "Southern Southeast" Beech, Sugar, App and the Cat!
Temperatures forecast near average to slightly below
Snowfall forecast average to slightly below average but better then the past few years!
So stay tuned for weekly updates again this is just a seasonal forecast and no way indicates a specific forecast for any particular date. Just the overall pattern trends for the upcoming winter season in the southeastern U.S.
For more information, comments or a specific forecast for upcoming storms please contact Chief Meteorologist Brad Panovich at firstname.lastname@example.org