October- Winter connection

Here are el nino years that had cold october's, all of which were part of my analog set for my winter outlook:

Precipitation looks wet overall:

This is what these years looked like for winter verifying the fact that cold and wet October's mean that a cold winter is coming up for the eastern u.s. We are heading down that road right now with a major trough in the east and widespread frost's/ freezes in the northeast tonight. Don't forget the early season snowfalls across minnesota earlier this month and hundreds of record high's and lows shattered across a wide area of the central and northern u.s.

This october looks mighty cold so far across the central u.s with more coming as another series of troughs reappear next week.

8-16 day temperature anomalies bring the chill back into the northern and western parts of the u.s:

GFS trends stronger on eastern trough, EPO supports this

This upcoming week temperatures will average near normal with pacific air masses moving into the east behind low pressure systems that will move in from the west. Arctic air will not get involved in the u.s pattern until next week. 18z GFS ensembles at hour 192 show the trough moving into the east.

We can see the change in the pattern by the trend to a negative EPO pattern by next week:

I think that we take a break from the cold this week before it comes back again for the last week and a half of october. I believe that the models will begin to trend towards an eastern trough around the 23rd or 24th of october as that would match up with the typhoon recurvature. The indicies are starting to line up well in the long range with a -NAO, +PNA and -EPO indicated on the GFS. The european weeklies support this as well. With the active pattern coming up backed by the MJO and the LRC cycle in the observation period and may be beginning its new cycle. This would argue for an active january. A stretch of just a few very active weeks can change the entire impression of the winter. When we get powerful low pressure systems moving North into cold arctic air masses it spells trouble in January.

High Res NAM puts snow swath across the North

The high resolution NAM shows the snow potential tonight across central ontario and quebec. I still think the snow stays predominantly north of montreal and Ottawa with marginal boundary level temperatures. The precipitation will be fairly light as well. Wet bulb temperatures are above the zero degree mark which shows signs of a less favourable situation for many populated areas in ontario and quebec. Nonetheless flakes can be seen tonight in Ottawa and Montreal as well as cottage country in ontario and should NOT be ruled out. Accumulating snow seems less likely in these areas but further north near quebec city or trois rivieres this is possible tonight and tomorrow. Back end snow showers in  southern ontario and northern michigan may be possible as well tomorrow morning.

NAM composite reflectivity may be a bit too warm but is on the right track:

850 mb temps and surface wet bulb temperatures on the GFS are just below zero:

HRRR says rain with the initial wave but some snow showers on the back side for ottawa, montreal and central ontario before the system pulls northwards. People across this area might wake up to some exiting weather! A line of showers is depicted for the northeast tomorrow morning as the cold front moves eastwards ushering in the last of a series of arctic air masses for the east this week.

Have a good night everyone!

Long Ranger: MJO says wet pattern for Great Lakes

The MJO will be headed away from the COD and into a high amplitude phases eight and one. Here are  various forecasts from a few models.

ECMF:

EMON:

GEFS:

If we look at phase 8 and 1 in october we can see a very wet pattern across the great lakes, ohio valley and the northeast. In phase 8 the wetness will be further west across the upper great lakes and parts of the midwest. In phase one the wetness spreads further south and east into most of the eastern two thirds of the u.s. B.C and the pacific northwest will get in on some enhanced precipitation as well as the northern jet supplies some precipitation and more systems barrel into Alaska(-PNA pattern develops).

There is support on most of the modelling for a strong system in this time period with warm air advection out in front of it and a SW flow of air bringing above normal temperatures for the east. Less cold air will penetrate the east as this system moves out because the source region will be a pacific airmass instead of an arctic airmass like we are experiencing with our current trough. Notice the very strong cold front associated with this and the potential for a severe weather outbreak. In my opinion it will be a small outbreak and lower then current expectations by some. The pre-existent cold air mass will limit a large temperature gradient from setting up and lower dew points will develop in front of the cold front. Nonetheless, any October severe weather outbreak is impressive as we are in between the two main severe weather seasons.

Going further down the road, Phase 8 MJO precipitation correlates well with the impressive precipitation field and a classic comma shape configuration shown on the 18z GFS at hour 192. The look of this system reminds me of what the groundhog day blizzard looked like on february 2nd 2011 except it is 2 months early. If this were to occur in december then we are in business for big snows in the east. This may be a sign of a more inland track this winter as well as the classic east coast phaser with a ridge axis centred over the rockies.

 Another interesting thing to take note of is a more active northern jet in the long range with more arctic air masses available and small pieces of the main western trough breaking off and moving eastwards getting departures down and setting up a very active and interesting pattern for the east.

European agree's with a typhoon recurvature

Yesterday I mentioned how the european model was tracking a strong typhoon west into china. On the most recent run of the ecmwf we can see a recurvature similar to what the GFS is showing. You can see the typhoon beginning to take a turn to the east of Japan at hour 216.

From this we can infer that a trough will move into the east between the 20th and 25th of october. Despite all of this the 06z GFS keeps the trough in the west and more ridging in the east.

 Something doesn't look right here  especially considering that the long term AO/NAO are going negative. I think blocking is going to develop like the GFS shows but the trough will progress further east into the great lakes, northeast and the ridge in Western Alaska will be centred further east in the GOA.

The european weeklies show this cool down across the east during this time period. This may set the stage for what I believe will be a colder then normal start to november.

Solar Activity Foreshadow's Pattern, will AO tank?

Geomagnetic Activity has reached the minimum but is going towards the max in the next twelve days which argues for warmth outweighing the cold over the u.s in the next two weeks once this trough lifts out.

After this I see a cool down for the end of the month before things get very interesting in the first week of november and the NAO appears to go negative in the long range. The GFS and canadian are seeing the AO tanking around the 24th of october which may be an attempt to hint at a possible typhoon recurvature(17th-20th) and eastern u.s trough connection at this time.

AO:

 NAO:

 If these indicies stay negative for the start of november and solar activity is declining we may see a very interesting start to november. The strength of these trough are still uncertain but the pattern has been one of major eastern u.s trough depicting weather one month in advance. Some examples are the august cold shot that made it feel like september and the september cold shot that felt like october. Keep in mind that both of these cold shots were leading up to the solar mins.

Then theres our current cold shot and a forth that may be lurking down the road for the end of october and /or beginning of november. Things may get very interesting...

Cold will back off but may come back stronger

Record breaking cold was felt for much of the u.s and southern canada this morning as a strong trough is digging into the east as a result of a typhoon recurvature around 7 days ago.

 The cold will back off between the 15th of october to the 24th of october. Another strong typhoon is forecast to recurve east of Japan around the 18th which would argue for an eastern u.s trough between the 24th and 28th. One thing that worries me is the fact that the european has a stronger typhoon heading for china contrary to its previous runs. I'll continue to watch this very closely because it is a very important wild card. GFS operational for this time frame shows this.

GFS operational is already showing some extreme cold coming down as a result of the the typhoon propagating east of japan. Nothing is written in stone but just remember how the models were having trouble picking up on our current trough. What is most important is to know where the typhoon tracks in the western Pacific to get a jump on all the model mayhem. Have a great week everyone!

Volcanism Update by Request

I got a question about possible volcanic activity, what implications it can have on the u.s and some analogs to support this.

In response I don't see any major eruptions right now besides a small eruption in guatemala by the name of mount fuego. Heres a quote from the smithsonian weekly report "Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua." I don't think fuego is a threat to the global climate right now because it is only spewing a small amount of ash and its only reaching 1.1km at the most which isn't high enough into the atmosphere to create any disruption to the weather patterns. The ash will eventually get precipitated out within weeks. Besides that all is quite right now. Some other analogs which depict the global cooling effect volcanoes have on the globe include 93-94,94-95,95-6 which followed the mount pinatubo eruptions causing major global cooling as well as a frigid north america.

 There was also the winters of 83-84,84-85 and 85-86 which were frigid across the u.s caused by the major eruption of Mount St Helens. Take note of the +PNA and negative EPO pattern across north america which set up cold winters as well as the high latitude blocking.

Take a look at the global cooling that occurred as a result of so2 that was spewed into the stratosphere  adn converted to volcanic aerosols deflecting incoming solar radiation from the sun. This favours high latitude blocking. This is common in major high latitude volcanoes especially in low solar regimes as we are currently experiencing. Tropical volcanoes do the opposite and cause short term cooling and long term warming because it weakens the easterlies in the pacific and creates an el nino (producing long term global warming). Notice the warming of the last decade caused by little volcanic aerosol's in the stratosphere.

Something very interesting is Katla, a neighbouring volcano to Eyjafjallajökull which some say is overdue for a major eruption. There are signs of higher activity between the much larger and more deadly katla in iceland which may be a sign of an upcoming eruption. Eruption from katla occur on average every 60 years and oddly enough have occurred within months after its neighbouring Eyjafjallajökull erupts. Last July, a flood of water burst from beneath the ice cap on top of Katla, washing away a bridge. This indicates that an extra pulse of heat reached the base of the ice. Since then, there have been erratic movements of the surface of the volcano, measured by precise GPS instruments, and bursts of high earthquake activity beneath Katla’s caldera. These observations imply that magma has risen to shallower depths. Katla’s eruption in 1918 produced five times as much ash as the 2010 Eyjafjallajökull one. A major eruption could result in large parts of Iceland being flooded as snow and ice melted; significant poisoning of Icelandic agriculture; destruction of property; and, of course, the grounding of aircraft across Europe. Also major global cooling will be produced for years to follow if this threat comes to fruition. 

La Nada analogs, is El Nino dead or reloading?

Latest MEI update shows a large dip which can be expected due to the cooling of the ENSO regions and pop in the SOI values in September.

Notice the pop in the SOI recently to slightly positive. Current SOI values:

 ENSO region 3.4 cooled to +0.2 and nino 4 is at +0.4. Notice the warmest water centred west towards the dateline with a cool plume along the equator in most of the ENSO regions. A quote from Klaus Wolter the MEI founder shows the possibility of another surge of warmth in nino 3.4 and 4 "The burgeoning El Niño event of 2012 may have already run its course, considering an overall environment that appears to favor La Niña conditions since 2006. Or it could get a "second wind" if a currently evolving westerly wind burst northeast of New Guinea manages to penetrate south and east to the equatorial central Pacific. In either case, it would be unprecedented to see a switch back to La Niña before 2013."

The wind flow pattern across the region shows that westerly wind burst near 150 east which may help to move the warm pool westwards helping the el nino.

The cross section shows the warm pool between 160E and 140W:

My thoughts are leaning towards more of a weak el nino with nino 3.4 anomolies near +0.5 but a positive neutral winter is definitely in the cards as well which is why i constructed an analog set based on some la nada years that best represented my thinking on this winter and were positive neutral winters. This set is very close to my thinking with warm condition over the northwest, cool conditions over the southwest, south central and then colder conditions as you get further east. I think coldest departures may end up further south but i really like the look of this temperature outlook which is close to what i have out for this winter. I think the cold in the dakota's is a bit overdone but a slightly below normal year is possible. I have normal across most of the midwest and northern plains. I like the look for chicago as well. I don't agree with the wetter signal that i am getting on these years in the pacific northwest because i believe that the southern jet will track south into california and northern mexico as opposed to the pacific northwest. I would switch the wet anomalies from washington to california. I feel that on the precipitation analogs it is too dry across the great lakes and ohio valley although the area with the driest anomalies just SW of chicago may end up right. It may end up slightly below normal across the eastern great lakes but right now i don't believe that this is the case. I think too wet across the northern plains and interior northwest and feel pretty confident on that.  I believe the interior southeast will average above normal for precipitation.

Temperature:

Precipitation:

One thing to remember is in la nada winters other indicies such as the nao, ao, QBO and PNA play a larger role in the overall pattern across north america. This means that if a la nada occurs and the NAO and AO end up negative(which is favoured this year) we are in store for some serious cold. Don't be fooled warm neutral years can pack a punch. 

The cold may also be reinforced by the QBO and stratospheric warming events.

The last east QBO warm La Nada that occurred is one of my analog years 2003-04 and look what happened in the stratosphere and at the surface.

December started off warmer but as the stratospheric warming events occurred frigid temperatures and high latitude blocking  overruled in january. January was tied for boston's 2nd coldest ever with an average temperature of 20.7F and was NYC 7th coldest january ever with an average temperature of 24.7F. 

Official Winter 2012-13 Outlook

Key points:

• A split jet stream pattern will occur with the northern branch extending over a ridge stationed along the west coast (positive PNA signal). The southern branch will track through southern california, arizona,texas and east towards alabama, and georgia.

• Larger snowstorms will track along the east coast this year with a more active southern jet and the northern branch supplying colder air into the pattern.

• I expect phasing of the branches to occur especially in mid to late december and most of February with storms tracking further north along the east coast. Major strengthening of low pressure systems can occur with very warm water off the east coast.

• With the jet stream branches well to the north and south of the area the pacific northwest will remain dry and average warmer then normal this winter.

• The gulf coast and southeastern states will be wetter then normal with a strong 

southern jet providing precipitation.

• The southwestern u.s will stay wet with higher elevation snows above normal.

• The midwest and northern plains can be drier then normal with large temperature swings especially in western parts of the midwest.

Zone Summary:

The east:

The northeastern part of the u.s will have better snowfall opportunities this year with phasing of the northern and southern branches. I expect snowfall to average above normal from the eastern great lakes all the way east to southern new england. Warmer then normal water off the east coast will allow for rapid strengthening systems and higher amounts of snow. The lake effect machine will be turned into high gear. With a cold december expected an early lake effect season will occur around the great lakes.The southeast can be wetter then normal especially early in the season as the southern jet will be the main source of precipitation, as is typical in an el nino year. An area from  northern Georgia and Alabama, interior sections of the Carolinas up the Appalachians into eastern PA and NY will experience the highest snowfall compared to normal this year. Systems will track further west into the eastern or central lakes at times but the main track will stay further east along the apps or up the coast. This is why I have areas further west closer to average. Northern new england will have its fare share of snow this year and i believe a slightly above average snowfall season is in store for them. Some systems may track off the southeast coast especially when cold air is laking(weak northern branch) or excessive suppressing the storm track to the south. What may occur this season is northern branch features will track to the east off the northern new england coast and may redevelop causing 4-8” snowstorms that may surprise you and go above expectations. The gulf coast states as well as the southern plains will experience above average precipitation and cool conditions. The chance of a snow/ice storm is higher then normal this winter especially in areas that are a little further north away from the gulf. 

The West and Rockies

The pacific northwest and northern rockies will stay dry and warmer then normal with the mean ridge position setting up along the west coast with a +PNA signal. Southern california, the Southern Rockies, Arizona and New Mexico will average cooler then normal with above average precipitation. Higher elevations will experience above normal snowfall including Denver, CO. An early start to the ski season is likely and should be watched out for. Cities like Tucson, Az should be on the watch for a snowfall event, which will be more likely to occur this winter with a more active southern jet and the cold air building to the north.

Central U.S and Great Lakes

The western Great Lakes and the Northern Plains will be dry this winter with clippers as there main source of snowfall. There will be little influence from the southern jet and major storms will tend to track to the east of the area. The northern plains will be normal to slightly warmer then normal with areas further east in the midwest experiencing more seasonal temperatures that will vary at times. Temperatures swings can occur across the midwest as the western ridge shifts to the east at times promoting a SW flow of air. Another possibility is a deeper trough further west setting up sometimes producing cooler temperatures across this area. In terms of snowfall weak el nino seasons are highly variable for the midwest. For example weak el nino seasons like 1976-77, 1977-78, were snowy seasons in the area but years like 1953-54,2006-07 and 1968-69 were well below normal for snowfall.  I believe chicago can expect near normal snowfall as well as areas further east of there. Anywhere further north west of chicago(away from the lakes) will miss out on snowfall this year. Lake effect snow will be well above normal in areas downwind of the lakes especially in december as arctic air masses may plunge southwards very frequently. Because of very above normal lake temperatures, freezing of the lakes will be unlikely and late season lake effect will help up snow totals in many areas. I expect the great lakes area to average near normal but cities along the eastern lakes and/or effected by LES will average above normal with more apps runners moving northwards carrying snow on the NW side. Clippers will lay down swath’s of 1-3 and 2-5 inch snows but areas effected by the southern branch will cash in on much more snowfall this season.

Reasoning behind the forecast

ENSO:

Firstly a very important factor in this winter forecast is the positioning of the nino in the pacific. East based nino's are warm in the north and west and cooler in the southeast. Central or West based el nino’s are cold across the east and warm in the west. 

East based nino’s:

West based ninos:

I am expecting a weak  el nino this winter. 

IRI forecast has it peaking out somewhere between 0.5 and 1.

Some people believe that this el nino is going to have trouble developing and might end up being a la nada winter. I  think that the el nino is going to start strengthening this fall much like 2009. In 2009 we didn’t see very much development until october when the SOI values really began to crash. Notice how the SOI values stayed around zero for a few months, just like this year before falling in october. Despite the break in august and September I believe that the El Nino will be stronger soon with the daily SOI values falling.
2009 SOI values:

This year:

After a September break the last few days may be a precursor of whats to come in october...

QBO

What is the QBO? The Quasi-Biennial Oscillation (QBO) is a slow oscillation in the strength and direction of the zonal wind in the lower and middle stratosphere over the equator. It has a period of roughly 28-29 months (hence the 'quasi-biennial' title) and has been observed for more than 50 years now in climatological records. The alternating wind regimes develop at the top of the lower stratosphere and propagate downwards at about 1 km (0.6 mi) per month until they are dissipated at the tropical tropopause. Downward motion of the easterlies is usually more irregular than that of the westerlies. The amplitude of the easterly phase is about twice as strong as that of the westerly phase. At the top of the vertical QBO domain, easterlies dominate, while at the bottom, westerlies are more likely to be found. Negative (white) are easterly, positives (shaded) are westerly. Notice we are seeing an easterly phase of the QBO right now except between 50 and 70mb.

Current QBO chart:

The QBO is a huge factor when it comes to snowfall across the eastern U.S. Recent QBO values depict a negative state that in my opinion will hold through the winter. This will help to enhance blocking across high latitudes sending more widespread cold air across north america. Cities in the northeast such as New York and Boston tend to do better with snowfall totals in a westerly QBO el nino season. In east QBO el nino years northeast cities tend to be average to slightly above average in terms of snowfall. In east QBO el nino’s with an MEI between 0.0 and 0.5 NYC averages 25” of snow. Boston averages 45” of snow. Toronto averages 155cm of snow. In east QBO el nino years like 1968-69 and 1976-77 cities in the northeast and great lakes were much above normal for snowfall. Other easterly QBO years had more precipitation further southeast with a storm track out to sea off the southeast coast. I don’t think this storm track will occur frequently this winter but it may occur at times. Here's the correlation between an easterly QBO at 30mb and 500mb heights across the globe.

If the QBO ends up switching to a westerly phase a snowier winter but less cold will be felt in areas further north along the east coast and further west in the eastern great lakes/interior northeast. We tend to see  more apps runners/coastal’s as opposed to out to sea storms that take a southern track. For snow lovers I don’t think that would be such a bad thing.

West QBO el nino’s in a cold PDO:

AVG snowfall in NYC with MEI between 0 and +1:  32”

Boston: 55”

Toronto:165cm

This is what east QBO el nino’s with a -PDO look like across North America. Notice the wide spread cold.

Another wild card this winter will be blocking which varies from week to week and month to month. It is very difficult to predict NAO and AO values far in advance but there are several factors that could influence these teleconnections which I will explain along with what is setting up this year.

Some factors include...

1. A profound warm atlantic tripole (warm,cold, warm SST’s) helps to enhance blocking across Greenland. This was a major contributor to a very -NAO this summer. We can see that in the year of 2009-10 contributing to the strong persistent blocking that showed up.

Also in the winter of 1952-3 we can see the warm, cold then warm pattern setting up. This winter had consistent blocking for most of the fall, winter and spring.

1952 10 -0.28

1952 11 -1.32

1952 12 -0.49

1953 1 -0.12

1953 2 -1.00

1953 3 -0.45

1953 4 -1.96

: 90% of original size [ 565 x 437 ] - Click to view full image

Here is the correlation between SST’s and the NAO. Notice the warm AMO tripole. This is a very important factor.

Here are the temperature effects of the NAO state on various ENSO states. I think that we will see a mix of the -NAO La Nada and -NAO El nino temperature trends.

Effect of the AO and NAO on winter:

Taking a look at this years SST’s we can see a favorable pattern in the Atlantic starting to take place. Notice the very warm water near Greenland. That will be a very key factor in determining this years NAO state.

2) Solar activity 

We know that years with low solar had strong blocking showing up. This year we are heading towards the solar maximum. The peak is expected to be sometime in 2013 with an estimated sun spot number at 76. The sun spot number is very low when compared to other solar max years. I don't feel as though there is a very strong effect that solar activity will have on this winter besides  favouring the cold idea. I do not expect any big flare ups this winter unlike last winter when the sun was more active with some large solar flares mid season. This could have been responsible for some of the extreme warmth last winter. In el nino’s with high solar blow torch winter are common but just a few spots have been the normal in this very quiet cycle.

3) Volcanic activity 

Years which arctic volcanoes erupted had very strong persistent blocking such as 2009-10. This also contributes to a big drop in global temperatures the following years. Due to the volcanos that recently erupted in 2009 we may see some strong cooling showing up this winter or the following winters as a result. In the year of 1912-13 we saw mount novarupta erupt and this produced major cooling 3,4 and 5 years later.

In the winter of 2009-10 we saw Mt. Redoubt in Alaska, Sarychev in Russia and Eyjafjallajökull in Iceland. If we do the math we can see that as history is shown to repeat itself we will see a lot of cold showing up in north america in the winters of 2012-13, 2013-14 and 2014-15.

4. Mid and upper level temperatures. Very cold mid and upper level temperatures like we saw last winter will force the bundling of the jet northwards(a stronger polar vortex) toward the poles and force the positive AO that we saw last winter! This is also why alaska, greenland and higher latitudes experienced a very cold winter. The reason for last winters very positive AO and NAO was the very cold mid and upper level temperatures that were present before and during the winter time. The mid and upper level temperatures have warmed up significantly this year which is why I believe that an overall -NAO/ AO pattern will setup this winter with a chance for much colder air masses to get locked into the east. In summary, with an east QBO, low solar activity, a warm AMO tripole and near normal temperatures in the stratosphere  I believe that a negative NAO will be favoured this winter.

Analogs:

My analog years were chosen based on weak el nino seasons, east QBO’s, a negative NAO and AO, positive PNA, near normal to above normal stratospheric temperatures, a warm AMO tripole, a negative PDO, central based el nino’s coming off of a la nina. I also looked at years with similar summers, low solar and atlantic hurricane activity. Weak el nino’s tend to vary largely from year to year so I focused on other factors besides the ENSO trend. Here is a chart I made in order to help me construct my analog set and eliminate analog years that didn’t correlate as well. I listed all my potential analog years with all the indicies as well as 2012-2013 winter’s forecasted indicies.

This winter I am expecting a positive PNA with a mean ridge centred along the west coast with a downstream trough over the great lakes. A mean ridge will form across greenland promoting a less progressive and more amplified pattern. Remember this is a mean pattern and is not something that will always hold. These troughs and ridges will shift east and west at times which is why the midwest and northern plains may experience large temperatures changes. As we get into mid to late december the northern branch will get stronger allowing for more phasing of the jet streams to occur. I see two periods that will stand out this winter, in terms of being the harshest. Mid to late december and most of february. In these periods more storms will move northward up the coast or inland. If november is cold across north america more snow cover will build up in NW canada allowing for colder air masses to move through earlier on in the season. Snowcover will be a very important factor this winter, one that should be watched closely going forward. Longer lasting cold shots will promote more LES and more phasing will cause larger snowstorms to form. If this scenerio plays out then colder air will grip the east earlier on and hang around for a longer time. Snowcover across high latitudes is already beginning to build and its only the beginning of october. Here’s the 8 day forecast in these areas. I believe that because of these reasons an early start to winter will be on the table this year. 

Asia:

North America:

Northern Europe:

Now on to the best part, the final forecast!

Mean upper level pattern forecast for this winter:

I have a couple analog sets that I based this winter forecast off of:

1. Here is my main analog set for DJF:

These are my QBO analog years (east QBO,weak el nino’s)

Month to month forecast with analogs:

December:

The winter of 2012-13 will start off with a bang. I expect a colder then normal December overall with the action really getting going mid to late month. Phasing will have a good chance of ocurring with a west based -NAO block showing up, a ridge in the west and a cold southern and eastern U.S. Snowcover will build up this month setting the stage for a long lasting cold winter. I expect several storms to make a run up the east coast or the apps this month.

Analogs:

Forecasted Temperatures:

Precipitation and snowfall:

 January:

The coldest anomalies will back off a bit this month but don’t be fooled slightly cooler then normal temps in January can be quite cold. Chilly air masses will move down from the arctic feeling frigid in the heart of winter. The snowpack will hold up this month but I expect more storms to move OTS this month. A less amplified ridge will shift to the west, more of a -PNA signal will show up will colder air across NW canada and the southeastern u.s. A more transient pattern will take place this month sharing the wealth of cold air. The pacific NW will stay warmer then normal with the influence of the ridge to there west but may get in on some more cold air masses. More widespread cold is expected in January. Clippers will allow for some snow to fall across the north but the snow machine will generally take a bit of a break this month.

Analogs:

Forecast:

February:

Winter will recharge and make a  comeback in February as phasing begins to take place again and a more locked in pattern develops with a +PNA and negative NAO. Snowfall will average well above normal for the east coast with storms packing quite a punch as they track further north. Phasing of the jets will cause more frigid air to attack the east with little break. The worst of winter will be felt this month for the east and southeast. Ridging in the west will keep departures above normal.

Analogs:

Forecast:

DJF forecast:

Winter highlights:

I really hope you guys enjoyed my outlook. A lot of research and hard work was put into this! Feel free to post your thoughts, comments and any questions you have for me about this winter!