Monday, January 18, 2016
You Get Nothing!
How I feel waiting for the next round of models... Euro trended colder as I suspected and had a CRAZY output where everything went perfect and it "modeled" 30 inches of snow. DT from Wxrisk posted the map. I still have concerns over the amount of mixing that takes places. Would be the difference between 3 to 6 with sleet and rain or 8-12 or more. Will do full synoptic update later this evening or early tomorrow.
Sunday, January 17, 2016
The BIG storm: What we know..... and what we don't know??
Social Media has been blowing up all day about the POSSIBLE big storm. Let's break down the details with What we know...and what we don't know??
What we know!
1. Cold Monday and Tuesday where temps don't get above Freezing most areas.
2. We will have a storm Thursday into Saturday Time Frame.
3. I expect Lynchburg, Danville, Roanoke and Blacksburg to have at least an inch of liquid fall (Could be snow, ice, rain)
4. Starting time could be as early as 9pm Thursday evening far western regions and as late as 9am Friday far eastern regions.
What we don't know??
1. Snow amounts. Social media will be flooded with maps from XYZ run of whatever model. There are so many issues with them I don't know where to start. 5 days out, we don't know yet. Remember, now we look broad and get specific as the event gets closer.
2. Exact storm track.. This is HUGE and ties into number one. Remember we want to be on the cold side of the low. This means the north and west side.. the model runs that take the low into Kentucky are NOT great for our region. My guess is a somewhere into Georgia, reforming near Myrtle Beach, but that's an educated guess. If a primary low drives UP into Kentucky, we are icy and rainy.
3, Exactly how much cold air will be in place and then reinforcing during the event. Antecedent cold air is very important for a big storm. However, getting cold air funneled in as the storm progresses is also important. Remember our Presidents day storm last year. We had snow and 12 degrees and it changed to sleet-- we had no cold air reinforcing the mid levels. Model data has trended a bit colder and I think this may continue for another day.
Wow, you said a lot of nothing...
YES I DID!
I can speculate a little. This is speculation and will change. My goal will be to create a framework and then fill in the fine details as the event gets closer.
1. I believe the models will trend colder over the next day and give a decent idea of what to expect. The warmer models have stepped towards the colder models and the colder models conceded a few points and it's slowly coming together. The ensembles (same model run at lower resolution with some intentional changes added to weed out biases) have been more south and colder than the "operational" runs.
2. Once the models bottom out cold/south track wise- we see what corrections will be made back north and warmer.
3. Basement and ceiling for main locations...
Roanoke/Blacksburg- Lumped in together because this has some marks of an I-81 special. The floor of snow and ice accumulations is 2 inches with a ton of ice and freezing rain mixed in. The ceiling is a storm of over a foot or maybe more. Their odds of over a foot of snow is HIGHEST at this point. I'd estimate 40% at this point.
Lynchburg- Basement is the same 2 inches of sleet, snow and slush. Ceiling is also over a foot of snow or more but the odds are much lower at only 25 %. Their 40% number is 8 inches.
Danville and Southside- Basement is a coating of slush and sleet, ceiling is also a foot but odds are down at under 10%. Their 40% number is 6 inches.
As we move closer, I will update and refine to give more details. We will be moving from broad to specific.
Please share my blog on FB/Twitter. If you like what you read, click and add--- I do get paid for that. :)
I'll continue to live tweet thoughts and progression during model run times. Feel free to retweet or ask me questions.
What we know!
1. Cold Monday and Tuesday where temps don't get above Freezing most areas.
2. We will have a storm Thursday into Saturday Time Frame.
3. I expect Lynchburg, Danville, Roanoke and Blacksburg to have at least an inch of liquid fall (Could be snow, ice, rain)
4. Starting time could be as early as 9pm Thursday evening far western regions and as late as 9am Friday far eastern regions.
What we don't know??
1. Snow amounts. Social media will be flooded with maps from XYZ run of whatever model. There are so many issues with them I don't know where to start. 5 days out, we don't know yet. Remember, now we look broad and get specific as the event gets closer.
2. Exact storm track.. This is HUGE and ties into number one. Remember we want to be on the cold side of the low. This means the north and west side.. the model runs that take the low into Kentucky are NOT great for our region. My guess is a somewhere into Georgia, reforming near Myrtle Beach, but that's an educated guess. If a primary low drives UP into Kentucky, we are icy and rainy.
3, Exactly how much cold air will be in place and then reinforcing during the event. Antecedent cold air is very important for a big storm. However, getting cold air funneled in as the storm progresses is also important. Remember our Presidents day storm last year. We had snow and 12 degrees and it changed to sleet-- we had no cold air reinforcing the mid levels. Model data has trended a bit colder and I think this may continue for another day.
Wow, you said a lot of nothing...
YES I DID!
I can speculate a little. This is speculation and will change. My goal will be to create a framework and then fill in the fine details as the event gets closer.
1. I believe the models will trend colder over the next day and give a decent idea of what to expect. The warmer models have stepped towards the colder models and the colder models conceded a few points and it's slowly coming together. The ensembles (same model run at lower resolution with some intentional changes added to weed out biases) have been more south and colder than the "operational" runs.
2. Once the models bottom out cold/south track wise- we see what corrections will be made back north and warmer.
3. Basement and ceiling for main locations...
Roanoke/Blacksburg- Lumped in together because this has some marks of an I-81 special. The floor of snow and ice accumulations is 2 inches with a ton of ice and freezing rain mixed in. The ceiling is a storm of over a foot or maybe more. Their odds of over a foot of snow is HIGHEST at this point. I'd estimate 40% at this point.
Lynchburg- Basement is the same 2 inches of sleet, snow and slush. Ceiling is also over a foot of snow or more but the odds are much lower at only 25 %. Their 40% number is 8 inches.
Danville and Southside- Basement is a coating of slush and sleet, ceiling is also a foot but odds are down at under 10%. Their 40% number is 6 inches.
As we move closer, I will update and refine to give more details. We will be moving from broad to specific.
Please share my blog on FB/Twitter. If you like what you read, click and add--- I do get paid for that. :)
I'll continue to live tweet thoughts and progression during model run times. Feel free to retweet or ask me questions.
Saturday, January 16, 2016
First Measurable snow of the season likely tomorrow.. Friday looking healthy!
Now, Measurable means more than a trace. I think most places see a coating to an inch starting near sunrise and ending early afternoon. A few lucky places, best shot from the VA/NC border to 460 could see up 2 inches.. depending on where banding sets up.
Friday's event looks better. Our problem getting snow has been that the flow is fast with many moving pieces, which prevents cold from meeting storms. (Adding many shortwaves working against each other)
It seems like the cold air SHOULD be in place as a low approaches from the west Friday...
3 options...
The Canadian model cuts the storm well to our west, we have some cold air and should get a snow to sleet and ice event, maybe even rain for awhile. Shows big snows JUST north of here (Staunton north, Up 81 into PA)
The GFS (American model) storm cuts west but reforms south. We flirt with the rain/snow ice for a while in the event but still see a pretty big event. Not throwing out snow totals but it would be nice event.
Euro- more suppressed with the event and the storm goes out to sea we are on the northern fringe. Possible low Warning event (3-6 inch range type deal)
Looking at the pattern, I think we trend more towards what the Euro shows at this point. The GFS was a HUGE event, but in part was overdone because the cut west held on too long and pulled in a lot of warm air, making more precipitation. Still, Gulf Lows always have good potential.
Cold weather this week-- 2 days won't get above freezing. (Monday, Tuesday) and Friday may not if the ice/snow comes early enough.
Friday's event looks better. Our problem getting snow has been that the flow is fast with many moving pieces, which prevents cold from meeting storms. (Adding many shortwaves working against each other)
It seems like the cold air SHOULD be in place as a low approaches from the west Friday...
3 options...
The Canadian model cuts the storm well to our west, we have some cold air and should get a snow to sleet and ice event, maybe even rain for awhile. Shows big snows JUST north of here (Staunton north, Up 81 into PA)
The GFS (American model) storm cuts west but reforms south. We flirt with the rain/snow ice for a while in the event but still see a pretty big event. Not throwing out snow totals but it would be nice event.
Euro- more suppressed with the event and the storm goes out to sea we are on the northern fringe. Possible low Warning event (3-6 inch range type deal)
Looking at the pattern, I think we trend more towards what the Euro shows at this point. The GFS was a HUGE event, but in part was overdone because the cut west held on too long and pulled in a lot of warm air, making more precipitation. Still, Gulf Lows always have good potential.
Cold weather this week-- 2 days won't get above freezing. (Monday, Tuesday) and Friday may not if the ice/snow comes early enough.
Saturday, January 9, 2016
Powerball number ideas for snowlovers!
If you'd love to win the powerball and you like snow-- here are some numbers to play.
We have three threats to watch: Jan 15, 18 and 21.
Add in 58 and 66 for the blocky stronger el Nino years that were snowy here in Lynchburg, Roanoke, Danville and Blacksburg. (15,18, 21, 58, 66)
3 for your money ball for 3 threats.
We could have 3 events, (Unlikely) We could have NO events, (Unlikely) For our specific region, a good guess at this point is that we get one decent event out of the 3 and one that flirts with us. Decent doesn't JUST mean snow. Could be snow, ice ..etc.
What could go wrong?
We have many moving pieces between the northern jet and the subtropical jet. The models have not resolved any of these pieces and much can go wrong still. The Euro model last night has us on the fringe of 2 events, the 15th and the 18th.. and with that being 7 and 10 days away I'd take those solutions at run with it because stronger events just about always trend north. As of now, the Crush NC and parts of eastern VA. However, with fast moving pieces, the energy CAN get shredded and the northern branch COULD crush the southern branch.
As the model run ends day 10, the 18th storm is east of Hatteras and one more threat can be seen emerging from the 4 corner regions.
My 1966 analog has been front and center on the Super Ensemble page and some of the less snowy 1998 analogs are showing up still, but have dropped on the rankings.
We could also see some light snow and flurries for a period Tuesday. Not a big event, but perhaps a warning shot much like we had on Valentines day last year.
*** Read this closely: I'm not forecasting 3 storms. I am creating awareness of 3 possible events. That means we could get 1, 2, 3 or NONE of these events ***
I'll start to FB and Tweet out more specific information about model runs over the next few days. You can follow me personally, my Lynchburg Weather Page or LynchburgWx twitter handle.
** read this carefully** Don't fall for the schmucks putting computer generated snow maps 5 to 10 days out on facebook. It's such a bad practice. Feel free to ask me, and they can be very fun to look at BUT they create bad expectations and are hard to work around because of the expectations people feel from them.
Please continue to share me on FB and twitter. I'm not "buying" false likes, I'm earning them.
We have three threats to watch: Jan 15, 18 and 21.
Add in 58 and 66 for the blocky stronger el Nino years that were snowy here in Lynchburg, Roanoke, Danville and Blacksburg. (15,18, 21, 58, 66)
3 for your money ball for 3 threats.
We could have 3 events, (Unlikely) We could have NO events, (Unlikely) For our specific region, a good guess at this point is that we get one decent event out of the 3 and one that flirts with us. Decent doesn't JUST mean snow. Could be snow, ice ..etc.
What could go wrong?
We have many moving pieces between the northern jet and the subtropical jet. The models have not resolved any of these pieces and much can go wrong still. The Euro model last night has us on the fringe of 2 events, the 15th and the 18th.. and with that being 7 and 10 days away I'd take those solutions at run with it because stronger events just about always trend north. As of now, the Crush NC and parts of eastern VA. However, with fast moving pieces, the energy CAN get shredded and the northern branch COULD crush the southern branch.
As the model run ends day 10, the 18th storm is east of Hatteras and one more threat can be seen emerging from the 4 corner regions.
My 1966 analog has been front and center on the Super Ensemble page and some of the less snowy 1998 analogs are showing up still, but have dropped on the rankings.
We could also see some light snow and flurries for a period Tuesday. Not a big event, but perhaps a warning shot much like we had on Valentines day last year.
*** Read this closely: I'm not forecasting 3 storms. I am creating awareness of 3 possible events. That means we could get 1, 2, 3 or NONE of these events ***
I'll start to FB and Tweet out more specific information about model runs over the next few days. You can follow me personally, my Lynchburg Weather Page or LynchburgWx twitter handle.
** read this carefully** Don't fall for the schmucks putting computer generated snow maps 5 to 10 days out on facebook. It's such a bad practice. Feel free to ask me, and they can be very fun to look at BUT they create bad expectations and are hard to work around because of the expectations people feel from them.
Please continue to share me on FB and twitter. I'm not "buying" false likes, I'm earning them.
Wednesday, January 6, 2016
If I could update my Winter 2015-2016 outlook-- I would change??
At this point, NOTHING!
Look, I blew December. I figured there'd be a warm spell. No idea it be a top 2 warmest Christmas week ever and the warmest December on record by 5-6 degrees most areas. Simple didn't see that and even if I did, I'd have tempered it back because that was such a rare event.
The meat of my forecast was Slightly above normal snowfall, centered from Late January till Middle to late February. The "Godzilla" El Nino is making the pattern look different than last year, but in a "sensible weather" (AKA, what you get outside") may not be off that far from last year where we had some colder temps, but the bulk of the snow fell in 2-3 weeks. (Subtract the -10 temp departure and make it -3 to -5 for a 30 day period. )
I still like that Jan 20th ish till Mid February Time frame for the bulk of our winter. I still like my original numbers which are WinterOutlook
Lynchburg 20-25 inches. Roanoke 25-30 inches, Blacksburg 30-40 inches, Danville 10-20 inches.
Now, there is never a sure thing and somethings can still go wrong. I want to show you the Super Ensemble matching dates for 11 days from now
This is a 500 MB map. Pay no attention.. Look at the dates on the lower right hand side. They "match" 5 day patterns from 11 days out. Those dates are clustered..
2 dates in 1983 where we were 2-3 weeks away from a HUGE snow storm. (but not that close that this pattern mattered)
4 dates in 1998-- 3 are close to 2 big Nor Easters. the first one was a HUGE Mountain snow storm that just missed LYH, and changed to Rain in Roanoke and the second was a near miss, but so close too.
Random 06 date that did nothing.
1978 2 days before a HUGE blizzard to our Northeast.
1958 2 weeks before a BIG snowstorm.
1966-- A day in between 2 storms that dumped a collected 2 feet on our area, 12 or so each event.
Point being, we are entering into a "loaded" pattern that still has a legit shot to verify my outlook snow wise. Temperatures, no way to recover from that +12 last month, but I think we do finish January below normal and likely February too.
With that, you can see how some analogs years LOOKED close with the pattern but did not deliver. 1998 downfall was cold air.. and I looking at the arctic oscillation I think that's not going to be a problem. If a pattern like this holds on long enough, eventually it will deliver something to our region.
Speaking of the arctic oscillation, it looks to drop VERY low and when it does, it tends to drop that low again not soon after. Remember that a POSITIVE AO tends to keep the cold air bottled up in the Arctic Region and the Negative Phase is a "weaker polar vortex" which pushes cold air AWAY from the north pole and down to the middle latitudes where we live. This supports my idea of a nice 20 day run of winter. So, Martin Luther King day and forward, I am expecting my pattern to deliver and there is actually a "chance" middle of next week something brings us a little snow or ice.
Last idea and then I'll let you be. Don't trust anyone who puts "weather" in a Facebook page. Outside of the "news media" there are very few places I would trust. If anyone posts a map of snowfall totals for 2-3 weeks out, my suggesting is to not follow them. ONE run of any model can get you any solution, especially 12 days out. I don't mind questions being asked to me ever.. you all know I love this stuff. However, I want my readers to be educated enough to know that people who post hype are not good follows.
Look, I blew December. I figured there'd be a warm spell. No idea it be a top 2 warmest Christmas week ever and the warmest December on record by 5-6 degrees most areas. Simple didn't see that and even if I did, I'd have tempered it back because that was such a rare event.
The meat of my forecast was Slightly above normal snowfall, centered from Late January till Middle to late February. The "Godzilla" El Nino is making the pattern look different than last year, but in a "sensible weather" (AKA, what you get outside") may not be off that far from last year where we had some colder temps, but the bulk of the snow fell in 2-3 weeks. (Subtract the -10 temp departure and make it -3 to -5 for a 30 day period. )
I still like that Jan 20th ish till Mid February Time frame for the bulk of our winter. I still like my original numbers which are WinterOutlook
Lynchburg 20-25 inches. Roanoke 25-30 inches, Blacksburg 30-40 inches, Danville 10-20 inches.
Now, there is never a sure thing and somethings can still go wrong. I want to show you the Super Ensemble matching dates for 11 days from now
2 dates in 1983 where we were 2-3 weeks away from a HUGE snow storm. (but not that close that this pattern mattered)
4 dates in 1998-- 3 are close to 2 big Nor Easters. the first one was a HUGE Mountain snow storm that just missed LYH, and changed to Rain in Roanoke and the second was a near miss, but so close too.
Random 06 date that did nothing.
1978 2 days before a HUGE blizzard to our Northeast.
1958 2 weeks before a BIG snowstorm.
1966-- A day in between 2 storms that dumped a collected 2 feet on our area, 12 or so each event.
Point being, we are entering into a "loaded" pattern that still has a legit shot to verify my outlook snow wise. Temperatures, no way to recover from that +12 last month, but I think we do finish January below normal and likely February too.
With that, you can see how some analogs years LOOKED close with the pattern but did not deliver. 1998 downfall was cold air.. and I looking at the arctic oscillation I think that's not going to be a problem. If a pattern like this holds on long enough, eventually it will deliver something to our region.
Speaking of the arctic oscillation, it looks to drop VERY low and when it does, it tends to drop that low again not soon after. Remember that a POSITIVE AO tends to keep the cold air bottled up in the Arctic Region and the Negative Phase is a "weaker polar vortex" which pushes cold air AWAY from the north pole and down to the middle latitudes where we live. This supports my idea of a nice 20 day run of winter. So, Martin Luther King day and forward, I am expecting my pattern to deliver and there is actually a "chance" middle of next week something brings us a little snow or ice.
Last idea and then I'll let you be. Don't trust anyone who puts "weather" in a Facebook page. Outside of the "news media" there are very few places I would trust. If anyone posts a map of snowfall totals for 2-3 weeks out, my suggesting is to not follow them. ONE run of any model can get you any solution, especially 12 days out. I don't mind questions being asked to me ever.. you all know I love this stuff. However, I want my readers to be educated enough to know that people who post hype are not good follows.
Thursday, December 24, 2015
Weather for Santa's ride and other medium range outlook.
I've gotten several texts, calls and messages asking why I've not updated. Here is the skinny-- When the weather is boring and warm, I usually won't update. Your local TV guy, app does a decent job telling you to expect 55 and sunny. The blog is dusted off when winter weather is approaching or worth discussing.
Crazy warm today- likely near record level today and a tad cooler but not much cooler Christmas day.
Now, I did expect a warmer than normal December but NOT this warm. We are 8.5 degrees above normal in Lynchburg and 7.9 degrees normal in Roanoke.
When will the pattern change?
We should start to regress back towards normal temps by the New Year. I'm not sure if this is short term 7-10 days or a longer range shift. It's typical for El Nino winters to have second half loaded winters, as mentioned in my winter outlook. There is some reason to "hope" for winter weather in that period.
We are seeing a "disruption" in the force so to speak which should disturb the polar vortex. This should allow for some colder weather by Jan 20th or so as previously discussed in our winter outlook.
Merry Christmas to all!
Crazy warm today- likely near record level today and a tad cooler but not much cooler Christmas day.
Now, I did expect a warmer than normal December but NOT this warm. We are 8.5 degrees above normal in Lynchburg and 7.9 degrees normal in Roanoke.
When will the pattern change?
We should start to regress back towards normal temps by the New Year. I'm not sure if this is short term 7-10 days or a longer range shift. It's typical for El Nino winters to have second half loaded winters, as mentioned in my winter outlook. There is some reason to "hope" for winter weather in that period.
We are seeing a "disruption" in the force so to speak which should disturb the polar vortex. This should allow for some colder weather by Jan 20th or so as previously discussed in our winter outlook.
Merry Christmas to all!
Wednesday, November 4, 2015
Official 2015-2016 Winter Outlook
I'll give you the quick outline of how I think this winter turns out and then do some "splaining" about why and how I got there.
Winter snow totals: Lynchburg 20-25 inches. Roanoke 25-30 inches, Blacksburg 30-40 inches, Danville 10-20 inches.
Month Temps: December Normal to +1, January +2 February -2 to -4
Seasonal Average 0 to +1
Summary :Winter temps slightly above normal, snowfall above normal.
If I use a term and you don't know what it is, GOOGLE it.
Discussion:
The "Godzilla El Nino" as labeled has behaved as expected and it makes for somewhat of challenging forecast. There are honestly quite a few good reasons why going warmer and less snow is not a bad call including the QBO and some calculated risks about what the El Nino will do.
Remember.. Western Based El Nino's are usually colder with more snow, while eastern based tend to be much warmer with less snow. Basin wide events are less frequent and have mixed results. We currently have a basin wide el nino, stronger in the west but not much stronger. The overall belief seems to be that it will trend more west based and then weaken, but not sure exactly when. This is a key factor to a later winter surge of cold and snow.
As a result, hedging on things that we are not certain about is always a risk and needs to be treated that way.
The QBO is measurement of winds in the tropical stratosphere and a negative reading favors high latitude blocking while positive is usually more associated with less blocking. The number is strongly positive currently. On the flip side, certain snap shots of the AO from the summer reflect a likely hood of a negative AO in the winter.
I've mentioned the topic before of Snow cover in Eurasia and it grew quickly in October-- the second best advance on record. This DOES support high latitude blocking. High latitude blocking is associated with longer lasting cold snaps AKA, ways to get cold and keep it cold so we can snow. (-EPO, -AO and or -WPO)
The General feel for winter :
December starts off warm but trends colder later in the month. A week either side of Christmas has a shot at a snow/ice event. The El Nino of 09-10 had a big event December 18th. 02-03 had a Dec 5th event PLUS a big Nor Easter on Christmas Eve/Day (That was north of here, but close enough to consider) 97-98 had a small event on Dec 27 and then 4-8 incher on December 30. 86-87 had a 4-8 inch snow ending as rain in early January.
Early January trends warmer and this will last most of the month. By mid to late month we see the pattern change clearly and we know it's on the way. By late month, we are back in a colder regime and should get 1-2 small to moderate events and ONE big event that helps us reach above normal snow during February.
March - some Data supports some risks for additional snow/cold but I'm going to punt that off and avoid it as of now predicting a benign weather month.
I'm not to jazzed about basing my forecast on the hopes that we get ONE big snowfall to push us above normal. Talking with Kevin Myatt from the Roanoke Times, he cited that El Nino's winters push our likely hood for a 12 + event snowfall from 20% to 40% . I'd like to add that we could end in a near perfect pattern, storm track is a little off or cold air isn't deep enough and we end up with ice rather than snow.
Another factor is that often if we get ONE 10+ event, we see another. 09-10, 86-87 and 65-66 are prime examples of this. So, I could be too low too..
Some clunker winters with El Nino's are : 06-07 but it was east based little snow, one ice event. 91-92, least snowiest winter on record, the Eruption of Mt Pinatubo has been offered as a reason why. 72-73 in many areas to our north had NO snow, but we managed 10 inches down here so not horrible winter here. 41-42 winter had only 5 inches, but if you look at the bigger pattern you'd think we had a snowy winter. 97-98 wasn't horrible here with a few snows east of the appalachians and 2 near misses, one that crushed those west of the Blue Ridge.
Some snow el nino winters: 09-10, big snow in December then a pretty brutal stretch from late January till Mid February. We missed the worst with 20-30 inches in a 10 day stretch but places up from DC to Philly had 40-60 inches in 10 days. 02-03 Pretty cold and snowy all winter, with the BIG event being a sleet storm. 86-87- One snow to rain just after new years then back to back events Late January, a few more events in February. 65-66- one of my favorite winters where from Mid January till early Febryary 40-60 inches fell in a 3 week period.
So, outside of a cold snap and possible snow/ice near Christmas- We wait for the pattern to develop in the second half of winter and should have some decent snow to enjoy. If you recall last winter, we had literally nothing then for 2 weeks it snowed 3 times, including a 6-10 inch snowfall and schools were out the most past of 2 weeks. This winter may reflect that in our "sensible" weather.
If you want my confidence level:
50% we end up within a reasonable range of this forecast.
30% we end up warmer/less snow
20% we wend up colder/ more snow and ice.
I'm using 82-83 as my top analog. We had a December snow, but a warmer month. January was warm and basically snowless, February flipped colder and had a decent event on 6 of 3-6 inches then a NICE storm of 15-20 inches region wide on February 10-11.
Winter snow totals: Lynchburg 20-25 inches. Roanoke 25-30 inches, Blacksburg 30-40 inches, Danville 10-20 inches.
Month Temps: December Normal to +1, January +2 February -2 to -4
Seasonal Average 0 to +1
Summary :Winter temps slightly above normal, snowfall above normal.
If I use a term and you don't know what it is, GOOGLE it.
Discussion:
The "Godzilla El Nino" as labeled has behaved as expected and it makes for somewhat of challenging forecast. There are honestly quite a few good reasons why going warmer and less snow is not a bad call including the QBO and some calculated risks about what the El Nino will do.
Remember.. Western Based El Nino's are usually colder with more snow, while eastern based tend to be much warmer with less snow. Basin wide events are less frequent and have mixed results. We currently have a basin wide el nino, stronger in the west but not much stronger. The overall belief seems to be that it will trend more west based and then weaken, but not sure exactly when. This is a key factor to a later winter surge of cold and snow.
As a result, hedging on things that we are not certain about is always a risk and needs to be treated that way.
The QBO is measurement of winds in the tropical stratosphere and a negative reading favors high latitude blocking while positive is usually more associated with less blocking. The number is strongly positive currently. On the flip side, certain snap shots of the AO from the summer reflect a likely hood of a negative AO in the winter.
I've mentioned the topic before of Snow cover in Eurasia and it grew quickly in October-- the second best advance on record. This DOES support high latitude blocking. High latitude blocking is associated with longer lasting cold snaps AKA, ways to get cold and keep it cold so we can snow. (-EPO, -AO and or -WPO)
The General feel for winter :
December starts off warm but trends colder later in the month. A week either side of Christmas has a shot at a snow/ice event. The El Nino of 09-10 had a big event December 18th. 02-03 had a Dec 5th event PLUS a big Nor Easter on Christmas Eve/Day (That was north of here, but close enough to consider) 97-98 had a small event on Dec 27 and then 4-8 incher on December 30. 86-87 had a 4-8 inch snow ending as rain in early January.
Early January trends warmer and this will last most of the month. By mid to late month we see the pattern change clearly and we know it's on the way. By late month, we are back in a colder regime and should get 1-2 small to moderate events and ONE big event that helps us reach above normal snow during February.
March - some Data supports some risks for additional snow/cold but I'm going to punt that off and avoid it as of now predicting a benign weather month.
I'm not to jazzed about basing my forecast on the hopes that we get ONE big snowfall to push us above normal. Talking with Kevin Myatt from the Roanoke Times, he cited that El Nino's winters push our likely hood for a 12 + event snowfall from 20% to 40% . I'd like to add that we could end in a near perfect pattern, storm track is a little off or cold air isn't deep enough and we end up with ice rather than snow.
Another factor is that often if we get ONE 10+ event, we see another. 09-10, 86-87 and 65-66 are prime examples of this. So, I could be too low too..
Some clunker winters with El Nino's are : 06-07 but it was east based little snow, one ice event. 91-92, least snowiest winter on record, the Eruption of Mt Pinatubo has been offered as a reason why. 72-73 in many areas to our north had NO snow, but we managed 10 inches down here so not horrible winter here. 41-42 winter had only 5 inches, but if you look at the bigger pattern you'd think we had a snowy winter. 97-98 wasn't horrible here with a few snows east of the appalachians and 2 near misses, one that crushed those west of the Blue Ridge.
Some snow el nino winters: 09-10, big snow in December then a pretty brutal stretch from late January till Mid February. We missed the worst with 20-30 inches in a 10 day stretch but places up from DC to Philly had 40-60 inches in 10 days. 02-03 Pretty cold and snowy all winter, with the BIG event being a sleet storm. 86-87- One snow to rain just after new years then back to back events Late January, a few more events in February. 65-66- one of my favorite winters where from Mid January till early Febryary 40-60 inches fell in a 3 week period.
So, outside of a cold snap and possible snow/ice near Christmas- We wait for the pattern to develop in the second half of winter and should have some decent snow to enjoy. If you recall last winter, we had literally nothing then for 2 weeks it snowed 3 times, including a 6-10 inch snowfall and schools were out the most past of 2 weeks. This winter may reflect that in our "sensible" weather.
If you want my confidence level:
50% we end up within a reasonable range of this forecast.
30% we end up warmer/less snow
20% we wend up colder/ more snow and ice.
I'm using 82-83 as my top analog. We had a December snow, but a warmer month. January was warm and basically snowless, February flipped colder and had a decent event on 6 of 3-6 inches then a NICE storm of 15-20 inches region wide on February 10-11.
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