If there was an actual "snow meter" I'd have to raise it to 6.5

Two models, the GFS and ECMWF have had subtle shifts in the past 2 days-- one shifted east, one shifted west, both had a weaker storm. It seems like SLOWLY they are coming to an agreement.

It not locked in-- but late Friday evening rain should develop and once it becomes heavy it will mix with or change to snow. High elevations are at the best chances to see SOME accumulations but I'd not be shocked it even close to Lynchburg sees a coating. These storms are tough as it involves upper air energy diving our way and spawning a storm that forms JUST far enough south to throw back moisture into our region. While it's cold enough aloft- 3k feet down as modeled is just above freezing.

This could be a pretty damaging storm to trees up towards Wintergreen, Afton Mt and other places NE along the Blue Ridge Parkway.

If your nose has been twitching-- Could it be "snow" has been mentioned MAYBE in our region??

October snows are rare-- but no unheard of. Oct 1979 had a rather large event that dumped 2.5 inches in Lynchburg as heavy rain changed to heavy snow. Parts of the Blue Ridge- Skyline drive had upwards of a foot or more in that event- Drastic change as the temps near midnight were 53 degrees and 9 hours later we had heavy snow falling-- in OCTOBER.


We currently have a strong short wave ( upper air energy) diving in from the MN region and it spans a storm that spins up and on some modeled data shows rain changing to snow for our area. (Not ALL areas-- seems to be mainly rain S and E of Lynchburg). Time frame on this event is Friday night into Saturday AM.

Here are a couple snow maps-- the first is made by the GFS and shows a strip of snow along and east of the Blue Ridge-- 1-2 inches.
Next, the ECMWF has the storm more amplified and the snow is MAINLY to our north, but-- its a ton of it!

Wild stuff!

I'd guess that there is some type of "abnormal" even happening, but I'm not convinced we see here. Hot Springs has a good shot, up into the Mts of WV, PA and NE from there- if anything changes, I will certainly update.

Winter Sneak Peak

I'm not ready to fully commit to a winter outlook-- so, let's consider this my preseason outlook. I'll lock and load it in by Nov 10th or so as there is a little more data that I'd like to see before a final outlook.

This will be the 3rd winter I've made a public outlook-

09-10 was pretty cold- called for 30-45 inches of snow region wide, colder then normal and targeted the end of Jan/ Feb as the BIGGEST snow threats. 

LINK to the forecast

https://www.facebook.com/note.php?note_id=174886414694

Good outlook, A grade IMHO

10-11

Went cold December-cold breaks in January, 5-10 inches of snow for the winter.

Good call, not cold enough but it's foolish to go -9 or whatever the mean December and broke the cold to early. Part of the cold hanging on longer was a spike in the PNA (PNA= ridging or trough on west coast--ridging on west coast translates to trough on the east coast-- troughs are characterized by colder and stormier in general terms.)

Good outlook, I'd put in in the B+ range. 

http://lynchburgweather.blogspot.com/2010/11/winter-outlook-2010-2011.html

Winter 2011-2012

We are in a second year La Nina that is in the weak to moderate range. 

La Nina's in general feature colder then normal Decembers that warm once we move into January and usually have  mild February in our region. This happens because the mean trough shifts west and get riding along the SE coast. 

Why I'm not 100% locked in yet--

1. Something called the QBO or

 Quasi-Biennial zonal wind Oscillation

  -- we have a tendency to see more high latitude blocking. High latitude blocking. This blocking helps keeps cold air on our region. The QBO has dropped to just below positive and I'd like to see a stronger drop when the October data comes out. Further, we have a a split QBO where the 30 MB is negative but the 50 MB is positive. 

When the QBO runs negative (based on wind direction WAYYY up in the sky which was discoved in 1883 when Volcano Krakatau erupted and the ash circled the globe in 15 days on strong westerlies at this level and further research developed from there)

2. Recent tendencies of Artic Oscillation and North Atlantic Oscillation to run negative.- This links the first point-- this is the high latitude blocking I was talking about. 

3. Solar flares-- reading some research on this and they've some what established a lag time between low solar flares and impact on global weather patterns. I'm still chewing on this one in my hierarchy  of impact- this impacts the amount of blocking as well. 

This summary- our entire winter depends on how much high latitude blocking we get. If we lack the blocking-- it's going to be a warm winter. Conversely, if the blocking is stronger, more dominant we could be colder/more stormy as the mean storm track slides east putting us in the colder, stormier pattern. 

Early Thoughts--

I like the idea of a colder pattern developing late November and lasting 3 weeks into December. Pattern relaxes into mid January and the block emerges again Mid month to early February. Pattern relaxes again with another "possible" block 2nd week of March to the end of the month. 

So, starting Dec 1-- Cold 3 weeks, warmer 3-4 weeks, cold 3 weeks-- warmer/relaxed 3-4 weeks, colder march 10th or so but that's all relative to seasonal averages when you get into March. 

Snowfall-- this is what people care about most, yet has the highest element of luck as you can't really time short waves. 

La Nina's tend to low on sub tropical jet - think of those big snows in 09-10 where the tv guys showed this STRONG wave that came from the equator. So, we are dependent on the northern (polar jet) to provide storms. Unless we get strong blocking, we won't get a HUGE storm. 

Can we get a huge storm-- Yes! The polar jet gets forces south and becomes a part of the subtropical get provided the short wave (spin the weather men like to show on sat. shots)  If we DON'T get that via timing or other issues the "colder events" will be light on the precipitation, like .25 of an inch to maybe .75. Issues with the strorm track will always have mixing as a risk. I'm leaning we can see a 4-8 region wide snowfall-- good event, not historic or memorable and a bunch of 1-4 inch mix messes. (More in those events in the Mts to our west) Good risk of an I 81 special where the heaviest snows(BIG EVENT) run up 81 and tails of quickly east of there due to mixing/rain. 

The cold snaps will have a bit to them and the warm breaks will seem GREAT comparatively speaking. - Snowfall total ideas-- I like a pronounced gradient from NW to SE where I can see Harrisonburg and Staunton being a good bit about normal, Blacksburg and Roanoke very close to normal, Lynchburg slightly below normal and Danville to Richmond below normal. This is caused by a storm track that approaches from the west/Soutwest and the low ends up in eastern TN or SW West Virginia and jumps to the coast east of Virgina Beach or even the Delmarva/ NJ. The snow is usually slower to slide east and the mountains due to dry air and the Mt regions have snow for HOURS before even Lynchburg does. Once the moisture gets in the air is warming aloft and while Blacksburg/Staunton have already had 4-5 inches, Lynchburg gets a quick inch and it changes to sleet/freezing rain. Danville gets some sleet and freezing rain that changes to rain. 

Expect a final call with more exact data, comparable years by November 10th. 

Winter Outlooks are trickling in--

Keith Allan is a "Professional Forecaster" from the DC region-- His outlooks at time have held "heavyweight" status to those who read and follow him. I'm going to share the forecast for this year plus some raw data from what he did in years past. I have a resource who has his forecasts all the way back to the 80's. I'd define his finest moment as the legendary winter of 1995-1996 where he called for 45 inches of snow in DC for the winter and there was 46.2.

His forecast is DC centeric, but I do read it and extrapolate what that should mean down in our region.

Snowfall for DCA:20-24".

December:+1
January:+2
February:-3

** Even though it's a math 0.0 he says the 2 out of 3 months being above average gives it a mild lean.

He thinks a 4"+ snow event in mid December, then quite mild until very late January and then turning very cold. He thinks a 6" to possibly 12" event will occur in February and well below average temps. He believes the cold will continue well into March. Even with a mild January he thinks there will be 1-2 freezing rain/sleet events for DC area.

Analogs:1946-47, 1966-67, 2006-07.


From Keith--


I'll let you grade him on his own merits once the winter ends. Longer range forecasting is some skill and some luck. With that, I'm hedging the first half of winter is "colder/snowier and the second half is milder/drier. 


His past years--
ACTUAL NUMBERS IN PARENS

2001-02

DEC: +2 (+6.0)
JAN: -2 (+6.7)
FEB: +3 (+4.5)

Overall: +1 (+5.7)


DCA SNOW: 10" (3.2")


2002-03

DEC: +0.5(-2.3)
JAN: -1(-3.8)
FEB: -3(-4.4)

Overall: -1.2(-3.5)

DCA snow: 20-25"(40.4")


2003-04

DEC: +1(-0.3)
JAN: -0.5(-4.3)
FEB: +2(+0.1)

Overall: +0.8(-1.5)

DCA snow: 12-14"(12.4")


2004-05

DEC: +2 to +3(+0.6)
JAN: +2(+1.2)
FEB: -2(+1.5)

Overall: +0.7 to +1(+1.1)

DCA snow: 14"(12.5")

2005-06

DEC: -1 to -2(-3.1)
JAN: -1 to -2(+8.2)
FEB: +3(+0.5)

Overall: -0.33 to +0.33, but call for slightly below normal(+1.9)

DCA snow: 25"(13.6")

2006-07

DEC: +2 to +4(+4.7)
JAN: +2 to+4(+5.8)
FEB: +2 to +4(-7.2)

Overall: +2 to +4(+1.1)

DCA Snow: 8" (9.5")

2007-08

DEC: +2 to +4 (+2.3)
JAN: +2 to +4 (+5.1)
FEB: +2 to +4 (+2.9)

Overall: +2 to +4 (+3.4)

DCA Snow: 10" (4.9")

2008-09

DEC:-1.0 (+0.8)
JAN:+1.0 (-3.3)
FEB:-2.0 (+1.7)

Overall: -0.67 (-0.3)

DCA Snow: 25" (7.5")

2009-10

Dec: +3 to +4 (-1.6)
Jan: +0.5 to +1.0 (+0.4)
Feb +3.0 or higher (-3.9)

Overall: +2 to +3 (-1.7)

DCA snow: 10-12" (56.1")

2010-11

Dec:-1 (-4.9)
Jan:+1 (-1.2)
Feb:-2 (+3.7)
Average:-0.67 (-0.8)

Snowfall DCA:20-24" (10.1") 


Some people just read patterns better-- he's never revealed the method to his madness, but ENSO isn't a HUGE factor as shown by many years. 




For our region--


06-07 was warm till Feb and once it got cold, the storms still tracked will to our north. We had one minor sleet storm, one 3 inch snowfall and ONE ice storm. 


66-67 was a good winter snow wise-- with a MAJOR snowfall region wide on Christmas eve-- 6+ inches in the NRV and Roanoke and over 10 inches in the LYH region. Over 30 inches of snow fell that winter, with + falling in December. 


46-47 was a a snow winter with almost 30 inches region wide. We had three 8 inch snowfalls in late Feb lasting into the end of March. 3 separate snowfalls of 8 inches. 


Take it for what it's worth-- 


My outlook should be out by mid November at the latest. 

Home from Hampton

I drove up to Hampton Roads region to "enjoy" the storm. A good friend from college lives up there with his wife and daughter and they "sponsored" me by letting me sleep at their home. The storm was rather large with the impact felt far from the center-- our worst conditions were actually late AM Saturday vs late evening with the EYE was only 50 miles or so to our east.

Wide reach-- wide damage. I've never heard a good reason why they keep it as a hurricane as long as they do when NO surface obs show hurricane strength winds. (I'm sure there were some over SE VA, but that's about all) Not to downplay this storm, it dealt a huge blow to many, but not many observations outside show hurricane winds.

Here are a couple videos-- They are set to public, but I can embed them for some reason.

http://www.facebook.com/video/video.php?v=10150358106272059


http://www.facebook.com/video/video.php?v=10150358110137059&comments

All systems go to "Rock you like a Hurricane"

Just heard this song on a lead in on a radio show-- haven't had something that "tacky" since the Tampa Bay Buccaneers cheer team did a dance to it while playing the New Orleans Saints 2 weeks after Katrina devastated the Gulf Coast. Having said that-- being a weather fan, I do like this song. 

The storm track seems to be set in mud-- I don't think there is much to shift it WEST. Showers may reach Lynchburg, HIGH doubt anything reach Roanoke. You may notice a breeze, but nothing out the norm. 

Landfall will be someplace between Moorehead City and Cape Hatteras. It should be close to or just on the coastline heading towards NYC-- so for all those in points in between, it's going to a rough 24 hours. Regions closest the shore/water will have the worst winds. Rains will be 5-10 inches for those nearest to the track. It's been rather wet from the Philly region north, so even wind gusts of 50 MPH could cause some bad tree damage. 

Quick update later-- I'm possible heading to the Hampton Road area for some "Hurricane Chasing"

Early AM Irene thoughts

I was tempted the last few days to start writing about Irene, but the model data became LESS ominous for region. While I am rather interested, my interest was NOT quite enough blog. There's been a slight jog west and it's going to be a HIGH impact event EAST of 95 in Virginia. 

Brief review-


It was rather clear Irene would form and have a good threat to make landfall on the USA. Most of the model data tried at one point or another to pull it into the Gulf of Mexico. Looking at the overall set up, it was clear this was not an option. Model data began to shift east and I really thought that the Myrtle Beach area would be in the landfall region. My personal error was assuming that the east shift on the model would stop. That is NEVER a safe or good assumption to have. The models had trended at one point just about was a total whiff for the NC region (Landfall wise, not impact)

For those who wonder WHY the models struggle with these fine details. Short waves, (energy aloft) approaching the US Pacific NW were hard to gauge along with their potential impact. It's hard to quantify an impact when you don't have a good gauge on the strength. Secondly, there is a ridge to east of the US. (I think most heard the term Bermuda Heat Ridge before) The model data was a tad to strong ( Strength= HEIGHT-- ridge was not as big as anticipated) For people who like to "blame" weather man for NOT being accurate-- this is like trying to be an accountant and neither given all the receipts or all the incoming payments. You simply can estimate, but won't be "accurate".

The NWS has added extra " information" into the computer models by way of extra drops into sky over the east coast and Montana to fill those gaps. This has lead to better sampling and a slight shift WEST.

Where is she going?


When the model data was making landfall near Charleston, SC-- that would have been a big ticket item for our region.(Lynchburg/Roanoke) We would have had near Tropical Storm force winds and rains of 3-6 inches region wide. As it moved to a landfall near Hattaras, we'd be breezy, maybe a shower east of the Blue Ridge. As the data has maybe shifted west, places east of the Blue Ridge MAY are getting close to a more substantial rainfall event (Maybe 1-3 inches and a tad more windy/breezy)

Landfall will be somewhere between Wilmington NC and Cape Hatteras as a Cat 3-- I expect it to peak as a cat 4 sometime today. Still a pretty wide spread on landfall but that should become more clear later today.  From there it heads N and depending on the interaction with a shortwave from the W it will move NE, N or maybe just west of N for a while. Any place east of Richmond along the 95 corridor will have SOME to MAJOR impact. Coastal regions will have the greatest impact-- for obvious reasons.

It should hold together hurricane strength winds for a LONG while after landfall-- especially in coastal regions where there is less friction from the land.

This is the ECMWF run-- it's the most left landfall and brings landfall near Moorehead City, NC.

The furthest west option currently on the table-- brings the rain VERY close to the Blue Ridge.  Any further west jog brings more substantial rain to our region. 

This is a 500mb (18000 ft or so) map in motion. It shows a short wave diving
in from the NW and pushing IRENE just west of due north. This is the furthest
west of ANY other guidance currently. Click on this image to see it in motion.

My current thoughts would say that landfall is just east of this depicted model and the worst of the conditions stay Richmond east. Lynchburg may see a half inch of rain from showers, Farmville maybe 1-2 inches and much worse conditions Richmond east. Hampton Roads/VAB gets Hurricane conditions.

 My friends and family up in Delaware/Philly region=

Expect a pretty nasty event- Flooding rains along the lines of 5-10 inches. Winds inland will be sustained at 50, gusts to hurricane force and coastal regions (Near my Mom's in Rehobeth Beach) winds will be sustained at hurricane force, gusting to maybe 100mph. 

Model data should continue to improve today as we get that extra information added- will update later this evening. 

Link to the National Hurricane Center's website-- has some cool maps estimating winds, etc. 

http://www.nhc.noaa.gov/