The bad news-- my 4-8 or 3-7 won't work in this. The good news, those who went 4-6, 3-5 won't be right either. Just cheked radar and its winding down REALLY fast.
We may see 1-2 inches, but the snow is SO wet that its melting on the bottom and compacting as fast as it lays. I would not be shocked if the official if we get another half inch or so at best. I've got about .8 of an inch on my official snow board, but its a big pile of slush.
What went wrong--
I expected the rain, some sleet-- but expected much stronger banding on the backside when we changed to snow. We had some nice snows, but even the past hour with .09 of liquid falling, the snow depth didn't really increase at my house. If we had persistent snow bands, the temp cools a little more and the snow piles up faster.
Ideally, I' thought we'd get 3-5 inches in 2-3 hours and while some of the RAIN bands had that much liquid, but not so much when we flipped to snow. Some of the modelling data stated this was possible, as the upper air support nudged a little further north each run.
Still a big ticket event from Harrisonburg to DC up 95 to Boston.
Expect a late night or early AM mid range outlook.
Wednesday, January 26, 2011
Sweating bullets Watching this thing evolve **added link** 3:49--update
Radar looked very promising to me, then start to sink SE rather then move NE-- We have a few hours left of snow, but I'm not seeing the intense banding that I had hoped.
Hoping for 2 inches! (3:49)
Right on time, rain and sleet have switched to snow with NICE flakes...
How we get our 3-7 if its going to happen.
Hoping for 2 inches! (3:49)
Right on time, rain and sleet have switched to snow with NICE flakes...
How we get our 3-7 if its going to happen.
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| Snap shot of radar. |
Link to live radar-- watch this evolve.
Mid day updated **edit**
Sleet mixing in Ferrum to Roanoke to NRV, marching east. Snow not far behind.
No changes to snow totals--- Low side near 460 is 2-3 inches, if switch is early and good banding, 5,6 is possible.
Link to NWS RNK Radar--
http://radar.weather.gov/radar.php?rid=FCX&product=NCR&overlay=11101111&loop=yes
Reports of sleet and thunder in Grenta. Extreme vertical motion changes places to the DUE south of Lynchburg to sleet.
No changes to snow totals--- Low side near 460 is 2-3 inches, if switch is early and good banding, 5,6 is possible.
Link to NWS RNK Radar--
http://radar.weather.gov/radar.php?rid=FCX&product=NCR&overlay=11101111&loop=yes
Reports of sleet and thunder in Grenta. Extreme vertical motion changes places to the DUE south of Lynchburg to sleet.
The Fast and Furious- My final outlook.
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| Simulated radar view-- not often we see YELLOW returns for snowfall. |
Having a first grade daughter, I've been watching the schools close today. Likely a good call because although I expect the snow holds off to between 12 and 2 in Lynchburg, any slight change could make this very bad. I do my best to be objective and not hype-- keep track of me on twitter, facebook or this blog. If your school doesn't cancel, and you have the means, get your child home by 1 PM, get yourself off the roads. 4-5 inches isn't a huge amount of snow but 4-5 inches that falls in 2 hours is a huge deal. That's blinding snowfall rates and the roads will be a MESS. If you can't do that, plan on working late and driving home 7 ish when the road crews have had time to clear things up. I can not stress enough how rough travel will be in that 2pm to 5pm window .If you have friends and family up towards DC to Philly, they are going to get BLITZED with 6-10 inches (local maxes of 12 very possible), most falling in 4-5 hours.
Winds are a little gusty as I type-- coming out the NE at 10 w gusts to 20. Hatteras Light house has winds gusting over 50, inferring the coastal low starting to crank and when the upper air support reaches east of the Appies, this thing really blows up. I've made a new map to show better how this plays out. This is akin to tracking a severe thunderstorm.
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| final call-- Fast and Furious, best snows fall in 2-3 hours. |
Tuesday, January 25, 2011
Late evening trends-- a baby step back.
Watched most of the evening data roll in..
We have a very dynamic system heading our way. My biggest fear all along has been the "north" trend that the models often show. Consider the Dec 18-19 09 event that the models had dumping 2 inches of liquid here in Lynchburg-- all snow, 20 inches. Ended up with 14.5 here at the house-- about 75% of the total possible. The models in the last second jogged something called the 700mb a little to close. If you've heard the term dry slot-- it basically is a place in the development of a low that a wedge of dry air works up. We never got into the dry slot, but sat close enough to turn hours of HEAVY snow into hours of LIGHT snow.
My point-- some data is pulling the 500mb low just a little too close. This is the catalyst, the gasoline that makes our system go. There is a physical connection between the exact tract of this feature and the snow bands that will develop. The more north this 500mb low travels, the shorter time we spent in these bands. The less time, the less snow that falls.
My original call was 4-8. Since I jumped on that number early, I am completely OK with being graded on that amount. If I had waited, I'd likely thrown out 3-7 for the regions marked 4-8-- based on the data today.
SOME data shows 2-3 inches, with a shot at 5-6 depending where the banding sets up.
My point-- grade me on the 4-8. meaning if the official totals from LYH and ROA are 4, its a win. I'd lean towards 3-7 being the range at this point, the 7 being in the places where the best bands set up.
If you are wondering why I can't say exactly where-- these are like a thunderstorm. One can pinpoint a region where these set up, but not an exact location. Random example-- Roanoke gets 3, Bedford 5, Forest 4, Evington 5, Concord 7, Spout Sprints 3.
Best snows fall between 1 and 5 PM..
Grade me on the 4-8, now expect 3-7.
We have a very dynamic system heading our way. My biggest fear all along has been the "north" trend that the models often show. Consider the Dec 18-19 09 event that the models had dumping 2 inches of liquid here in Lynchburg-- all snow, 20 inches. Ended up with 14.5 here at the house-- about 75% of the total possible. The models in the last second jogged something called the 700mb a little to close. If you've heard the term dry slot-- it basically is a place in the development of a low that a wedge of dry air works up. We never got into the dry slot, but sat close enough to turn hours of HEAVY snow into hours of LIGHT snow.
My point-- some data is pulling the 500mb low just a little too close. This is the catalyst, the gasoline that makes our system go. There is a physical connection between the exact tract of this feature and the snow bands that will develop. The more north this 500mb low travels, the shorter time we spent in these bands. The less time, the less snow that falls.
My original call was 4-8. Since I jumped on that number early, I am completely OK with being graded on that amount. If I had waited, I'd likely thrown out 3-7 for the regions marked 4-8-- based on the data today.
SOME data shows 2-3 inches, with a shot at 5-6 depending where the banding sets up.
My point-- grade me on the 4-8. meaning if the official totals from LYH and ROA are 4, its a win. I'd lean towards 3-7 being the range at this point, the 7 being in the places where the best bands set up.
If you are wondering why I can't say exactly where-- these are like a thunderstorm. One can pinpoint a region where these set up, but not an exact location. Random example-- Roanoke gets 3, Bedford 5, Forest 4, Evington 5, Concord 7, Spout Sprints 3.
Best snows fall between 1 and 5 PM..
Grade me on the 4-8, now expect 3-7.
Because you're mine, I walk the line-- Mid day update.
Noon data is about done-- except the ECMWF
Some of the data infers that the snow is all but done at 7PM and our best snows fall between 1 and 5 PM-- a little quicker compared to before.
There's quite a bit that could go wrong, but so much about this event looks great.
What can go wrong--
1. Temps are borderline-- will start as a mix or rain and change over. Any delay kills the forecast 4-8 inches.
2. The pieces in motion are not set in stone, any deviation can change a forecast. One concern is the upper air support nudges just a little too far north and spares our region the best snows.
3. The overall storm will be moving fast. I've made some assumptions that it snows hard for 4 hours give or take. If the development is SLIGHTLY delayed, we have issues.
4. Some of the model data races the precip out of the MNTS area pretty quickly leaving the Mt. Empire and NRV on the lower side of accumulations.
The good--
1. The models all have about the general same idea-- the fine details is what makes this a 2-3 inch event or 6-8 inch event.
2. The model ideas are slowly clustering towards a general track.
3. Dynamics-- strong upper air low. History tells me this blows up early and not later. Thundersnow is likely some places, especially to our North.
My early AM map stands-- any changes would likely be to adjust the NRV if needed and "MAYBE" a little better detailed for the southside areas. Trace to 4 inches is broad. (But, I don't think I have any readers down there anyways.)
Some of the data infers that the snow is all but done at 7PM and our best snows fall between 1 and 5 PM-- a little quicker compared to before.
There's quite a bit that could go wrong, but so much about this event looks great.
What can go wrong--
1. Temps are borderline-- will start as a mix or rain and change over. Any delay kills the forecast 4-8 inches.
2. The pieces in motion are not set in stone, any deviation can change a forecast. One concern is the upper air support nudges just a little too far north and spares our region the best snows.
3. The overall storm will be moving fast. I've made some assumptions that it snows hard for 4 hours give or take. If the development is SLIGHTLY delayed, we have issues.
4. Some of the model data races the precip out of the MNTS area pretty quickly leaving the Mt. Empire and NRV on the lower side of accumulations.
The good--
1. The models all have about the general same idea-- the fine details is what makes this a 2-3 inch event or 6-8 inch event.
2. The model ideas are slowly clustering towards a general track.
3. Dynamics-- strong upper air low. History tells me this blows up early and not later. Thundersnow is likely some places, especially to our North.
My early AM map stands-- any changes would likely be to adjust the NRV if needed and "MAYBE" a little better detailed for the southside areas. Trace to 4 inches is broad. (But, I don't think I have any readers down there anyways.)
No Basic Changes--yet?? Winter Storm Watches issues for the Blue Ridge West.
Most of you know I'm a guy who always loved weather-- even took a couple years online classes in the early 00's and do this "tracking and forecasting" all winter. I'm usually tempered with calls and yesterday and I pushed the BIG BUTTON a little early. I was hoping the model data would increase my confidence but reality is it dropped somewhat.
The basis of this was model support was growing for that solution with some adjustments made on climatology and past behavior of systems like this. Last nights model runs where ALL over the place-- most give a minimal of 2-3 inches and some get closer to the 8.
In a set up like this, the exact track of the upper air support ( the tv guys often show a little swirl in the clouds away from the surface low) will make all the difference. Also, often its possible SOME areas verify in the 4-8 ranges while others fall short. During the March 09 storm-- Most of the Lynchburg region had 8-12 inches while 15 miles away in Big Island had only 3 inches.
The basis of this was model support was growing for that solution with some adjustments made on climatology and past behavior of systems like this. Last nights model runs where ALL over the place-- most give a minimal of 2-3 inches and some get closer to the 8.
In a set up like this, the exact track of the upper air support ( the tv guys often show a little swirl in the clouds away from the surface low) will make all the difference. Also, often its possible SOME areas verify in the 4-8 ranges while others fall short. During the March 09 storm-- Most of the Lynchburg region had 8-12 inches while 15 miles away in Big Island had only 3 inches.
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| No major changes today-- Final call after tonights model data. |
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