Saturday, December 19, 2009

Updated snow totals from across the region...

Here are some snow totals, updated late Saturday evening:

RIC Airport: 7.0"
City of Richmond (Willow Lawn): 11.5"
Short Pump 14.0"
Glen Allen 14.0"
Chesterfield 9.0"
Ashland 14.0"
Beaverdam 13.0"
Coatesville 12.0"
Lake Louisa: 18.0"
Bumpass 18.0"
Louisa 19.0"
Powhatan 11.0"
Sandy Hook 15.5"
Manakin-Sabot 15.5"
Columbia 15.0"
Crozet 22.0
Stuarts Draft 28.8"
Fishersville 26.0"
Staunton 22.0"
Charlottesville 21.0"
Waynesboro 28.0"
Ruckersville 19.5"
Wintergreen 30.0"
Massanutten 20.5"
Orange 16.0"
Luray 21.0"
Front Royal 21.0"
Chancellorsville 18.5"
Belmont 19.0"
Ruther Glen 18.0"
Bowling Green 15.0"
Studley 12.0"
Warsaw 10.0"
Wakefield 3.0"
Victoria 5.0"
Disputanta 4.5"

Friday, December 18, 2009

One of the biggest all-time December snows in Virginia

The snow is really piling up in many locations tonight, as the monster storm is likely to be historic for parts of the region. While mixed precipitation will inch north and west overnight into the Metro Richmond area, as the storm deepens along the coast, we should go back to all snow tomorrow. Even coastal areas will see a bit of the white snow...and locations west and north of Richmond will be buried! The wind will be an issue as well, sustained at 10-20 mph with higher gusts in Metro Richmond. This will cause considerable blowing and drifting of the snow. Along the coast, sustained winds of 20-30 mph with gusts over 45 mph are possible.

Here's a look at what to expect by tomorrow evening.

Monster storm could bring a memorable December snowfall to the Mid-Atlantic...

Everything is on target for big snow across parts of the Mid-Atlantic tonight through tomorrow night. It will begin as a light mixture of wintry precipitation from south to north over central Virginia and then pick up later tonight. A bit of milder air aloft will be responsible for the mixture. However, to the west and north of Richmond, it should be mainly snow overnight and that's the area that will end up with the highest totals when all is said and done. In the metro area, sleet and snow will be mixed during the early morning hours, but will likely change to snow, which could be heavy at times. Locations east of I-95 and especially south of I-64 towards the coast will have more liquid precipitation and so accumulations will be lower.

The key to precipitation type is a surge of milder air aloft that will cause the mixture of precipitation. How far inland this line moves and sets up will ultimately determine accumulations. There will be a fine line between the mixture and heavy snow, and this line may be very close to Richmond at least through tomorrow morning. Eventually it will shift south and east, causing a change to snow for much of the region. The only exception will probably be coastal areas and extreme southeast Virginia, where they may see a mix or changeover late in the day or at night.

Even with the mixed precipitation early on, I expect a heavy snowfall for much of the Metro Richmond area and places west of I-95 will really see a lot. This event has the potential to be historical here and across the Mid-Atlantic. It's interesting to note the top two December snowfalls on record in Richmond are 17.2" (December 22-23, 1908) and 10.4" (December 12-14, 1917).

Here's what I expect in terms of accumulation:

Metro Richmond to the Tri-Cities: 6-10 inches (higher west, lower east of I-95 and down near the Tri-Cities)
North and West (Short Pump/Goochland/western Hanover west to Charlottesville, north to Fredericksburg and southwest to Farmville): 12 inches or more
Northern Neck/Middle Peninsula: 2-4 inches along the coast, 5-10 inches well inland
Emporia northeast through Wakefield and up to Charles City: 3-6 inches

Thursday, December 17, 2009

Big winter storm to affect the entire region Friday night and Saturday...

LATE NIGHT UPDATE: The evening computer runs are very consistent. The forecast stands with big snows on the way for many. See below...

All of our computer model data is now coming in line with the storm for Saturday. While it will be a big one, we're still not sure on accumulation amounts for the Metro Richmond area and points south and east, due to the fact that there will be a fine line between a mix of wintry precipitation and heavy snow over our area. The key will be a possible surge of milder air aloft as the storm deepens just off the North Carolina & Virginia coasts. It doesn't appear this surge will move very far inland, which means the Metro Richmond area could end up with a lot of snow. However, just a few miles could be the difference between a foot of snow and significantly less.

Regardless, this looks like it will be a memorable snowstorm for central Virignia and much of the Mid-Atlantic. The top two December snowstorms on record in Richmond are 17.2" (December 22-23, 1908) and 10.4" (December 12-14, 1917).

Here's the timeline for the metro area:

Friday night: Precipitation begins during the evening and continues overnight as a mix of wintry weather types
Saturday morning: Mainly snow and sleet
Saturday afternoon: Snow, possibly heavy at times

As colder air gets drawn south and east during Saturday, we should see most places change over to snow. The only exception will likely be right along the coast and extreme southeastern Virginia, although they may get into a wintry mix later in the day.

As for potential accumulations, here are my thoughts:

Metro Richmond down to the Tri-Cities: 6-10 inches, although this all depends on where that fine thin line sets up and as usual, we'll be right near it! 12 inches are certainly a possibility for the western suburbs of Richmond
North and West (Goochland/western Hanover going west and Ashland going north to Fredericksburg): 12 inches +
Northern Neck/Middle Peninsula: 2-4 inches near the coast, 5-10 inches well inland
Wakefield down to Emporia: 3-6 inches

Keep in mind these are potential acccumulations. If mixed precipitation occurs longer than expected, accumulations will be lower. One thing is for sure, I think places west of Richmond will see a very heavy snowfall!

Stay tuned for updates...

Friday, December 4, 2009

A Taste of Wintry Weather Tomorrow...

A cold rain will spread over the region from the south during the wee hours of the morning as low pressure develops along the coast. The rain will continue through much of Saturday, mixing with some snow well west of Interstate 95. As the storm moves north-northeast and pulls away from the area, colder air will continue to take hold. As our temperature profile gets colder, we'll see a changeover to snow from west to east by late afternoon and evening. An upper level disturbance will keep enough moisture over the region to produce some snow during the evening in Metro Richmond and possibly even points east towards the coast. With the relatively warm ground temperatures, I don't expect much accumulation. However, being that it will be nighttime and temperatures will be lowering through the 30s, I think we could see some minor accumulation on grassy surfaces, decks, etc. Road surfaces should remain wet. Well to the north and west of Richmond, from western Goochland and Hanover back to Charlottesville, I wouldn't be surprised to see an inch or two of accumulation, with some local amounts of 3 inches.

The Latest on Saturday...

No real change to the Saturday forecast everyone!

Low pressure develops along the coast and that means a cold rain by early Saturday morning. Temperatures will start out very close to 40 and hover there for a while before slowly lowering through the 30s by late afternoon and evening. Critical values in the atmosphere will be a little too high for snow for most of the day from the I-95 corridor east, but a mixture of rain and wet snow is possible during the afternoon well west of I-95.

As the coastal storm moves north-northeast and begins to pull away from the area, the atmospheric profile will get colder. While often in this situation drier air moves in with the cold, that won't necessarily be the case here. An upper level disturbance will still have to cross from the west and that will leave more available moisture for Saturday evening. It's then that I think we'll have our best shot at some snow in the Metro Richmond area.

With relatively warm ground temperatures, it will be hard to get anything to stick, although since it will be nighttime we may see some light accumulation on grassy surfaces, decks, etc. The roads should not be an issue. Stay tuned for any updates...

Thursday, December 3, 2009

Snow on Saturday?

Another coastal storm will impact the Mid-Atlantic on Saturday. It will be too warm when everything gets going for any snow over much of the region. So right now a cold rain is the call for Saturday morning and afternoon in and around Richmond. There could be a mix of rain and snow well west of Interstate 95, where temperatures and conditions will be more ripe for wintry precipitation.
By later in the day, the storm will begin to pull north-northeast, bringing even colder air into central Virginia. Even though the storm will be moving away from us, there will be a good batch of upper level energy that still has to rotate through from the west, so precipitation chances will continue Saturday night. It's then that I think we could see a swath of snow over much of the region. Since it will be nighttime and temperatures will be lowering through the 30s, accumulation could be a possibility (at least on grassy surfaces, decks, etc.). So stay tuned for further updates!

Wednesday, December 2, 2009

Tornado Watch Until 4 A.M.


A Tornado Watch is in effect until 4 A.M. for much of central and eastern Virginia. Isolated thunderstorms developing over the region could produce strong, damaging winds and a tornado or two.

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