Wednesday, January 30, 2008

Briefly cooler...nice weekend on the way...

We've got a chilly night in store, with very dry air settling over Virginia. Dew points are in the single digits and I expect low temperatures in the teens and lower 20s over much of the area. With this dry air in place, there will be plenty of sunshine tomorrow. However, clouds will be on the increase during the afternoon...as the next storm tracks into the Ohio Valley. This storm will bring significant snow to parts of the Midwest and Lower Great Lakes/Upstate NY over the next several days. Here, moisture will be on the increase and we should see some decent rain on Friday.

Still looks like a great weekend...

High pressure is still scheduled to arrive in time for the weekend...so expect plenty of sunshine and temperatures well above average Saturday and Sunday (mid to upper 50s for highs). The warmer weather will linger into the early and middle part of next week.

Down the road...

The next storm is still on target for Feb. 5/6, with the track north of us again. The associated cold front will cool us down a bit, with a secondary surge front bringing the main surge over the following weekend (Feb. 9/10). However, honestly the pattern isn't really showing any sustained cold air over us...so this may be another one of our brief shots of cold air we've received this winter. This isn't unsual for a La Nina winter. We shall see if the second half of February brings any more true winter weather.

Tuesday, January 29, 2008

Gusty breezes...more rain on Friday

After a mild Tuesday, a cold front bringing showers will then usher in slightly cooler air for the middle of the week...with some very gusty west-northwest breezes. The wind in the morning could be 15-25 mph sustained, then diminishing a bit by evening. Thursday will be a quiet but seasonably cool day with temperatures in the 40s. Clouds will be on the increase as our next developing system comes our way. This storm will track well to our north and west, potentially bringing significant snow to parts of the Midwest and Lower Great Lakes. We'll see some rain on Friday, with the heaviest precipitation likely to be north and west of us.

A nice weekend in the wake of the storm...

High pressure will build over the Mid-Atlantic behind this storm and the upper flow should be conducive to rather mild air. We should see temperatures well into the 50s each afternoon Saturdya through Monday, and I wouldn't be surprised if we jump into the 60s. The next rain chances will come by mid-week.

Longer range...

No changes today in the longer range data. I still don't see the very cold air up north plunging south all that quickly, but more gradually. The main system to drag it south will likely impact us on Feb. 9th. It does look like we'll be somewhat colder the week of Feb. 11th, but how long that cold spell will last is rather uncertain at this point.

Monday, January 28, 2008

A milder week...

This week will certainly be milder across the region, with most days featuring temperatures of 50+ in the afternoon. In the near term, a cold front approaching the area will bring a round of showers Tuesday evening through early Wednesday morning. Behind this front, gusty breezes will usher in a brief shot of cooler air on Thursday.

End of the week rain, then a nice weekend...

Another storm will affect the Mid-Atlantic on Friday. Its track will be north and west of us, which will help to usher in milder air again from the south. Rain will overspread the region on Friday, but be gone in time for the upcoming weekend...which looks rather nice, with ample sunshine and afternoon temperatures in the pleasant 50s. A mild start to February...

The longer range...any colder weather?

Down the road, the longer range computer models show another system impacting us on February 5th/6th, with somewhat colder air behind it. The cold looks like it may gradually return over the weekend of the 9th and 10th, but it certainly doesn't come in full force. The GFS model shows a close call with a coastal system on the 9th...something to certainly keep an eye on in the days to come. There is a core of very cold air building to the north over Canada and eventually that will probably slide south...so it could be a much colder second half of February. As always, stay tuned...

Tuesday, January 22, 2008

A little light rain, as the cold eases...

The cold will ease a bit today, with a system arriving from the west. The model data shows pretty light amounts and a temperature profile just warm enough for rain in Richmond. I've heard reports around town about precipitation during the morning commute...and I don't buy it...it's just a bunch of hype. The air is just too dry. However, it will saturate pretty quickly, and by afternoon we'll have some rain in Richmond. To the west and north of town, the precipitation could begin a bit earlier...and that's where the threat is for some light freezing rain, sleet and even snowflakes. We're talking a line from Caroline/western Hanover down through western Goochland and points west and north...again NOT the immediate metro area. If you're travelling west towards Charlottesville or north of Ashland towards Fredericksburg, it's possible a few roads could be slippery.

A bit more chill to finish the week...

More cold air should dominate the rest of this week. Daytime temperatures may stay in the 30s on Thursday with an upper trough swinging on through. I wouldn't even rule out a passing flurry or two. Temperatures at night will dip down into the teens both Thursday and Friday nights.

A few more systems down the road, but...

There are a few more systems showing up on our long range models, and while there could brief shots of cold air behind each, I don't see any strong push of Arctic air or any sustained cold air mass until at least the end of the first week in February. So look for a seasonable chill or even temperatures above average (highs in the mid 40s this time of the year). Dates to watch for these storms are Jan. 30/31, Feb. 3 and Feb. 6. Stay tuned...

Saturday, January 19, 2008

What to expect...

Saturday midday update:

The precipitation is on schedule and the situation hasn't changed much over the last 12 hours. The model solutions continue to show the track well south and east of Metro Richmond. There is still a QPF of about .15"-.20" and the NAM has actually come in line with the GFS on this. The one problem is somewhat warm boundary layer temperatures at the start of the event. Despite many critical temperatures aloft and thicknesses being low enough to support snow, the warmer boundary layer will cause rain or a mix to fall at the start. Eventually everyone should go over to snow, but this will hold down potential accumulation. I still expect a coating to an inch in the Metro Richmond area down toward the Tri-Cities and east to New Kent County. Counties north and west will see little if anything. The focus remains well south and east, where 1-3 inches are possible in a line from Williamsburg to Emporia. There could be a bit more in the interior of extreme southeastern Virginia.

Storm update...early Saturday morning...

The newest model runs are finishing up now and the trend clearly continues to push everything south and east of Richmond. The NAM model has virtually taken all of the precipitation out of the metro, while the GFS has .15"-.20" liquid. Normally with such a dramatic shift in the NAM, I would be inclined to toss it out, BUT it has come around to the European solution that has been consistent for many runs now. The European tends to be a superior performer when it comes to winter events along the East Coast and it looks like this case may be no exception.

What to expect...

Come Saturday afternoon/evening, I do expect some light snow or flurries in the Metro Richmond area. Accumulation of a dusting to an inch is possible. North and west of Richmond, you'll be lucky to see flurries...more as a result of the push of Arctic air arriving than the storm moving well off the coast. The area to watch remains well south and east of Richmond. In a line from Williamsburg to Emporia and points south and east, a couple of inches could accumulate by late Saturday night/early Sunday morning. Coastal areas in Hampton Roads will have a mix of rain and snow, eventually changing to snow with some accumulation.

Friday, January 18, 2008

Late afternoon update...

The new NAM run is in and it continues to trend toward the European solution...a track farther south and east. It leaves Metro Richmond with very little precipitation...so the call here will likely be an inch or less of snow. Counties north and west would see nothing more than flurries (if that), as the Arctic air enters the state. The main focus will be counties well south and east of Richmond, from Williamsburg to Emporia and out to Hampton Roads. It may be too warm to snow in this region when precipitation starts...but any rain should change to snow and there is the potential for a couple of inches. But again...the Richmond area/Tri-Cities probably will just get some light snow or snow showers amounting to less than an inch. More updates as new data arrives...

Friday midday update...

The latest model solutions are trending a bit south and east with the storm track. This is especially true of the NAM, which is inching toward the European solution...but not quite as far off the coast. Often when the NAM starts trending toward the European, it can be a good indicator of what might happen. So what does this mean for potential snowfall in Virginia? The highest amounts will be where the deeper moisture tracks, likely across southern Virginia. In the Metro Richmond area, earlier model runs put us at about .25" liquid...now it's down to around .15"-.20". So while a 2-4 inch snowfall certainly isn't out of the question, the trend would suggest less...maybe 1-3 inches. There may be a pretty sharp cut-off between little to no accumulation...to significant accumulation. I'll have an update this evening, when I will try to pinpoint forecast amounts over the region.

Snow looks likely Saturday afternoon/evening...

All the signs continue to point toward snow over central Virginia tomorrow afternoon and evening. Low pressure developing in the northern Gulf will track up along the coast and be just off the NC coast Saturday evening. This should spread moisture over our area during the afternoon. Colder, Arctic air will be oozing in from the west and the meeting of the two will trigger the development of snow. Then the question is how much? All of the model solutions are converging on a track off the coast, but they differ a bit in the amount of moisture that is thrown back into our area. In general, the consensus is for slightly more than .25" of liquid, which could equate to a 2-4 inch snowfall. The exact track of the storm will determine whether we get more or less. The European model has shown a track farther east for the past few runs. That is concerning for snow lovers, as it would mean much less precipitation. But the fact there is general consensus amongst most of the model suite has me thinking we'll see at least some accumulating snow. An update coming later today, when we should have a better idea on potential amounts...

Thursday, January 17, 2008

Storm reports...and the potential Saturday system

Here are some snow/sleet accumulation totals from around the region:

Metro Richmond/Short Pump 0.5"-1.0"
Ruther Glen (Caroline) 2.0" (some ice on top)
Coatesville (Hanover) 1.0"
Locust Grove (Orange) 3.0"
Stafford 2.0" (ice on top)
Spotsylvania 2.5" (ice on top)
Northumberland 1.0"
Charlottesville 4.3"
Harrisonburg 5.0"

Thanks to John Wheeler, Patsy Colley, Rick Rice and Skip Bond for their updates!

Except for areas well north and west of Richmond, we'll see a bit more rain into the evening before it tapers off. All eyes will turn to Saturday afternoon/evening, when another storm tries to ride up the East Coast. This could potentially lead to more snow. The model data continues to struggle with this system, with the NAM model showing a whopper of an event for us, while the other popular American model, the GFS, takes the system farther east resulting in lighter preciptation for us. The overall pattern is rather complicated, as the Arctic air will be nosing in from the west/northwest and as always, the timing will be key. Energy around an upper trough to the west will need to buckle the flow a bit to bring the storm into Virginia. Otherwise it will get shoved out to our south and east. There are so many questions right now, and I'll try to sort it out a bit more in a post later this evening.

Storm update...

No real changes here. All is going according to plan with a transition to rain in most places. A good burst of snow early on brought accumulation over much of the metro. Here's a review of the details:

Metro Richmond

* Around an inch accumulation, mainly on grassy surfaces
* Rain this afternoon

Counties north and west (Goochland/Hanover/Powhatan/Amelia/Cumberland/Louisa)

* Snow and sleet accumulation of 1"-3"
* Some icing possible from sleet/freezing rain
* A transition to rain during the afternoon

Tri-Cities/Middle Peninsula

* Little if any accumulation
* Mainly rain

Northern Neck

* Up to 1" accumulation inland away from the coast, otherwise little if anything
* Rain everywhere this afternoon

Farmville/Crewe

* Snow and sleet accumulation of 1"-2"
* Some icing possible before transition to rain

South Hill

* Rain this afternoon

Charlottesville

* Snow accumulation of 2"-4"
* Icing from sleet and freezing rain afterwards
* There may not be a complete transition to rain

Fredericksburg

* Snow and sleet accumulation of 1"-3"
* Some icing possible with a transition to rain this afternoon

Wednesday, January 16, 2008

What to expect in your neighborhood...

I expect snow and sleet to fall across much of the region Thursday morning, eventually changing to rain in most places as milder air surges in aloft and at the surface. Here's what we can expect:

Metro Richmond

* Snow and sleet developing between 8 A.M. and 10 A.M.
* Some accumulation possible, especially on grassy surfaces
* A change to rain by early afternoon

Counties north and west (Goochland/Hanover/Powhatan/Amelia/Cumberland/Louisa)

* Snow develops between 8 A.M. and 10 A.M.
* Accumulation of 1 to 3 inches
* A change to rain by the mid-afternoon (around 3 P.M.)

Tri-Cities/Middle Peninsula

* A mix of snow, sleet and rain developing during the morning (by 8 A.M. in the Tri-Cities, before 10 A.M. on the Middle Peninsula)
* Little if any accumulation
* A quick changeover to rain

Northern Neck

* A mix of snow, sleet and rain developing between 9 A.M. and 11 A.M.
* Up to 1" possible, mainly away from the coast
* A changeover to rain by early afternoon

Farmville/Crewe/South Hill

* A mix of snow and sleet developing between 6 A.M. and 8 A.M.
* Accumulation of 1-2 inches in Farmville/Crewe, 1" or less in South Hill
* A period of sleet and freezing rain could produce some icing on top of that
* A changeover to rain before midday in South Hill, by early afternoon in Farmville/Crewe

Charlottesville

* Snow develops in the morning
* Accumulation of 2-4 inches likely
* The snow mixes with sleet and freezing rain by early afternoon, with ice accumulation on top of any snow
* Could change to rain later on in the day

Fredericksburg

* A mix of snow and sleet develops by late morning
* Accumulation of 1-2 inches possible with some icing
* A mix of sleet and rain by evening

Snow/sleet Thursday morning???

A developing storm to our south will throw moisture our way by Thursday morning. The lastest computer data suggests that overrunning precipitation will break out in the morning, when the air is cold enough to produce a mixture of snow and sleet. All indications are that the precipitation should be light to start and that by the time it picks up in the afternoon, the critical levels of the atmosphere will be warm enough to support rain. One word of caution, overrunning precipitation is often under-forecast by the models, so the situation does concern me a bit and bares watching. Stay tuned for updates...

Saturday, January 12, 2008

A few storms to deal with, plus extremely cold air poised to move in next weekend...

With rather quiet weather this weekend, we've got a couple of storms to watch over the next 7 days. The first probably won't be a major weather-maker for us, zipping up the coast Sunday night. By the time this system really strengthens, it will likely be north of our latitude. Plus, it will be somewhat off the coast, meaning most of its impact will be felt along and east of I-95. At this point, I just expect a bit of rain Sunday night into very early Monday morning. IF the storm tracks a little farther west and the precipitation shield gets pushed that direction, the I-81 corridor would have the potential of some winter precipitation...but at this point, that's a big if.

The coming work week...

We'll start the new week with mainly dry and cool conditions, with at or slightly above average temperatures. The next storm could bring a good burst of rain later in the week, mainly late Thursday through Friday. We'll again have to watch areas west of the metro, where it could be marginally cold enough for some winter precipitation. It's too early to tell, but we'll keep an eye on it.

VERY COLD next weekend...

The models differ on exactly how cold it will be, but expect some extremely cold air to surge into our area next weekend. Daytime temperatures will likely be held in the 30s for a couple of days, with overnight lows in the teens. This certainly goes along with the Winter Outlook, which by the way is panning out pretty well at this point. We expected a mild January, with a surge of cold around mid-month.

Monday, January 7, 2008

New blog posts this week...

Due to a family emergency, I was unable to post the last few days...but never fear, my posts will return this week. Get ready for some very WARM weather Monday and Tuesday.

Mike

Tuesday, January 1, 2008

Cold blast to start the new year...

The cold blast is moving into the Mid-Atlantic and will be with us over the next couple of days. As the core of the cold moves in, the upper trough may produce some snow showers or flurries on Wednesday. Temperatures will dip into the teens to near 20 Thursday and Friday mornings, with afternoon temperatures only in the 30s on Thursday.

Moderation for the weekend...

Surface high pressure will move over the area by Friday, and temperatures will moderate quickly this weekend. We should be well into the 50s during the afternoon and near 60 on Sunday.

Very warm for January early next week...

The big warm-up will continue early next week, with temperatures likely to reach the 60s Monday, Tuesday and probably at least into Wednesday. In fact, it's possible we could flirt with the 70-degree mark.

Changes beyond next week...

There are signs of significantly colder air coming back, potentially during the week of January 14th. I'm not sure this will be a prolonged spell though, as there appears to be a lack of blocking in the Atlantic, meaning the cold air can easily spill off the coast of North America. While there is a building ridge showing up in the model data over the eastern Pacific, the flow may eventually be quite zonal over the central and eastern U.S. Nonetheless, there should be at least a spell of colder weather for the middle of the month.