Friday, January 30, 2009

Up and Down Temps This Weekend...And An Update on the Big Storm...

The weekend looks fabulous, with lots of sunshine...but a quick change in temperatures. Saturday will be chilly, with afternoon highs only near 40. Then the wind swings around to the southwest and temperatures fly to around 60 or even a little higher Sunday afternoon.

Now the main event...

We're still watching developments for the "big" storm early next week. Over the last 24 hours, the model forecast suite has shifted dramatically to a track much farther east. Some would think this might increase our snow chances, but honestly it might just take most of our "precipitation" chances away. It will be quite mild on Monday, with an approaching cold front sliding in from the northwest. Showers will be possible later on and at night, but based on the latest data, I think the threat for heavy rain has diminished considerably. The storm track may very well be to our south and east and far enough away that we might not see that much precipitation. Of course with such a shift in the data the last 24 hours, we could see more changes in the upcoming runs...so we shouldn't jump to conclusions too fast. Anyhow, the reason for the changes is the upper level pattern. Yesterday I talked about a potential slower storm track due to the digging upper trough and deepening surface system. Well it looks like the trough won't dig as far south, waiting for another piece of energy on Tuesday. So this allows the storm to scoot by rather quickly off the coast. It indeed makes meteorological sense. What we're left with is a good piece of upper energy digging the trough south behind the storm later Tuesday and Wednesday. This actually induces a second area of low pressure on the European run over the Carolinas. I don't know that it will be that significant, but I can't rule out the possibility of squeezing some snow showers over us later Tuesday night into Wednesday morning. It certainly makes the whole situation more intriguing. Even though it looks like the inland storm track won't happen, we'll still be dealing with some strong winds Tuesday and Wednesday. I've posted the latest model maps below...the GFS effective Tuesday afternoon and the European effective Tuesday morning. I'll keep you posted on any developments over the weekend...

Thursday, January 29, 2009

A Quiet Weekend, Then A Big Storm...

Our weather will be pretty uneventful over the next few days, as we enjoy a good amount of sunshine. Temperatures will be seasonal tomorrow, with afternoon highs in the upper 40s. A brief shot of chilly air will start the weekend (temps near 40), but Sunday should be a much warmer day, with readings well into the 50s. The milder weather will stick around early next week, as a big storm takes shape over the Gulf states.

I'm hearing rumors of snow...why?...

I had many folks ask me today whether we were going to see snow early next week and said that's what they had heard from other sources. I must say I was quite surprised. The computer data is very consistent with an inland storm track, which would bring rain to our area, as temperatures would be rather mild. As the storm passes, colder air will plunge southward into our area, but most of the moisture should be gone by then. Bottom line, I really don't think we're going to see any snow (the exception being up in the mountains). The only reason I could see a forecast of snow is if one reads the early morning run of the GFS verbatim. It is a faster storm track, with a lot of moisture on the backside. I really don't buy the solution. The track is fine, but two things don't line up. First, the digging upper trough and deepening surface system should lead to a bit slower forward motion of the storm, like the European model has. Second, the abundant moisture on the backside just doesn't make sense. Our flow will be downslope by then, and even though the cold air will come plunging in, it will be much drier air as well. Either way, we will be dealing with high winds from later Monday night into Wednesday due to the strength of this storm. Check out the computer model run solutions below. First is the European...with the storm center right over Virginia Tuesday morning. Below that, if you want some fantasy...look at the GFS. The storm is WAY north of us (over northern New York early Tuesday afternoon), but there's a good slug of moisture over us. This is probably due to the upper trough, but the downslope flow will probably shut down such a possibility. Being that this event is still many days away, anything could change...so I guess you never know. But honestly, I see this as just a big rain and wind maker for us.

Wednesday, January 28, 2009

A Few Seasonable Days...Big Storm Next Week...

It's been a pretty wild day across the region with quite a bit of fog and a huge variety of temperatures. Warmer air surging north made its way into Metro Richmond, but not much farther north. As of mid-afternoon, temperatures were near 60 in Richmond and approaching 70 in Norfolk, but still in the mid 30s in Hanover County! The warmer air won't get much farther north, as a cold front approaches from the west. This front will bring more showers this evening and possibly a rumble or two of thunder. Gusty breezes will diminish later tonight as the front moves through, and temperatures will lower to near 30 by sunrise.

The next few days should be rather quiet. A secondary front will move across the region on Friday and Saturday should be a rather chilly day, with afternoon temperatures likely staying in the 30s. We'll warm back up on Sunday and Monday though, with readings of 50+ possible.

Early next week, the model data agrees a big storm will take shape over the Gulf states and move north-northeast through the Mid-Atlantic later Monday and Tuesday. There is general agreement that the track will be inland, so barring any significant changes, this will certainly be a rain event for us. As the storm wraps up, high winds are likely to be an issue here as early as Monday night, but more likely Tuesday into Wednesday. Stay tuned...

Tuesday, January 27, 2009

Threat of Black Ice Tonight...The Days Ahead...

Temperatures remain near 32 degrees this evening, despite the changeover to liquid precipitation throughout much of central Virginia. This will cause spots of freezing rain/drizzle and black ice, so please use extra caution if you have to be out travelling. I expect temperatures to slowly rise during the wee hours of the morning as the wind eventually swings around to the south. Well north and west of Richmond, problems will persist into the early morning hours, with sleet and freezing rain causing more potential ice accumulation.

Milder air will surge into region tomorrow, boosting temperatures well into the 50s for most, with gusty southwest breezes. Steadier rain during the early morning hours will likely taper, but showers will redevelop quickly and be with us during the afternoon and evening. There may even be a few rumbles of thunder as a cold front approaches from the west.

Looking ahead...

Several dry days are on the way from Friday through the weekend, although temperatures will be heading back down. Afternoon readings on Saturday will likely remain in the 30s, making for the coldest day of the next few. We'll then warm up later in the weekend and probably eclipse 50 degrees again either Sunday or Monday. Interestingly enough, the longer range model data is showing a potential coastal storm by Tuesday. However, the support for a lot of cold air is highly questionable, so winter weather lovers shouldn't get too excited. It will bear watching over the next few model runs, and I'll certainly keep you posted.

Again, be careful if you have to travel tonight!

Some Wintry Weather Today...


Precipitation will arrive across the region this morning as a mixture of snow, sleet, freezing rain and rain. The Metro Richmond area is likely to see some snow and sleet through midday, before a change to rain by the afternoon. From the Tri-Cities south, mainly rain is expected and north and west of town, wintry weather will persist into the afternoon.

The model data remains consistent with critical values in the various levels of the atmosphere, which would indicate a mainly liquid event during the afternoon from the metro south. The initial batch of precipitation will help to cool the column of air, causing the snow and sleet at the start. As milder air gradually advances in from the south, everyone will eventually go over to rain, but it may take until at least Wednesday morning up in the higher elevations well north and west.

Here are my expectations for potential accumulation:

Metro Richmond: a light coating of snow and sleet possible with some icy/slick spots, but no "significant" accumulation is expected (although freezing rain could be a threat for a couple of hours)

North & West Suburbs (from Ashland/Goochland N & W): An inch or two of snow and sleet, with some additional ice accumulation

Charlottesville over to Fredericksburg: 1-3 inches of snow and sleet with additional ice accumulation

Harrisonburg/Staunton: 2-5 inches

Monday, January 26, 2009

A Bit of Wintry Weather Tomorrow...


Tomorrow looks like a rather nasty day no matter what way you look at it. Milder air will be running up and over colder air at the surface (what we call "overrunning"), setting the stage for precipitation to break out over the region early tomorrow morning. I think the average start time in the metro will be around 8 A.M. The model data has been very consistent with critical values in the various levels of the atmosphere, indicating a mainly liquid event in the Metro Richmond area. However, the initial batch of precipitation will help to cool the column of air, causing some snow and sleet at the start. Well south of Richmond, from the Tri-Cities south and east, all the precipitation may very well be rain. As milder air gradually advances in from the south, everyone will eventually go over to rain. Up in the higher elevations well north and west, this process will likely take until Wednesday. So here's what I expect in terms of potential accumulation:

Metro Richmond: a few icy/slick spots, but no "significant" accumulation (freezing rain could be a threat for a couple of hours)

North & West Suburbs (from Ashland/Goochland N & W): Up to 1" of sleet and snow, some ice accumulation

Charlottesville over to Fredericksburg: 1-3 inches of snow and sleet with potential ice accumulation as well

Harrisonburg/Staunton: 2-5 inches

Nasty Weather Tuesday/Wednesday...

We may be dealing with some wintry weather over parts of the area tomorrow morning and early afternoon, as moisture spreads back into the region. At this point, the critical values look to be warming up just enough to provide mainly liquid precipitation in the Metro Richmond area and points south. However, surface temperatures near 32 degrees could spell a few periods of freezing rain. The higher chances for wintry weather will be to the north and west, where a mix of snow, sleet and freezing rain could persist for a while before milder air moves in.

Stay tuned for a complete update later this afternoon...

Saturday, January 24, 2009

Mixed Precipitation Possible This Week...

Colder air will filter back into the region tonight and tomorrow, setting the stage for a rather chilly and unsettled period during the coming week. A boundary setting up shop over the Mid-Atlantic will focus some moisture over us by Tuesday. This will be the result of milder air running up and over the colder air at the surface (known as overrunning). Temperatures at several levels in the atmosphere will be critical to what type of precipitation we receive. Right now, it looks like a mixture of precipitation types over central Virginia...mainly snow and/or rain. Any turn to a colder profile would provide the possibility of some accumulating snow, so we'll have to watch this developing situation rather closely. It appears that eventually the milder air will win out by Wednesday, meaning just rain showers. However, this is a rather dicey situation, so we'll just have to see how it plays out. Either way, it looks rather unsettled through the middle of the week. Stay tuned for updates...

Thursday, January 22, 2009

Briefly Milder...Then A Bit Unsettled Next Week...

We're in for a nice, mild day to finish the work week...with afternoon temperatures closing in on 60 degrees! Then a cold front will move across the region Saturday, although temperatures should still be close to 50 degrees. The chill will settle in on Sunday, with afternoon readings back in the 30s. Then early next week, we still expect a boundary to set up near VA & NC, potentially offering some moisture. Temperatures will be borderline for rain vs. snow. It appears at this point, the greatest threat for precipitation probably won't come until Tuesday. After that, some model data points to this boundary moving north and enabling us to warm up a bit. However, the pattern is still rather unclear. For now, be prepared for the possibility of some unsettled weather by Tuesday and Wednesday. Stay tuned...

Unsettled Early Next Week...

We're still on schedule for more cold air to arrive later this weekend. However, the potential storm that looked some impressive on Tuesday's data has changed dramatically. The model data is still in pretty good agreement, but there are major adjustments. It appears we'll be near a boundary early next week that could spread a few waves of moisture into the Mid-Atlantic. This could lead to some light precipitation, either rain or snow showers. The main event is now advertised to take a track well to the west and north of us, through the Ohio Valley. This would usher milder air back north and make any precipitation for us rain later in the week. However, the European model is still in question as to its exact track, as it continues to try and build high pressure to the north through the week. With a split flow in the upper levels, this will be an interesting pattern to watch develop. More with the next update...

Tuesday, January 20, 2009

All Eyes Turn To Next Week...

Well now that this storm has basically missed our area, we can turn our eyes to the next developing situation that warrants our attention. It's over a week away, but the computer data is hinting at a potential winter storm for the Mid-Atlantic next Wednesday (1/28). The overall upper level pattern is expected to become a split flow over the week. This could be a major factor in helping us get winter weather in Virginia. We'll need the northern stream to supply the cold air and the southern stream to supply the moisture. It looks like the cold will gradually settle in, particularly behind a system that passes by on Tuesday (assuming the data is correct this far in advance). It's unusual to see such agreement this far out between the GFS (American) and European models. I have posted the maps from each model, effective next Wednesday morning. I find it rather interesting that this is a similar set-up to a somewhat "surprise" storm we had pop up on December 5, 2005 which dumped a quick 3-4 inches on Metro Richmond with slightly higher amounts to the north. Of course that was an early season storm and this one will be in the heart of winter. I certainly see some good potential here...so stay tuned!

Here's the European solution:























And here's the GFS solution:

Another Disappointment For Central VA Snow Lovers

Well another storm has come and gone, grazing the area and leaving virtually all central Virginia without any snow on the ground. Southside residents did get some accumulation, with an inch and half reported in Lunenburg County and 2 inches in Mecklenburg County. The problem here in the Metro Richmond area was a stiff north breeze ushering in drier air and pushing the storm just south of us in North Carolina. Residents in northeastern NC are the jackpot winners for snow...4-5 inches has already fallen in Raleigh with moderate snow continuing during the midday hours. While it's a disappointment for snow lovers here, don't completely give up yet...winter is not over!

The Snow Today...

I don't have any changes to the forecast this early morning. A very light snowfall is expected over the region. The quickly developing area of low pressure will strengthen off the Carolina coast. It should be too far south and east of us to provide any significant snow for central Virginia, but accumulation up to around an inch is possible. Higher amounts will be found as you head south, with up to 2" in some locales near the Tri-Cities over to Williamsburg and 2-4 inches along the North Carolina border over to Norfolk/VA Beach. They will see a few heavier bursts as the storm begins to deepen.

Here's the lowdown on accumulation potential:

Richmond Metro: Up to about an inch or so
North of Ashland & West of Goochland: Nothing more than a few flurries or snow showers
Tri-Cities over to Williamsburg: 1-2 inches possible
Emporia and Franklin over to Norfolk/VA Beach: 2-4 inches possible

Monday, January 19, 2009

Tuesday Snowfall: What To Expect


OK, the time is upon us...most of us are actually going to see some snow tomorrow!
The new data coming in is consistent with earlier model runs. Some light snow will develop over southern Virginia late tonight and then spread up to the Metro Richmond area early tomorrow morning. The developing area of low pressure will cross the Carolinas and move quickly off the coast and begin to strengthen. It should be too far south and east of us to provide significant snow for central Virginia, but a light snowfall with accumulation up to around an inch is a good possibility. Higher amounts will be found as you head south, with up to 2" in the Tri-Cities over to Williamsburg (a Winter Weather Advisory is in effect) and then 2-4 inches along the North Carolina border over to Norfolk/VA Beach (where a Winter Storm Warning is posted). They will see a few heavier bursts as the storm begins to deepen. The snow jackpot winners will be northeastern North Carolina, from Raleigh east to the coast, where a swath of 3-6 inches is possible!
Keep in mind that this is a close call, and any slight change in the storm track to the north could bring more significant snow to central Virginia, so check back later tonight/early tomorrow morning just in case.

Here's the lowdown on accumulation potential:

Richmond Metro: Up to about an inch or so

North of Ashland & West of Goochland: Nothing more than a few flurries or snow showers

Tri-Cities over to Williamsburg: 1-2 inches possible (Winter Weather Advisory in effect)

Emporia and Franklin over to Norfolk/VA Beach: 2-4 inches possible (Winter Storm Warning in effect)

Monday Midday Update

Newer data continues to filter in...it's consistent with what I was talking about earlier this morning. The main focus is very late tonight and more so tomorrow. Look for some light snow in the Metro Richmond area (maybe an inch or so), a bit more significant over Southside VA. Locations north and west of town will likely see nothing more than a few flurries, if that. The core of heaviest snowfall potential will be down in northeastern NC, where Raleigh and especially points east toward the NC coast could end up with a swath of 3-6 inches! Norfolk and Virginia Beach are under a Winter Storm Watch, and several inches could accumulate there as the storm slides off the NC coast and clips SE Virginia. Please note that any change in the storm track to the north could bring more significant snow to Virginia, so stay tuned! I'll have a complete update coming later this afternoon!

Early Monday Morning Update...Snow Tonight?

You'd think as we get close to any potential event, things would be clearer. It appeared to be heading that way Sunday afternoon (as posted), but now the model solutions are a bit convoluted. The NAM in its late night run produced a pretty good snowstorm for SE Virginia and northern NC, even extending into part of central Virginia on Tuesday. It has since backed off a bit for us (still looks pretty good for NC) and the big problem remains resolving the pieces of upper energy rotating into the eastern U.S. trough. There are several pieces and that has caused confusion in the model solutions.

Honestly, it doesn't look like we'll see much precipitation during the day...maybe a few snow showers (mixed with a little rain south and east). My focus remains on tonight into early tomorrow morning. Moisture races ahead of the upper level energy and there may be enough "lift" in the atmosphere to produce some light snow. With this in mind, we could still wake up to some accumulation...maybe around an inch or so in spots. Then as the surface low pressure takes shape, it moves off the Carolina coast. Remember in my Sunday afternoon blog post that I mentioned that what happens here depends on how fast the surface low develops and moves. Based on the latest data, it would appear the low doesn't really get its act together until it gets to or off the coast. If it is able to strengthen closer to the coast, then we could see a bit more snow and this might be more of a Tuesday event. But if it moves faster and farther off the coast, we could easily lose out on any decent precipitation. So we're still in a holding pattern at this point. The more data we get, hopefully the better feeling we'll have about what is coming in the next 24-36 hours. I think the best call is to stick with what we've got in the forecast, especially considering we've been hinting at this overall situation for many days now and sometimes the initial hunch is the right one! As always, stay tuned...

Sunday, January 18, 2009

Tomorrow Is Clearly The Time To Watch...

As mentioned in my early morning post, tomorrow is now becoming the "hot" time to watch for potential snow. There are still timing and strength differences amongst the model suite, but there is clearly some agreement on the general pattern and set-up. The upper level energy swinging into the eastern U.S. trough (still in a couple of pieces) will provide some lift for surface development, which should eventually get its act together along the East Coast. What happens before that is key to our snow chances, as once the low moves off the coast, it should take most of the moisture away with it.

So as the upper energy approaches tomorrow midday, some light precipitation is likely to break out by the early/mid-afternoon. The temperature profiles indicate that it should be snow in Metro Richmond and most places in our area, although I would not be surprised to see a mix or even rain to start well south and east of town (Williamsburg, Emporia, South Hill). Evaporational cooling should enable basically all of the precipitation to be snow by early evening. I think the key to accumulation potential will be how long the precipitation continues into the evening and possibly overnight. This is where the model solutions are particularly having trouble. They have wavered back and forth as to how fast the surface low develops and moves. If it strengthens closer to the coast, then we'll see light snow (maybe even a few heavier bursts) into the night and we could easily wake up to an inch or two Tuesday morning. If it moves faster and farther off the coast before taking shape, then we'll lose out on any decent precipitation. I favor the middle of the road right now, basically the light accumulation that I've been promoting for several days now...so my best bet is up to around an inch or so. This doesn't mean everyone will see that...but it's certainly a possibility for any location in our region (central Virginia). As always, stay tuned...

Early Sunday Morning Update...

All along I've been saying this won't be a big event, but honestly I thought the model data would be putting out a bit more by now. It looks quite dry over the region and this dry air is going to take some time to dislodge. The upper level energy that will be swinging over the region late today through Monday is quite significant and may still trigger some precipitation. The model data continues to show two pieces of energy to be dealt with. As I mentioned in the Saturday afternoon post, the lowest layers of the atmosphere will warm enough today that any precipitation may be liquid during the afternoon and early evening. That said, I don't think we'll see more than sprinkles (or possibly some flurries). There might be a better shot at some light precipitation overnight. Of the two main short range models (GFS & NAM), the GFS is now quite dry. Earlier it had painted more precipitation over us. It does spit out minimal precipitation by Monday morning and if snow lovers are lucky, it would be a dusting of the white stuff. Meanwhile the NAM now has a more significant piece of upper energy crossing the Commonwealth on Monday, leading to a period of light snow that could accumulate. This matches the European, which continues its focus on this second piece of energy. SO...it remains possible that some of us could have a white ground on Monday or even Monday night, especially the grassy surfaces. While it wouldn't be the "snowstorm" that many are looking for, it might put that small taste of winter weather in the air again. As always, stay tuned...

Saturday, January 17, 2009

Saturday Afternoon Update...

Well folks, the set-up is still rather complicated regarding tomorrow's weather. And unfortunately for snow lovers, several things are just not coming into place. First of all, despite the fact we've had a bone-chilling Arctic air mass over us, it's already lifting out of the region and there's nothing to hold cold air in place. As low pressure moves over the Ohio Valley/Great Lakes, an upper level trough sinks southeast toward the Mid-Atlantic. This is the feature I've been keying on for several days. The first problem here is that the air remains quite dry. The other problem is a developing southwest flow will be warming the lower layers of the atmosphere and it appears we could just see a little rain tomorrow afternoon, as surface temperatures climb into the low 40s. The one big question mark remains tomorrow night, as temperatures "cool" again and the upper level set-up becomes more favorable for snow. How long will any precipitation hang around? I still believe we could see some light snow over at least some of the area overnight into early Monday morning. This means we could wake up to see a white ground. But as is typical around here, a lot of factors have to come together and play out just right. The other big issue involved is the second disturbance I've been referring to. The European model still develops an area of low pressure just off the Carolina coast on Tuesday. The moisture fields are basically south and east of us, but it's still something to watch. It's a rather complex pattern that shows potential, but could also end up being a total miss for us. All I can say is we'll have to watch how the pattern evolves over the next 24 hours...but the potential is still there.

Friday, January 16, 2009

Update on Our Upcoming Snow Chances...

Well it's now Friday afternoon and things really aren't much clearer concerning the weekend situation. It's funny, because the model data is actually pretty consistent...but it just doesn't give a clear indication as to specific developments for us. My gut feeling is still that we will see the potential for some light accumulating snow, most likely overnight Sunday into Monday morning. My concern is that the lower layers of the atmosphere warm a bit on Sunday and by the time any precipitation develops, we may see a light mixture or even light rain. Doesn't that always seem to happen around here? Regardless, if everything goes according to plan, there should be some light snow in the air Sunday night. And...there may be the possibility of another event on Tuesday. This is something I mentioned the European model hinted at yesterday, and it is still waving the flag today.

The NAM and the GFS are our main short range models. The NAM is quite dry with this approaching system and while it's colder in its temperature profile, it would suggest little if any precipitation over Virginia. The GFS has become quite consistent in its track of the upper level energy heading well south and triggering some development along the coast. Take a look at the Monday morning map below. It's quite impressive! If this solution verifies, we would likely see some mixed precipitation Sunday afternoon/early evening, but then probably go to snow overnight. In terms of the second disturbance the European is hitting rather hard, the GFS shows some weak development along the Gulf coast (no closed low), which then tracks quickly well off the coast (second map below).






























As for the European, kudos for showing this Sunday system first and giving me the confidence to put it in the forecast back on Monday! Even though it has weakened its solution quite a bit, the general pattern is consistent. There is the upper trough that swings over the area, with some surface development along the coast (although nothing like the current GFS). The main reason for a weaker Sunday system is the model is focusing on the second system that would impact us on Tuesday. (the model's Tuesday morning map is shown below). It doesn't look quite as agressive as yesterday's runs, but still something to watch closely. If this becomes the primary wave/system, then we could be dealing with winter weather in the Mid-Atlantic on Inauguration Day.

So that's the rundown on our latest data. Hopefully things will really clear up over the weekend...but it's apparent that we have two POTENTIAL threats here...one on Sunday and another on Tuesday. I doubt both will be a big deal, but one should be able to give us at least a "taste" of winter weather. Stay tuned!

Thursday, January 15, 2009

Thursday Update on the Potential For Sunday Snow...

As the Arctic cold settles in, we're still watching potential developments for later in the upcoming weekend. The computer data is still a bit scattered and is likely having trouble dealing with this pattern. The disturbance that we're tracking has been over an area with sparse data fields, so the sampling may not provide an accurate forecast. With that in mind, the key model runs will come later tonight and tomorrow as we get a better sampling.

Here's the situation. The GFS, which has not dealt with this approaching upper level energy very well, has come around and now shows a "logical" solution (Sunday's solution...upper level and surface are shown below). Like most of the computer models, it places the surface low over the lower Great Lakes, a track way to our north. However, the upper trough digs south and actually taps into moisture from the Gulf (not necessarily a likely scenario). Nonetheless, it does suggest some precipitation over us (in the form of snow) later Sunday and Sunday night.














Meanwhile, the European has been my model of choice for several days, as it has been consistent with showing this feature. However, it had been tracking the surface system farther south and then shifted north with yesterday's runs. It remains farther north, with some apparent secondary development along the coast. Maps for Sunday, Monday and Tuesday are shown from the new run below. The big concern is its trouble handling the following disturbance (after the initial one) that enters the eastern U.S. trough. The Euro now seems to be focusing a bit more on this second disturbance, which could trigger another round of possible snow showers/flurries on Tuesday. It will be interesting to see whether the model data eventually shifts its focus to this system. So putting it all together, my thoughts haven't changed much. I still feel we have the potential of a light accumulating snow on Sunday/Sunday night. However, if the focus shifts to the second disturbance, we might not have much if anything to deal with on Sunday...and we may need to turn our attention to Tuesday. Of course with our track record the last few years, anything could happen and nothing is a guarantee. Stay tuned!

































































Wednesday, January 14, 2009

Wednesday Update on the Weekend Potential...

Not much new on the Sunday front at this point. The European model has shifted its low track a little to the north today and is not as impressive with the approaching upper level energy. However, it should be noted that the disturbance that is being tracked is quite a ways south of the Aleutian Islands today in an area that lacks some data...so I wouldn't lean too much on one model run this far out. The earlier European gained some support from the Canadian GEM today and I still believe we have a shot at seeing some accumulating snowfall Sunday and/or Sunday night. The GFS seems to have caught on to the basic developing situation, with low pressure developing along the coast, although it looks too far south. The transfer of energy to the coast may be the key here, as the European still shows the new development off the coast, lingering moisture over our area into Monday morning (today's run with solutions for Sunday AM and Monday AM are posted below).

At this point I see no reason to alter the forecast. I still believe this will not be a major event, but the possibility exists for some accumulating light snow. Stay tuned for updates!

Tuesday, January 13, 2009

The Arctic Chill Arrives...Snow Possible On Sunday...

The Arctic chill is right on schedule and we'll certainly be feeling it the next few days. Look for afternoon temperatures mainly in the 30s tomorrow. A disturbance crossing the region on Thursday may produce a few flurries and will usher in the core of the cold air for Friday and Saturday. High temperatures on Friday will only be in the upper 20s, with overnight lows in the teens and single digits. Then things get interesting...

Accumulating snow possible on Sunday...

If you've been reading the blog the last couple of days, you know I've been intrigued by a system that could bring some snow here on Sunday. Well I'm becoming a bit more confident that this may very well happen. The European model has been very consistent and presents a very logical forecast solution. While it has been an outlier in the model suite, it has been a consistent performer during the winter months along the East Coast, not only this year, but most in the recent past. Below are two sets up maps from the European run today. The first set is valid Sunday morning. We can clearly see the developing system moving across Kentucky in the digging upper trough over the eastern U.S. This would spread a swath of moisture over us Sunday morning and with the air extremely cold aloft, snow would be likely. By Monday morning, the system has redeveloped along the coast and moved north, with yet another disturbance coming down in the trough over the Great Lakes. That would keep us pretty cold early next week, especially if we have snow cover on the ground at that point. The Gulf of Mexico would virtually be shut off from this system, so we're not talking abundant moisture here. However, a powdery snow could produce several fluffy inches Sunday afternoon and evening. Of course we're still several days away and a lot can change, as we know all too well around here, so stay tuned for updates!

Monday, January 12, 2009

Is Snow On the Way???

As promised, the initial surge of much colder air will be arriving behind a system that crosses the Mid-Atlantic later tomorrow. The warm layer near the surface will be too significant for any snowflakes, so a few rain showers are in the forecast. Wednesday's temperatures will probably not get out of the 30s, and then the next disturbance races over the area on Thursday. The model data has been consistent with this system over the last few days and continues to indicate most of the moisture going just north of us. However, I wouldn't be suprised to see a few snow flurries/showers during the day. The Arctic freeze arrives on Friday, with daytime temperatures only in the 20s and overnight lows in the teens and single digits.

Things could get interesting later in the upcoming weekend. Our next system comes in from the west, and while several models don't make much of it, the European drives the system a little farther south in the upper trough, with more moisture involved. Below is a look at the European model forecast for surface features on Sunday morning. We can see the low pressure moving across Kentucky. By Monday morning, it's just off the North Carolina coast. While it's quite early to draw any conclusions, this could potentially mean some snow for us Sunday into Monday, so stay tuned.

Saturday, January 10, 2009

Saturday Update on the Coming Week...

We remain on schedule to see the arrival of Arctic air later this week, and certainly the coldest of the season. The question remains will we see any snow? There will be a series of disturbances travelling across the Mid-Atlantic through a developing upper level trough in the eastern U.S. Each one may bring a threat for precipitation. The leading edge of the Arctic air will be following a system that comes over us on Tuesday. This may trigger scattered rain and snow showers. Behind it, temperatures on Wednesday will probably struggle to get out of the 30s. The most intriguing situation to me remains late Wednesday night and Thursday, as the next disturbance comes through the trough. I have posted the European model charts for Thursday morning below. The upper left shows the upper level flow, and we can clearly see the trough digging south and east. The top right shows the surface features and the area of low pressure is tracking over northern Virginia. The bottom charts show moisture and all the models agree at this point with keeping most of the moisture north of us. This means there won't be much to work with, but don't be surprised if we can squeeze out something. This won't be a major storm, but I'm still suspicious we'll see some of the white stuff flying in the air on Thursday (at least snow flurries/snow showers). The bitter cold will follow on Friday into the next weekend. Stay tuned for updates...

Friday, January 9, 2009

Update on Next Week's Cold...and Snow Chances...

A quick update on the model runs for next week...the extreme cold may be delayed by a day or two, due to a series of disturbances in a very fast flow aloft. The lead system comes through on Tuesday with a few rain/snow showers, with a second one following later Wednesday into Thursday. This is the one I was looking at for snow chances, although it appears most of the moisture with this will be just north of us. The track and evolution of the upper level features will be key as to whether we see anything in Virginia. At this point, I'm not calling for anything more than flurries, but it bears watching. The deep chill will follow later Thursday into Friday. Stay tuned...

Thursday, January 8, 2009

Up and Down Temps...Snow Next Week???

Another blast of chill is on the way, as temperatures tumble well down into the 20s overnight. A sunny, but seasonably chilly day is on tap to finish the work week. Then our next cold front will approach from the west on Saturday. Ahead of the front, temperatures will jump to 50 or a little higher, with afternoon showers likely. Then afternoon temperatures in the 40s will be the rule Sunday and Monday.
Yet another front (and this time an Arctic front) will approach the Mid-Atlantic on Tuesday. A few scattered rain and snow showers will likely break out, with a major cold blast following for the mid-week period.

Snow later next week???

Some of our computer model data is showing moisture gathering north of the Arctic boundary later next week, which could mean some precipitation for us. If there is, it would be snow, as the air will be more than cold enough. However, the models are not in agreement on how deep the upper level trough will be over us and its exact strength and placement will be key to whatever develops (if anything at all). Below is the European computer model projection for next Thursday morning (1/15). You can see a weak area of low pressure, and it puts a slug of moisture over our region. It looks like either way, it will be mighty cold for a while. Remember in the winter outlook, I focused on the period from January 15-25 for a cold spell and potential winter weather. I still believe this will be a time to watch closely. Stay tuned...

Monday, January 5, 2009

A Cold Rain For Most...


Surface temperatures remain in the 50s this afternoon, but will slowly lower into the mid and upper 30s by morning as colder air oozes in from the north. This colder air will continue to inch its way in tomorrow, but warmer air aloft will mean mainly rain for central Virginia. In the Metro Richmond area, we expect a cold rain, with afternoon temperatures mainly in the upper 30s. Off to the northwest, the fact that surface temperatures have been higher today will probably alleviate the threat for freezing rain tomorrow, however, as the cold air leaks in, a shallow layer of it could help to produce periods of sleet from Charlottesville up to Fredericksburg. I don't expect major problems in these areas though, with any significant issues confined to the Blue Ridge, Shenandoah Valley, and just north and west of Washington, DC.

Get ready for a significant amount of rain though, with the model data showing the potential for a good 1 1/2-2 1/2 inches by Wednesday afternoon (see the forecast graphic from the National Meteorological Center above). There remains the possibility of a few passing snow flurries or showers on Thursday, as an upper level trough swings across the Mid-Atlantic.

Sunday, January 4, 2009

Tuesday Storm Update...

There remains a threat for wintry weather early Tuesday morning across the region, particularly points north and west of Richmond. Moisture caused by overrunning (warmer air up and over colder air at the surface) should provide precipitation by early morning. Temperatures will lower into the low and mid 30s as colder air sneaks in at the surface from the north. A mix of sleet and freezing rain is possible at the start, even in and around Metro Richmond, although it shouldn't be widespread. Places north and west of the city will have the greatest threat for some icy weather, with temperatures hovering near 32 degrees. While there could be some snowflakes mixed in as well, the air aloft will warm rather quickly and therefore the change to liquid. It will be a cold rain for most Tuesday afternoon.

Thursday snow chances remain...

It shouldn't be a big deal, but a few snow showers/flurries are still possible on Thursday, as an upper trough swings across the Mid-Atlantic. Stay tuned...

Saturday, January 3, 2009

Wintry Weather Chances This Coming Week...

Moisture ahead of our next system tomorrow will likely just produce a few showers in the Metro Richmond area. Well off to the northwest in the Shenandoah Valley, there may be a few pockets of freezing rain in the morning.

Problems could be on the horizon for Tuesday...

A more significant storm will affect the region Tuesday into early Wednesday. High pressure sliding off the coast to our north will keep cold air funneling down the coast into early Tuesday morning. The air aloft will be warming, but cold air trapped near the surface could spell a significant period of freezing rain or sleet, mainly to the north and west of Richmond. This could involve some of our nearby counties, such as Goochland, Louisa, Caroline and possibly Hanover. It's a little too early to tell, but certainly something to watch. In Metro Richmond and points south, there is the possibility of a little mixture at the start, but for the most part it should be a cold rain.

Flakes could be in the air Thursday...

An upper trough swinging through the Mid-Atlantic will usher in another blast of cold air later in the week. As the upper trough crosses Virginia, we may see a burst of snow showers/flurries on Thursday. Stay tuned...