Computer models have come into pretty good agreement that a significant storm will develop in the South early this coming week. However, there is a lot of variability in the projected storm track - which is the key to this forecast. The important thing to emphasize right now is that the cold air necessary for snow will be moving away as this storm approaches. So unless the storm takes the perfect track - far enough east to hold remnant cold air in place but close enough to us for significant precipitation - we're almost certainly going to have some, if not mostly rain.
Today's highs in the 20s are some of the coldest of the season and there is no major letup in sight through the beginning of the week. In fact, after nearing 30 on Sunday, Monday may feature another dip in readings. By Tuesday, cold becomes less of the main story as a precipitation -- snow and rain -- threat moves into the area.
Temperatures peaked early to midday in the low-to-mid-30s and have slowly declined ever since. Winds gusting to over 30 mph at times have made it feel even colder. Everyone is now below freezing and may well remain that way into early next week.
The models are converging toward the possibility of a winter storm Tuesday into Wednesday. The cold air mass settling over the region now now is setting the stage for wintry precipitation. However, like most such storms projected so far into the future, there is a lot of uncertainty about the storm's track and intensity. The majority of the models suggest this storm will have quite a bit of precipitation with it. How much of the precipitation will be snow, sleet or rain is very much in question.
Who got snow last night? I actually awoke to a dusting in NW D.C., which surprised me as little as bleak as snow prospects looked around 10:15 p.m. last night.
Cold air is on the way in behind last night's light snow shower activity. Today is the windiest of the next few as highs struggle to get into the mid-30s. Tonight through tomorrow night are super cold with highs likely not to hit 30 to start the weekend! We stay pretty frozen into the early week when another snow threat approaches the area.
This evening's radar shows rain and snow showers breaking apart as they cross the mountains. Very few reports of precipitation can be found in the metro region. The best chance of precipitation may be after midnight when low pressure begins to develop to our east, but the latest NAM model simulates an incredibly underwhelming 0.03" liquid equivalent at Reagan National Airport from this storm.
While a step down from yesterday's low 50s, today's high temperatures of 40 to 45 were manageable and about average for this time of year. Tonight's weather system ushers in colder air that hangs around through early next week. It also brings our much-discussed period of snow or mixed rain and snow, enough for some light accumulations especially north of the District.
This winter, at least so far, appears to the winter of the little storm. That's not to say that we can't or won't get a big one at some point, but it's almost certainly not going to be tonight's, which is probably too weak and tracking too far north to produce more than half-inch or so in the D.C. and south, with maybe a little more north.
Despite major advances in scientific understanding and the development of computer-based weather models, there remains much room for improvement. Anyone who has followed this season's winter storm predictions has, no doubt, observed this. While there never will be perfect forecasts due to chaos (i.e. the butterfly effect), there is considerable opportunity for more accurate predictions and better estimates of associated levels of confidence in hazardous winter weather systems.
Winter is back with a vengeance starting with light snow tonight and then a kayak-full of cold air for the weekend. Lows in the teens should be prevalent, and weekend highs probably stay below freezing.
Today was a treat! Highs near and past 50 with plenty of sun and light winds made it feel a little more like early spring than late winter given all the cold weather of recent. But, it's just a brief hint of mild as colder air filters back in tomorrow ahead of a snow risk heading into early Friday morning.
A massive storm in the northern Pacific ocean, that deepened to levels equivalent to a category 4 hurricane early Tuesday, threatens the coast of Hawaii with 30-40 foot waves. The same storm is bringing snow and gusty winds to parts of Alaska.
We've been on the edge of almost every snowstorm this winter, struggling to accumulate an inch from any given event. Here we go again. We're on the southern fringe of a storm system in the works for late Thursday night through Friday's rush hour. Most likely snowfall accumulations are from a dusting to an inch or two over most of the area
After our latest ice storm, I broke out the flyer sled and gave it a try. The flyer sled is the type of sled with two metal runners under a wooden frame with a large steering handle; it's the same type of sled that many of us grew up with as kids. The "Flexible Flyer" is the most common brand of flyer sled, which has existed since the late 1800s. Let us know if you have any flyer sled stories.
This video is from Pittsburgh Tuesday. Video description: "Conditions were extremely treacherous on Fallowfield Avenue in Beechview, Pa. after an overnight mix of snow and rain caused ice to form."
It's an active pattern, and any time you combine that with cold temperatures you have a recipe for repeated wintry weather opportunities. Our next one comes Thursday night into early Friday - though first we have to deal with lingering slippery spots this morning - followed by a really cold weekend.
Although the process was slow, temps steadily rose above freezing today in most of the metro region. Inside the beltway, we reached the mid-30s. However, a few pockets well north and west of the beltway did not exceed 32. It's these areas that may experience more iciness and even some snow as another area of precipitation moves through tonight.
With the ice storm in our wake, it's time to look forward to the next chance of accumulating snow which arrives Thursday night and may continue into part of Friday. This doesn't look to be a huge storm as it will be a fast mover. But for at least parts of the region, the storm may be strong enough to produce light to moderate amounts of precipitation, which may fall in multiple forms rather than being all snow.
Another difficult to predict winter storm in 2010-11 has come and gone. So how would I evaluate our forecast effort? I actually think we did pretty well with this one. Yes- we missed some important details - mainly underestimating the extent and duration of cold air at the surface. But we identified the potential for a wintry mix of precipitation well in advance and correctly characterized the timing and evolution of the storm.
A thick glaze of ice fell in many spots overnight so be very careful this morning. Temps slowly rise above freezing today before showers (mixed with snow north and west) could return tonight. Then we get one dry day on Thursday ahead of the next storm system Thursday night and Friday morning.
Tonight's precipitation transitions from snow to ice, and to plain rain for most areas by early-to-mid morning. Though the further north and west of D.C. you go, the longer ice lingers.
The National Weather Service has issued a Winter Weather Advisory for all of the metro region with the exception of Calvert and St. Mary's county. The advisory is in effect through 9 a.m. in the immediate metro area and through noon Tuesday in the north and west suburbs. The NWS and CWG are both predicting up to an inch of snow in the immediate metro area before changing to sleet, freezing rain, and eventually rain.
For most of the winter storms in 2010-2011, the question has been snow or no snow. This time around, we entertain the possibility of multiple precipitation types which evolve from snow to sleet to freezing and then rain, starting this evening and continuing through Tuesday morning.
A complex weather scenario sets up Monday, providing the metro region with a good possibility of mixed precipitation Monday night through Tuesday morning. This does not look like a major storm, but may result in slippery travel Tuesday morning, especially west of I-95.
We're cold but precipitation-free today and through most of Monday - two days to breathe before our next wintry weather challenge Monday night into Tuesday. The big questions for that period are what kind of precipitation and how much.