www.roanoke.com

Roanoke's official low fell to at least 32 briefly this morning, the first freezing temperature of the 2009-10 cool season. Blacksburg dropped to 28 and was below freezing for a few hours, indicating a growing season-ending freeze probably occurred in many areas away from the Roanoke metro area, especially north and west of Roanoke. While the first hard freeze of the year renders additional freeze warnings unnecessary, similar temperatures on Tuesday morning have led the National Weather Service in Blacksburg to issue a frost advisory for the second consecutive morning for locations from the Roanoke Valley south and east.

My storm chasing friend Dave Carroll from Blacksburg ventured up to Salt Pond Mountain today (the one Mountain Lake is on). He saw a little light snow blowing around and shot some photos of a wintry mountaintop with an autumn background. My favorite, small at the left and a larger version linked here, showns rime ice on tree branches above 4,100 feet at Bald Knob. Riming is caused by winds blowing water droplets in clouds against surfaces that are below freezing. He also shot a picture of a wee bit of snow accumulation on some of the many ferns found on the mountain. Just a hint of winter today at the area's highest elevations.

Some more snow showers are possible overnight at elevations generally above 3,000 feet (possibly creeping lower into the New River Valley after midnight) as another disturbance swings through. The bigger issue will be the potential for a growing season-ending freeze tonight and again Sunday night over most of Southwest Virginia west and north of Roanoke. Freeze warnings and watches have been issued.

A late week snow set records for earliest on record in some states to our northeast.

This taste of winter won't last long, as gradually warming temperatures are expected through the coming week.

As I write about in today's Weather Journal column, there was no big shock when the National Oceanic and Atmospheric Administration (the overseeing agency for the National Weather Service) came out with its winter forecast, which is basically a textbook moderate El Nino pattern. Cooler than normal temperatures with near average precipitation would be the general call for our region, based on the forecast maps.

I alluded to Accuweather.com's forecasts, which are widely followed, and are very robust on snow potential for the East this winter (as they seem to be quite frequently). I've added a few links to those forecasts and one other from some private forecasters ... all thanks to my readers who have watched out for these forecasts while I've been otherwise occupied this fall.

It does remind me a bit of the buildup to a football season ... it's all hype until the pigskin flies and the pads pop. And when it comes to snow, there have been several losing seasons recently for the region's winter fans.

Accuweather.com compares its forecast to that released by NOAA on Thursday ... overall pretty similar.

Accuweather.com's Joe Bastardi going very big on winter snow forecasts for our region.

Accuweather.com's Henry Margusity calls for 46 inches of snow for Roanoke in big Eastern winter

Forecasters Hunter Outten and Mike Petro with a similar snowy outlook (Adobe Acrobat required)

Meanwhile, winter fans, enjoy any snowflakes you see tonight or Saturday, especially in higher elevations and locations west of I-81. I will get to my thoughts ... and introduce the Winter 2009-10 snowfall prediction contest ... in two weeks.

It appears that the airport at Hot Springs ... actually located on top of the mountain above the town and The Homestead ... experienced some snow overnight and this morning as temperatures dipped to just above freezing.

And it appears almost certain that Roanoke will set an Oct. 15 record for coldest high temperature today ... and it likely won't even be close. We're sitting at 44 this morning, the record is 53 set in 1978 and 2002, and rain is moving in as cold air damming maintains its hold on our region.

A cold front and some more snowflakes, especially in the higher elevations, are still on the way for Friday and Saturday. If a flake or two blows into the Roanoke Valley, Saturday morning would be the best bet.

Chilly, rainy weather is on tap through the weekend with some cold-air damming from the northeast and an active jet stream bringing a series of storms across the country that will sling Gulf of Mexico moisture over that cooler air. The rain is on the Roanoke Valley's doorstep right now (click here for local National Weather Service radar).

And by the weekend, higher elevations in our area may see the first snowflakes of the season behind a cold front.

It will take me a few days to get back in the weather groove. I've barely paid attention during the past week after being in Arkansas for my dad's funeral.

I do know that, suddenly, the weather pattern looks a lot like winter.

First off, you can note in the pattern of projected rainfall over the next 5 days  (courtesy of the Hydrometeorological Prediction Center) something resembling an El Nino-like character, with the heaviest rainfall concentrated from Texas toward the Gulf Coast. There is also a secondary stripe of enhanced rainfall through the northern U.S. where the main branch of the jet stream currently flows, basically west to east. Note the dry hole over Virginia though ... not much rain is expected in our region, as we will likely be between the best dynamics to the north and best moisture to the south.

Perhaps more interesting to anyone looking for a more winterlike pattern is that a cold air mass from the Arctic is expected to slip down into the north-central and northwest U.S. -- much below normal temperatures are expected -- and then steadily shift eastward as the Friday's 6-to-10-day and 8-to-14-day temperature projection forecast maps from the Climate Prediction Center illustrate. These maps show a progressive flow with some cold air moving across the nation, as cold fronts are dragged eastward by low-pressure systems moving to the north.

Some pieces more like winter than summer are beginning to appear on the board. That's typically what October is about, a transition time between the slower, warmer, more stagnant pattern of summer and the faster, cooler, crisper pattern of winter. Colored leaves will be flying through the air within weeks, and who knows, maybe something cold and white mixed within them a time or two.

Sometimes, cold fronts aren't really "cold" fronts. Such will be the case Friday night when a Pacific cold front zips through. It might trigger a few showers, but not many, as it pushes across the area. But it will not introduce any dramatically cooler weather. In fact, temperatures over the next several days will be a tad warmer than they have been the last couple, as a Pacific air mass replaces on of more Canadian origin. It does look like a dry, fairly seasonable pattern ahead, with highs in the 70s and lows in the 40s and low 50s each day until another front arrives with some rain about the middle of next week.

Blacksburg's morning low reached at least 37, and Roanoke's dipped to at least 43. I say "at least" becasue sometimes a later analysis reveals a lower dip. As they are, these mark the lowest temperatures at those sites since May 20, when Blacksburg was 36 and Roanoke was 42 (after being 33 and 37, respectively, the previous day). You can click here for various other weather observation sites in the area, at least one of which dipped as low as 30. (I'll let you find it.)

While most mornings the next week are expected to be seasonably cool in the 40s and low 50s, daytime highs will creep back into the 70s. So this taste of frosty chill is, for now, a brief one.

UPDATED 12:20 P.M.: Several counties west of the Roanoke Valley are under a frost advisory for Thursday morning.  END UPDATE

You might need a jacket this morning with temperatures in the 40s to low 50s, but autumn chill will settle in big-time by Thursday morning. Some valleys could see lows a few degrees above freezing, with frost possible, with most everybody in Southwest Virginia no warmer than the low 40s. Temperatures will moderate some by the weekend, but it does appear that rather mild fall weather is with us for several days.

A thin line of showers marks the arrival of the next cold front that will breezy conditions by afternoon and even cooler weather by tonight. Don't be surprised to see a brief shot of rain during the day, but most of it probalby won't make it over the mountains because of the downsloping nature of the westerly winds.  Behind the front, we will have two or three days of highs in the 60s and lows in the 40s, perhaps even a few readings in the 30s in some elevated valleys and very high elevations. It could indeed be sweater weather the next few mornings.