2009.01.27
Precipitation is on its way -- what will it be?
Well, here it comes, pretty much right on schedule. The regional radar composite at the right shows abundant precipitation spreading across Kentucky as of shortly before 1 a.m., heading our way rapidly. For a more recent image whenever you are looking at this overnight or early in the morning, click here for a series of regional and national radar images, or you can click here for local radar from the National Weather Service in Blacksburg (the radar dome is located on Poor Mountain in Roanoke County).
The big question is what kind of precipitation it will be when it arrives, and then throughout the day. Temperatures in the low to mid 30s with dew points in the low to mid 20s would tend to indicate that as the precipitation falls this morning, evaporational cooling will take us down to the freezing mark. Very early in the event, it may be cold enough at all layers for snow, but that shouldn't be more than an hour or two. If heavy precipitation falls very fast early in the morning, we could pick up a few inches of snow. More likely, the snow will go quickly to sleet with less than an inch in the Roanoke area (more to the north), then to freezing rain or rain, depending on exactly where the mercury lands at your location. Whatever the temperature is when the evaporational cooling levels off, it may not change for several hours, and if it's 32 or below, ice accumulation could be a problem in your local area. It could vary across the region, even within a few miles in some areas, but the National Weather Service in Blacksburg is continuing to fly winter storm warnings for the counties north of Roanoke and winter weather advisories along and just south of the Roanoke-Blacksburg-Lynchburg corridor (U.S. 460). Click here for the latest warnings and advisories.
While roads may get very treacherous in some areas, the biggest concern with freezing rain when it's in the low 30s is collection on trees and power lines. If several hours of freezing rain occur, there could be power outages in some locations. Eventually, temperatures will likely rise above freezing, but whether that occurs later today, tonight or Wednesday will vary across the region, and will determine much about how severe the ice is in your local area.
As precipitation begins and conditions develop, please leave a comment below about what it is doing where you are at (I will have to approve those for publishing when I get back to this in the morning). Remember that just because it may not be icy on your doorstep doesn't mean that everyone in Southwest Virginia is missing the winter storm.
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I got up at 530 to check the storm progress, and it looks a lot like previous storms. Moisture riding north up the spine of the mountains, with us well above freezing at the moment at 36. We have not gone below freezing at all overnight and held a steady 36 from our high yesterday. The dewpoints are below freezing though, so we'll see what happens to the temps when the precip does arrive...but at this point I'm leaning toward a mostly rain event with pockets of ice in the usual places and farther north, with this turning into our 2007-2009 typical winter storm. Given the threat of ice and almost no chance for snow...bring on the liquid-only rain and let's hope the next storm can deliver the white stuff.
Comment by Other John — January 27, 2009 @ 5:48 am
It's a warm rain. It's not freezing on surfaces here in Blacksburg
Comment by Henry — January 27, 2009 @ 6:42 am
Blacksburg is very close to freezing according to observations there. I would expect some people near you are getting some ice, and it may lose a few degrees as the rain falls.
Comment by kevinmyatt — January 27, 2009 @ 6:48 am
At 6:50 a.m., we have started a sleet/rain mix in south Roanoke County ... still above freezing, we'll see what the temperaures do as the precipitation eases in.
Comment by kevinmyatt — January 27, 2009 @ 6:53 am
It's just plain old rain here in New River this morning, well above freezing at 36 at my house. The Dublin airport shows 34 with a 32 dewpoint, and VT airport 34 with a 30 dewpoint.
Comment by Other John — January 27, 2009 @ 6:59 am
At 7AM...at the lake (near the bridge)...it just started raining with a few sleet pellets thrown in...temp is 36...
Comment by Betsy — January 27, 2009 @ 7:04 am
Roanoke airport has fallen from 37 to 36 in the last hour and the dew point is still 22, so still room for evaporation cooling here. Will be interesting to see what it does, whether it can saturate quickly enough to stall us at 33 or 34 or if the temperature gets pulled below freezing. Obviously some warming aloft has occurred since last evening over New River.
Comment by kevinmyatt — January 27, 2009 @ 7:04 am
North Roanoke county here, just a cold rain thus far. Not freezing to surfaces. Temp is 35.6F.
Comment by P. Kelley — January 27, 2009 @ 7:12 am
Down to 34...
Comment by Betsy — January 27, 2009 @ 7:31 am
nothing freezing here just yet here just off of willaimson road in roanoke. all liquid right now with the temperature a few degrees above freezing outside my door right now at 8:25 A.M
Comment by Daniel Argabright — January 27, 2009 @ 8:26 am