UPDATE 12:30 AM, 3/12: Rain should end not long after sunrise on Tuesday morning, with westerly winds kicking in behind a cold front during the day. Downslope warming from the winds blowing over the mountains and some sunshine may allow temperatures to climb well into the 50s (a few low 60s?) in most locations in Southwest Virginia, but the front is introducing an air mass that will bring colder weather for midweek. New blog post by mid-morning Tuesday. END UPDATE
With highs of 64 at Blacksburg and 65 at Roanoke, Sunday was the first day of this month to average above normal at both sites (despite near- to slightly below normal lows in the upper 20s/low 30s) and the warmest day since the late January thaw that preceded the flooding rains.
Monday may be almost as warm with highs around 60, but it appears that we won’t repeat the flooding rains of late January. A cold front is due to push through with a band of Gulf of Mexico moisture Monday night, but it appears it will be a quick hit of rain and nothing prolonged or especially torrential, around a half inch or so for most, maybe closer to an inch the farther west you go in our region. Guidance leans to an arrival of the main area of rainfall after sunset Monday, but some showers may occur during the daylight hours.
The cold front will bring temperatures back to down to below-normal 40s for highs in many locations by Wednesday. The general northwest flow in the upper levels of the atmosphere is likely to promote more colder than normal weather through the next week or two, though not every single day may not be what we would call purely “cold” with highs moving back into the 50s to near 60 between cold fronts, perhaps even late this coming week. Some disturbances caught in this northwest-flow may trigger a few bouts of showers — either rain or snow being possible, depending on timing and location — and there are a couple of systems a week or more out to watch for more widespread precipitation potential. One thing that is growing increasingly clear about this March is that it will be a far cry from last year’s warmest March on record, and may even be the first colder than normal March in Southwest Virginia since 2005.
(0 to 10 chance of 1 inch of snow during week)
Roanoke 1 snowflake *
Blacksburg 2 snowflakes **
Outlook: The final week of the 2012-13 snow meter starts off mild and rainy late Monday into Tuesday, then turns breezy and a bit cooler for a few days, with some colder than normal weather maybe settling in by the weekend. But “colder than normal” in March means something very different than it does in January. Even low 50s for highs could qualify as colder than normal at Roanoke, and upper 40s at Blacksburg. That said, there may be some chance of mountain snow showers developing, behind the early week cold front on Tuesday, or perhaps next weekend with a possible Alberta clipper system moving southeast. So, while I don’t see much accumulating snow risk in any of that, I won’t plop zeroes down on the last week.
Looking back: Mission accomplished at Roanoke – 2.5 inches of snow measured on Wednesday during a week I went above five (seven snowflakes) on the snow meter clinched my goal of a 10-win season. At Blacksburg, I concede total defeat in this relentlessly quirky winter. Less than half an inch fell there, even though I picked seven snowflakes, my eighth straight defeat. I simply can’t adjust to a winter when it can snow for hours at Roanoke while it’s raining at Blacksburg. That never happened in my 13 previous winters in Southwest Virginia, and now it’s happened twice a month apart (recall 3.5 inches at Roanoke to 0.8 at Blacksburg on Feb. 6-7). The snow meter is entirely defective for Blacksburg in 2012-13.
Current records: 10-4 at Roanoke, 5-9 at Blacksburg.