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Something besides thunder rattled things in Cave Spring this morning. I remember waking up and stuff was rattling, and I wondered if it was a gust of wind, but it seemed like stuff inside the room was rattling too. It was a magnitude-3.0 earthquake.

It's not really weather, but the National Weather Service did put out a public information statement about it early this morning (the magnitude has since been upgraded slightly):

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
457 AM EDT SAT MAY 16 2009

...PUBLIC INFORMATION STATEMENT...

AT 408 AM EST...THE NATIONAL EARTHQUAKE CENTER IN BOULDER DETECTED
AN EARTHQUAKE 4 MILES WEST SOUTHWEST OF ROANOKE. THE EARTHQUAKE
MEASURED 2.6 ON THE RICHTER SCALE. SO FAR...REPORTS INDICATE THAT THE
QUAKE WAS FELT IN THE ROANOKE...VINTON...AND SALEM AREAS.

INFORMATION RELEASED IN THIS STATEMENT IS PRELIMINARY.
UPDATES...INCLUDING RICHTER SCALE MAGNITUDE...WILL BE PROVIDED AS
MORE INFORMATION BECOMES AVAILABLE FROM THE NATIONAL EARTHQUAKE
CENTER IN BOULDER COLORADO.

I don't often link to articles on the major weather Web sites, but this blog entry on AccuWeather.com is just too much on the money, specifically pointing out Roanoke's recent-years snow drought and noting that the Eastern snow drought is really part of an overall year-round precipitation drought -- a familiar theme of mine.

Thanks to reader Douglas Rutz for pointing this out to me.

Several interesting weather things have been going on across the nation.

* Tonight's severe weather outbreak in the Plains has been hamstrung by a lack of moisture and limited instability, thankfully for residents out there who have a long season yet ahead, but still enough atmospheric dynamics for a handful of tornado reports and scattered large hail and high winds. Click here for a look at the Storm Prediction Center's severe weather reports.

* Mount Redoubt in Alaska has been in a series of ash-belching eruptions, the latest late Sunday. Volcanic ash injected into the atmosphere often tends to have a medium-range (several months to a year or two) cooling effect. We'll see in time if these eruptions have emitted enough ash to have a noticeable effect on North American or Northern Hemisphere climate.

* The same storm system responsible for severe weather in the central and southern Plains is blasting the western Dakotas and nearby parts of Montana and Wyoming with a massive blizzard.

* Meanwhile, eastern North Dakota is bracing for massive flooding as a winter of deep snowpack rapidly melts, with some rain on top of it.

Southwest Virginia looks cool and rainy most of the week after Tuesday. Temperatures will hover in the 40s and 50s most days. That should dampen the severe weather risk, while any rain that falls will help with continuing dryness that has improved some with March rains.

If you haven't, be sure and read Mason Adams' story on water levels at area lakes and reservoirs. It does a good job of answering some questions you may have been wondering about regarding how recent rain and snow have affected water tables, and how normal rainfall this spring would put our region in pretty good shape to escape the drought ... provided we have normal rainfall, of course.

You may have also read my Weather Journal column for today, and the two pieces may seem to contradict each other. But note that my column was referring to dryness regionally and nationally over the December to February period, while Mason's story was more about the effects of rain and snow locally over the past 2 1/2 weeks. I probably could have made my last paragraph a little clearer to note that.

Speaking of a dry spell ... I'm taking a few days away from Weather Journal, both the blog and the column. This week's weather looks pretty straightforward: After a warm day today, there will be a few showers with a cold front Thursday, then cooler and dry (50s for highs, 30s for lows Friday) and gradually warming by dry through the weekend.

I will pop back on the blog if something extraordinary happens or is forecast, but otherwise expect me to back on the blog early next week and back in print next Wednesday.

A National Weather Service public information statement reported Roanoke's official snowfall total as 7 inches, listing WDBJ as the source. But WDBJ is reporting 3.6 inches as the storm total. And a national weather summary used 9 inches as the figure for Roanoke.

Robin Reed, meteorologist at WDBJ (Channel 7), which serves as the official reporting site for snowfall in the Roanoke Valley, told me tonight via e-mail that 3.6 inches was measured at the studio, and therefore that will stand as the official record for this storm. However, other sources reported some larger amounts, one of which was 7 inches for Roanoke, which was relayed to the weather service by WDBJ. That's where the 7-inch report came from ... WDBJ was the source reporting it to the weather service, not the location, for that snowfall report.

And the 9-inch report came from yet another source that was actually 3 miles southwest of Roanoke, according to the weather service. Yet the Hydrometeorological Prediction Center picked up that report and listed it as the snow total for Roanoke.

There are many reasons why snowfall amounts were so variable across short distances in this storm. The first is subtle temperature differences, largely related to elevation changes but also perhaps to urban development, that caused some areas to accumulate more of the early wet snow than did others. Elevation difference almost always lead to varying snowfall amounts in mountainous regions. Another factor was the streaky nature of the overnight snow bands, which moved slowly, repeatedly slamming some localized areas while others received lighter snow.

Snowfall in the area was also compacted at different levels by the brief late evening sleet/graupel episode (I will get back to explaining graupel), and there were uneven patterns to accumulation related to differences between grassy and open areas, drifting from winds, and how much snow was already on the ground underneath from Saturday night.

So I have no trouble believing the range of accumulations. But let it be noted now that 3.6 inches will go down as Roanoke's official snowfall from this storm. It still takes the winter out of the realm of the least snowy on record, but may not represent the way you remember this snowfall. It's about half what I got where I'm at, a little south of the city. 3.6 inches wouldn't get inside my boots.

In Friday's Weather Journal column, looking at Thursday's winds but primarily reviewing the Feb. 10, 2008, windstorm, I only got to use a very small portion of my Q&A with Stephen Keighton and Phillip Manuel of the National Weather Service in Blacksburg. If you are interested, I have posted the entire e-mail conversation we had regarding the Feb. 10, 2008, windstorm in the extended entry below (click on "Read More" if you are in full blog mode). Read more »

The cold front that pushed through Southwest Virginia today, and has left blustery northwest winds in its wake, slammed into more moist, unstable air to our southeast earlier today. With strong wind dynamics aloft creating spin, the result was a series of rotating thunderstorms that produced several reports of tornadoes from northern South Carolina into central and eastern North Carolina. At least two people have been killed in North Carolina southeast of Raleigh. (Photo at left, from the Associated Press, shows damage at Kenly, N.C.) Several tornado watches remain in effect along the East Coast from Massachusetts to the Carolinas this evening as the cold front continues to press eastward.

Meanwhile, southern California continues to be blasted by strong Santa Ana winds that are fanning enormous wildfires that have already scorched hundreds of houses and forced thousands from their homes.  (The photo at left, from the Associated Press, shows an intense wildfire in northern Los Angeles) The two violent weather episodes are linked by a large high pressure system over the central U.S. that, at once, because of its clockwise rotation, is forcing viciously dry and hot easterly winds into southern California and chilly northwest winds into the East. So, yes, the California wildfires, the North Carolina tornadoes and the start of a cold, windy, possibly snowflake-dotted week of weather in Southwest Virginia are all linked together.

I'm taking a few days off from blogging, partly because of a software change. The weather looks pretty quiet the next few days anyway. I hope to be blogging again by Tuesday or so.

I will be continuing to answer reader questions, including some I took from blog comments, in my Sunday and Wednesday Weather Journal columns that appear in the Roanoke Times newspaper. Today, I have a column about a possible seismic tornado warning system.

You can click here to see the Weather Journal columns.

We've had some discussion about fall foliage on here ... here's a link to a Web site with some regular folilage updates and other information on fall in Virginia.

As for weather this week ... there may be a few showers mid to late week as a new cold front presses eastward, but at this time it doesn't look like a widespread, appreciable rain.

In my Weather Journal column for Wednesday, I've started answering some of the questions you e-mailed to me or posted on my Sept. 17 blog entry soliciting weather questions. I started with a question about fall foliage this year, one I frequently get, but often struggle with as my area of knowledge is weather, not biology. I found a little help from a North Carolina State University article on the Internet, linked here in full. Do you have any ideas about how the fall foliage will be this fall? Feel free to post a comment below.

I will continue answering some of your questions in my shorter Sunday and Wednesday Weather Journal updates the next couple of weeks. These appear on the back page of the Virginia section of The Roanoke Times, and also on the Weather page on Roanoke.com (which is separate from this blog).