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January 30, 2010

Snow possibilities on the rise here

With computer models trending more northward, the possibilities for more significant snow seem to be on the rise for the Baltimore area today.

UPDATE: The snow continues to fall, and the Winter Storm Warning is creeping farther north into the Baltimore area. Here's the latest from NWS Sterling:noaa



Earlier post resumes:

The National Weather Service has issued Winter Weather Advisories for Central Maryland, with 2 to 4 inches of accumulation possible later today. The lower amounts are predicted for the northern part of the forecast area (from the Mason-Dixon Line southward) to 4 inches in Arundel and PG counties.

Farther south, the NWS has issued Winter Storm Warnings, with those folks bracing for a big AccuWeather.comsnowstorm. Lexington Park, down in St. Mary's County, is forecast to get 5 to 10 inches. The Lower Eastern Shore is in the same boat, with up to 10 inches due there.

It's already (10 a.m.) snowing in Washington, D.C. Here's a webcam view.

Temperatures will not be a problem with this one. It's pretty darn cold out there, with forecast highs for BWI only in the mid-20s.

The heaviest snow from this storm is predicted for central and southern Virginia , with a nasty mix now due in the Carolinas, with a foot or more possible there. Here's on the prospects.

The snow here should get started around mid-day, but it will be a hard start. The air here on the WeatherDeck in Cockeysville remains very dry. The dewpoint is at 1 degree, with a relative humidity at 46 percent. (It's around 5 degrees at The Sun). We will need a lot more moisture here to start the snowmaker.

If you want a line on how close we are to the start of the snow, keep an eye on the dewpoint on The Sun's weather station at North Calvert and Centre streets, When the dewpoint begins to approach the actual temperature, you can start to watch for flakes. But remember that it's the dewpoint upstairs, where the snow has to form, that matters. It may still be drier at the surface.

UPDATE: Flakes on the WeatherDeck at 11:15 a.m. Dewpoint at the surface now 0 degrees, 44 pct rel. humidity; temp 19 degrees. Must be some much wetter air at altitude. 

Anyway, kudos to Mr. Foot and his students for being among the first to see the storm's northward trend in the models over the last 24 to 48 hours. They have been all over this shift.

And as always, once the snow gets going, feel free to post your thoughts and observations here. I will check back during the day and post them as fast as I can (between Honey-do List chores).

Posted by Frank Roylance at 8:45 AM | | Comments (23)
Categories: Forecasts


Received this Friday in response to readers' discussion in comments on earlier posts asking why the NWS does not provide snow estimates sooner in the winter storm cycle. Steve Zubrick is the science guy at NWS Sterling:


"After reading your blog...I have a comment to share.

"There is an official NWS product that serves as a "heads up" on potential significant weather in the next 7 days.

"That product (discussed at the winter Media workshop held Dec 2009 you attended) is the "Hazardous Weather Outlook" or simply "HWO".

"We issue this HWO text product at least once daily, typically in the early morning (4-6AM). It's updated as frequently as needed. Usually, there is at least 1 other update later in the day.

"The URL to this product (and 40 previous versions) is:

"One can also go to the web site and click on any part of the map...and can usually find the HWO on each WFO's site.

"For this coming weekend's snow event... the HWO issued early Tue morning (553 AM- Tue Jan 26) highlighted the potential for accumulating snow for the region:

530 AM EST TUE JAN 26 2010

"This product has consistently highlighted a threat of snow since early Tue (Jan 26).

"Basically, if forecaster has determined that there is a potential for having to issue any watch/warning or advisory for any kind of weather-related threat (winter storm, severe thunderstorms, coastal flooding, small craft/gales, river flooding, etc) in the next 7 days...then we give a brief mention of that threat in the HWO. Often, if a threat if many days in the future, we express some level of uncertainty and/or confidence associated with the threat.

"This product is geared toward emergency management officials, as well as the media and the general public. It speaks about the weather threat in layman terms."

My husband and I just love Foot's Forecast! Those guys are not only diligent and accurate as hell, they're adorable in the way they write. Sorry, they probably won't take that as a compliment, but it's meant as one. They're so earnest.

Thanks for the heads up. I've been following them for some time now and am impressed with the remarkable job they do!

I am in Leonardtown, St. Mary's County, and thus far I have 5 inches with a moderate snowfall. It has not stopped snowing since I woke at 8:00 am.

Wish i was a wetherman. You guys are never held accountable for your forecasting....12 inches of snow for the weekend...storm will miss us to the south...winter weather advisory 2-4 inches...must be nice to be able to blame everything on a computer instead of using your own skills to determine weather

FR: First, I am not a forecaster. My degrees were in history and communications. I write a blog and pass along what forecasters, and readers, are saying. Second, weather forecasting is not orbital mechanics, which can forecast eclipses thousands of years in advance. Meteorologists deal with millions of variables in a chaotic atmospheric system. It ain't easy. And third, they are held accountable. Forecast offices are rated on their performance. And then there is the public, and readers like ours, who hold them accountable every day.

Kudos to Mr. Foot and his collaborators.

At 1:15 there is already an inch to an inch and a half in Carroll County (with fairly bad road conditions - just slid right through an intersection). Might have to revise that North trend even further if the current pace of snowfall continues.

FR: I just drove from Cockeysville to White Hall and back. Very slippery roads, little sign of salt or plows. Three inches on the WeatherDeck.

About 3.5 inches in Bel Air already (1:37PM) and coming down at a steady rate. If this continues on until evening (like I heard), this is going to be a fairly significant amount. Forecasts be darned!

What a horrible forcast. Again the weather people are never held accountable for making terrible forcasts. It took me almost 2 hours to get home from hunt valley driving down york road i live in towson. The storm is going to stay to the south and we probaly won't get any measurable accumalation. What bull ....

Here's more, just in from Mr. Foot:

"Below is an email to Jack Larkin at 95.1 Shine FM - They interviewed me briefly back on Wed and yesterday for just a few minutes. I told Jack last night I felt the students would be able to predict arrival time to within the hour. Boy was I wrong! They got it within a minute for the DC metro area. Key points in bold below.

"To: Jack Larkin
Subject: Forecast update

"Hi Jack,

"... Wanted to point out for your listeners-- using a little known forecasting technique called "shortwave tracking" one of my 11th grade forecasters (Mr. Snowlover) from NW Baltimore County projected the arrival times DOWN TO THE MINUTE for DC-- he said 9:00 AM today at 11PM last night. At 9:01 the snow began as reported by several observers. He also said by 11AM for Baltimore, and snow was reported here in Dundalk at 9:56. Keep in mind these are high schoolers who had the day off and our Penn State forecasters as well. We were up until nearly midnight on a Friday tracking air movement in the upper atmosphere. Not exactly what you would expect sophomores and juniors to be doing on a Friday night, huh?

"We cannot go back and change previous numbers as they are part of an experiment (4 BWI / 5.7 IAD) , but will add new ones--- 8" in Downtown DC at the Arborteum, 6" in Dundalk, 4" in Bel Air."

Well, I am no weather forecaster, but its only been snowing for 2 1/2 hours here in Jacksonville and we already have over 4 inches (I just went out and measured on our outdoor table), and its still snowing like crazy! My prediction? Well get 6-8 inches, so much for the expensive computers!

I'd say one of the biggest underestimated storms in a long time. You can NEVER underestimate a Northern Trend!

Why is a guy with a history degree writing a weather blog for a commercial sight?

FR: Because I have been a journalist for 35 years, covering science and weather for almost all of that time; and because The Sun, which signs my paychecks, asked me to.

There are two things I've come to realize about snow in the Baltimore area.

1. People with rear wheel drive vehicles should stay off the road during snow events... *and*

2. The NWS forecasters should pay more attention to Mr. Foot's students.


I am usually a staunch defender of weather forecasters (maybe largely because my daughter has a weather-related degree from SUNY/Albany), but this storm seems to have been especially difficult to get right. What was it this time that made the timing/location so very ... fungible? Also...what can you tell us about forecasting's overall record for "getting it right"?


Some of the comments here a bit heavy on the vitriol.

Weather forecasting is a inexact science at best.


Some of you all are inconvenienced I know and are lashing out. But I find the comments about forecaster accountability ludicrous.

What do you suggest we do. Burn the inaccurate forecasters at the stake (Metaphorically Speaking) ??

Should we stone the messenger in a public square (In This Case Our Resident Weather Blogger)

Well you would have no forecasts at all eventually as you would run out of forecasters and furthermore no one would dare say anything about the subject at all.

Personally even at my advanced age I still get excited looking out my window as I arise to see what the day is like. I absolutely was giddy when I saw the snow falling today. Its a gift in my mind to have variables both good and bad in life. If I knew what the weather was with 100% certainty I would lead a boring existence as far as weather goes.

Maybe someday science and technology will give some of you your accurate forecasts or maybe even control weather into a bland ok for everyone sameness. I hope to NEVER live to see such a day myself. I love the idea that Mother Nature is in control. Not us insignificant humans.

Now yes I did go off on a tangent here. But really people ?? What is it that you want ?? Be careful what you wish for. You might get it and not really care for it and there would be no turning back.

Francesca In Baltimore

We have 5 and a half inches on my deck in Kingsville at 5:30 p.m. I wonder if there is a site where I can see updated local snow totals posted by others. I have looked around and cannot find anyone doing that. Frank, do you know of such a site? It does strike me that many forecasters rely too much on models and do not look at the movement on radar. I could see we were in for much more than an inch of snow just looking at the weather radar and the northeast movement of the system and the totals down south this morning. Hats off for Foot's Forecast for being right on!!! The National Weather Service is still predicting 2 to 4 inch totals at least as related on WBAL's 5 p.m. forecast. You would think they would update their Baltimore metro forecast based on actual amounts received.

FR: You can check snow totals from around the state in the morning on CoCoRaHS. The NWS Winter Storm Warning at 3:30 was calling for 4 to 7 inches in Baltimore. And yes, the forecasters at Sterling watch the radar all the time. They do seem to have been behind the curve on the northward movement of this snow. I've asked Steve Zubrick for comment on that. I'll post his comments when I get them.

I also listened to the forecasters who predicted little snow for Baltimore and was stuck trying to get home on snow-filled streets today. I think the reason people are so mad is the local tv stations have commercials boasting how great their radar and forecasting skill is and then they completely screw it up. If they wouldn't go on about how wonderful they are I think people would hold them to a lesser standard.

I measured at 7pm on our deck out back here in Owings Mills: 6" on the nose.

I called this last night in one of your posts. You could see from the radar map at the time that the storm was shifting North. I knew then we'd see at least 6 inches. And it's still snowing. We may get another inch before all is said and done.

Snowblower John of white hall thinks this is a bit more than a light dusting...

I would love to here the comments from Mr. Zubrick. As one of Mr. Foot's forecasters I wasn't extremely surprised by the event (although it was more than we thought).

But what did surprise me was the lateness of winter weather advisories and winter storm warnings. The lack of those warnings I think did cause a lot of chaos on the roads as drivers did not have a clue, and the roads weren't treated nearly as much as they should have been.

Okay so the forecasters didn't see it and they were late, it happens. But then what got me really frustrated was when winter storm warning criteria was being met, but there were no winter storm warnings. The criteria for a winter storm warnings is 5+ in our area. When you see reports of 4' or 4.7' in Frederick (at 3pm) a winter storm warning needs to go into effect for Frederick County. This was the case for Frederick and Carroll County.

I don't think its ever too late put out advisories like this because when people see something like "warning" it really turns them off to traveling. No one in my house went anywhere because I told them what was going to happen, however one of my mom's friends had no clue and was on her way home and got stuck in heavy snow. Call it ignorance on her part, but normally people like her heed weather advisories and stay at home.

I posted this comment on here because I know there is some chance that I could get some feedback from Mr. Zubrick and that would be awesome. I realize I am being nit-picky because the NWS (especially Sterling) does a superb job the majority of the time. I just felt in this case the situation was ridiculous.

Love everything you do Frank and that guy giving you flack is outrageous. Don't read if you have a problem with it!

Here's the last word from Mr. Foot and his crew:

"As posted on the site for Central/Southern and Eastern MD:

Frederick 7.3 | Westminster 7.5 | Reisterstown 7 | Towson 8.5
Elkton 7.5 | Belair 6.3 | Dundalk 7.0 | Annapolis 8.0 | Rockville 6.8
Olney 6.0 | La Plata 10.5 | St. Mary's 12

Cambridge 8.0 | Easton 7.5 | Centreville 8.0
Salisbury 12 | Ocean City 11.5 | Crisfield 13

"Our forecast team, forecast team wishes to point out that this situation is due in large part to departure of the 500mb upper level polar vortex which in turn created somewhat of a vaccuum for the energy digging through the southwest to force Gulf moisture much farther north than many forecasters anticipated. Once the vortex eased toward the Canadian maritimes, the Great Lakes high settled into southern Ontario as shown on current surface maps. That created the ideal setup for what you are seeing now: a classic coastal snowstorm with I-95 and east being the battleground. It is a textbook example of the old rule: "Predict the high and you predict the storm."

"The high school forecast team comprised of students from Carroll County, Baltimore County and Anne Arundel and County on Friday night, January 29, 2010 used a little-known forecasting technique called "shortwave tracking." Based on analysis by an 11th grader and a 10th grader in Baltimore County, the start time for the Washington metropolitan area was 9:00 AM Saturday. The Baltimore metro area onset was projected to occur no later than 11:00 AM. National Weather Service forecasts were calling for snow to begin by 1:00 PM. At 9:01 AM, several observers in Anne Arundel County reported snow, followed by Dundalk, MD at 9:56 AM. In a moment of irony, the actual student forecaster whom made the projections also reported snow starting at his home in Reisterstown, MD at 10:57 AM - only 3 minutes off from his original forecast made 12 hours earlier.

"Using this same tracking technique at approximately 3:00 PM Saturday, the 11th grade student from Baltimore County projected the snowfall should come to an end in the metropolitian area between 7:00 and 7:30 PM. Once that occurs, Mr. Foot's Forecast team believes the area will have received the general six to twelve inches they originally predicted for the storm six days prior, as reported in the Baltimore Sun on Monday January 26.

"Mr. Foot
Science Teacher ~ The Crossroads Center
Baltimore County Public Schools"

This is my first ever post to any blog on any subject anywhere. Why? Because like others, I am frustrated. Mr. FR, I dont disrespect your education, experience or the difficulty of the inexact science of weather forcasting. Like most folks, all I really want is to actually hear a weatherman, just once, stand in front of the camera at 6pm and say "Sorry folks, this one snuck up on us and we obviously got more snow than we had forcast earlier today." The frustration arises in me (and I assume others as well) when instead, you look and sound like politicians dancing around your earlier claims. You either misquote (inflate) your earlier predictions, or you press on with the current weather with a smile and no reference to earlier forcasts. I am a professional in my field. At times I make mistakes. When I do, I acknowledge them, make corrections if necessary, and move on. You guys could greatly reduce the frustration level of your viewers by doing the same. Honesty breeds patience and understanding, arrogance breeds contempt.
Jim Curtis, Pasadena

wow.sons second birthday party. what a debacle. all showed though. but 3 had accidents on their way home. good job kids on great predictions. and happy b-day to my two year old boy mason. oh yeah, traffic stunk yesterday. 7.0" in overlea

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About Frank Roylance
This site is the Maryland Weather archive. The current Maryland Weather blog can be found here.
Frank Roylance is a reporter for The Baltimore Sun. He came to Baltimore from New Bedford, Mass. in 1980 to join the old Evening Sun. He moved to the morning Sun when the papers merged in 1992, and has spent most of his time since covering science, including astronomy and the weather. One of The Baltimore Sun's first online Web logs, the Weather Blog debuted in October 2004. In June 2006 Frank also began writing comments on local weather and stargazing for The Baltimore Sun's print Weather Page. Frank also answers readers’ weather queries for the newspaper and the blog. Frank Roylance retired in October 2011. Maryland Weather is now being updated by members of The Baltimore Sun staff

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