« Tues. snow chances 90 pct; amounts light | Main | Want more snow? Get on any interstate and drive »

January 10, 2011

Storm shifts to Tues. P.M.; 5 inches or less due

Snow chances for Tuesday in Central Maryland have now reached 100 percent, and forecasters at the National Weather Service have issued a Winter Storm Watch for Central and Southern NWSMaryland, as well as much of the Eastern Shore.

UPDATE: 3 p.m.: The latest Winter Storm Watch out of Sterling has the snow starting in the late afternoon or early evening Tuesday. No problem for the morning rush. And light snow in the evening may spare us a really bad commute home. Earlier post resumes below.

The Watch means snow accumulations of 5 inches or more are possible within 12 hours as the snow falls, but most areas would likely see less. The snow totals will fall off sharply from east to west. Carroll and Howard counties are at the western edge of the Watch area.

A lesser Hazardous Weather Outlook statement has been issued for the western counties to Allegany, calling for "accumulating snow." Garrett County is under a Winter Storm Watch calling for 6 inches or more.

Forecasters at the Baltimore-Washington forecast office in Sterling, Va., say they expect the snow to begin falling at BWI-Marshall airport a bit later than previously stated - around mid-day Tuesday or during the early afternoon. It is likely to continue through Tuesday night.

Daytime highs during the storm will be in the low 30s. The precipitation is expected to be all snow in the Baltimore region, but could become mixed with sleet in Charles, Calvert and St. Mary's counties in Southern Maryland. The Lower Shore should expect a mix of rain, sleet and snow, with little or no accumulation, forecasters said.

The snow comes as two storm systems approach the region. The largest system is hitting much of the South today with snow, ice and rain. It is expected to move east and emerge off the Carolina coast tonight. That one will be sending increasing moisture into the region from the Gulf and from the Atlantic.

The second low is approaching from the Great Plains, with the center passing to our north on Tuesday, putting Central Maryland in between the two systems. says the twin storms will merge to our northeast and hit New England especially hard after whitening the mid-Atlantic corridor:SNow map for Sunday 1/9/11

"Plenty of cold air will remain in place to support snowfall along much of the heavily populated I-95 corridor in the Northeast, while some mixing, including treacherous ice will occur farther south through the mid-Atlantic Coast. This means that heavy snowfall with amounts of up to a foot could slam a corridor from perhaps as far south as New York City and northern New Jersey to Boston and eastern Maine."

"Philadelphia also looks like it is line for plowable snow that will disrupt travel, while the Baltimore-Washington, D.C. corridor may only get a couple of inches of snow from the storm. It should be noted that the storm track is still not set in stone. A wobble in the storm's track by only 50 miles can make a major difference in snow totals for the big Northeast cities."

The map at right shows the snow cover for the continent on Sunday. You can see the new snow in Oklahoma, Arkansas and Mississippi from the developing southern storm.

Eric the Red, a professional meteorologist in Baltimore, has chimed in with this:

"Early morning data has the phasing occurring just in the nick of time to give the region 2-4" ... with the heavier snow across northeast MD. The WRF/NAM [models]  has the snow arriving in DC about 4-7 p.m. on Tues., and shortly after 7 [p.m.] in Baltimore. This would be ideal, giving everyone a chance to get home.

"The WRF also has a quick burst of moderate to perhaps even heavy snow during the late evening hours, and then cuts the [precipitation] off abruptly between 1 and 4 am Weds morning.

"Still have other model data to come in, but the early guidance supports 1-3" south and west of Baltimore (even in DC) ... while 2-4" from Baltimore and points north and east."

Posted by Frank Roylance at 7:01 AM | | Comments (19)
Categories: Forecasts


5 inches or less? couldn't that be said on any day?

I have never ever seen a forecast that says anything definite. It always gives the caveat, or I should say, a way out for the alleged meteorologists. Every storm in this area is always "well it could be a dusting to an inch or two; but if this moves 50 miles this way, we could get 4 to 8 inches; another couple miles and we could get over a foot. But then again it could miss and we get nothing." What a joke. And these are the same people who claim that 100 years from now we'll all be underwater due to global hoaxing, er warming. They can't get a 48 hour storm forecast correct but they sure can predict 100 years in advance. The above forecast? Keep it for the next several "storm" forecasts for the area. They're all the same, everytime. I think the alleged "meterologists" on television should have to show their true credentials as "real meteorologists."

FR: Sure, it would be great if meteorology were as precise as celestial mechanics, and predicting snowstorms were as easy and precise as predicting solar eclipses. It just isn't. There are far more variables, far more difficult mathematics. Wishing it were easier will never make it so. And bashing forecasters for laying out the uncertainties so we can plan our day just makes no sense.

Anybody else confused why there is a Winter Storm watch for the Baltimore metro area for 5 inches or more, but nearly all forecasts are saying 1-2 inches??? If that is true, why not change the Winter Storm Watch to exclude the metro area. It's just getting my hopes up only to be let down tomorrow!

FR: I suspect it's because forecasters recognized a potential for five inches or more (which is the threshhold for a Winter Storm Watch) in at least part of their forecast area (especially the northeastern portion). But it's also true that the risk drops off quickly to the west. So most of us would see just a few inches, while some get 5 or so. Given the remaining uncertainties in the forecast, they are erring on the side of caution. It's that, or write this storm off at a couple of inches, and put lives and property at risk when people are caught by surprise, skidding around on 6.

Monica, it is much easier to predict a broad 100-year trend, than to predict the motion of a single snow band on a single day. That's the difference between climate and weather. The global warming people have science on their side, and the self-proclaimed debunkers don't.

FR: Well said. Thanks, your Majesty!


The Alarmists have skewed models and grant funding on their side. (That pesky 'hockey-stick, et al)

We debunkers do have 'science'...

Ah, Henry, do I hear you calling, as your namesake once did, to be rid of those turbulent "self-proclaimed debunkers"? Out of respect for Your Highness and the peace and good order of this fine blog, I will only say to you who have "science on their side" to mind the disorder in your own house (Climategate) and let the "Maryland Weather Blog" be about _weather._

I'd MUCH rather have the meterologists and forecasters do as they have been and be honest and tell us what the various scenarios are and the ranges of possibilities that exist.

That way, you can prepare for the worst and hope for the best.

The "science" that global warmists claim has been proven to be falsified and debunked. Anthropogenic man made climate change is a hoax. It is about controlling the population via regulations and taxes. To think that mankind is so powerful that we can alter the environment in a few short decades is both dangerous and narcissistic. We will see a mini ice age well before any global warming induced ecological problems.

Does anybody know if our location in relation to the jet stream or being about halfway up the East Coast makes it more difficult to forecast the weather here? I too get frustrated with snow forecasts that seem to be all over the place time and time again and was wondering if there were meterological factors that could explain it.

FR: Absolutely. This region is very difficult for forecasters, especially in the winter. We're far enough north to have plenty of cold air in place; far enough south to get copious moisture from the Gulf and Atlantic; and close enough to the ocean and the Gulf Stream to provide a nearby source of warmth. Add to that the familiar track of winter storms across the South and up the coast, and you have a pretty tight area within which to work out storm track variations, and rain/snow lines. It also happens to be one of the most densely populated regions of the country. As the forecasters keep telling us, a 50-mile twitch in the storm track (or the rain-snow line) can make all the difference. A 50-mile error in Wyoming would hardly be noticed.

Your map is hard to read - what part of the Baltimore Met area is in the 4 inch purple, etc.

Can you post a map with the latest predictions that might be a little less cool but more helpful?

FR: Sorry. That's how it comes from the NWS. Here's a link that will give you a better, though not great, view. Basically, the purple 5-inch zone runs from the Bay to I-95, but also includes the city, Harford, most of Baltimore County and a bit of northern Carroll, plus most of Arundel, Calvert, eastern PG and Charles. But I wouldn't put too much stock in the precision of those lines, which are drawn by a computer model. The idea is to show the potential (read, "maximum")12-hour accumulations dropping from 5 inches along the bay to 3 inches in Western Maryland (not including Garrett).

According to, the snow is supposed to start at 6AM on Tuesday and continue until 5AM on Wednesday.

FR: I suspect that's an outdated report based on earlier model runs. The NWS Sterling has it starting in the Baltimore area at mid-day or early afternoon.

A reminder to commenters: The names of the commenters here appear BELOW their comments (below the very faint line), not above. Please try to bash the right person.

Is it me, or does Purple on the NWS map represent 5.0, 13.0, and 35.0 inches? Or does that numbered blue and purple bar across the top represent something else?

FR: In this case, 5 inches. If this were last year, maybe 35. There are numbers on the map to provide a clue.

I think there should be a system of snow forecasting in place for this region based on quantities of bread, milk, eggs, and toilet paper that any given household should arrange to have on hand, rather than potential accumulation in inches.

A two-inch snowfall might translate to one quart of milk, a quarter of a loaf of bread, five eggs, and a third of a roll of toilet paper per adult per household, adjusting quantities as suitable for children, vegans, and those with allergies, not to mention individual appetites, preferences for quilted or plain toilet paper, and so on.

Naturally, a system of easy-to-read icons would need to be adopted for such weather reports.

The utter disappointment of no snow.

I think people get so upset with weather reports because local stationsare always proclaiming their such accurate and dependable forecasts with their sophsiticated doo-dads, hub-bub instruments and what-nots,

Just checked again and the 6AM-Tuesday to 5AM-Wednesday snowfall is still there.

FR: I see they have a 30 pct chance from 6 a.m., rising to 60 pct at 3 p.m. and 90 pct by 5 p.m. That doesn't seem to conflict much with the NWS. Thirty percent means the odds are roughly 2 to 1 that it won't be snowing in the morning.

Shane wrote: "To think that mankind is so powerful that we can alter the environment in a few short decades is both dangerous and narcissistic."

A few short decades? The Industrial Revolution, fueled by the burning of high sulphur coal, began in about the mid 18th century. So mankind has been at work altering the planet's atmosphere for, oh, about 300 years. And conditions aren't worse thanks to regulatory efforts, such as the Clean Air and Water Act of the 1970s, which eliminated acid rain by drastically reducing particulates produced by coal burning power plants.

FR: I'd also suggest reading up on the Antarctic ozone hole, depletion of oceanic fish stocks, Eastern forests, Great Plains grasses; the Aral Sea; the introduction of invasive species, extinctions and extirpations globally; dead zones; "brownfields" and Superfund sites; mountaintop removal coal mining; the human population growth since 1800; Chesapeake Bay grasses, oysters ... Shall I go on? Why would anyone suggest humans can't alter the environment? That's precisely what humans have been doing, for better or worse, since the invention of agriculture. Is it such a stretch to imagine we could also be altering the chemical composition of the atmosphere as we move billions of tons of carbon from deep underground into the air? If so, add some reading on the physics of CO2 in the atmosphere, which has been well understood since the 19th century.

Bottom line...we were told that if we didn't drastically reduce carbon emissions that by the year 2000 we would see current coastal areas underwater. That hasn't happened but the people telling us this (Al Gore, et al.) stand to reap billions of dollars from potential and real carbon regulations because they founded/invested in companies that will benefit from the regulations. Mother Nature herself puts more carbon and other particulates into the atmosphere than mankind does. The current extremely cold winter in Europe and the northern U.S...try looking at the volcanic activity caused by the subduction of the Pacific and Bering plates under the Kamchatka Peninsula. Believe it or not the current cold snap has nothing to do with global warming (as normally claimed by your average global warming alarmist). But then again, everything can be blamed on global warming according to them. Either that or it's Bushes fault...but global warming is probably his fault too.
If you truly want to understand climate read

More sulfuric ash was thrown into the atmosphere by the eruption of Krakatoa then by man...not mention the eruptions of Mt. St. Helens, Mt. Pinatubo, etc.

So, let's say, all of us "global warmists" are totally wrong.
What bad could come from polluting less, driving fuel efficient cars and taking care of the environment?

...and then, what if it turns out we're right?

Post a comment

All comments must be approved by the blog author. Please do not resubmit comments if they do not immediately appear. You are not required to use your full name when posting, but you should use a real e-mail address. Comments may be republished in print, but we will not publish your e-mail address. Our full Terms of Service are available here.

Verification (needed to reduce spam):

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

Sign up for FREE weather alerts*
Get free Baltimore Sun mobile alerts
Sign up for weather text alerts

Returning user? Update preferences.
Sign up for more Sun text alerts
*Standard message and data rates apply. Click here for Frequently Asked Questions.
Maryland Weather Center

Area Weather Stations
Resources and Sun coverage
• Weather news

• Readers' photos

• Data from the The Sun's weather station

• 2011 stargazers' calendar

• Become a backyard astronomer in five simple steps

• Baltimore Weather Archive
Daily airport weather data for Baltimore from 1948 to today

• National Weather Service:
Sterling Forecast Office

• Capital Weather Gang:
Washington Post weather blog

• CoCoRaHS:
Community Collaborative Rain, Hail and Snow Network. Local observations by volunteers

• Weather Bug:
Webcams across the state

• National Data Buoy Center:
Weather and ocean data from bay and ocean buoys

• U.S. Drought Monitor:
Weekly maps of drought conditions in the U.S.

• USGS Earthquake Hazards Program:
Real-time data on earthquakes

• Water data:
From the USGS, Maryland

• National Hurricane Center

• Air Now:
Government site for air quality information

• NWS Climate Prediction Center:
Long-term and seasonal forecasts

• U.S. Climate at a Glance:
NOAA interactive site for past climate data, national, state and city

• Clear Sky Clock:
Clear sky alerts for stargazers


• Hubblesite:
Home page for Hubble Space Telescope

• Heavens Above:
Everything for the backyard stargazer, tailored to your location

• NASA Eclipse Home Page:
Centuries of eclipse predictions

• Cruise Critic: Hurricane Zone:
Check to see how hurricanes may affect your cruise schedule

• Warming World:
NASA explains the science of climate change with articles, videos, “data visualizations,” and space-based imagery.

• What on Earth:
NASA blog on current research at the space agency.
Most Recent Comments
Blog updates
Recent updates to news blogs
 Subscribe to this feed
Charm City Current
Stay connected