From the ABC 7 Weather team

Archive for December 2012

D.C. Weather in 2012: A year of records

December 30, 2012 - 05:59 PM

It may come as no surprise that 2012 was a busy year for weather in the nation’s capital. Despite the high and low temperature on New Year’s Eve, it will go down as the warmest year in recorded history for Washington.



Here is just a glimpse at the records set at Reagan National:

♦ 26 daily records, including 1 monthly record (Driest September with 0.05 inch) 

♦ 4 days in mid to late March where the low temperature was warmest on record 

♦ High temperature of 105 degrees on July 7 came within a degree from the all-time record high in Washington of 106 degrees set on July 20, 1930

♦ Two highest minimum temperature records set in early August and early September 

♦ Trace of snow on November 8th set a record for most snow on that date 

♦ Last record high for the year was December 3rd at a toasty 71 degrees

♦ 1.42 inches of rain on December 26 set the record for the most precipitation for that date

♦ Total precipitation was 32.45 inches, which is 7.29 inches below average for the year. Only 13 years have been drier than 2012 since records began in 1871.

♦ Although the official number can’t be tallied yet because the year is not over, 2012 will rank as the warmest ever in D.C. 1991 with an average annual temperature of 60.2 degrees will move to second place and 1990 and 1998 will be tied for third place at 60.0 degrees.

Now, here’s some additional trivia as we close the year. There is 3 times as much area of the U.S. covered with snow as this time last year! Specifically, 63.1% of the U.S. has snowpack on the ground today versus only 19.5% of the U.S. on December 30, 2011! Check out the difference in the two snowfall depth maps below and take note of the time stamp at the top of each.



This day last year...


Now, here’s to a quieter weather pattern for 2013! Have a safe and enjoyable New Year!


Continue Reading


D.C. area snow on Saturday (Live Blog)

December 29, 2012 - 06:54 AM

Doppler Radar  |  HD Cameras  |  Advisories

12:20 pm - Snow that swept through the DC area has mostly moved beyond the Metro area. Much of the snow didn't stick in the immediate area. But several inches are on the ground in some parts.

11:19am - The Winter Weather Advisory has been cancelled in parts of the area but is still active for Loudoun, Montgomery and points NW.

Winter Weather Advisory

10:57am - Here's a picture of a light dusting of snow in Fairfax sent in by our Morning Meteorologist Jacqui Jeras.

Snow in Fairfax, VA

10:52am - Here is a list of snow reports so far in the D.C. area. The highest snowfall totals so far have been in Frostburg, MD (3") and in Martinsburg, WV (2").

10:47am - The snow has ended at Mike Stinneford's place close to Front Royal, VA. He received around 0.75". Snow will continue to come to an end through lunch time in the D.C. Metro. Track it on our Live Super Doppler Radar.

10:30am - Be sure to check out our Interactive Radar as this snow begins to end in some areas. Snow will continue to move from southwest to northeast as the system departs. I think it will exit the D.C. Metro close to Noon, so there may be enough snow for a quick dusting and the potential for a couple of slick spots on the roadways. Enjoy it while it's here!

9:58am - Snow has now been reported through much of D.C. and is actually falling outside our window here in Rosslyn too. We're still not expecting too much with maybe a dusting in and around D.C. in spots and up to an inch or two in the western suburbs. Snow should come to an end around Noon as this system continues to move to the northeast.

9:29am - The Metropolitan Washington Airports Authority has reported that light snow has begun at Dulles Airport but they have snow crews ready for it as only light accumulations are expected.

9:24am - Some light snow has been falling at our very own Meteorologist Mike Stinneford's home in the Blue Ridge. Keep in mind the snow on the ground was from the last storm!

Snow near the Blue Ridge

9:19am - Light snow is beginning to be reported through much of the D.C. area but mainly in the western suburbs. Light rain has been reported east and southeast of D.C. Here is a great place to see some of the snow...the traffic cameras in Virginia!

8:50am - I just looked out the window here in Rosslyn, VA and saw some light flurries, sleet and some rain. Heavier activity is still located to the south of D.C. with more rain and snow. This will make it to D.C. over the next hour. I expect it to mainly be rain in the D.C. Metro, but snow will still be likely west of the city where the Advisory is posted.

8:30am - Snow is still in the forecast. Here is our latest snowfall map. Keep in mind closer to the D.C. Metro, some flakes may be mixed in with rain which would keep the totals down. Snow is just beginning to pick up west of D.C.

Snow forecast for the D.C. Area

8:14am - Light snow and rain is beginning to show up on Live Super Doppler 7 to the south of D.C. near Culpeper and Fredericksburg. This will be what to watch over the next couple of hours.

7:54am - Who will see the big snow today? Really the only areas that will get some nice measureable snow will be the Boston area as well as Rhode Island. Here is the NWS forecast office in Taunton, MA. You can see there is a Winter Storm Warning posted up there in the pink shading. In those locations, 4 to 8 inches of snow can be expected along with some gusty winds.

7:48am - Be sure to check out some of our HD WeatherBug cameras across the region to see if it is snowing near your house. So far I have seen snow in Wintergreen, VA, Frostburg, MD and Frederick, MD.

Snow in Frostburg, MD on our HD WeatherBug cam

7:42am - From Josh Knight in WSHV in Harrisonburg, VA, there have been some reports of snow beginning to "really come down" in northwestern parts of Rockingham county. This is relayed from NWS Chat.

7:31am - Here is an idea of the energy I am speaking of as it is expected to move through the D.C. area by 1pm this afternoon. This is a look at the 500mb vorticity plot from the 6Z GFS model that ran earlier this morning. Continue to watch that swath of precipitation over southwestern Virginia as that is where our snow will be coming from.

500mb Vorticity as of 18Z Saturday from the 6Z GFS Model (WeatherBELL Models)

7:06am - Even though you haven't seen much snow in the D.C. area just yet this morning, the chance is still there as we are still awaiting some energy that is positioned to the southwest. Check out this Mid Atlantic radar loop that shows some snow falling over southwestern VA. That is the energy we are watching and it should get to the region later this morning.

The main question will be whether or not it falls as snow or rain. The farther northwest from the D.C. Metro you are located, the better chance you will see snow. We will continue to keep you updated with any reports and pictures we receive. Please send us pictures if you see some snow!

Continue Reading

Snow Saturday: Storm timeline and amounts

December 28, 2012 - 10:37 PM

OK it's late and late info doesn't give me any reason to make any significant changes. Tomorrow's storm is now developing in Lousiana. It will be a fast mover that is expected to be "in by 4 out by 5."  Here is a timeline I worked up.  Most of the D.C. area getting the dreaded "wintry mix" with all snow will be well west and north. Have a look. 

Enjoy a touch of winter on a Saturday.

Continue Reading

D.C. Snow: Another Chance Saturday

December 27, 2012 - 03:12 PM

Thursday's big storm only gave Washington 0.2" of snow but a record 1.42" of rain.  After a long dry pattern from October until recently, the pattern across the county is sure more stormy. 

Another much weaker storm will be forming to our south Friday and, as always, the key questions for our area are, "Will it be rain or snow? And if snow, how much?"  Here is the latest weather map for Saturday morning from the folks at the National Weather Service:


Right on the line. One of the keys I look at is the "ensemble" simulations I talked about in this old blog.  Here is an example from the great weather page at Penn State:


These maps indicate that the primary storm that will bring moisture in early Saturday will weaken and a secondary storm will be rapidly forming off the North Carolina coast and with strong winds above, this second storm will race off to the east. 

Here are two other simulations of key temperatures near us and a fine scale model of the precipitation. Both trend toward snow around D.C., but the main area of moisture well south with the new storm Saturday midday. 


I think D.C. will get some light snow beginning around dawn and ending by noon.  I think a 70 percent chance right now of 1" of snow on grassy areas, snow rain mix for folks in southern Maryland and 2-4" snow western high spots such as western Loudoun County and Frederick County in Maryland. 

Everything should be gone by Saturday afternoon and it's sure not a big storm, but something for snow lovers to look forward to.


Continue Reading


Winter Storm : Rain DC but still icy west

December 26, 2012 - 04:08 PM

The big storm is now redeveloping off the coast and racing to our north.  This storm produced the worst outbreak of Christmas Day tornadoes on record. Cold rain has been in D.C. all afternoon and if all the rain had been snow, D.C. would have close to a foot of snow by now.  Here is what produced this storm and what is coming next. 


Continue Reading

There is still a chance for a White Christmas in the D.C. area

December 21, 2012 - 10:31 AM

A weak area of low pressure appears like it will move into the D.C. area on Christmas Eve and there is still an outside chance that at least parts of the region may receive some snow. Model guidance depicts a disturbance that is currently out over the Pacific Ocean moving into the western states and eventually getting to the D.C. area by Monday evening. With high temperatures only forecast to be in the low to mid 40s through the afternoon hours, it may be cold enough for snow by Monday evening and night.

Surely with the recent snowfall across the country, the D.C. area should get in on the action too right? Below is a look at the snow analysis across the U.S. with the heaviest snowfall totals across the mountains in the western U.S. but also some heavy snow through parts of Iowa, Wisconsin and Michigan.

Snow Analysis as of 12/21/12

For now, the best chance for snow would be at the onset of precipitation Monday evening, as this is when the atmosphere needs to moisten and the temperature will drop to reach saturation as precipitation moves in. This may give the area some snowflakes for a few hours before a changeover to light rain.

Global Ensemble Forecast System Spaghetti Plot

There is another scenario though, that would be better for snowlovers, as the area of low pressure could actually be located a bit farther to the south. This would help allow for more cold air in the region and a better possibility for snowfall. Currently the guidance has a bit of a spread in the exact location of the low but a fair number of the models keep the are of low pressure a bit farther north. This would mean warmer air for the D.C. area and a better chance for rain. If you look in the red circle in the above image, you can see there isn't much of a consensus as to where this low will move, so there's still hope.

There is just one more thing you can do to try and help... Give a little Christmas spirit and sing!

Continue Reading

White Christmas this year? Not looking likely

December 20, 2012 - 05:00 AM

While the western and central parts of the U.S. are going full throttle into winter this week, the East can’t seem to buy a snowflake. So, what are the odds of a magical turnaround in the weather pattern and snow for Christmas Day in Washington?

First of all, what defines a “White Christmas? At least 1 inch of snow being on the ground the morning of Dec. 25. This does not necessarily mean that the snow fell on Dec. 24 or 25.

Statistically speaking, it’s a rare occurrence to have a White Christmas in Washington. There is a 15% chance that snow will be on the ground on December 25th with an even lesser chance (8%) of snow falling on Christmas Day. This means 1 in about 6 Christmases will see snow on the ground while 1 in 12 Christmases have snow falling on Christmas Day.

The last time there was enough snow on the ground to qualify as a White Christmas was 2009 only because of the leftover from the mid-December blizzard that walloped the Mid-Atlantic. The last time snow fell on Christmas Day was in 2002; 0.2 inches accumulated in Washington.


An average Christmas Day in the Nation’s Capital is partly cloudy with a high of 44 degrees following a morning low of 30 degrees. Guess what? The look ahead to Christmas Day as of now is for just that; partly cloudy to mostly sunny skies and highs in the middle 40s. Click here for the latest forecast.


Heavy snow that will blanket the western Maryland mountains and Potomac Highlands of far western West Virginia will likely remain on the ground through Christmas Day. Otherwise, the Plains with the midweek blizzard, Northeast and Mountain West are the other lucky areas of the U.S. that will have a White Christmas.

Have a safe and enjoyable holiday season!

Continue Reading


Christmas Travel: Friday Weather Headaches

December 19, 2012 - 08:00 PM

"Over the river and through the woods, to grandmother's house we go".  Well, you may want to pack your patience if grandma (or your loved ones) lives in the Upper Midwest, Ohio Valley, or New England where winter weather, whipping wind, and blizzard conditions could slow you down. 

Friday will be a big travel day for many, since it's right before the weekend and the Christmas holiday Monday and Tuesday.  Just in time for tons of travelers, a big storm system is brewing in the mid section of the country.  See how many weather warnings are posted across the country late Wednesday.  The red indicates blizzard warnings, the pink, winter storm warnings and the blue, winter weather watches.

National Weather Service

A big dip in the jet stream will allow the cold air that's been trapped in Canada, for much of this winter, to slide South.  Couple the cold air with a strengthening area of low pressure with a good bit of moisture and you get a winter weather travel headache.  The snow and blizzard conditions East of the Rockies and through the Central Plains will end by Friday, but the storm will then move into the Midwest, Ohio Valley, and New England by Thursday and Friday causing a slow go for many. 

Temperatures will plummet across much of the country after this weather system moves East.  Highs will only be in the teens and 20s in the upper Midwest and highs in the 30s and 40s, here, in the Mid Atlantic.  Beautiful weather in the South with sunshine and highs in the 50s and 60s.  Keep all of this in mind for packing purposes!

Here's hoping it's a smooth travel day for you and your loved ones.  Happy holidays!

Continue Reading


Snow: How Do snowflakes form-any in sight

December 18, 2012 - 02:29 PM

For area snow lovers there are only been a few flakes so far and still not a sign of our first big snow.  Sorry no sign either of a "White Christmas" this year but we will be into some pretty cold weather before the week is over.  Here's a confession-myself along with most meteorologists love snow.  There's nothing like going our after a nice dry snow of a few inches and seeing the diamond sintillations in the light of perfect snow flakes and hearing that "crunch" of the cracking snowflake crystals as you walk along.  Even wondered how snowflakes form?  Here is a great video from the American Chemical Society explaining how these beautiful creations of nature form. Is it really true no two are the same?  Well watch this short video and make sure to enjoy our first snow.  It will come : >)


Continue Reading

Check our Interactive 7-day for your travel forecasts

December 17, 2012 - 04:49 PM

Are you leaving town this week or weekend and would like to know the 7-day forecast for that area? Check out our interactive 7-day forecast, which has the latest forecast updated every day. For instance, here's the forecast for Chicago, IL for the next 7 days:

Interactive Forecast for Chicago, IL

So I am guessing not every place you will be traveling will be as cold as this, but you get the point as to what this tool can help you with! I'm actually heading to South Carolina this Saturday, where the forecast calls for sunny skies and highs around 60 degrees.

San Francisco  |  New York City  |  Los Angeles  |  Dallas  |  Miami

What makes it interactive is that you can scroll your mouse over each day and it will give you even more information such as sunrise and sunset, wind, humidity, dew point, and the important chance of precipitation. Give it a try and let us know what you think. We wish all of you safe travels and a wonderful holiday.

Continue Reading

International Space Station: Visible over DC this evening

December 14, 2012 - 04:04 PM

On a day when it's impossible to comprehend or understand  the worst of what can happen, an evening to perhaps look up and see some of the best of what we are capable of.  The international space station with it's international crew of 6 will be very bright this evening rising in the southwest and high in the northwest sky a 5:48 and moving into the earth's shadow at 5:51 in the northeast. On a very sad, sad day something positive to share with your children and parents.

Continue Reading

Weather Watches and Warnings: An Experiment for Better Understanding

December 12, 2012 - 11:00 PM

For many years, there has been public confusion of the difference between a weather "Watch" and a weather "Warning" especially various winter weather statements and terms issued by the National Weather Service. Here are some examples and discussion of the confusion the Wa-Wa statements (as we meteorologists refer to the current wording) cause. 

After much hard work ( including dealing with much legacy) a team within the National Weather Service is conducting an experiment this winter to see how significant changes in wording for preparation before storms, may help eliminate the confusion.  The experiment products delete the word "WATCH" from preparation statements and will only use "WARNING" meaning it is time for people affected by any upcoming storm to take action.  Here is an example of the current and proposed wording.  


Here are the local forecast offices that will be participating in this experimental program this winter.  



The local forecast office here in Washington will not be participating because it is already involved in several projects involving better, more effective communication of winter weather and snowfall forecasts.  But the National Weather Service wants your input.  Frankly for many years I have been pushing for such a change.  Some studies have show that as many as 60% of people are confused between what is a "Watch" and what is a "Warning". 

The National Weather Service is your service.  Effective communication is critical in helping you make the best weather related decision.  Government officials, various government organizations, emergency managers all have an interest, and frankly I think some legacy in maintaining the current system and language.  But you the public are our most important customer.  Let your National Weather Service know what you think and learn more here.  



Oh and make sure to take part in our poll on the subject.  I'll share it with the program leader of this very worthwhile effort and initiative.

Continue Reading

2012 Geminid Meteor Shower (Video)

December 12, 2012 - 12:18 PM

The 2012 Geminid Meteor Shower will peak over the next few nights with the potential for over 100 meteors per hour. With fantastic viewing conditions expected late tonight and tomorrow night, this could be a vivid light display. There should still be some high thin clouds across the region tonight, but skies should begin to clear in the predawn hours tomorrow morning. One of the best aspects of this shower is you don't need to worry about light pollution from the moon, which is about 1% right now, or basically a new moon phase.

This shower is caused by a rock streaming through space called 3200 Phaethon. It was discovered in 1983 by NASA's IRAS satellite. When you're going out to look for them, be sure to look east towards the Gemini constellation before midnight.

Continue Reading

The D.C. area is already adding daylight in the evenings

December 12, 2012 - 09:19 AM

December 11th was the last time this year the sun will set at 4:46pm. This stretch of darkness extended this year from December 1st through the 11th, which is the period of days with the earliest sunset. Here we are now on the elusive 12/12/12 and the sun sets at a managable 4:47pm. Hey, every minute counts when you absolutely hate leaving work in the dark.

Sunrise and sunset times for D.C.

So when will the D.C. area really begin to gain some ground? Well, let us not forget that the duration of daylight in the D.C. area continues to lose ground through the winter solstice. The shortest days for our region in 2012 are December 20th through the 22nd, which only have 9 hours and 26 minutes of daylight. With that being said, here on 12/12/12 we still have 9 hours and 29 minutes of daylight, so we'll continue to lose it in the morning, but not in the evening.

Related: See the Earth from Space at Night

So how about some good news that will make most of you (just a wild guess) happy. The sunset was 4:46pm yesterday, but by the end of the month, we gain 10 minutes of daylight in the evening for the sunset to get to 4:56pm. The sunset reaches 5pm on January 4th, and is all the way to 5:29pm on January 31st. The end of February on the 28th sees the sun until 6pm. We will of course gain all of this ground through Sunday, March 10th, when we enter Daylight Saving Time once more and Spring Forward.

As far as the sunrise is concerned, the latest sunrise occurs from December 31st through January 9th, when it rises at 7:27am. It will be slow going through January, rising at 7:15am by the 31st and finally back to 7am by February 14th.

Continue Reading

Hurricane Sandy: Assessment team

December 11, 2012 - 04:52 PM

Hurricane Sandy was a devastating storm and some of the warning decisions and communications have been criticized as been documented in many blogs and articles.  Following every major/devastating weather event such as Sandy, the National Weather Service and NOAA assemble a team to evaluate or access the accuracy of the forecast and how the end to end process of observation, forecast, communication, dissmeination and decisions were done.  Today NOAA released this statement about the makeup of the Sandy assesment team.

On behalf of the NOAA Deputy Under Secretary for Operations, below is a statement on the forthcoming NOAA service assessment on Sandy:

NOAA has commissioned a team to assess the performance of the National Weather Service during Hurricane/Post-Tropical Cyclone Sandy.

It is a multi-disciplinary team that includes two social scientists and 10 experts from across NOAA, the Federal Emergency Management Agency, and the Centers for Disease Control and Prevention. Members of the team who work for the National Weather Service were chosen from around the country and did not forecast Sandy. This allows for an impartial and unbiased review.

The team leader is a scientist with NOAA’s National Marine Fisheries Service who has extensive management and team lead experience. He will oversee all field work, the development of findings and recommendations, and the drafting of the assessment report.

The team will focus on three main areas: the philosophies and policies behind the forecast and the weather watch and warning products and how they are communicated; how storm surge products are produced and issued from multiple NOAA Line Offices; and the web presence as a tool for communicating with the public.

The team will deliver a concise report that identifies facts, findings, and best practices, and it will make recommendations for process changes and service improvements that can be made within six months. The team will start work this month and will begin its field work on January 6. Interim findings are due to NOAA leadership in the spring, with the final report due shortly thereafter.

I look forward to the findings and any recommended ways the National Weather Service can do an even better job to protect life and property through timely and accurate forecasts.

Dr. David Titley
NOAA Deputy Under Secretary for Operations

Continue Reading

Lay wreaths at Arlington National Cemetery this weekend

December 10, 2012 - 02:03 PM

Wreaths Across America is a nonprofit organization which has laid wreaths at veterans' cemeteries across the U.S. since 1992.

Their goal is, "to spread our message about the importance of remembering our fallen heroes, honoring those who serve, and teaching our children about the sacrifices made by veterans and their families to preserve our freedoms."

I am volunteering this year with a bunch of friends at the National Cemetery here in Arlington (about 2 blocks from WJLA's building in Rosslyn) and wanted to spread the word. It looks like a great event and if you're in town and not busy this Saturday morning around 9am you should join as we'll try to cover every single grave in the cemetery. Be sure to contact the volunteer location leader for all of the information if you plan on attendning.

If you can't come, you can always show your support by donating. You don't even have to donate to the Arlington Cemetery either, you can choose from over 600 cemeteries across the United States. I am actually donating wreaths to the Beaufort National Cemetery in South Carolina as my grandparents were laid to rest there.

Continue Reading

Remembering the Great Nor’easter of 1992

December 9, 2012 - 06:37 PM

So far since October, one Nor’easter has plowed up the coast bringing heavy snow north and east of the District from eastern Pennsylvania into New England. A much stronger one walloped the East Coast December 10-12, 1992, so much so that it was termed the Great Nor’easter of December 1992.

The storm began to form on this day 20 years across the Texas Panhandle. By the next day a strong high pressure positioned across the East began to retreat a bit as the low moved towards the Mississippi Valley. Upper-level energy helped strengthen the low as it moved to the North Carolina Coast on December 11th. The low reached then bombed out or reached near peak intensity late on December 11th through the 12th.


A METEOSAT-3 satellite image of the December 1992 Nor'easter.

The end result was a massive Nor’easter that produced tremendous damage from New Jersey to New England and locally brought a gamut of weather conditions. Wind-whipped heavy rain inundated the Chesapeake Bay region with 120,000 customers without power. Moderate flooding was observed in Ocean City, Md., with high winds. General rainfall amounts of 1-2 inches fell in the District but it was a whole different ball game west of the Blue Ridge.

Continue Reading


See the Earth at night from space

December 7, 2012 - 06:19 PM

NASA compiled a number of images of the Earth taken from a satellite at night. Can you find your house?

Continue Reading

Earth: A trip around the world at night

December 6, 2012 - 05:30 PM

This is a great annimation from NASA of a series of night views of our home taken by the new polar orbiting Suomi NPP satellite.  Learn more here and enjoy the view


Continue Reading

First D.C. snow: Magic date is December 5th

December 6, 2012 - 05:00 AM

Following record warmth earlier this week, some of you may be asking yourself, “Where’s winter?” The holidays are here and some folks would like to see some snow to add to the spirit! Well, historically, December 5th usually kicks off the winter season in the nation’s capital.

After doing a bit of research, I have compiled some compelling data that shows December 5th wins the award for the first measurable snow in Washington. As a matter of fact, some of the first snowfalls have been on December 5th within the last decade. In order to qualify for the first measurable snow, at least 0.1 inch must fall. Anything less than that is considered a “Trace” of snow.

Here’s a look…


December 4, 1910 was the date of the second measurable snowfall during that winter season with 0.1 inch. The earliest measureable snow in the District was October 10, 1979 with 0.3 inches The latest measureable snowfall, on the other hand, was April 28, 1898.

Winter will likely remain absent in the District through at least the next week as the jet stream winds stay north of the area and Pacific origin cold fronts move through, replacing above average temperatures with more seasonal readings.















Continue Reading