December 10 2017

Our first snow storm of the season on December 9 had a slow start, but a strong finish. Here is a compilation of the snow reports around the region along with a comparison to my final snow forecast. The significant notes about this storm are:

  • Delayed start until after sunrise. That was four or more hours later that expected.
  • Since the snow competed with the sunlight, less could stick early and cut back on early totals.
  • The surge of snow in the afternoon made up for lost time with accumulations.
  • Late afternoon and evening snow with colder air made for tough travel.

Baltimore’s BWI: 2.8 inches 

  • This official report from The National Weather Service fit my main call, but fell below my final call of 4 inches.
  • This is 0.2 below the entire season total last winter = 3.0 inches
  • This is 0.2 average Baltimore December snow total = 3.0 inches

 

Grade My Forecast

I am putting my map here so you can compare to the larger region map and then read the reports below.

I was cautious with this storm until Thursday. I was conservative with my snow forecast until Friday night after seeing the over-achieving amounts in southern Maryland and lower Eastern Shore.  That last bump was a little aggressive, but still fit pretty well.

The delay of the arrival made all the difference with how much stuck early.

What I got right: The wet roads during the day; the snow surge in the afternoon; highlighting for roads developing and more accumulation into the evening.

  • Snow amounts north of Baltimore were at or exceeded my forecast.
  • Carroll, Northern Baltimore, and Southern York County got 6 to 8 inches. This continues to be an over performing region.
  • Highest amounts on the Lower Eastern Shore

What I got wrong: I went agains all of my reports about the warm bay and upped the total snow in the I-95 and Bay areas.

  • The Washington to Annapolis portion of Maryland was on the lower end of snow due to the later start time. This was my poorest performing area and deserving of a C-.

If I stayed with my original forecast, this would have been a solid A.

I give my forecast a B

Please share your grade with me and be honest. I know you may grade for you location and not the storm as a whole… but I hope you ended up getting the snowy day you expected after all.

Please share your thoughts, best weather pics/video, or just keep in touch via social media

 

Official Snow Report: NWS Report Map

These are from NWS Baltimore/Washington

Please note that the other NWS regional offices do not make it easy to see their snow reports in an organized list like this. That limits what I can share at this time.

Maryland: Top part of list

Virginia: Bottom part of list

********************STORM TOTAL SNOWFALL********************
LOCATION          STORM TOTAL     TIME/DATE   COMMENTS
SNOWFALL           OF
/INCHES/   MEASUREMENT
DISTRICT OF COLUMBIA
...District Of Columbia County...
1 WSW National Zoo     2.4   901 PM 12/09  Trained Spotter
MARYLAND
...Anne Arundel County...
1 SSW South Gate       3.5   845 PM 12/09  Trained Spotter
3 WNW Riveria Beach    3.2  1015 PM 12/09  Trained Spotter
2 NNE Crofton          3.2   800 PM 12/09  NWS Employee
1 NW Herald Harbor     3.1   930 PM 12/09  Trained Spotter
1 NW Annapolis         3.0   800 PM 12/09  Trained Spotter
Bwi Airport            2.8  1200 AM 12/10  Airport
Crofton                2.5  1100 PM 12/09  NWS Employee
2 WSW Harmans          2.0   930 PM 12/09  Trained Spotter
...Baltimore County...
1 E Bentley Springs    6.0   700 PM 12/09  Trained Spotter
S Parkton              5.5   700 PM 12/09  Trained Spotter
1 E Glyndon            5.0   700 PM 12/09  TRAINED SPOTTER
1 SW Glyndon           5.0   617 PM 12/09  Trained Spotter
1 WSW Glyndon          4.8   801 PM 12/09  TRAINED SPOTTER
Reisterstown           4.5   736 PM 12/09  State Emrg Mgmt
4 N Long Green         4.1   942 PM 12/09  TRAINED SPOTTER
1 NNE Upper Falls      3.9   914 PM 12/09  Trained Spotter
1 E Kingsville         3.9   910 PM 12/09  COCORAHS
2 NW Long Green        3.8   830 PM 12/09  Trained Spotter
2 NNW Brooklandville   3.8   755 PM 12/09  Trained Spotter
2 E Perry Hall         3.5   920 PM 12/09  Trained Spotter
Cockeysville           3.5   711 PM 12/09  Broadcast Media
1 ENE White Marsh      3.5   855 PM 12/09  Trained Spotter
1 SSE Catonsville      2.5  1030 PM 12/09  Trained Spotter
...Baltimore City...
SE Pimlico             3.5   915 PM 12/09  Trained Spotter
...Calvert County...
2 WNW Huntingtown      3.0   900 PM 12/09  Trained Spotter
1 S Prince Frederick   2.5   900 PM 12/09  Trained Spotter
...Carroll County...
2 SE Westminster       6.5   900 PM 12/09  Trained Spotter
NE Oakland             6.1   640 PM 12/09  Trained Spotter
1 WNW Gamber           5.7   630 PM 12/09  COCORAHS
3 SE Winfield          5.4   550 PM 12/09  Trained Spotter
4 NE Millers           5.0   700 PM 12/09  Co-Op Observer
SE Westminster         4.5   600 PM 12/09  Trained Spotter
1 SE Eldersburg        4.3   550 PM 12/09  Trained Spotter
1 W Westminster        4.0   600 PM 12/09  COCORAHS
...Charles County...
1 SW Dentsville        2.3   954 PM 12/09  TRAINED SPOTTER
La Plata               1.8   840 PM 12/09  TRAINED SPOTTER
...Frederick County...
N New Market           3.0   615 PM 12/09  Trained Spotter
3 N Thurmont           1.4   630 PM 12/09  Trained Spotter
...Harford County...
3 W Norrisville        5.5   700 PM 12/09  Trained Spotter
3 WNW Abingdon         4.0   800 PM 12/09  Trained Spotter
1 SW Bynum             4.0   911 PM 12/09  Trained Spotter
...Howard County...
Ellicott City          3.5   828 PM 12/09  Broadcast Media
2 N Columbia           3.3   847 PM 12/09  TRAINED SPOTTER
Elkridge               3.3   803 PM 12/09  Other Federal
1 SSE Simpsonville     3.3   730 PM 12/09  Trained Spotter
1 NW Ellicott City     3.1   743 PM 12/09  TRAINED SPOTTER
2 W Elkridge           3.0   910 PM 12/09  Trained Spotter
2 W Savage             3.0   910 PM 12/09  Trained Spotter
Columbia               2.0   620 PM 12/09  NWS Employee
1 ENE Columbia         1.5   917 PM 12/09  Trained Spotter
...Montgomery County...
Germantown             5.5   610 PM 12/09  Broadcast Media
3 SSW Damascus         5.2   831 PM 12/09  Co-Op Observer
1 ESE Clarksburg       4.6   715 PM 12/09  Other Federal
2 W Derwood            4.4   650 PM 12/09  NWS Employee
1 ESE Montgomery Vil   4.0   700 PM 12/09  COCORAHS
Gaithersburg           3.5   714 PM 12/09  County Emrg Mgmt
Poolesville            3.5   530 PM 12/09  TRAINED SPOTTER
1 ENE Potomac          3.5   806 PM 12/09  TRAINED SPOTTER
1 S Olney              3.5  1000 PM 12/09  TRAINED SPOTTER
1 ESE Norbeck          3.3   800 PM 12/09  Trained Spotter
1 ENE Montgomery Vil   3.2   830 PM 12/09  Trained Spotter
1 SSW Montgomery Vil   3.0   700 PM 12/09  Trained Spotter
1 ENE Garrett Park     2.5   755 PM 12/09  Trained Spotter
Glen Echo              2.1   838 PM 12/09  NWS Employee
...Prince Georges County...
1 E Bowie              2.5   630 PM 12/09  COCORAHS
1 S Forest Heights     1.4   645 PM 12/09  Trained Spotter
...St. Marys County...
1 ENE Ridge            6.2  1100 PM 12/09  Trained Spotter
1 NNE Park Hall        5.2   830 PM 12/09  Trained Spotter
2 WSW Clements         3.0  1100 PM 12/09  Trained Spotter

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VIRGINIA
...Albemarle County...
Crozet                 3.0   839 PM 12/09  Trained Spotter
1 S Boyd Tavern        1.4   600 PM 12/09  Trained Spotter
...Arlington County...
1 WNW Barcroft         2.3   931 PM 12/09  TRAINED SPOTTER
Reagan National Airp   2.0   700 PM 12/09  Airport
1 NNE Westover         1.8   548 PM 12/09  Trained Spotter
1 S Rosslyn            1.2   715 PM 12/09  Trained Spotter
2 W Reagan National    1.0   728 PM 12/09  TRAINED SPOTTER
...City of Fairfax...
1 N Fairfax            2.5  1045 PM 12/09  NWS Employee
...City Of Falls Church County...
1 W Falls Church       2.2   825 PM 12/09  Trained Spotter
...City of Fredericksburg...
2 NW Fredericksburg    1.2   800 PM 12/09  TRAINED SPOTTER
...City of Harrisonburg...
Harrisonburg           2.0   445 PM 12/09  Broadcast Media
...Fairfax County...
3 N Chantilly          3.6  1030 PM 12/09  NWS Employee
1 S Centreville        3.5   735 PM 12/09  TRAINED SPOTTER
2 ENE Herndon          3.2   825 PM 12/09  Trained Spotter
1 NNE Herndon          3.2   615 PM 12/09  Trained Spotter
1 NNE Fairfax Statio   3.0   852 PM 12/09  TRAINED SPOTTER
1 SE Centreville       3.0   922 PM 12/09  TRAINED SPOTTER
1 SE I66 And I495 In   3.0   900 PM 12/09  NWS Employee
W Centreville          2.9   915 PM 12/09  Trained Spotter
1 ENE The I66 And I4   2.4   800 PM 12/09  COCORAHS
1 SSW Franconia        2.1   900 PM 12/09  Trained Spotter
1 SSE Dunn Loring      2.0   930 PM 12/09  Trained Spotter
1 NE The I395 And I4   2.0   826 PM 12/09  TRAINED SPOTTER
1 SE Langley           1.9   700 PM 12/09  Trained Spotter
...Fauquier County...
4 SSE Warrenton        3.4   930 PM 12/09  Trained Spotter
...Loudoun County...
3 WSW Ashburn          4.5   700 PM 12/09  NWS Employee
Dulles International   4.0   700 PM 12/09  Airport
2 E Leesburg           3.5   635 PM 12/09  Trained Spotter
1 ESE Leesburg         3.1   657 PM 12/09  NWS Office
2 NW Leesburg          3.0   602 PM 12/09  TRAINED SPOTTER
Purcellville           2.2   647 PM 12/09  NWS Employee
3 NW Hillsboro         1.8   648 PM 12/09  TRAINED SPOTTER
1 WNW Lincoln          1.5   430 PM 12/09  Trained Spotter
1 S Purcellville       1.5   427 PM 12/09  TRAINED SPOTTER
...Orange County...
Thornhill              2.2   814 PM 12/09  TRAINED SPOTTER
1 N Flat Run           2.0   450 PM 12/09  Trained Spotter
...Prince William County...
1 SW Woolsey           5.0   630 PM 12/09  Trained Spotter
3 N Independent Hill   2.1   801 PM 12/09  Trained Spotter
1 W Dale City          2.0   828 PM 12/09  TRAINED SPOTTER
1 E Dale City          1.5   619 PM 12/09  County Emrg Mgmt
...Rockingham County...
4 ESE Linville         3.3   436 PM 12/09  TRAINED SPOTTER
...Stafford County...
3 SSE White Oak        2.2   826 PM 12/09  COCORAHS
1 SSW Spring Valley    2.1  1035 PM 12/09  Trained Spotter
1 W Ramoth             2.0  1000 PM 12/09  Trained Spotter
1 SSE Glendie          1.7   829 PM 12/09  TRAINED SPOTTER
1 ESE Brooke           1.6   820 PM 12/09  Trained Spotter
5 SSW White Oak        1.6   811 PM 12/09  Trained Spotter
2 WNW Roseville        1.5   800 PM 12/09  Trained Spotter
...Warren County...
2 N Linden             3.0   525 PM 12/09  Trained Spotter
1 ENE Front Royal      2.0   505 PM 12/09  TRAINED SPOTTER

 

 

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Also See:

My Winter Outlook 2017-2018 for more snow

Maryland Winters

La Nina Formed: What it could mean to our winter

NOAA Winter Outlook: Not The Best But Not The Worst For Snow

Two Farmers Almanacs Winter 2018 Outlooks

Winter Weather Folkore: Suggestions from Animals and Crops

First Frost and Freeze Dates For Maryland (southern PA and northern VA)

My Preliminary Winter Outlook Notes

Low Snow Winters In Baltimore: To Repeat Or Not Repeat

NOAA Ranks Blizzard 2016 4th Worst Snowstorm On Record

Blizzard 2016 Record Top Snowstorm: Area Totals

Extreme Weather of 2015 balanced out on both ends