Showing posts with label Capital Weather Gang. Show all posts

23 January 2016

Storm updates: Steady snow, gusty winds to slowly wane this evening 23JAN16

LATEST on our blizzard from the +Capital Weather Gang at the +Washington Post and me! Is is still cold, snowing and blowing. I was out with friends and neighbors shoveling our walks and around our vehicles. We have about 36 inches of snow on the ground with drifts thigh to waist high and the piles of snow from our shoveling are almost as tall as me, I'm 5 feet 7 inches tall. The Ashburn hoa nazis still haven't plowed my street, the one and only time we saw a plow as mid afternoon on Friday, 22 JAN 16. If it isn't plowed by morning I will not be able to go to work. Will have pictures from me and my friends posted tomorrow. And so it goes......

Storm updates: Steady snow, gusty winds to slowly wane this evening

By Jason Samenow January 23 at 6:47 PM

Snow totals have reached 22-35 inches west, north, and northwest of the Beltway (locally 35″+), 17-24″ inches inside the Beltway, and 10-20 inches south and southeast of the Beltway.
Steady snow and gusty winds are likely for a few more hours
Snow tapers off between 9 and midnight tonight
Blizzard conditions were achieved late this afternoon, but have relented some.
Total snow accumulations of 16 to 30 inches are expected with some 30-36 inch totals well north and west of the District (Frederick and Loudoun counties). 20-30 inches totals will be most common in the immediate metro region. Totals in the 12-20 inch range are most likely near the Bay into Southern Maryland.

6:47 p.m. update: Believe it or not, New York City has received even more snow than D.C. JFK has logged it snowiest single day total on record. Former Capital Weather Gang contributor Andrew Freedman, now science editor at Mashable, sends us the following report from Brooklyn:

Manhattan and the Bronx along with Newark are closing in on 24-30 inches. JFK now at 24. Some areas of northern NJ could exceed 35 inches. Unreal here, in terms of snowfall rates all day and the National Weather Service has been playing catchup.
It was clear days ago that this was an excruciatingly tough forecast for New York City, with a shift of 40-50 miles making a huge difference. Unfortunately for many people, that shift happened in the models with evening runs on Friday, catching people off guard on Saturday morning, and forcing forecasters to up totals every few hours.
Historic storm in NYC, and it’s still going.

6:10 p.m. update: Between 3 and 5 p.m., the conditions outside qualified as a “blizzard” in the D.C. area.

5:50 p.m. update: Dulles Airport, as of 4:20 p.m., had tallied 26.5 inches of snow, second most on record there. It only trails Snowmageddon of Feb. 5-6, 2010, when 32.4 inches fell. Records at Dulles date back to 1963.
5:25 p.m. update: Here’s the latest snow total map assembled by the National Weather Service. Notice pretty much everyone north and west of the Beltway is over 20 inches. Many of these numbers are at least an hour or more old.
5:10 p.m. update: D.C.’s official storm total, as of 5 p.m., is 17.5 inches which puts it ahead of the Blizzard of 1996 and into 5th place among the top 10 greatest storms. Just 0.3 inches need to fall for it to pass Snowmageddon.

[Where Snowzilla fits into D.C.’s top 10 snowstorms]

5:00 p.m. update: BLIZZARD! D.C. has officially met the criteria for a blizzard: Three straight hours with winds gusting over 35 mph, visibility of 0.25 miles or less and snow and blowing snow. At 5 p.m., National Airport, D.C.’s reporting station, observed heavy snow, winds gusting to 37 mph, and visibility of 0.06 miles.
4:45 p.m. update: Here are some recent snow totals:
Va.: Woodbridge 22″, Arlington 22″, Tysons-Vienna 23-25″, Leesburg 28-31″, Gainesville 27″, Fair Oaks 23″, Brambleton 35″, Great Falls 27″, Herndon 28″, Manassas 25″, Alexandra 21″, Fairfax 26″, Annandale 17″
Md.: Laurel 24″, Potomac and Rockville 24-28″, Silver Spring 28″, Pasadena 20″, Wheaton 22″, Eldersburg 34″, Greenbelt 20″, New Market 35″
D.C.: Petworth 19″, Mt. Pleasant 21″, Adams Morgan 23″, Navy Yard 19″

4:25 p.m. update: Let’s just say Columbia Heights is snowed under…
4:10 p.m. update: Reagan National Airport, D.C.’s official observing location, reports a storm total of 17.0 inches as of 4 p.m. This puts this storm, Snowzilla, in 6th place among D.C.’s top 10 biggest storms, passing the Blizzard of 2003, which dropped 16.7 inches. It is poised to move further up the list.
4:02 p.m. update: D.C. (Reagan National) reports heavy snow and blowing snow, winds gusting to 39 mph and visibility of 0.25 miles at 4 p.m. If this persists for another hour, true blizzard conditions will have been achieved.

3:57 p.m. update: Look at the satellite (top) and radar (bottom) presentation of this storm. It’s just massive and isn’t done with us yet.
3:38 p.m. update: “This looks to last four more hours,” says Capital Weather Gang winter weather expert on this current blast of heavy snow and strong winds. With snowfall rates of 1-2 inches an hour, you can do the math of how much more snow is possible. Lighter snow should follow before the storm ends in the 8-11 p.m. window.

3:20 p.m. update: The following locations in Virginia and Maryland report an astounding 30 inches or more of snow…Md.: Parkville (33″), Olney (30″), Point of Rocks (31″), Jefferson – Frederick Co. (40″), Germantown (30″)
Va.: Brambleton (32″), Haymarket (31″), Ashburn (31″), Lovettsville (32″), Hillsboro (37″), Purcellville (32″), Bristow (30″), Round Hill (31″)

3:00 p.m. update: This last phase of the storm is a knockout blow. Near whiteout conditions have overtaken much of the region. Reagan National is reporting heavy snow, winds gusting to 36 mph and just 0.13 miles of visibility at 3 p.m. Do not attempt to drive in this.
Photos:

2:53 p.m. update: When does it end? Here’s a simulation from the HRRR model, which suggests in the 8-11 p.m. timeframe this evening.
One caution is that sometimes in these very wound-up storms, the snow lasts a little longer than the models predict.
2:40 p.m. update: The National Weather Service has posted a map of totals, and they are impressive. Bear in mind this map is an hour old now, but you can see the consistency of totals over 20 inches north and west of the Beltway… and these are just going to go higher.
2:20 p.m. update: In areas from I-95 and east, after an extended lull (6-8 hours), the snow is picking back up in earnest and winds are howling. Visibilities are extremely limited so do not attempt to drive in this. Across much of the region, another 3-6 inches of snow is possible and potentially more depending on how long this heavy band persists over the region.
(For our previous updates,, covering 6 a.m. to 2 p.m. today: see, Snow continues through the afternoon, winds increasing)

Jason is the Washington Post’s weather editor and Capital Weather Gang's chief meteorologist. He earned a master's degree in atmospheric science, and spent 10 years as a climate change science analyst for the U.S. government. He holds the Digital Seal of Approval from the National Weather Association.

21 January 2016

IS A BLIZZARD REALLY COMING & Blizzard Warning: High winds, about two feet of snow forecast for D.C. area 21JAN16

LOCAL weather forecasters are doing their best to incite hysteria about the blizzard that is supposed to hit Norther Virginia, D.C. and Maryland (convince me they aren't getting kickbacks from the grocery stores and hardware/home improvement stores). I have always found the weather forecasting from USWX reliable, and they still don't have blizzard warnings or any winter weather warning posted for any of these areas. Below is the forecast for Dulles Airport / Chantilly and then the severe weather forecast for the entire U.S. Then there is the forecast from the +Capital Weather Gang / +Washington Post . Are we doomed? I have bier, wein, coffee, chocolate, and TP AND I drive a JEEP so come on Mother Nature, bring it on!!!!!!

: :

Thursday, January 21, 2016, 5:21 PM EST

Herndon, VA
County: Fairfax NWS Zone: VAZ053 (Fairfax)
5:21 PM EST (22:21 GMT)

77.3873 W
38.9812 N
Thu, Jan 21, 2016

Severe Weather Statements
Type	Issue Time	Expire Time	Expires in
Special Weather Statement	Thu, Jan 21, 4:05pm EST	Thu, Jan 21, 10:05pm EST	4 hr, 43 min
Special Weather Statement	Thu, Jan 21, 4:04pm EST	Thu, Jan 21, 10:04pm EST	4 hr, 42 min

Current Conditions

Observation for Dulles Airport, Chantilly, VA as of 4:52PM (30 min ago)

Current Conditions		Few clouds
Temperature	30°F	-1°C


	Dew Point	11°F	-12°C
	Feels Like	20°F	-7°C
	Humidity	44 %
	Pressure	30.28 in	1025.5 mb
	Wind Dir	NW	310°
	Wind Speed	14 mph	22 kph
	Ceiling	Unlimited
Visibility	10 mi	16 km	Severe \| Temp \| Dew \| Feels \| Humid \| Pres \| Speed \| Dir
Coded		METAR KIAD 212152Z 31012KT 10SM FEW045 FEW250 M01/M12 A3027 RMK AO2 SLP255 T10111117 =

National Weather Service Forecast
Seven Day Forecast	Issued 9:27am EST -- Thu, Jan 21, 2016

Rest of today	Sunny. Highs in the lower 30s. Northwest winds 5 to 10 mph.
Tonight	Mostly clear. Lows in the lower 20s. Northwest winds 5 to 10 mph.
Friday	Partly sunny with a chance of snow in the morning, then cloudy with snow likely in the afternoon. Snow accumulation around an inch possible. Highs in the lower 30s. Northeast winds 5 to 10 mph. Chance of snow 70 percent.
Friday night	Snow. Snow may be heavy at times. Brisk with lows in the mid 20s. Northeast winds 10 to 15 mph with gusts up to 25 mph, increasing to 15 to 25 mph with gusts up to 35 mph after midnight. Chance of snow near 100 percent.
Saturday	Snow. Snow may be heavy at times. Brisk with highs in the lower 30s. North winds 20 to 25 mph with gusts up to 35 mph. Chance of snow near 100 percent.
Saturday night	Snow showers likely. Brisk with lows in the lower 20s. Chance of snow 70 percent.
Sunday	Mostly sunny. Highs in the mid 30s.
Sunday night	Partly cloudy. Lows 10 to 15.
Monday	Mostly sunny. Highs in the upper 30s.
Monday night	Mostly cloudy. Lows in the upper 20s.
Tuesday	Partly sunny. Highs in the mid 40s.
Tuesday night	Mostly cloudy. Lows in the mid 20s.
Wednesday	Partly sunny. Highs in the upper 30s.

US NATIONAL SEVERE WEATHER STATEMENTS
Type	States
Freezing Rain Advisory	NC SC
Freezing Fog Advisory	TN
Winter Weather Advisory	AL AR CA GA KS LA MO NC OH OK PA TN WA WV
Winter Storm Warning	GA IL KY MD MO OH PA SC WA WV
Winter Storm Watch	AR IN KY MO MS NC NJ NY OH PA TN
Wind Advisory	AR CA GA LA MS MT NC NM OR TN TX VA
Tornado Warning	LA MS TX
Tornado Watch	LA MS TX
Severe Thunderstorm Warning	LA MS TX
Special Weather Statement	AL AR CA DC IL KY LA MD MN MO MS NC ND NE NY OH OK PA SD TN TX VA WI WV WY
Lake Wind Advisory	AR LA OK TX
High Wind Warning	CA
High Wind Watch	DE MD NJ VA
Flood Advisory	AR IL MI MS TN
Flood Warning	AR FL GA IL LA MS NC NE OR SC TX WA
Dense Fog Advisory	AL IA LA MN SD TN TX
Flash Flood Warning	MS
Flash Flood Watch	AL TN
Areal Flood Advisory	WA
Areal Flood Warning	IL MS
Areal Flood Watch	GA WA
Blizzard Watch	NJ NY

Blizzard Warning: High winds, about two feet of snow forecast for D.C. area

By Jason Samenow January 21 at 4:50 PM Follow @capitalweather

It’s a broken-record forecast that may lead to broken records: A textbook Mid-Atlantic severe winter storm is primed to unload snow totals measured in feet starting Friday afternoon and ending late Saturday night.
A blizzard warning spans the entire region from 3 p.m. Friday to 6 a.m. Sunday, when a vicious combination of heavy snow and strong winds will make travel difficult or impossible. (In Fauquier County, a winter storm warning is in effect instead of a blizzard warning because of forecast lesser wind speeds.). The visibility will drop to near zero in whiteout conditions. Some power outages are likely.
There is some chance that snow amounts will be so great that poorly built roofs and structures will collapse.

[Metro trains and buses will close all weekend]

Snow totals are forecast to be at least 16 inches, with 24 to 30 inches or so possible in some areas, especially north and west of the District. Lesser amounts are likely in southern Maryland where snow is more likely to change to a wintry mix for a time.
This storm shares characteristics of many of D.C.’s greatest snow events, such as Snowmageddon in 2010 and the blizzard of 1996. Snow amounts will probably be comparable to those during Snowmageddon, and winds may be stronger.

[How to prepare for this storm]

This is a serious and life-threatening winter storm. Preparations should begin today and be completed by Friday afternoon. Wherever you happen to be Friday evening, plan to potentially be there into Sunday or early next week.
Key points

This is long-duration event, with snow forecast for 36 hours or so.
Models are converging on storm onset in the noon-to-5 p.m. period on Friday.
Conditions are the worst after dark Friday continuing through Saturday night.
Thunder snow is possible Saturday.
Winds may gust to 40 mph on Saturday, causing whiteout conditions and some blowing and drifting snow. Strong winds east of the District toward the bay.
Biggest forecast uncertainty is near and especially southeast of the District, where there remains some potential for a dry slot that would interrupt the snow and potentially result in a brief changeover from snow to sleet, cutting down accumulations.

Timeline for immediate metro area.
Noon to 5 p.m. Friday: Snow moves in from southwest to northeast. Temps: 30-35. An inch or less accumulation.
5 p.m. to 10 p.m. Friday: Light to moderate snow. Temps: 25-30. Storm total accumulation: 2-3 inches.
10 p.m. Friday to 7 a.m. Saturday: Snow, heavy at times. Increasing winds. Temps: 25-30. Storm total accumulation: 8-12 inches.
7 a.m. to 5 p.m. Saturday: Snow heavy at times. Possible blizzard conditions. Temps: 25-30. Storm total accumulation: 16-20 inches.
5 p.m. Saturday to 1 a.m Sunday: Snow and blowing snow, gradually decreasing. Temps: 23-28. Storm total accumulation: about two feet.
Answers to frequent questions
When do I need to be off the roads on Friday? The snow will probably begin between the early and late afternoon. You may be able to sneak in a half-day at the office. However, the wiser move will be to telework as we want to avoid a mass exodus on the roads and a repeat of Wednesday evening. Even if traffic is light and the storm eases in initially, you definitely want to be home by dark Friday as snow will be increasing in intensity, with a few inches possible by around 10 p.m.

[What led to last night’s D.C. traffic disaster: We are not blameless]

Where are power outages most likely? East of the city, but plausible anywhere in the region. The reason we think areas east of Washington and toward the Chesapeake Bay have the highest outage potential is because winds will be strongest there and the snow will have more of a heavy, wet consistency.
West of the District, the snow will have more of a powdery consistency, which will probably lead to to greater amounts but less clinging to trees and power lines. Also winds will tend to decrease the farther west you go in the region.
Will this be a true blizzard? The National Weather Service defines a blizzard accordingly:
A blizzard means that the following conditions are expected to prevail for a period of 3 hours or longer:

Sustained wind or frequent gusts to 35 miles an hour or greater; and
Considerable falling and/or blowing snow (i.e., reducing visibility frequently to less than a quarter mile.

These conditions are possible in the region, particularly on Saturday.

[Some of D.C.’s greatest blizzards over the years]

Could this storm underperform? Yes, but unlikely. The signal for a historic storm emerged days ago, and models have not wavered in their forecasts for extreme snow amounts. Capital Weather Gang winter weather expert Wes Junker says the possibility of snow changing to sleet could cut down on totals in some areas:

There is still a chance that the snow could mix with or change to sleet for a period of several hours in the city and especially for locations to the south and east. The 1996 snowstorm, which had a similar evolution, ended up having a period of sleet sandwiched between two periods of moderate to heavy snow. During big D.C. snowstorms, folks east of the city are usually at risk for mixing or even a changeover.

Junker noted that last night’s NAM model simulation introduced the potential for mixing even in the District.

[How to protect yourself and your home]

orthy of the frenzy they caused. (Claritza Jimenez/The Washington Post) Could this storm overperform? Yes, by a little. The latest model forecasts are generally for at least near-20 inches of snow and up to 30 or so inches. We also must consider that the model snowfall amounts make the assumption that 10 inches of snow will fall for the equivalent of every inch of rain and, in some areas, particularly north and west of the District, perhaps 15 inches of snow will fall for every inch of rain, especially during the second half of the storm as colder air is drawn in. In general, model simulations advertise the equivalent of 2 to 3 inches of rain over the region. Someone in the region is likely to receive more than 30 inches.
Where will the heaviest snow fall? Some models have placed the snowfall bull’s-eye in west-central and northwest Virginia, while others place it closest to the immediate metro area. Based on D.C. snowstorm history, we favor the heaviest amounts in these western areas, especially near Interstate 81 from around Harrisonburg to Winchester and in the Blue Ridge. Having said that, where localized heavy bands set up is always a wild card, and that could even occur just east of the city.
“The models have a really hard time predicting where one of these bands will set up prior to their formation,” Junker says. “Where such a band sets and persists longest will determine who in the area will get plastered with the heaviest snow.”

[The laws and fines for not shoveling around Washington]

What should I do about my flight? Many carriers have announced that you can change your flight plans without penalty. Check your airline. Flights should be able to get in and out of the airports for much of the daylight hours on Friday before conditions really deteriorate after dark. On Saturday, airports may need to shut down temporarily. Air travel is likely to be possible on Sunday, but expect considerable backlash delays and some cancellations.
What will Amtrak and Metro do? Metro has decided to shut down the rail and bus system for the entire weekend. Amtrak will attempt to continue operating, but consider that many trains were canceled during Snowmageddon in 2010.

[Metro, Metrobus and MetroAccess will shut down for the weekend]

What will schools and the federal government do? In past storms of this magnitude, even those that occurred over the weekend (many of them, in fact), schools and government closed up to several days in the week following.
As for Friday, many schools have already decided to close and we expect more will follow suit.

[What will be closed on Friday]

We think the Federal government will likely offer the telework option and may dismiss early on Friday.
Why might there be thunder snow? Yes, on Saturday, Junker says. His technical discussion:
The forecast atmospheric profile or sounding from last night’s NAM and GFS both argued for a period of thunder snow though they differed on when. The NAM liked early Saturday morning while the GFS early Saturday afternoon.
The GFS sounding below is a classic one trumpeting there is likely to be elevated instability, conducive to thunder. Note that the unstable layer is located above the warm layer due to the east wind off the ocean and below the dry layer. You can tell that the sounding is unstable because the temperature and dewpoint lines are squeezed together and the slope of their line tilts to the left more than the curved dashed line on the sounding (below).
READ MORE:
What to do if you see someone who needs help in freezing weather
How extreme cold can damage your body and what to do
Snowball fights and Capitol Hill sledding are already planned

NORTON META TAG

23 January 2016