JUST IN: Our detailed look at the winter storm expected to bring two bouts of snow to the DC area between Wednesday afternoon and Friday morning. Complicated forecast, lots of variables. Read the briefing to understand the maps: wapo.st/3a1Qk3l
Important to understand the event will come in two waves. Here's our snow forecast for the first wave, Wednesday afternoon into Thursday morning: (1/2)
Here's our snow forecast for the second wave, Thursday afternoon to Friday morning: (2/2)
If you added the first wave and the second wave, that's how you get the 3-day totals which we show in the first map that was tweeted at the top of this thread.
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Forecast update! Our call for 1-4" of wet, slushy snow is on track for Sunday morning. Rain to develop between 1-4a and should switch to snow by sunrise and then taper off by early afternoon. Detailed update-write-up here: wapo.st/3aAg6L6 (1/x)
We'd lean more toward 1-2" than 2-4" near downtown DC due to mild temps and better chances for 2"+ in hilly areas with more elevation, but so much is dependent on where any heavy precip sets up. (2/x)
Most snow accumulation on grassy area but some on paved surfaces not impossible during heavy bursts. Snow can stick at 33-34 degrees if it's heavy enough. Temps - frankly - are pretty marginal for a meaningful snow event here but sometimes weird stuff happens. (3/x)
Sound the sad trombone snow lovers, we've lowered predicted totals slightly one more time. Wednesday's storm will be a mess. Detailed briefing: wapo.st/3akwBfX (1/x)
Huge range in conditions from east to west in DC region Wednesday. Flood watch east of I95 for 1-2" of rain. Winter storm warning for I81 for 6-12"+ snow. (2/x)
Between the heavy rain (east of I95) and heavy snow (near I81), a swath of freezing rain is possible, with some icing possible west of I95, esp west and north of the Beltway. Here's a model forecast of freezing rain. (3/x)
A historic and devastating onslaught of wildfires has ravaged the West since mid-August. @NASAEarth satellite imagery has captured the punishing blazes which have devoured over 3.9 million acres in California alone.
Extreme cold East/warm West jet stream pattern to set up next week. Core of the cold to initially focus west of the Appalachians but should make it to East Coast in 7 to 9 days. wapo.st/3cuDgmG (1/x)
Pattern is EXACTLY the opposite of what we had last year when eastern US set dozens of all-time October heat records, including DC which was 98F. NWS calling for moderate to high risk of much below normal temps Oct 1-7 this year. (2/x)
If you love fall, colors are already starting to pop in the mountains of New England & northern parts of Upper Midwest and this cool weather will bring them out farther south and at lower elevations. (Map from smokymountains.com) (3/x)
The air quality along the West Coast is the worst on the planet, due to wildfire smoke, and it's not even close. Many areas with code purple and amber air quality levels, signifying very unhealthy and hazardous pollution.
Residents of SW Louisiana navigating minefield of hazards:
* #HurricaneLaura aftermath with 250K w/o electricity, over 100K w/o water
* Punishing heat/humidity...heat index values 105-109 today
* Coronavirus pandemic wapo.st/3gPPSVS (1/x)
Several parishes in SW Louisiana still almost entirely without power, including Calcasieu Parish - home to Lake Charles - amid the relentless heat. “It’s terrible right now. I’m on my third shirt today," said resident. (2/x)
Generators are hard to find, expensive, and dangerous if improperly installed. 8 people have died from carbon monoxide poisoning in Louisiana since Laura struck. (3/x)