EstorilM

Nice - I was waiting for the update, they seemed all-in on the previous AFD as well (unusual for them.)

Sterling NWS

Exactly my thoughts, even sterling NWS said the same thing. I'm doing some of these QPF numbers in my head and it's kinda crazy what we're potentially looking at here. Also zero initial melting issues, lows Sat night are frigid. Sterling AFD earlier: This comes with the presumed snow- to-liquid ratio of 10:1 which this system will not be given the Arctic nature of the air mass."

That's pretty impressive considering how conservative they typically are. The big storm that went south last year didn't have this type of confidence (at any point.) I guess we've been burned so many times that I'm not sure how to handle what's happening. There's a unicorn appearing before my very eyes and I'm not sure how to interpret it lol. Sterling NWS / LWX AFD - https://forecast.weather.gov/product.php?site=LWX&issuedby=LWX&product=AFD&format=CI&version=1&glossary=1&highlight=off In a multi- day sense, global ensemble probabilities remain very high for seeing 6+ inches of snow. This comes with the presumed snow- to-liquid ratio of 10:1 which this system will not be given the Arctic nature of the air mass. Ratios could be considerably higher yielding a fluffier snow. With the parent features still across the more barren high latitudes, models may take another day or two to resolve such features with better precision (note: recon flights are expected to take place near the Southwest CONUS later today - that`s where models have been most sensitive to changes, so hopefully this additional data will help hone in on details). The details will be important in determining any precipitation type transitions. However, given the very cold air locked in at and near the surface with strong Arctic high pressure anchored firmly to our north, plain rain is highly unlikely anywhere in the region. It will therefore come down to snow versus ice, both of which could be significant and highly impactful across a widespread area. . KEY MESSAGE 2...Frigid temperatures are looking like a virtual certainty this weekend into early next week. As mentioned in the winter storm section, Arctic high pressure takes charge over the weekend which yields frigid temperatures across the area. On Saturday, forecast 850-mb temperatures range from -15 to as low as -20C which even dry adiabatic mixing would keep surface temperatures below freezing. However, given the time of year and the fact 1000-850 mb winds are northerly, mixing largely tops out around 900 mb. With that said, Saturday`s high temperatures should struggle to escape the teens in most spots, with a few low 20s possible across far southern Maryland. Along the Allegheny Front, single digits are likely all that can be mustered. As snow comes in Saturday night, this will fall amidst temperatures in the single digits to lower teens. I'm still not used to the "key message" numbering thing for AFDs vs. the normal 1 day, 3 day, extended, etc.

Low sat night out here is 12, high Sunday is only 19. DC will be a bit warmer, but I’d expect ratios way above 10. I suppose it’s a safe bet to stick to 10:1 the way things go around here.

Yikes I’ll be at Wisp with my friends this weekend for an annual ski trip - coming home on Sunday to NoVa should be interesting. This after the HIGH on Saturday is going to be 7 degrees! I guess I asked the weather gods for winter weather for the weekend so - can’t complain.

Perhaps the precip shield, but I'd be comfortable locking in this cold. I mean most models have almost a week of single-digit lows; you could have models swing +15 degrees and it would still wouldn't even be "marginal" yet.

I'm not sure it'll matter much with the temps we're looking at now... insane prolonged cold.

Wow, the whole 23-26th time frame changed overnight it seems (as it does..) This is the weekend I'm going out to Wisp though. A few days ago the high on sat was like 40. Now it's 10! Low Friday night is -5. I kinda wish I had a block heater for my truck ugh. Looks like precip popped up for almost every day/night during the period as well, but that's like extreme NW MD in the mountains / resort areas so that's different.

Can you post? I know it’s a clown map but again, that’s when I’m going skiing so.. maybe I can needlessly hype up the crew lol.

What’s happening around the 22nd to 25th? Going skiing for the first time in 10+ years with some friends for the weekend, it would be awesome if we got some snow (it’s just Wisp lol, so deep creek md area.) I keep seeing some stuff popping up in the long-range for that period. More than half of my ski trips (only every 4ish years before this time) had some big snows those weekends. How’s that for an analog?

Bummed that I missed it, but wow! Temps dropped 11 degrees in less than 15 minutes, with a peak gust of 35.3 MPH.

Wow, it got cooler way later yesterday evening vs the day before, so I figured it wouldn’t be quite as cold. I was proven very wrong when I woke up this morning lol.

Whaaaat is the deal with central/SW Virginia this (and last I believe?!) season? Theres no way RIC has more annual snowfall than IAD lol. Then again as someone above said, they could be at their annual snowfall for the season in a few days.

So much for a forecast low of 31! Down to 21.4 last night. The nearby PWS that isn’t in the creek valley area is ~4 degrees warmer though.

Well that was unexpected!

Your daily rain record for 5yr is an inch? What about the summer storms that dump like 2+” and such??

PWS’s say 1.35” south of Leesburg, 1.25” near Middleburg. Didn’t most high-res models show 2-2.25? Don’t get me wrong, the rain is great - but it the models are (once again) off by this much, winter is going to be a huge PITA lol. It was about .90” till that last storm-wide band (NW to SE) came through a little while ago.

Due for it?! I got down to -2.4 degrees last year in Northern VA! We had some brutally cold stretches last year (with absolutely ZERO precip.) Actually, wasn't that most of last winter? lol

Hit 32.0 exactly this morning for the first time... today has this raw winter post-FROPA kinda look to it, with gusty winds and the lower sun angle (and shorter days) casting plenty of cloud shadows and making them seem darker in the process. Definitely one of those afternoons where you can tell it'll be cold tonight! Freeze warning for all of Loudoun.. I'm usually about 3-5 degrees cooler than forecast so we'll see.

Agreed - hardly any discussion about it. I guess we got burned on the last one though.

.12" near Leesburg per my PWS - shafted as usual. Was hoping for at least .25"

Still got your hopes up for a second, so it served its purpose. The weather Gods will allow our weekend activities to remain, as long as this shockingly boring and dry pattern continues (save for this trough / cold front thing tomorrow night / wed AM.)

I came in here just to ask this! It filled in like some late evening fog / humidity will sometimes (usually in clear air mode) but it’s in precipitation mode. It’s accurately showing the rain to the NW… nothing wrong with the radar it would seem, unless the software isn’t filtering out stuff like it usually does. There is motion / waves to it that reflects what moisture in the atmosphere would be doing - just not sure why it’s only visible around IAD / the radar. edit: They just now put it into clear air mode. My bet is they’re troubleshooting the filtering.

Yeah, what's the deal with that anyways? Getting kinda nervous about my camping trip already. I actually wanted a day or two of rain (it's kinda relaxing) but if it all turns to mud, I'm OUT lol.