Weather Will

Could a man expert chime in here? 12k looks sheared or has a double center going on after ;8 hours. Precip shield looks weird or am I just tired?

33/ Rain, sleet, and flurries

Snow accumulation at 8ET Sunday (Mostly from Sunday storm as 3k does not give much tonight.)

About 2-3 hours of rain the snow line begins to shift east on 3K through Frederick/Carroll County into extreme NVA.

Why are the snow depth maps further SE on the 12K at 18z compared to 12Z? More sleet?

NAM 3K Snow map which includes tonight through 7ET. (12z run)

No, it is the 850 line. Wintry precip should be falling NW of that line 7pm Sunday (form will vary depending if all levels are 0 celsius or lower.)

I do feel the pain of those 30-50 miles to the East on this one. (It is not a given that anyone east of the Appalachians and south of the MD line is getting anything yet.) I spent my first 30 years living east of the Capital Beltway. A slight shift SE is still possible with this one for various reason already posted. I have one stupid question. Do the models take into account forecasted snow fall when predicting air temperatures? What I'm asking is whether the 2 inches tonight in the Northern tier could factor into surface temperatures Saturday and Sunday.

Frederick County, MD also has a Winter Storm Watch 7pm Sunday-7:00am Monday.

One of the things I like to watch as we approach the short range is how the 3K NAM lines up with the globals. Watch the NAM over the next several runs and compare to the EURO/GFS. It did a nice job with today's system. (MAP is from WEATHERBELL. It seems it lets me copy the American maps, but Mods let me know if I should not post. Thanks.) Looking at the 850s, Using this as a guide, it would appear the rain/snow line will be North of 70 and SW of North Western Montgomery, Western Howard, and Western Fairfax.

If the King moves the Rain/Snow line toward I-95, I will happily take the 12z runs....

Northern Frederick, Carroll due ok this run as well. We need another 30-50 mile shift.

ICON has been consistent with itself, but so have the other models. Let's see if the GFS twins are as stubborn with their Northern tracks.

18Z NAM is horrible verbatim for everyone in our forum but being the optimist there is a silver lining. There are two lows. One right about where we would want it that travels along the NV/VA line and another further North that travels through northern WV and off the coast. Looks weird but if the southern low track were to verify without the northern low, we would be in business. (I know it is the NAM at 84 hours.)

Sterling NWS did a nice write up on the late weekend Not much change in the 12z guidance in regards to the storm that will impact the region late Sunday night into Monday morning. A potent shortage will eject out of the southwestern US into the southern Plains saturday night into Sunday morning, inducing cyclogenesis over Texas Sunday morning. Additionally, a shortwave rotating around a Canadian upper low will swing a trough out of Canada through the Great Lakes at roughly the same time. These two systems look to phase and bring the surface low up the east coast, however the exact track of this low is still a bit uncertain, though guidance seems to be coming to some sort of a consensus. Guidance has been trending slightly north over the past several runs it seems. The 12z GFS and Canadian deterministic runs seems to continue that trend, albeit slightly. Both are still slightly farther south compared to the 00z European run. So, what this means is that much of the area, especially along I-95 and southeast, will see a plain cold rain. However, north and west of I-95 is still a bit uncertain. Depending on where the low tracks, these areas could see some snow, or some rain/snow mix type of scenario. The 12z run of the GEFS ensembles lights up eastern WV and western/north-central MD with snow, so that seems to be the focus for wintry precipitation at this time. Given the lack of a blocking surface high to the north to funnel in cold air at the surface, would think this will be a rain or snow event primarily, and predicting exactly where that line sets up several days out is just not going to be accurate. So, have kept a fairly large area of rain/snow mix north and west of I-95, with all snow in the farthest northwest portions of the CWA. So, though some things are becoming more clear, there are still many question marks when it comes to northern VA, eastern WV and western/central MD. If there is enough moisture left on the back edge of the system, when cold air wraps back around, could see some snow across the entire area, but likely wouldn`t amount to much.

Very confusing reading this thread. Seems like we may now may have the potential for two small bursts of snow. A Friday am snow burst from 2-5am and perhaps another snow burst Saturday early am. If you happen to be under both bursts, and temps cooperate. you may end up with 4 or so inches. Then again, you may end up with fizzle or a dusting. GOOD LUCK!

Thanks.

Are the models already completely accounting for the low blowing up off of the coast on Saturday in terms of where the next low will track? I guess what I am asking is what factors can shift the low to track another 50 miles south from West to east (arctic high pressing more, slightly stronger Sat coastal low?)

I posted in the wrong thread. Agree there are slight improvements. My nonexpert comparison of 0z v. 12z EURO using 6z Monday as a reference point. Slight improvements. The low is centered over PAX River rather than SE PA. There is a heavier snow band across NW MD-thru North Central MD. If there is another 30-50 mile shift SE over the next day there will be a lot of happy people.

My nonexpert comparison of 0z v. 12z EURO using 6z Monday as a reference point. Slight improvements. The low is centered over PAX River rather than SE PA. There is a heavier snow band across NW MD-thru North Central MD. If there is another 30-50 mile shift SE over the next day there will be a lot of happy people.

Looks like about .2-.3 inch of liquid in Northern areas. Only about .1 around DC. There is also a JI slot, I mean dry slot in NW VA....:)

Winter Weather Advisory area wide from 10pm-10am. 1-3 in DC- nearby suburbs; 2-4 north.

Agree NAM looks good! Hopefully the 2 inch appetizer before the main course Sunday night....but that is for another thread.

Inside 5 days: check; decent amount of moisture: check; exact track: no consistency yet. Stay tuned!!! Seems like no one should start really getting excited before 0z Saturday operational runs. It will avoid a lot of emotional ups and downs over the next two days. Remember the models have been awful outside 48 hours.

3K noticeable shift North in accumulations. Nothing for DC South. Only snows from about 3-7.am. (Rain changing to snow 1-3 am.) 2 inches within 30 miles or so either side of 70 from WV line to North of Baltimore.