csnavywx

3" on ground. Pouring sleet here. Transitioned over a period of about 90 minutes. Coming down hard enough that it's still accumulating.

3" on ground. Pouring sleet now. 18F. Coastal front appears to be set up over on the lower eastern shore (coastal side), but moving a bit slower than forecasted.

One of the reasons this is being detected early is probably because the primary shortwave is already an entity over the Pacific east of Japan.

Good thing is, even on a super aggressive warm nose solution like the 18Z NAM, you may not be completely cooked: Switches over to PL at 2:00am or so at LYH, but it takes until about 1:00pm for it to transition over to ZR. About 0.5" liquid falls as ZR in this run.

Best you can reasonably hope for is to get stuck in a melting-enhanced band embedded in some intense frontogenesis and really crank for a couple of hours before changeover.

Careful. Vertical resolution on TT Euro maps is limited to the standard levels. Devil is in the details:

Fret not. Even if we only get a partial here, the pattern remains very favorable into Feb. Need some true vodka cold to start freezing the Bay up in preparation, if you ask me.

Run to run variability has calmed down since 00Z last night and while I think we get a bit more adjustment south/slower, it's probably not going to be enough to save the eastern shore from changing over to all rain at this point. Enjoy the front-end thump, it'll probably only last a few hours before flipping to sleet and (briefly) ZR. Inshore is going to have a rough time of it, especially immediately away from the Bay. Hopefully we get near or just above freezing here late Sunday and at least pause the icing before it starts back up overnight. 3-6" Eastern Shore + 1" sleet, then brief freezing rain to rain; DE side will get more snow (add an inch or two) before changeover to sleet. 4-9" inshore southern MD, + 1" sleet, then 0.25-0.75" ZR A band of heavy convective rain showers is looking increasingly possible overnight Sunday into early Monday morning. If the coastal has developed sufficiently, then northwest flow should advect the remaining CAD wedge back into the inshore area and result in some additional quick accretion of ZR overnight. Am a bit concerned about some freezing drizzle and/or light snow on Monday ahead of the big upper trough. Still some moisture left below 700mb after the dry slot comes through.

It does on the GFS, which tells me (regardless of whether this is correct verbatim), that we may not be done with meaningful adjustments there.

Eesh.

Despite the look at the surface, we got some incremental improvement aloft. The phase was sloppier. Northern vort is not digging in one piece now. Cutter primary was weaker. Incrementally cooler upstairs (above 850). Saw same kind of improvement as the 18Z NAM, GFS and (early on) with the Ukie.

18Z GFS is exactly the kind of scenario we need. Screw up that phase and prevent the cut.

The profiles are still active on IA state's Bufkit Warehouse and PSU website.

Yeah, though the closer you are to the mountains, the deeper the cold wedge is likely to be. Once we get close enough I can start posting some BUFKIT profiles for folks that want them.

Yeah, pushed the forecast out earlier than we normally do to highlight the potential here. Proper ice storms are rare in these parts and very little of this vegetation has been "tested" in the past 30+ years, so anything over 0.6-0.7 is going to start breaking stuff very quickly.

You aren't joking. Surface temps in the low-mid 20s with 0.1"/hr+ accretion rates will be a big problem in a hurry.

Trending towards a flatter orientation of the thickness gradient ahead of it with cold air damming setting up faster. Small but meaningful trend. The flatter, the better. Will help inhibit the strength of the surface reflection/low of the trailing upper trough and favor coastal development a little more. It would be even better if we could continue to get that trailing N/S wave to slow down and eject the Baja low a little faster instead of fully phasing with it. Anything to inhibit the development of the inland low and favor the coastal, basically.

RRFS-A coming into range and has basically the same evolution. Slower/less perfect interaction between 00 and 06Z and a bit stronger with the eastern lobe of the high. Interested to see if this becomes a trend given that both trailing N/S waves have yet to become their own entities.

The northern stream is going to be problematic. The one time we actually don't want a triple-phaser. In this case, too early to get cute about where the mix line sets up, namely because both the kicker and the main trailing N/S shortwaves are still over the Russia and the Arctic Ocean and haven't yet become their own entities. My guess is we're going to get flung around for a while. Good news is anything but the perfect phase on the 00Z euro and ukie should result in a retreat south with time. Saw a bit of that on the 06Z Euro. A retreat or slowing of the primary N/S beyond what has already been modeled should result in an increasingly positive tilted trough that comes out more piecemeal than perfect.

Agreed on the big dog. We're waiting until the 12Z runs tomorrow at the office. Should have the main players mostly nailed down at that point. I'm personally kinda split between a solid 12-16" or a 9-13" w/some trailing mix.

More like orange at this point. All systems go for red tomorrow if this holds.

The floor is rising. 18Z runs are no longer slowing down the southern stream and we have some buffer room if it decides to come more north. GFS is no longer the odd man out. I do expect the NBM means to peak right around now as some of the extreme tails get clipped (and there aren't that many duds left to fill in). So don't be surprised if that comes down a hair. Should be able to do a first guess map by tomorrow at this rate.

AI-GFS considerably north of 12Z run. ~0.8 QPF for DC; ~1.1 for SoMD.

Yes.

Short range errors on the southern stream cutoff are still pretty damn high. Still have a full day until that thing cuts off under the ridge, so we may not be rid of trends related to it until that occurs (tomorrow's 12Z runs, in other words).