KAOS

Why on earth would they go with WSW? This is WWA all the way.

Bye...

Please get rid of troll.

See you all soon.

Just now, MillvilleWx said:

Well, I finally got to look at things for the storm and man, it's a pretty dynamic setup that should drop the hammer SOMEWHERE in this sub-forum, but the question is....where?

Let's take a look at the 500mb setup

There's a prolific 500mb shortwave (s/w) currently rotating around the base of a mean trough with closed reflection over northern AL. Historically, this is a great position for the sub-forum to cash in, so long as the ULL doesn't mess itself on the trek eastward. As you can see, it is forecasted to not only hold, but actually strengthen as it crosses the App front with a negative tilt of the shortwave trough. This provides a textbook level divergent signature downstream ahead of the ULL and attendant s/w. What happens is an explosion of the precip field with convective prevalence due to maxed ascent on the left exit region of the 500mb jet max. Also, here's another piece to tickle the fancy....

 

Here is the 700mb presentation on Monday morning. A closed 700mb low cuts across the NC/VA line which is a fantastic track for areas near Rt 50 and south as VV's will be off the charts on the northern periphery of the 7H low. This puts the NoVA area from Fairfax to the east in the core of the ascent within the mid-level profile. 

 

Looking at the 7H frontogen picture using the NAM Nest, you can see a distinct signature over NoVA into SoMD and the lower Eastern Shore with a convergent pattern within and just north of the main frontogenic forcing. This is where the most prolific banding would occur for those with winter precip. Another maximum will occur on the lead side of the low due to the moisture fetch off the Atlantic from SE flow (This is actually important for the snow lovers on the Lower Eastern Shore). 

Now, go back and look at the 500mb gif I posted above, There's a s/w zipping eastward out of the northern Midwest that will put a straight edge to the northern side of the precip field. It's a developing confluent signature that will create a sharp cutoff on the northern side of the mid-level moisture field, which means someone will get hung out to dry, literally where this ends up developing. I will say there is a distinct northern mini max potential about 30-50 miles south of the main convergent area created by the confluence. This area typically maxes with the localized ascent, plus the favorable thermodynamics at play. Don't be surprised of some interesting totals coming out of areas within that zone to the north of where the main area gets slammed. 

So, when it comes to the dynamic nature of the mid and upper-levels, there will be no shortage of ascent to work off, and that in turn will help establish a healthy area of precip for the event, especially those within the perfect setting of the mid and upper closed lows. 

Now, lets talk about the caveat to the setup, thermal profiles. Right now, we have modest cold air advection (CAA) areawide with drier boundary layer air working behind the front that slid through earlier. This is important as wet-bulbing at both the lowest 100m of the boundary layer AND the layer b/w 600-800mb will generate the ptype separation a few hrs after the precip begins. Right now, thermals are borderline for the first 3-6 hrs of the event as sleet will likely mix or be the predominant ptype for the very beginning. As the mid and upper levels traverse eastward, you'll see a considerable cooling aloft that will mix into the boundary layer and change everything to snow from northwest to southeast. Areas on the very northern edge might only see a brief period of liquid and/or sleet before completely changing to snow. I think the area from Rt 50 south to the AKQ area will be the sleet zone for the first stage of the event. This area is also in the benefit of being within the "crush zone" for precipitation due to the expected ascent from the mid-level frontogen. There will probably be a period where sleet/snow mixes with massive flakes before shifting to all snow and then raging with continuous large aggregates. Boundary layer will be improving through the AM, so ratios will start pretty meager, but quickly shift to a climo norm, perhaps final 3 hrs ending around an avg of 12:1 with some places seeing 15-20:1 pending local banding. 

As I see it, there will be a line about 30-50 miles wide of pretty decent snowfall with the northern edge tapering back in a gradient caused by the confluent area to the north. Here's my current thoughts on snow totals. This is all from everything I've looked at and adjusted based on current ground temps needing some time to recover from the warmth earlier today.

 

Hope everyone here gets some snow. Enjoy y'all!! 

That is one hell of an analysis. The best part is this...

Sorry... not sorry.

Pasadena. Just started. I hear sleet. Temp/Dewpoint DGAF.

both work

The 959 says let it snow...

3 minutes ago, mappy said:

oh boy. it does have a look to it

That's good you got the alert. My mom is in Pasadena, should miss her to her east. Looks like it will go towards Lake Shore/Gibson Island (she's closer to route 2, along 648)

Hi from Lake Shore area in the Dena.

Just now, Stormfly said:

This how we do severe in MD.  Build up to a huge climax, wind up with drizzle and barely enough breeze to move some leaves off the walkway.

Same approach as winter. Typical....

5 drops of rain. At least they were big drops. Plenty of thunder and lightning... with nothing to show for it.

20 minutes ago, WxUSAF said:

Back to drought concerns 

Your not alone.

Even a line of thunderstorms splits Pasadena. I need to move.

0.004 so far... I'm sure we will break 0.01. Judging from the radar....

I am looking at this and waiting for the pivot.... We have lost some sun angle and I'm not sure if there is enough hot air damning to create the instability necessary for heavy banding. Also concerned about ground temps. The last 24 hours have allowed the ground to cool. Fortunately we have daylight savings time on our side. That said, I see some back building on the radar. In the end.. I knew I shouldn't have watered the lawn and sharpened the blades on my lawnmower in advance of this storm. Please accept my apology... thanks in advance.

Just now, WxUSAF said:

Steady light rain. Almost a car topper.

I noticed a couple of drops on my grill as well.

Let the pasadena split and fringing begin....

On 7/6/2021 at 3:19 PM, Stormfly said:

What a weird TSW.

Agreed

5 droplets of rain.

42 minutes ago, North Balti Zen said:

So, it was bad.

For those that know the city - the Univ. Balt School of Law at corner of Mt. Royal and Charles - just before you get to the train station. Right as I crossed over Mt. Royal I realized the water was a LOT higher there than I had suspected. I've never seen high water there so me and the car next to me drove into what you are told not to drive into. It was up to hood level and I think I may have lost contact with the road briefly. I did re-grip, car engine never cut off, and got through it. But now my check engine light is on as is the traction warning light. Got home, parked it, crawled inside, and am getting an early drink. If, when it dries out, those lights stay on, anyone had experience with this and car insurance? Should I make a claim if it ends up being something got damaged due to the high water?

The check engine light will probably not turn off until you clear the fault code. But I would want to know that fault code before clearing it. You can probably reset/clear the codes by disconnecting the positive lead from your battery. You may have other problems like water in the fuel system as well. Hood level water has to be within the range of the air intake for the motor... not good unless it is something like a jeep with a snorkle. You may want to call your insurance company.