March 12-15, 2023 | NE / Mid-Atlantic Winter Storm

[StretchCT]

Heck of a discussion from Upton. 

Spoiler

&& .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/... As the trough continues its approach, the low over the Great Lakes continues to weaken, as the low off the Southeast US becomes the primary low, still situated well south of the area by the end of the day Monday. An inverted trough develops and stretches north into the Northeast US. This will be the focus for some more moderate to heavy precipitation late in the day Monday into Monday night. There area indications in the deterministic models that another low pressure may form along this boundary, which will further aid in lift, and thus heavy precipitation. Additionally, the upper trough strengthens into a closed low, aiding in strengthening the surface low or lows. The primary surface low will south and east of the area, though there is still a fair amount uncertainty in the exact track, leading to uncertainty in precipitation amounts. Most models take the track of this primary low (that strengthens to ~980 mb to ~985 mb) over or east of the 40N/70W benchmarksometime Tuesday morning. The weaker secondary low track over Long Island. The primary low pivots northeast around the secondary toward the Gulf of Maine (or near Cape Cod) by the end of the day Tuesday. The trend with the track however, has been farther south and east, meaning a colder solution and therefore more in the way of snow, even along the coast. Much of the area will see plain rain for Monday, with perhaps a rain/snow mix across the higher elevation inland. As the low tracks east of the area, and strengthens, strong cold air advection will ensue, allowing a changeover to snow from northwest to southeast late Monday night into Tuesday morning. This time frame is also a period of when the heavier precipitation is expected. Heavy snow is expected across the interior, while there will be heavy rain for the coast. By early Tuesday morning, the changeover continues, even towards coastal areas, but by this point, the heavier precipitation will have ended. This changeover continues moving south and east. The snowfall forecast will be quite challenging as accumulating snowfall is possible, even along the coast. Some of the main challenges will be where the exactly the low tracks and how strong will it be (a weaker low will not bring in the colder air, just as a low closer to the coast will also mean a warmer solution), how much the March sun angle will aid in melting the snow as it falls (which will mean a snow ratio much less than 10:1), and the possibility of a deformation band developing and where it sets up which is being advertised in some of themesoscale models. Despite these uncertainties, it was prudent to increase snow totals, with close to a foot across western Orange County. However, much of the rest of the Lower Hudson Valley, and portions of northeast New Jersey and inland southwest Connecticut are expected to see 6 to 10 inches of snow. Have added western Bergen, Rockland, northern Westchester, and northern New Haven to the Winter Storm Watches. However, held off on converting any watches to warnings given uncertainty. Right now, 1 to 3 inches of snow is possible for the coast, including New York City. Most of the ensembles show this range. There is the possibility of seeing more snow, with advisory level snow not out of the question. A reasonable high end for New York City is around 6 inches, though this is an outlier right now. With a strengthening low, winds will also be strong. Eastern areas, such as the Twin Forks of Long Island and southeastern Connecticut are approaching Wind Advisory criteria (46 mph gusts and higher). Gusts of 40 to 45 mph are more likely, with isolated gusts to 50 mph.

 

 

[MaineJay]

Recon flight going out into the Atlantic tomorrow.

Quote

000
NOUS42 KNHC 121645
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1245 PM EDT SUN 12 MARCH 2023
SUBJECT: WINTER SEASON PLAN OF THE DAY (WSPOD)
         VALID 13/1100Z TO 14/1100Z MARCH 2023
         WSPOD NUMBER.....22-102

I.  ATLANTIC REQUIREMENTS
    1. FLIGHT ONE - TEAL 74
       A. 14/0000Z
       B. AFXXX 03WSA TRACK64
       C. 13/1830Z
       D. 10 DROPS AS PUBLISHED ON TRACK
       E. AS HIGH AS POSSIBLE/ 13/2030Z-14/0230Z

 

[MaineJay]

H7 analysis.

[PA road DAWG]

@JDClapper

you see WNEP forecast?  6-8 in northern wayne when NWS has warning out for 10-20 inches lol 

[MaineJay]

This thing sure is taking it's time.

[MaineJay]

Probably about the time to start watching if/when/how the radar is blossoming.  Important to check METARs to see if anything is hitting the ground.   If I was more ambitious, I'd look for webcams for more observational corroboration.

  I remember someone was checking the traffic, and slowdowns seemed a good proxy for snow.

 

 

[JDClapper]

13 minutes ago, PA road DAWG said:

@JDClapper

you see WNEP forecast?  6-8 in northern wayne when NWS has warning out for 10-20 inches lol 

Its like they dont know the area. That NE corner notoriously does well with these "close calls" for NEPA. Wednesday they will have someone onsite talking about the foot+ that fell in northern Wayne county.

[JDClapper]

5 minutes ago, MaineJay said:

Probably about the time to start watching if/when/how the radar is blossoming.  Important to check METARs to see if anything is hitting the ground.   If I was more ambitious, I'd look for webcams for more observational corroboration.

  I remember someone was checking the traffic, and slowdowns seemed a good proxy for snow.

 

 

Not much blossoming.... yet.

[so_whats_happening]

1 minute ago, MaineJay said:

Probably about the time to start watching if/when/how the radar is blossoming.  Important to check METARs to see if anything is hitting the ground.   If I was more ambitious, I'd look for webcams for more observational corroboration.

  I remember someone was checking the traffic, and slowdowns seemed a good proxy for snow.

 

 

Not much down this way just some very light random rain. Low cloud deck in and out and temps are hovering in the upper 30s and slowly dropping while dew point is holding low. Gotta see if we setup the little cold air damming that is left across the area. The low is a stretched mess still off the GA/SC coast. The remnant low that was over Ohio/ KY is now over PA and bringing decent SE flow across most of the area to about 850mb. See how quickly the 925 and 850mb low set up toward the coast looks like we should see a solid LP near Wilmington, NC by about 2am.

What a very interesting surface temp depiction on the models. I liked the 18z 3km NAM because it can really show some neat features it also follows similar to the HRRR as @Poco posted about. It also shows that low pressure that develops with the little vort we keep seeing out front.

[MaineJay]

11 minutes ago, JDClapper said:

Not much blossoming.... yet.

I threw the "if" in there. 

I'm patiently watching the mPing for Clappers report from the 'port.

 

[Penn State]

8 minutes ago, JDClapper said:

Not much blossoming.... yet.

We had some real fine snow flurries around 4-5pm.. no real accumulation, but I was stoked (sarcasm) 5th largest snowfall of the season so far lol.. 🙄

[PA road DAWG]

Wow!  The 18z euro just took a massive step north/northeast

 

[Chris2333]

6 minutes ago, PA road DAWG said:

Wow!  The 18z euro just took a massive step north/northeast

 

At this point in the game aren’t we shifting away from globals and now to nowcasting and short range models? You know a ton more than me but throwing my 2 cents (well really 1/2 cent out there). I’m going to get shafted either way haha 

[JDClapper]

11 minutes ago, PA road DAWG said:

Wow!  The 18z euro just took a massive step north/northeast

 

Wnep doesnt look so silly no mo.

[JDClapper]

16 minutes ago, MaineJay said:

I threw the "if" in there. 

I'm patiently watching the mPing for Clappers report from the 'port.

 

🤣 quit stalking me on mping

 

We also had a few flurries around 5pmish whilst I was grilling on that grill @StretchCT keeps asking if I have a cover for. 🍔

[Penn State]

I know it doesn’t look like much.. but business is picking up a bit. 

[Poco]

How many shifts have this storm taken either direction on the mid range, it’s be like every new run is the correct run and that’s not how you should look at a storm of this type that way.  You can repeat yourself over and over and it doesn’t matter 

11 minutes ago, Chris2333 said:

At this point in the game aren’t we shifting away from globals and now to nowcasting and short range models? You know a ton more than me but throwing my 2 cents (well really 1/2 cent out there). I’m going to get shafted either way haha 

 

[Poco]

Jma track at 18z 

gfs 18z

 

don’t have euro updated 

Edited March 13, 2023 by Poco

[JDClapper]

SREF pos snow depth change trends.. for 2am Wednesday.

[Blizz]

Man, if only this was even 50 miles southwest 

[so_whats_happening]

18 minutes ago, Penn State said:

I know it doesn’t look like much.. but business is picking up a bit. 

Yea gotta wait for the jet to make its way closer

Im still not sure how to make this with a white background. Anyways looks like the fun is out back toward Arkansas right now where the jet max is.

[PA road DAWG]

4 minutes ago, Blizz said:

Man, if only this was even 50 miles southwest 

Usually the case for us.  We shall see !

[Sentinel]

5 minutes ago, so_whats_happening said:

Yea gotta wait for the jet to make its way closer

Im still not sure how to make this with a white background. Anyways looks like the fun is out back toward Arkansas right now where the jet max is.

100%. The truth is that models do not know what to make of this right now. 

The dynamics with this are quite strong and so many moving pieces that 1 small deviation will make a huge impact. 

[StretchCT]

For Oxford - snow amounts to either end of run or end of storm.  Kuchera unless otherwise indicated.  Will note OXC is about 200 feet higher than I am. 

SREF  11.8

18z GFS  1.8

12z Ukie 10:1 4.1

18z Euro  5.1

12z CMC  11.7

12z NAM   16.4

18z NAM  6.8 (used two NAMs cause they were so different)

18z NAM 3k  13.6

18z ICON true slr 3

12z FV3  4.9

NWS 5pm 6-8" 

Average 7.8"

 

[StretchCT]

Upton's 5pm update