Feb 22nd/23rd "There's no way..." Storm Thread

[Shad]

RGEM a touch too warm similar to ICON

[LP08]

It’s not a great model but the fv3 is a beatdown and still going at 60

[psuhoffman]

Why are the Icon and rgem soooo warm!  It’s Feb with a sub 990 low off the Delmarva and moderate precip. And it’s close to 40!  WTF 

[NorthArlington101]

Just now, psuhoffman said:

Why are the Icon and rgem soooo warm!  It’s Feb with a sub 990 low off the Delmarva and moderate precip. And it’s close to 40!  WTF 

I'd say we bust low on temps as we have all week but we know that's not likely

[Scraff]

Goofy GooFuS time! LFG!!

[WxUSAF]

1 minute ago, psuhoffman said:

Why are the Icon and rgem soooo warm!  It’s Feb with a sub 990 low off the Delmarva and moderate precip. And it’s close to 40!  WTF 

Cuz it’s an absolute dog shit antecedent airmass?

RGEM overall has a lot to like. Better H5, closer tuck to the coastal, and a really nice IVT that gets most everyone in the metro area and east. Sorry CHO area…

[Shad]

The King is running.....let it cook

[SomeguyfromTakomaPark]

Still feels like some trending to go before the actual storm but it's nice to see the the total whiff solutions from the euro/icon a few days ago are basically gone.  

[arlwx12]

I'd be surprised if any watches get issued before the 00z runs.

Maybe after the 12z runs tomorrow?

[Terpeast]

1 minute ago, WxUSAF said:

Cuz it’s an absolute dog shit antecedent airmass?

RGEM overall has a lot to like. Better H5, closer tuck to the coastal, and a really nice IVT that gets most everyone in the metro area and east. Sorry CHO area…

Yep, we've been in a -PNA regime for weeks now. We're lucky we're even talking about snow at all rn

[Nomz]

All hail

[Terpeast]

Still changes with the SW canada shortwave on gfs even at hour 18

[TowsonWeather]

1 minute ago, Terpeast said:

Still changes with the SW canada shortwave on gfs even at hour 18

As subtle as they are, I would THINK they might bode well downstream? At least in theory. No point speculating, I guess, just too complex to say at this point. Could just as easily go sideways on us.

[arlwx12]

Slightly updated wording from LWX's AFD at 1029...

 

If the upstream ridge-building event takes place a bit further west
near 120 W longitude on Saturday, downstream trough amplification
would be favorable for phasing over the mid MS Valley into the OH/TN
Valleys Saturday night. A subsequent low track hugging the coast
would become more likely in this scenario, aided by downstream
blocking and a potential source of cold air given the upper lows
over Maritime Canada and surface high pressure attempting to ridge
into northern New England. There is also an appearance of an
inverted trough signature in a subset of model guidance over the
last couple cycles, given interaction between a more amplified
northern stream wave and a bit more distant offshore southern stream
low. This could factor into precipitation amounts and placement.

After reviewing the 00z model guidance suite, some subtle
consistency has been noted although subtle uncertainty remains. Most
of the models has a low tracking up from GA/AL toward the NC
coast and off the Delmarva coast during the late Saturday night
into late Sunday timeframe. The question remains in the proximity
toward the coast along with cold air availability, and the overall
scope of the precip shield pending the placement/intensity of the
system. 25 to 50 miles could make a huge difference between seeing
little to no wintry precip or impactful precip, especially for those
east of the mountains where the confidence remains low due to
thermal issues especially below elevations of 1500 feet. The 00z
GFS/GEFS solutions have come down a tad, but still produce
measurements on the order of 10+" of snow over a large chunk of the
area. Meanwhile, the 12z EPS ensembles came up some, but at much
more conservative levels which align with deterministic runs of the
NAM, RDPS, GDPS, GEM, CMC, EURO/EURO AIFS, and UKMET. The
latest NBM also came up a bit and aligns with the majority
compared to the GFS/GEFS outliers, especially along and east of
I-95. With that said, the 6/12z model suites should put the
remaining puzzle pieces together as we will sit 60 hours from
the event.

Three scenarios remain:

 1) The phase of all of these upper level features occurs too late,
  with low development offshore and too far southeast.

 2) Similar to scenario 1, but an inverted trough on the back side
of the low brings snow to eastern portions of the region.

 3) Low develops closer to shore and strengthens along Delmarva
Peninsula, resulting in the most snow for our areas.

We still remain in the "wait and see" period with this storm, so
just take precautions now, should the worst case scenario play out.
Having a preparedness kit stocked up is never a bad idea.

Lastly, no matter what plays out further east, it seems much more
likely that the mountains will see another round of upslope
snow. The key here will be with how much we manage to get. That
will depend on the storm track as well, but it seems much more
likely for at least advisory to perhaps warning level
accumulations through the Sunday/Monday period along/west of the
Allegheny Front. Of note, the higher sun angle later in the
season becomes a factor especially for lower elevations if
precip occurs during the day. Cold air will also be filtering
into the region as the storm in question approaches, rather than
being locked-in beforehand, which offers another layer of
uncertainty in p-type.

[EstorilM]

1 minute ago, arlwx12 said:

Slightly updated wording from LWX's AFD at 1029...

 

If the upstream ridge-building event takes place a bit further west
near 120 W longitude on Saturday, downstream trough amplification
would be favorable for phasing over the mid MS Valley into the OH/TN
Valleys Saturday night. A subsequent low track hugging the coast
would become more likely in this scenario, aided by downstream
blocking and a potential source of cold air given the upper lows
over Maritime Canada and surface high pressure attempting to ridge
into northern New England. There is also an appearance of an
inverted trough signature in a subset of model guidance over the
last couple cycles, given interaction between a more amplified
northern stream wave and a bit more distant offshore southern stream
low. This could factor into precipitation amounts and placement.

After reviewing the 00z model guidance suite, some subtle
consistency has been noted although subtle uncertainty remains. Most
of the models has a low tracking up from GA/AL toward the NC
coast and off the Delmarva coast during the late Saturday night
into late Sunday timeframe. The question remains in the proximity
toward the coast along with cold air availability, and the overall
scope of the precip shield pending the placement/intensity of the
system. 25 to 50 miles could make a huge difference between seeing
little to no wintry precip or impactful precip, especially for those
east of the mountains where the confidence remains low due to
thermal issues especially below elevations of 1500 feet. The 00z
GFS/GEFS solutions have come down a tad, but still produce
measurements on the order of 10+" of snow over a large chunk of the
area. Meanwhile, the 12z EPS ensembles came up some, but at much
more conservative levels which align with deterministic runs of the
NAM, RDPS, GDPS, GEM, CMC, EURO/EURO AIFS, and UKMET. The
latest NBM also came up a bit and aligns with the majority
compared to the GFS/GEFS outliers, especially along and east of
I-95. With that said, the 6/12z model suites should put the
remaining puzzle pieces together as we will sit 60 hours from
the event.

Three scenarios remain:

 1) The phase of all of these upper level features occurs too late,
  with low development offshore and too far southeast.

 2) Similar to scenario 1, but an inverted trough on the back side
of the low brings snow to eastern portions of the region.

 3) Low develops closer to shore and strengthens along Delmarva
Peninsula, resulting in the most snow for our areas.

We still remain in the "wait and see" period with this storm, so
just take precautions now, should the worst case scenario play out.
Having a preparedness kit stocked up is never a bad idea.

Lastly, no matter what plays out further east, it seems much more
likely that the mountains will see another round of upslope
snow. The key here will be with how much we manage to get. That
will depend on the storm track as well, but it seems much more
likely for at least advisory to perhaps warning level
accumulations through the Sunday/Monday period along/west of the
Allegheny Front. Of note, the higher sun angle later in the
season becomes a factor especially for lower elevations if
precip occurs during the day. Cold air will also be filtering
into the region as the storm in question approaches, rather than
being locked-in beforehand, which offers another layer of
uncertainty in p-type.

Haha I just clicked refresh on that as well and saw it was "updated" but it doesn't seem like they even touched the stuff regarding the storm potential. 

[Interstate]

I don't think I am liking the change... I could be wrong

[TowsonWeather]

At 30h, not quite as diggy out west, but the leading vort is slower, leading to more interaction between the vorts. Heights very slightly higher.  

[LP08]

Definitely a broader Trof through 36

[LeesburgWx]

1 minute ago, Interstate said:

I don't think I am liking the change... I could be wrong

I thought the changes look better. Who knows at this point. Let's see it play out

[Nomz]

Maybe more of the 00z solution than the earlier ones

[TowsonWeather]

1 minute ago, Interstate said:

I don't think I am liking the change... I could be wrong

Yeah, I was on the fence at 30h, I'm in the "don't like this" camp now for 36h. Shallower trough, not quite as diggy. 

[SnowenOutThere]

13 minutes ago, WxUSAF said:

Cuz it’s an absolute dog shit antecedent airmass?

RGEM overall has a lot to like. Better H5, closer tuck to the coastal, and a really nice IVT that gets most everyone in the metro area and east. Sorry CHO area…

Eh it’s get Shenandoah nice and good 

[arlwx12]

The next AFD should be out a bit before 4 pm.

[Interstate]

it is all about it going negative tilt now

[SnowenOutThere]

I actually don’t hate the GFS so far

[Jersey_Snowhole]

1 minute ago, Interstate said:

it is all about it going negative tilt now

It’s negative at hr 57

[stormtracker]

3 minutes ago, Interstate said:

I don't think I am liking the change... I could be wrong

Still seems decent.  Seems a bit more progressive.  

[Interstate]

it is way positive at 48 compared to 54@6Z

[TowsonWeather]

42h, the theme of shallower trough and more consolidated energy remains, but more energy rounding the back-side. 

[mitchnick]

Just now, SnowenOutThere said:

I actually don’t hate the GFS so far

This has become a love-hate relationship here.