January 6-7 Storm Discussion: we’re due?

[jayyy]

Euro trend..


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[jayyy]

GFS “wiggle” aka big shift - 12z vs 0z

Gotta imagine the Boston sub wasn’t thrilled about that run. Went from a foot+ to 1-3” around the Boston metro over 2 runs.

[jayyy]

GDPS trend… 12z vz 00z


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[jayyy]

Ukie trend.. 0z vs 12Z


All major guidance shifted in our direction tonight. Hope to keep it rolling come 6z


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[jayyy]

00z EPS

MSLP - 2 mb weaker vs 12z
HP - 2mb stronger vs 12z
Confluence - better
Track - a smidge further offshore


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[Weather Will]

WB 6Z ICON

[Weather Will]

Latest from NWS Sterling

LONG TERM /SATURDAY THROUGH TUESDAY/...
A strong southern stream mid/upper-level trough over the Mid-South
Friday night quickly moves northeast as it phases into a flat trough
over the OH Valley/Mid-Atlantic on Saturday. At the surface, an
associated area of low pressure develops along the northern Gulf
Coast and very quickly moves across the Southeast states through
Saturday morning. The surface low becomes better organized as it
crosses eastern NC into far southeast VA, where it moves offshore
along the NC/VA border.

Precipitation overspreads the area from southwest to northeast
starting late Friday night into Saturday. Temperatures Friday night
are forecast to be below freezing for most of the area. However,
there is considerable uncertainty to the east of US-15 as easterly
winds advect in a warmer marine airmass and strong WAA ahead of the
surface low help to increase temps along/east of I-95. All that
being said, precipitation is likely to start out as snow west of US-
15 and a rain/snow mix along/east of US-15. As the morning
progresses, areas east of I-95 are most likely to transition to a
cold rain, with steady snow west of US-15, and a mix in between.

Having the surface high well to the north and weak onshore flow
proceeding the surface low are not generally favorable for
accumulating snow along I-95. Any chance to see higher snow totals
there will be dependent on higher precip rates and wet bulb effects
overcoming the marginal temperature profile.

Still, p-type is going to be highly sensitive to the track of the
low, with a tight rain-snow gradient likely. Significant snow
accumulations are most likely along/west of the Blue Ridge and
Catoctins. Where precip is more likely to be in the form of rain,
near and east of I-95, there is the potential for instances of
flooding. Continue to monitor the progress of this storm as the
weekend approaches.

The coastal low tracks northeast and away from the area Saturday
night, then a reinforcing upper traverses the area on Sunday. Some
lingering rain and snow showers possible during the first part of
Monday north of I-66 and west of the Blue Ridge, though conditions
dry out quickly in the afternoon. Upslope mountain snow showers
continue into Sunday night.

 

[winter_warlock]

Sterling saying mostly rain for i95.. did they not see the 00z models? Lol

[CAPE]

5 minutes ago, Weather Will said:

Latest from NWS

LONG TERM /SATURDAY THROUGH TUESDAY/...
A strong southern stream mid/upper-level trough over the Mid-South
Friday night quickly moves northeast as it phases into a flat trough
over the OH Valley/Mid-Atlantic on Saturday. At the surface, an
associated area of low pressure develops along the northern Gulf
Coast and very quickly moves across the Southeast states through
Saturday morning. The surface low becomes better organized as it
crosses eastern NC into far southeast VA, where it moves offshore
along the NC/VA border.

Precipitation overspreads the area from southwest to northeast
starting late Friday night into Saturday. Temperatures Friday night
are forecast to be below freezing for most of the area. However,
there is considerable uncertainty to the east of US-15 as easterly
winds advect in a warmer marine airmass and strong WAA ahead of the
surface low help to increase temps along/east of I-95. All that
being said, precipitation is likely to start out as snow west of US-
15 and a rain/snow mix along/east of US-15. As the morning
progresses, areas east of I-95 are most likely to transition to a
cold rain, with steady snow west of US-15, and a mix in between.

Having the surface high well to the north and weak onshore flow
proceeding the surface low are not generally favorable for
accumulating snow along I-95. Any chance to see higher snow totals
there will be dependent on higher precip rates and wet bulb effects
overcoming the marginal temperature profile.

Still, p-type is going to be highly sensitive to the track of the
low, with a tight rain-snow gradient likely. Significant snow
accumulations are most likely along/west of the Blue Ridge and
Catoctins. Where precip is more likely to be in the form of rain,
near and east of I-95, there is the potential for instances of
flooding. Continue to monitor the progress of this storm as the
weekend approaches.

The coastal low tracks northeast and away from the area Saturday
night, then a reinforcing upper traverses the area on Sunday. Some
lingering rain and snow showers possible during the first part of
Monday north of I-66 and west of the Blue Ridge, though conditions
dry out quickly in the afternoon. Upslope mountain snow showers
continue into Sunday night.

 

NWS Mount Holly is in overall agreement-

A shortwave trough along the subtropical jet will eject out of the Gulf Coast region and lift across the Mid Atlantic. An associated area of low pressure will strengthen as it moves through the southeast and up the Mid-Atlantic coast Saturday and into Sunday. The exact track of this surface low will determine what specific impacts there will be. It is worth mentioning that the latest deterministic guidance has shifted slightly further offshore and leaned towards a weaker system overall, potentially allowing for a slightly colder solution, albeit still not enough for an "all- snow" solution. With that said, we can expect guidance to continue the "tug-of-war" of where to place the center of this low, thus it remains in our best interest to stick closer to the consensus blend, which continues to show a low track that gives our higher elevations along the I-78 corridor the best chance for snow with a highly uncertain precip type forecast for the I-95 corridor and points south and east. Guidance should come into better focus in the next 24-48 hours as the shortwave trough responsible for this system moves over the western US and can be better sampled by upper air observations. Bottom line, this system bears watching and is setting up to bring heavy precipitation, gusty winds, and potential coastal flooding though with strong onshore flow. See hydrology section below for more details regarding rainfall and flooding potential.

[CAPE]

For the coastal plain, the 0z GFS idea of weaker/souther is probably the only hope for some frozen in this setup. Snow starved lowlanders should consider taking a short trip for this one.

[Weather Will]

WB 6Z GFS

1pm Sat, 4pm, 7pm and precip.totals.

 

[Solution Man]

20 minutes ago, Weather Will said:

WB 6Z GFS

1pm Sat, 4pm, 7pm and precip.totals.

 

Lighter amounts this time, run to run variance

[midatlanticweather]

That was a huge precip nothing

[Solution Man]

19 minutes ago, midatlanticweather said:

That was a huge precip nothing

06z, wait till 12z

[WinterWxLuvr]

What impresses me about the gfs is it’s rock steady consistency 

[WxUSAF]

Good morning all, glad we came back overnight. I agree with something @Deck Pic said a few pages ago. Those of us in the metro corridor I think should be rooting for a big WAA thump in the 20-0z time period Saturday I think. Pile up some mashed potatoes quick and then it’s already dark by the time it flips to rain. And it’s probably all over before midnight Sunday. 

[osfan24]

Rough start this morning after last night's great runs. GFS is much faster and weaker. Also looks a tad warmer as well.

[Buddy1987]

32 minutes ago, osfan24 said:

Rough start this morning after last night's great runs. GFS is much faster and weaker. Also looks a tad warmer as well.

Well.. that was extremely disappointing to wake up to. Hopefully off run will come back at 12z. Don’t like the trend at all with weaker low exiting off the coast. GFS more like Euro this am.

[catoctin wx]

9 hours ago, Eskimo Joe said:

Spot on as usual. You can also see the Monocacy Valley snow hole illustrated. It seems to rear it's ugly head when there isn't sustained cold air draining into Frederick City. I know that's been the perennial bane of @catoctin wx and @Mrs.J

Bane is exactly the right word for setups where cold air is marginal.  I can often see the snow a few miles from my house on top of Braddock Mtn but it's rain in the valley. Pretty cool to see it showing up in the models now.

[H2O]

Just not any consistency between modes yet. Euro hasn’t budged much since yesterday but even its snow jackpot changed. GFS jumpy as well with huge shift last night. It had support tho. 
 

models still trying to resolve western energy and confluence and until they do it’s gonna be a back and forth. 
 

Wxmeddler said it best with models trying to also put low pressures along the baroclinic zone in the ATL. 

[CAPE]

6z GEFS 

[Weather Will]

WB 6Z EURO

[Weather Will]

Weak sauce on EURO, biggest Lucy on this storm is not the rain/ snow line but the poor intensity forecast.  I guess the flow is still too fast/ too many competing vortices, and not enough spacing between them.

[DDweatherman]

How fitting for 0z to crush on all major models for 6z to be our good ole fashioned Charlie Brown and be warmer, dryer, and norther. 

[aldie 22]

5 minutes ago, Weather Will said:

WB 6Z EURO

These 6z runs are way too drastic of a shift there's definitely something wonky or perhaps last night was the wonky but still...something smells 

[TSSN+]

Euro precip is fine it’s just way too warm 

[nj2va]

Here’s the 7z NBM

[WinterWxLuvr]

That Euro run only goes to 0z right? 

[Heisy]

Here’s the 7z NBM

This makes sense. Looks realistic and climo accurate


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[TSSN+]

Just now, WinterWxLuvr said:

That Euro run only goes to 0z right?