The January 5/6 Thing

[WEATHER53]

31 minutes ago, pazzo83 said:

which will be reflective of the surrounding area which is heavily urbanized and low-lying.

Camp Springs, BWI and Annapolis are if not close by then similar including water. Every one will be 3-4F colder due to impeding elements of DCA.  Your nice balcony may match DCA but that’s artificially high also 

[MillvilleWx]

11 minutes ago, NorthArlington101 said:

A couple smart degreed mets I'm in chats with are throwing out a yellow flag that the AI modeling is lighter on precip than the globals... their take on the AI is that they are essentially really fancy analogs, since they work by referencing the dataset of previous storms and then guessing the outcome from there. Food for thought, I guess, don't mean to deb.

No one storm is alike, but I do believe we’ll see QPF step back some in the areal extent, however the AI isn’t going to account for more complex mesoscale dynamics such as FGEN which will play a significant role in this setup. I’m hoping people realize that at the current juncture, we’re going to see some pretty sick banding during the storms height with some periods seeing better ratios than others during the event. That’s why I feel there will be dual maxima in these parts and those details will not be solidified until much closer to game time, and even so is very nowcast in nature. 
 

Trends are good so far for much of the region. It’s looking like a high end advisory at the worst and WSW potential increasing. Good times! 

[WEATHER53]

32 minutes ago, NorthArlington101 said:

Not to shill for DCA - but they were on point during the storms last year. No suspicious activity. They even recorded .1" this year during that morning sleet a week or two ago. Think they've found a generous slant-sticker to conduct the measurements. 

I’m not sure about their snowboard anymore as I think the access to it right out the door from their office was changed. They never did remote personal measurements . It was always not for  public release about how things were accomplished 

[WEATHER53]

33 minutes ago, pazzo83 said:

a lot of people make a big deal about this here and in NYC, forgetting that these are the stations of record for the cities in which they reside (technically DCA is barely in Arlington County, but Arlington and DC are more or less dense urban areas).  They are not the stations of record for someone's house at 500' of elevation 30 miles from the city.

When a lot of people make a big deal then they are probably correct 

[Kevin Reilly]

57 minutes ago, stormtracker said:

Appears wetter for the Northern tier folks...about the same everywhere else

Suggests more expansive precipitation field north through colder higher ratios works well wow normal winter. 

[T. August]

Euro ens is generally the same - 4-6” north to south.

[yoda]

 

[winter_warlock]

FWIW.  From Joe Bastardi...

 

"the axis of the heaviest snow looks like you take I-70 from the plains to BWI and then just extend it east. In this band about 150 miles wide is 6-12 inches of snow which is 10 to 1 south of the axis and up to 20 to 1 north of it. Some 15-inch lollipops will occur. "

[Solution Man]

43 minutes ago, MN Transplant said:

I know that this is a joke, but they've been doing way better since getting embarrassed back a decade ago.

This^

[blizzardmeiser]

7 minutes ago, winter_warlock said:

FWIW.  From Joe Bastardi...

 

"the axis of the heaviest snow looks like you take I-70 from the plains to BWI and then just extend it east. In this band about 150 miles wide is 6-12 inches of snow which is 10 to 1 south of the axis and up to 20 to 1 north of it. Some 15-inch lollipops will occur. "

Prepare for storms and rumors of storms

[SnowenOutThere]

Capital Weather Gang article mentions the possibility of frontal enhancement in its latest article as "There are also some indications that the jet stream pattern and localized fronts may help intensify snow over our region". Has 35% of 3-6 for DC, 35% 6+ for DC, 20% 1-4 because mixing issues, and 10% chance of 1-4 for DC due to missing to the south. 

https://www.washingtonpost.com/weather/2025/01/02/dc-region-snow-storm-forecast-ice-winter-weather/?utm_source=twitter&utm_medium=social&utm_campaign=wp_weather

[BristowWx]

Just now, blizzardmeiser said:

Prepare for storms and rumors of storms

looking forward to DT maps and Ellinwood maps.  

[Kevin Reilly]

8 minutes ago, winter_warlock said:

FWIW.  From Joe Bastardi...

 

"the axis of the heaviest snow looks like you take I-70 from the plains to BWI and then just extend it east. In this band about 150 miles wide is 6-12 inches of snow which is 10 to 1 south of the axis and up to 20 to 1 north of it. Some 15-inch lollipops will occur. "

Also keeping in mind this whole conversation is bumping about 8-10 miles north each run in some cases could make for very interesting totals further north in the coldest of air in regards to those rations.  I don’t think this is done bouncing around quite yet until at earliest this time tomorrow. 

[LeesburgWx]

Just caught up. I’ve gone from 5-8” to 8-12” expectations after the 12z runs. Lets lock this in!

[stormy]

I dropped from 9.3 at 06z to 5.0 at 12z on the Euro. It caved toward the GEM and GFS with the southern margin. It dropped qp in my area from .95" to .69"

[T. August]

Latest blend, 5-7”. Pretty much the same. About .5” north of Baltimore is from tomorrow.

[bncho]

43 minutes ago, LeesburgWx said:

Just caught up. I’ve gone from 5-8” to 8-12” expectations after the 12z runs. Lets lock this in!

That's a lot of snow. Here's hoping for solid 18z runs.

[StormyClearweather]

From LWX Disco 

THE BIGGEST AREA OF FOCUS OF THE THE LONG TERM WILL BE AN AREA OF   
LOW PRESSURE TRACKING FROM THE MISSISSIPPI RIVER VALLEY TOWARDS NEW   
ENGLAND, BRINGING WINTRY WEATHER TO THE REGION SUNDAY EVENING   
THROUGH MONDAY. THERE REMAINS A GOOD BIT OF MODEL DISCREPANCY   
REGARDING THE TRACK AND TIMING OF THE LOW PRESSURE SYSTEM, THEREFORE   
LEADING TO UNCERTAINTY WHEN IT COMES TO A SNOWFALL AMOUNT AND   
PRECIPITATION TYPE FORECAST. WHILE TEMPERATURES AT THE SURFACE ARE   
EXPECTED TO STAY NEAR OR BELOW FREEZING, MODEL SOUNDINGS INDICATE A   
PROLONGED WARM NOSE LEADING TO PRECIPITATION TYPE TRANSITIONING FROM   
SNOW TO SLEET/FREEZING RAIN. THIS WILL LEAD TO LOWER SNOW TOTALS   
THAN SOME MODELS ARE CURRENTLY INDICATING. 12Z MODEL GUIDANCE IS   
SHOWING A LIGHT SHIFT NORTH FOR THE LOW PRESSURE SYSTEM, WITH   
ACCUMULATION AMOUNTS CONTINUING TO SHOW A GOOD BIT OF DISCREPANCY.   
PRECIPITATION ONSET WILL LIKELY BE SUNDAY AFTERNOON THROUGH SUNDAY   
NIGHT WITH PRECIPITATION MOVING OUT OF THE AREA EARLY TUESDAY   
MORNING. 

[stormtracker]

9 minutes ago, StormyClearweather said:

From LWX Disco 

THE BIGGEST AREA OF FOCUS OF THE THE LONG TERM WILL BE AN AREA OF   
LOW PRESSURE TRACKING FROM THE MISSISSIPPI RIVER VALLEY TOWARDS NEW   
ENGLAND, BRINGING WINTRY WEATHER TO THE REGION SUNDAY EVENING   
THROUGH MONDAY. THERE REMAINS A GOOD BIT OF MODEL DISCREPANCY   
REGARDING THE TRACK AND TIMING OF THE LOW PRESSURE SYSTEM, THEREFORE   
LEADING TO UNCERTAINTY WHEN IT COMES TO A SNOWFALL AMOUNT AND   
PRECIPITATION TYPE FORECAST. WHILE TEMPERATURES AT THE SURFACE ARE   
EXPECTED TO STAY NEAR OR BELOW FREEZING, MODEL SOUNDINGS INDICATE A   
PROLONGED WARM NOSE LEADING TO PRECIPITATION TYPE TRANSITIONING FROM   
SNOW TO SLEET/FREEZING RAIN. THIS WILL LEAD TO LOWER SNOW TOTALS   
THAN SOME MODELS ARE CURRENTLY INDICATING. 12Z MODEL GUIDANCE IS   
SHOWING A LIGHT SHIFT NORTH FOR THE LOW PRESSURE SYSTEM, WITH   
ACCUMULATION AMOUNTS CONTINUING TO SHOW A GOOD BIT OF DISCREPANCY.   
PRECIPITATION ONSET WILL LIKELY BE SUNDAY AFTERNOON THROUGH SUNDAY   
NIGHT WITH PRECIPITATION MOVING OUT OF THE AREA EARLY TUESDAY   
MORNING. 

We always flirt.  Just gotta not fly too close to the sun

[Ruin]

11 minutes ago, StormyClearweather said:

From LWX Disco 

THE BIGGEST AREA OF FOCUS OF THE THE LONG TERM WILL BE AN AREA OF   
LOW PRESSURE TRACKING FROM THE MISSISSIPPI RIVER VALLEY TOWARDS NEW   
ENGLAND, BRINGING WINTRY WEATHER TO THE REGION SUNDAY EVENING   
THROUGH MONDAY. THERE REMAINS A GOOD BIT OF MODEL DISCREPANCY   
REGARDING THE TRACK AND TIMING OF THE LOW PRESSURE SYSTEM, THEREFORE   
LEADING TO UNCERTAINTY WHEN IT COMES TO A SNOWFALL AMOUNT AND   
PRECIPITATION TYPE FORECAST. WHILE TEMPERATURES AT THE SURFACE ARE   
EXPECTED TO STAY NEAR OR BELOW FREEZING, MODEL SOUNDINGS INDICATE A   
PROLONGED WARM NOSE LEADING TO PRECIPITATION TYPE TRANSITIONING FROM   
SNOW TO SLEET/FREEZING RAIN. THIS WILL LEAD TO LOWER SNOW TOTALS   
THAN SOME MODELS ARE CURRENTLY INDICATING. 12Z MODEL GUIDANCE IS   
SHOWING A LIGHT SHIFT NORTH FOR THE LOW PRESSURE SYSTEM, WITH   
ACCUMULATION AMOUNTS CONTINUING TO SHOW A GOOD BIT OF DISCREPANCY.   
PRECIPITATION ONSET WILL LIKELY BE SUNDAY AFTERNOON THROUGH SUNDAY   
NIGHT WITH PRECIPITATION MOVING OUT OF THE AREA EARLY TUESDAY   
MORNING. 

Lol models are always uncertain 

[Warm Nose]

8 minutes ago, stormtracker said:

We always flirt.  Just gotta not fly too close to the sun

In order to get larger totals we always live on the edge. Can't have boom without a potential bust.

[mitchnick]

19 minutes ago, StormyClearweather said:

From LWX Disco 

THE BIGGEST AREA OF FOCUS OF THE THE LONG TERM WILL BE AN AREA OF   
LOW PRESSURE TRACKING FROM THE MISSISSIPPI RIVER VALLEY TOWARDS NEW   
ENGLAND, BRINGING WINTRY WEATHER TO THE REGION SUNDAY EVENING   
THROUGH MONDAY. THERE REMAINS A GOOD BIT OF MODEL DISCREPANCY   
REGARDING THE TRACK AND TIMING OF THE LOW PRESSURE SYSTEM, THEREFORE   
LEADING TO UNCERTAINTY WHEN IT COMES TO A SNOWFALL AMOUNT AND   
PRECIPITATION TYPE FORECAST. WHILE TEMPERATURES AT THE SURFACE ARE   
EXPECTED TO STAY NEAR OR BELOW FREEZING, MODEL SOUNDINGS INDICATE A   
PROLONGED WARM NOSE LEADING TO PRECIPITATION TYPE TRANSITIONING FROM   
SNOW TO SLEET/FREEZING RAIN. THIS WILL LEAD TO LOWER SNOW TOTALS   
THAN SOME MODELS ARE CURRENTLY INDICATING. 12Z MODEL GUIDANCE IS   
SHOWING A LIGHT SHIFT NORTH FOR THE LOW PRESSURE SYSTEM, WITH   
ACCUMULATION AMOUNTS CONTINUING TO SHOW A GOOD BIT OF DISCREPANCY.   
PRECIPITATION ONSET WILL LIKELY BE SUNDAY AFTERNOON THROUGH SUNDAY   
NIGHT WITH PRECIPITATION MOVING OUT OF THE AREA EARLY TUESDAY   
MORNING. 

Now that's covering your azz.

[stormtracker]

Just now, mitchnick said:

Now that's covering your azz.

Yeah, they do that at the onset a lot.  But on the flip side, I'm actually glad to see they just don't rip and read model and incorporate regional climo in.

[NorthArlington101]

1 minute ago, stormtracker said:

Yeah, they do that at the onset a lot.  But on the flip side, I'm actually glad to see they just don't rip and read model and incorporate regional climo in.

ya know what we say, "our best events are when LWX is playing catchup..."

it is funny that perhaps the best meteorological agency in the world comes in and says something totally reasonable and we say "meh" lol. I honestly read that as very much in line with the 6" NBM... just probably not gonna hit 10"+.

[clskinsfan]

NAM looking juicy at 60. A little less cold push on the east coast than 12Z. But minimal changes. 

[CoastalWx]

Bastards

[MillvilleWx]

12 minutes ago, Ruin said:

Lol models are always uncertain 

They aren’t uncertain on the overall scheme that will unfold but small shifts in certain features can lead to detrimental shifts in QPF/Snow/Ptypes. NWP is not exact and will never be exact. It’s a complex physical process that so far we have done a crazy good job at depicting with better leads as we move through time. This storm has been on the radar for over a week….this was a very rare occurrence even 5-10 years ago, but here we are. 
 

The key is being able to parse details and understand the overall footprint of what is going on to depict these outcomes. Probabilities and utilizing ensembles who have different parameterization baked in to offer different results pending other variables are importantly in forecast things with greater certainty while also showing a probabilitistic outcome which is important for stakeholders. Considering the circumstance, NWP has been pretty good with this event and wavering at leads is par for the course. It’s up to humans to know how to interpret the data. There is no magically perfect solution to everything and until we solve every intricate detail that pertains to meteorological phenomena, we will never ever ever get it 100% on the nose. This isn’t finance when you count money and the answers are finite properties that can be discerned through analyzing accounts and what not. This is a complex, physically driven paradigm that takes more than just regurgitation when it comes to providing a forecast. 
 

If you’re looking for something more concrete in analysis, you are in the wrong hobby/profession. 

[Warm Nose]

I see we've reached the 'model disclaimer' portion of the storm. Next should 'gnashing of teeth' phase.

[Terpeast]

I think LWX is smart to call out potential for sleet/freezing rain because that will have bigger impacts on the Monday morning commute than an all snow event. Anytime we're flirting with the mix/changeover line, it has to be addressed and made known to the public. 

[clskinsfan]

Pummeled