Winter Storm Threat Feb 22-24th

[RU848789]

1 hour ago, Freezing Drizzle said:

NWS for central NJ (Mt. Holly) through the Five Boroughs (Upton) is going with a middle ground, 1-2 or 1-3 inches, forecast.  

That's incorrect.  NWS forecast for NB through NYC is 4-6" through 7 am Monday, which would be 5-7" through the end of the storm at 1 pm Monday, assuming use of the NBM (which they said they followed closely).  See my other post with the maps and such.  

[weatherpruf]

4 minutes ago, NEG NAO said:

Someone was late for work and had to go 75 MPH in the rain instead of the much lower posted speed limit - now you know one of the reasons your car insurance is so high here - anyways to keep this weather related if the GFS which has been very consistent with high snowfall amounts here the last few days is wrong - it should be retired ASAP on the other hand if the EURO comes to the party to late in the game it will just prove its not the best model anymore . Here we are fighting the battle between the warmsters - who have a proven bias towards no snow and warm weather and the snow weenies who get excited over any model showing high snowfall amounts.....and somewhere in the middle is the rest of us who keep an open mind...

lundberg def did not seem happy about snow, saying no one really wants it but what ca n you do....hard for people here to digest that most others feel that way.

[MJO812]

The last time I saw a big shift like this with the SREF was in Jan 2016 with Jonas. Sref was the 1st model to trend northward with the storm two days out 

[NEG NAO]

8 minutes ago, RU848789 said:

I'd argue that the NAM at the end of its range shouldn't be used to inform snowfall forecasts.  Also most of the 6Z models showed decent increases in snowfall for this subforum and the immediate NYC metro, as per below.  Based on the models and the NWS forecast of 6.5" for CPK assuming they'd follow the NBM through 1 pm Monday as per my other post, I'd maybe say 4-8" is a better call for NYC Metro, although I an also see 3-6" being a good starting point with the high uncertainty and huge range we have over the models, as per the NWS 10% low and high cases being <1" for CPK to ~10" for CPK  Just my thoughts.  

• 6Z ICON shows 6-12" for NYC metro and 9" for CPK (big increase from 0Z)
• 6Z GFS shows 12-18" for NYC metro with 15" for CPK (decent increase from 0Z)
• 6Z AIGFS shows 10-14" for NYC metro and 12" for CPK (a big increase from 0Z)
• 6Z Euro-AIFS shows 4-6" for NYC metro with 5.5" for CPK (same as 0Z)
• 6Z Euro shows 3-5" for NYC metro and 3.1" for CPK (a bit of a decrease from 0Z)
• 7Z NBM shows 6-8" for NYC metro and 7.8" for CPK (slightly more than 01Z).
• The 0Z CMC/UK both only showed 2-3" for NYC, but I'd argue these are outdated

also did you notice that extreme amount in the dark grey on the GFS seems to be moving north each run now its in southern half of NJ it was down in tthe Del Marva a day or 2 ago ???

[NEG NAO]

where is the snowfall contest here ? The last one was fun

[Rjay]

1 minute ago, NEG NAO said:

where is the snowfall contest here ? The last one was fun

Start it up but it hard forecast right now

[SACRUS]

 

Summary:

2/20 06z Total QPF 

 

NAM:

 

RGEM:

 

ICON:

 

UKMET (60H)

 

GFS AI AIGFS:

 

GFS   

 

EURO AI AIFS:

 

 

GEFS  (24 H) Mean Total QPF:

 

[nycsnow]

FWIW Nam has today’s system move east faster than 6z hopefully that helps with the separation 

[Jt17]

I would tame expectations the dual low needs to be watched could it be the gfs is about to cave come 12z? 

Been there for many runs now. Cave to what exactly? Every model and ensemble is more similar to GFS now except Euro OP.


.

[nycsnow]

Just now, Jt17 said:

Been there for many runs now. Cave to what exactly? Every model and ensemble is more similar to GFS now except Euro OP.


.

Or it could just be a double barrel low 

[Jt17]

Or it could just be a double barrel low 

Exactly.


.

[brooklynwx99]

regardless of what happens in the next couple of days, this is one of the most spectacular model shifts for the better I have seen at this range in a long time. let's reel this one in

[nycsnow]

[MJO812]

Nam is looking good so far

[brooklynwx99]

NAM is cooking with gas

[nycsnow]

[ForestHillWx]

Lots of energy being depicted on this run. Giggity. 

[ILoveWinter]

15 minutes ago, brooklynwx99 said:

regardless of what happens in the next couple of days, this is one of the most spectacular model shifts for the better I have seen at this range in a long time. let's reel this one in

IF the snowiest - à la GFS - solutions verify, it would almost be akin to Boxing Day 2010 when all hope was lost a few days beforehand. 

[nycsnow]

[mob1]

Ridge axis is further west on the NAM but the trough is also a bit broader.

[MJO812]

Just now, mob1 said:

Ridge axis is further west on the NAM but the trough is also a bit broader.

Precip further north on the nam

[mob1]

Just now, MJO812 said:

Precip further north on the nam

Backside energy is sharpening the trough quickly at 54, looks decent so far. 

[donsutherland1]

42 minutes ago, RU848789 said:

I'd argue that the NAM at the end of its range shouldn't be used to inform snowfall forecasts.  Also most of the 6Z models showed decent increases in snowfall for this subforum and the immediate NYC metro, as per below.  Based on the models and the NWS forecast of 6.5" for CPK assuming they'd follow the NBM through 1 pm Monday as per my other post, I'd maybe say 4-8" is a better call for NYC Metro, although I an also see 3-6" being a good starting point with the high uncertainty and huge range we have over the models, as per the NWS 10% low and high cases being <1" for CPK to ~10" for CPK  Just my thoughts.  

• 6Z ICON shows 6-12" for NYC metro and 9" for CPK (big increase from 0Z)
• 6Z GFS shows 12-18" for NYC metro with 15" for CPK (decent increase from 0Z)
• 6Z AIGFS shows 10-14" for NYC metro and 12" for CPK (a big increase from 0Z)
• 6Z Euro-AIFS shows 4-6" for NYC metro with 5.5" for CPK (same as 0Z)
• 6Z Euro shows 3-5" for NYC metro and 3.1" for CPK (a bit of a decrease from 0Z)
• 7Z NBM shows 6-8" for NYC metro and 7.8" for CPK (slightly more than 01Z).
• The 0Z CMC/UK both only showed 2-3" for NYC, but I'd argue these are outdated

We agree about the NAM. I mentioned it just for purposes of reference. I give it very little weight at this timeframe and I'm looking forward to its retirement. 

I started somewhat conservatively, as there is enormous spread among the guidance and among the NBM's 25th/75th percentiles and 10th/90th percentiles. Hopefully, the spread will be smaller after the 12z and 18z cycles. I'll revisit the numbers late in the day. Finally, as you note, 4"-8" might also be a better initial call.

[Brian5671]

[nycsnow]

Nam might be good, great trend from 6z

[mob1]

This looks good...

[njwx7]

12z NAM very similar to GFS at 500mb...this run may explode shortly.

[nycsnow]

[Joe4alb]

[Jersey_Snowhole]

HR 63