Interior NW & NE Burbs 2025

[eduggs]

25 minutes ago, wdrag said:

I've seen some comments downplaying the HRRR. 18z vsn nearly identical to the 12z.    I think we have to think confluence zone enhancement-band. I see BGM NWS just issued an inch higher terrain.  

I wont say what will happen but I dont even think our NWS offices will know at 3AM tomorrow when final day products are issued, since very few ground truth reports at 2-3A. The radar should be telling. 

Maybe I'll be wrong but I doubt if the HRRR is going to miss by more than inch or at worst 2. It should be slippery as outlined in the mid morning post. 

Pretty good %H Vort advection toward morning in EPA with decent 8H FGEN and lift in sw flow aloft. A warm frontal wave. It's over before you can say 9AM. 

 

I'm with you. I think there will be a decent swath of accumulating snow overnight tonight. I just personally think the 12z HRRR was too "wet" into the cold/dry air and a little too far north with the axis. It also keeps measurable precipitation going further east into NYS and CT. That might be suspect based on other guidance drying things out quicker. The 18z is a little drier and maybe a hair south of 12z. I think it has been incrementally shifting towards model consensus. The 18z RRFS also looks a touch drier and more reasonable to me. The GFS and CMC have likely been too far south and late to correct.

The best bet for accumulating snows looks to be in PA right now. But we've seen cases before where banding unexpectedly extended accumulating snows eastward as a shortwave decayed into the residual cold of a longwave trof. The radar will be interesting late tonight.

[wdrag]

I updated my 3PM comment with an apology explanation of ground truth knowledge aforehand of a product issuance. 

[wdrag]

Flurries have started in Wantage NJ... definitely a HRRR bust from yesterdays 12 and 18z modeling but lets see what the finals are. Sleet on parts of Long Island now. 

[IrishRob17]

2 hours ago, wdrag said:

Flurries have started in Wantage NJ... definitely a HRRR bust from yesterdays 12 and 18z modeling but lets see what the finals are. Sleet on parts of Long Island now. 

Agreed, just some flurries here. 

[ForestHillWx]

Accumulations on grass/tree limbs in Chester, NJ before the flip to rain. 

[wdrag]

will very briefly explain my laziness via process and the F forecast around 945A.

[wdrag]

Processes: Cannot circumvent checklists... pilots don't and they fly us successfully. 

I got a little lazy...circumvented processes.

Saw the trend in HRRR/RAP/RRFSA prior to 14z/18 yesterday, accepted HRRR resulting in an F forecast. Global CMCE an EPS ensembles (GEFS, SREF and SPC HREF snowfall terrible) had the axis right which was near I80 but amounts below 2" on 10-1.  That should have cautioned me on the 12z/18 verbatim HRRR post.  ANDDDD when we're on the gradient edge of qpf, caution flag.  I've grown confident in the ECAI but it failed miserably on the north fringe this morning and the EC OP through 00z/19 was lacking.  12z and 18Z/18 HRRR were very similar then I saw the 00z/19 HRRR drop back down to I80--wasnt sure it would hold there. It did.

 

Bottom line: Follow processes ALWAYS inclusive of merging ensembles and being careful on the gradient edge. I sure hope to remember this lesson.

Wantage Trace flurries and qpf... basically nil.   Attached CoCoRaHs snowfall.