wdrag

Tomorrow I'll probably update the headline to maybe add a tag???  and certainly make it clear that OBS for this next event just fall right into this thread. 

I'm probably gassed out for the day... and won't post much more til tomorrow morning. 

1 minute ago, tdp146 said:

What’s the rule for a “trace” of snow. I thought I remember someone saying even if it’s not accumulating whatsoever, if there are snowflakes falling, it’s considered a “trace”

It is..ditto sleet (ice pellets) and I think hail too. 

CoCoRahS climate sites final for D1. I'll have a D1-2 combo tomorrow at this time. Click maps for clarity.

This gives an idea... imperfect but quite a snow gradient in Sussex County NJ ranging from 6" southeast to over a foot northwest.  My count at 10AM in Wantage is 13.1.  

2 hours ago, guinness77 said:

I don’t know about hurricane gusts, but @wdrag has mentioned damaging winds as part of Tuesday’s storm for days now. I’ve been telling anyone who’ll listen to me (here on LI at least) that Tuesday night is the storm to be concerned about, not yesterday. 

Single model operational cycle guidance tends to be a little high, but I've attached the National BLEND OF MODFELS and is offering widespread 50-65 MPH gusts in the northeast USA Tuesday night, particularly the ridges even down to TN/NC and the coasts.  Expecting  850 MB (~5000')  winds in the 85-100 kt range for 3-6 hours across the northeast USA, I'd say we can't avoid at least scattered power outages, particularly NYS, and coastal NJ/LI.  The good news = few leafed trees. Still with leftover snow covered branches I84 north and/or rain softened ground due to the top 5 December rainfall up here and possibly January excesses (CP top 10 would be 6"), suggests to me to be prepared and no crying after the fact.  IFFFF and when the NWS issues watches for flooding and wind,  be smart and get safely ready and prepare.  Guidance is not perfect but am sure we'll construct a future outcome that will be of value.    I just interpret what I think is increasingly better guidance from numerous government resources (models etc).  The attribution for the improvement is a combination of research, higher resolution modeling both in the short and long term.  Cellar flooding and river flooding coming up for quite a few folks as well as power outages (percentage of population may be small but the impact radiates out to family-first responders, DPW's etc). Most of the oncoming rain in 9 hours Tuesday night. 

Here's the blend of model wind gusts... yellow starts 60 MPH. Snapshots at 00z/10 which is 7PM EST Tuesday and 06z/10 which is 1AM EST Wednesday. These numbers are tempered down via the blend from individual global model predictions. 

30 minutes ago, RU848789 said:

Walt - thanks and a question.  Can you highlight the differences between the "ensemble" river forecasts and what I guess I'd call the "regular" river flooding forecasts from the NWS (which are both under the "rivers and lakes" tab on the NWS page)?  What is the ensemble of?  Mostly curious why the ensemble forecast has the Passaic at risk of major flooding, while the regular forecast only has that in moderate flooding, as per below and in general the ensemble forecasts are much more serious.  Is one or the other more accurate?  

 

1.  
2. https://satable.ncep.noaa.gov › naefs

   Ensemble Situational Awareness Table

   The NAEFS Ensemble: A 52-member ensemble consisting of 31 GEFS ensemble members and 21 Canadian (GEPS) members. The GEFS has 30 perturbed members and a control member. The GEPS has 20 perturbed members and a control member. Although the GEFS and GEPS are run at native resolutions of 25 and 39 km, respectively, the NAEFS is distributed on a 1x1 ...

    

   THI Grand ensemble forecast is I think input once/day and then presuming the RFC has the antecedent conditions correct, the river responds to the qpf.  I'll show you with the attachments. 

    

   The RFC forecast itself only out to Jan 10 while this Jan 6 12z ensemble  is out to 10 days. Therefore its when the period ends that determines max river stage.

    

   If the ensemble is wrong, the river response is different. I think the ensembles are pretty good now, and it's a matter of forecaster input into the model that determines the river stages that make the curve.

    

   I use NAEFS in winter: GEFS seems conservative in winter. HEFS, I've no experience.

    

   I think it is wise to consider the NAEFS ensemble river forecast as a good first guess...

   The following should help for Pine Brook: I hope this is useful and you can verify Wednesday and beyond. 

    

    

3.  

This set of CPC hazard products posted on Jan 5 330PM was overlooked by myself since was embedded in storm 1.

This CPC guidance has the two storms 1/13 and 16.   If these get threaded, not yet sure how I'd like to do but probably separate.  Depends how new total qpf, snowfall/wind looks for those two combined vs separate. Tides should be pretty high Sat morning the 13th so that will need monitoring. 

3 minutes ago, LibertyBell said:

Thanks so much, Walt!  These are not final totals right-- even for Mount Pocono? There will an update later this evening around 7 PM with final totals?

 

Finals via CoCoRaHs will post tomorrow morning around 1030A.  

Finals via the NWS local storm reports where they use social media as well as CoCoRaHs and folks like us, probably complete at 8P tonight. 

emojis limit??? again stopped from expressing emojis?

Added prelim CoCoRaHs melted w.e. and snowfall. Will have more complete data at 10A. Click for clarity. 

The WPC moderate risk for flooding Tuesday-Wednesday is attached issued about 07z/7. Someone ping me if I missed this post earlier in the morning. 

Also... I am concerned about looking too far ahead beyond Jan 16.  While I like the idea of pummel storms for late Jan-Feb.... we might be seeing the main deal now?  

Go ahead with model cues that shoot my thinking down...  but I'm pretty sure what we're seeing in they Jan 6-16, 2024  time frame is not common.  

All with interest Jan 13... please hold off on buying a GFS intense warm wet windy midwest storm.  Indications from the last 3 EPS cycles that a lead strong shrug wave comes out the 13th and could be a colder event, especially if it does what this one did (6th-7th)  Clearly big differences at 5H between the EPS/GEFS for 12z/13. Take a look for yourselves via tropical tidbits.  I am siding with the EPS.  GEFS tends to get too wrapped up in single high amp troughs among other things, at least T+120(imo)

ThNka for the fix on emoji's

The future, besides additional snow today I78 in PA-NJ as well as LI northward.

Attached is an ensemble based map (CMCE and GEFS) of resultant potential river problems by Wednesday. Purple is potential major, red potential moderate and the brown = minor.  This guidance is accurate IF the 2-3" of rain and snowmelt materializes. 

We'll keep this thread going with storm two (9th-10th) instead of a separate OBS thread.  

The Tue - Wed, flood, heavy rainfall, wind damage reports will flow right into this thread will have integrity from start to finish. 

I dont plan to start any new threads beyond the 10th, until at least tomorrow or Tuesday.  Have a day and NYC, enjoy the new snow later this morning...maybe it can accumulate on grass-cars?

Adding some maps of snow reports to the NWS... obviously incomplete.  Will add CoCoRaHs after 9AM.  Storm still in progress especially I84 corridor. 

Both of these may need a thread depending on snow-rain-prolonging river flooding-power outage implications.  Just too early for me to start the threads with uncertainty on general track but these are potent systems. I dont want to thread MEH-we don't want boredom do we?  So just not sure enough yet, especially since we're still very active in one thread. 

Saturday the 13th Potential for 6+" snowstorm I84 corridor.  Solutions vary from just 1 inch of snow and 1 inch of rain prolonging flooding-power outages, to another big snow event. Still lots of uncertainty.

Tuesday the 16th might be the last of this 10 day spate of storms and of course, just don't know. It could turn noticably colder for the latter part of January.

1 minute ago, Logan11 said:

Nice to see you posting on here! I used to read your great discussions out of BOX in the 90's.

I think you may have come into our old Usenet #weather Channel a few times. Todd Gross started that in '94. 

Not sure why I can't add reactions---thank you for your comment. I do appreciate these.

Snow holds water initially, ripens and lets loose pretty quick.  My guess is that I80 north will hold water pretty good through 7AM Wednesday, even if the max temp in the 50s occurred prior to 7AM Wed, then it will go fast, til it freezes up Thursday or Friday. Problem area continues I95 corridor, in my opinion, and cellars, esp if power goes out and no back up generators(SAFE USE-PLACEMENT please- no carbon monoxide poisoning please.)

Wantage NJ (this part 12.6"): with freezing drizzle in progress at 28F and the settling has a SD of 11. 

OBS and discussion-OBS for second storm will continue here.  We still have 12 hours to go (4P) before its all dome out of our area. 

1 hour ago, LibertyBell said:

in the southern Poconos just north of you, it was around a foot of snow from Albrightsville up to Blakeslee.  It was snowing 3 inches per hour at Bear Creek.

 

 

Thank you...looks good.  I'd do a like but the system won't allow me to do reactions. 

1 minute ago, Albedoman said:

we had 5-8 in here in the Lehigh valley in most places. All I can say is that if you try to shovel this stuff, it is super wet. My snow thrower was having troubling handling it. I see many having heart issues if they try to shovel this stuff in the morning. Its like shoveling pure slush. The snow  ratio had to be less than 6:1. I have not seen this wet of a snow in five years here. The flakes were pancakes coming down for a few hours. 

Oh how I dread Tuesday night as the soils are now super saturated and not frozen. Wind thrown trees and huge flooding problems coming our way for sure from this tropical like  storm in January. Instability in the  soundings talking some thunder too on Tuesday night The water content in tonight's storm event of 6 inches of snow has to be at least one inch or more. Add that to the potential of 2-3+ inches of expected rain and we have record flooding. 

agreed on all...  if you get a water equiv...send it to NWS

fwiw: The two storm thread is available and will continue til the OBS thread for that storm starts around 7A Tue.

I am considering a MDT impact event for the 13th, but for now the snowstorm part is I84 so wind and extending the river flooding rain will have to be the drivers for I95.  

Another possibly behind that on the ensembles 16th  but no thread consideration for that one. 

This 6th-13th period is probably fairly unique in NYC subforum history with this more wintry event, followed by a flooder and power outage event, followed by a possible wintry event inland flooder-power outage event coast.   Dont want to overplay the 13th yet so not threading til Monday morning, if then. 

1 minute ago, sussexcountyobs said:

Wow. Very impressive. I just measured 6.75" here.

Moderate snow falling.

Blessed!  

Map of amounts posted by the NWS. They dont have mine in there yet.  

Anyway...   very difficult forecast with a very large gradient.  After all is said and done I'll get a map of amounts up here Monday morning.  This is one is not done yet... impact is major out here in the sticks.  More to come this storm and even for you NYC I think between 9A-2P Sunday. 

Also,  can mix talk of the next storm in here as appropriate... I'd probably wait til late Sunday, but this is winter, and it looks like much more to come.   

Wantage NJ (this prt at 740'MSL): 1030PM obs 11.5" of snow since it began 230PM. Most of that (9.8") in 3.5hours (7-1030PM. Mdt snow still at 1050PM 27.5F. Walt. Corrected 3.5 hour amount at 1056PM.  Sorry for my calculating mistake.