Jump to content
  • Member Statistics

    17,529
    Total Members
    7,904
    Most Online
    christians
    Newest Member
    christians
    Joined

OBS and nowcast Monday Feb 15 - Noon Tuesday Feb 16 2021


wdrag
 Share

Recommended Posts

610A updated thread....my last topic update and all my other posts will be in the observed below. Adding several graphics from the 4AM NWS forecast process inclusive of the ICE STORM WARNING coverage area (purple), the HPC HREF ensemble 1/2" of glaze expectation by 7A Tuesday (blue), WPC ensemble probs of .10 glaze (orange) by 7A Tuesday and the much lower prob of 1/2" glaze.  I would expect power outages in the  NWS warning area and SPC HREF Blue coverage area.  IF these amounts work out- I think it will be big.  Modeling doesn't necessarily guarantee freezing longer than 4AM Tuesday, so if it's not, then the rain is non freezing its heaviest 3 hour period. Still the ground is cold so I'd plan on a bad night, and in fact a bad day today in the  I84 corridor on all untreated surfaces.  Regarding info near NYC... just be careful. Untreated's slippery near NYC-LI today-this evening,  should ease sometime tonight. Looking at 06z/15 NAM FOUS...if that surface wind stays ne in NYC through tonight as the sfc low transits coastal NJ, the guidance will be too warm at the surface.  This needs careful monitoring. My guess, via the 06z/15 guidance, there may be an underplaying of extensive ice damage, especially just west of the 4AM warning.   Just a degree or two makes a huge difference. I'm not expert enough to know for sure. So for me here in Wantage NJ, if its still 31-32F at 4A Tuesday, we've got pretty big problems in far nw NJ/se NYS/nePA. We will see how the probs work. Prep worst and hope for the best. 

 

While a bit of snow is possible Monday along the northern edge of the subforum, most of this event should be freezing rain or rain with heaviest amounts Monday night.  Sleet may occur as well for a time Monday. If freezing rain lasts long enough in the warning area of the forum, and accretes thick enough, tree damage and power outages would occur. Spotty poor drainage street flooding is possible in NJ, LI. 

21z/14 NWS ensemble high probs for freezing rain and low probs for 1/2" glaze are posted.  

Screen_Shot_2021-02-14_at_8_36.22_PM.png

Screen_Shot_2021-02-14_at_8_36.51_PM.png

Screen Shot 2021-02-15 at 5.30.51 AM.png

Screen Shot 2021-02-15 at 5.10.29 AM.png

Screen Shot 2021-02-15 at 5.40.12 AM.png

Screen_Shot_2021-02-15_at_5_40.38_AM.png

Link to comment
Share on other sites

610A updated thread....my last topic update and all my other posts will be in the observed below. Adding several graphics to the topic part of the thread from the 4AM NWS forecast process inclusive of the ICE STORM WARNING coverage area (purple), the HPC HREF ensemble 1/2" of glaze expectation by 7A Tuesday (blue), WPC ensemble probs of .10 glaze (orange) by 7A Tuesday and the much lower prob of 1/2" glaze.  I would expect power outages in the  NWS warning area and SPC HREF Blue coverage area.  IF these amounts work out- I think it will be big.  Modeling doesn't necessarily guarantee freezing longer than 4AM Tuesday, so if it's not, then the rain is non freezing its heaviest 3 hour period. Still the ground is cold so I'd plan on a bad night, and in fact a bad day today in the  I84 corridor on all untreated surfaces.  Regarding info near NYC... just be careful. Untreated's slippery near NYC-LI today-this evening,  should ease sometime tonight. Looking at 06z/15 NAM FOUS...if that surface wind stays ne in NYC through tonight as the sfc low transits coastal NJ, the guidance will be too warm at the surface.  This needs careful monitoring. My guess, via the 06z/15 guidance, there may be an underplaying of extensive ice damage, especially just west of the 4AM warning.   Just a degree or two makes a huge difference. I'm not expert enough to know for sure. So for me here in Wantage NJ, if its still 31-32F at 4A Tuesday, we've got pretty big problems in far nw NJ/se NYS/nePA. We will see how the probs work. Prep worst and hope for the best. 

  • Like 2
Link to comment
Share on other sites

For check back Thursday: The Winter Storm Impact graphic which looks a little on the light side for northern PA/ I84 corridor.  Not sure why... but either this experimental product doesn't apply power outages, or some of the modeling is too warm? I don't know. Also added for the record the powertoutages, nationally, so that we may check back tomorrow. The only way to learn- in advance. 

 

I went back and grabbed the D2 ice WSSI graphic for VA - seemed to underestimate impacts, despite model guidance. 

Screen Shot 2021-02-15 at 8.08.16 AM.png

Screen Shot 2021-02-15 at 8.08.51 AM.png

Screen Shot 2021-02-15 at 8.24.28 AM.png

Link to comment
Share on other sites

Just now, crossbowftw3 said:

Thankfully we will all get above freezing by tomorrow morning so my concern of this ice not melting by Thursday is pretty much out the window. Even if it’s only for 3-6 hours that’ll be enough to get rid of most of it 

My main concern is that once you start getting above 0.25" ice accretion it's going to take down a lot of branches and power lines. Even though the temperature eventually gets up into the mid 30's by tomorrow morning the damage could already be done. The 3k NAM hasn't been doing great with regards to the spotty activity today and to use Rockland County as an example, doesn't reach 32 degrees until just before sunrise. 

  • Like 3
Link to comment
Share on other sites

1 minute ago, Brasiluvsnow said:

New City checking in,,,,,,,Deck is icy,,,my car is Icy,,,,,,,steps in front of house are icy,,,,,,,,safe to say it is ICY here with freezing rain falling lightly but thats all it takes,,,,,,,cant wait to walk my dog I will let you guys know how that goes

Exactly, it only takes a glaze to cause major impacts. We should be below freezing for at least the next 18 hours or so.

  • Like 1
Link to comment
Share on other sites

10 minutes ago, HVSnowLover said:

It's already above freezing in NYC/LI. May be some cooling at the onset of precip tonight but I really don't see frozen precip for NYC with this at all.  

This is going to be rain for NYC and inland areas. You have to go all the way upstate for wintry weather.

Link to comment
Share on other sites

10 minutes ago, Northwest NJ said:

I am supposed to drive  from Sussex County to NYC later this morning.  Straight down route 23 to route 80.  I am having second thoughts even though I  think the main roads would be treated and safe.

It’s going to be a disaster. That’s why they have a commercial vehicle ban on 287 in NJ.

  • Like 1
Link to comment
Share on other sites

12 minutes ago, NJwx85 said:

It’s going to be a disaster. That’s why they have a commercial vehicle ban on 287 in NJ.

Roads in my area aren’t bad now as they are being treated. When the precipitation increases later it will wash off the salt and with the cold ground temps along with air temps in the upper 20’s that’s not a good recipe for travel later, especially bridges and overpasses.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...