Jump to content
  • Member Statistics

    17,600
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Bands of Heavy Rain along and se of I84 Sunday 4AM-11PM


wdrag
 Share

Recommended Posts

On 8/16/2020 at 7:05 AM, bluewave said:

The  Euro has been too suppressed at times with the northern edge of precipitation with tracks near the benchmark in recent years. ECMWF did a good write-up on the January 2016 historic blizzard. Maybe the model upgrades did something in the 2014-2015 time frame? I can remember it doing very well with the February 2013 Nemo blizzard from 5 days out.


https://confluence.ecmwf.int/display/FCST/201601+-+Snowstorm+-+US+east+coast

5. Good and bad aspects of the forecasts for the event

  • Early signal (from Sunday 17 Jan 00z) and very consistent forecasts
  • Too low accumulation over NYC
  • Question about snow density for the case

 

the NAM did very well there

  • Like 1
Link to comment
Share on other sites

Here is the wrap from my perspective, using CoCoRaHS and radar best estimate (2 day since it's 12z-12z).  CoCoRaHS TWO DAY I don't think works correctly on some of the stations, either that or the reporting posting mechanism may have some sort of cumulative error.  So for CoCoRaHS I used the one day, but some rain occurred prior to the ~12z/16 reports and is not included on this map.

AND,  the radar sensor blend, please ignore extreme w Orange County westward to n of Scranton and sw NYS when all that occurred Saturday.

 

In Summary...you can see two bands pretty clearly, one from the Philly area into nw NJ to near HFD. A second band from Ocean County across Suffolk.  Had this been mostly snow, it would have been a widespread 6-12 hour advisory event with pockets of Warnings, especially Ocean and Suffolk counties.  

The EC and UK Operational runs were terrible for our NYC forum area until the 00z/16 cycle. The EPS finally started picking up on something with the 12z/15 cycle.

The NAM was too heavy, especially near I80, but it was the one that suggested to me that two bands were going to develop.  Placement is never 100% accurate but the NAM had enough idea for us to discuss except NYC (less than 1/2" there).   The NAM 06z/16 cycle was a miserable failure less than 5 hours prior to the start. 

In the end, if we can blend all the models, we get some sort of muted idea of what should happen, without the extremes.  

It is unusual that the EC/UK models didn't have much of an idea of what would happen til the 00z/16 cycle. 

Timing start: Most models were too slow. NAM was the best, I thought.

Timing end: It appeared to me the models were bit  too slow in ending the qpf.  1123A/17

 

Screen_Shot_2020-08-17_at_10_58.36_AM.png

Screen_Shot_2020-08-17_at_11_02.17_AM.png

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

So I was driving back from NE PA to Long Island.  Ran into a huge dark thunderstorm on I-80 near the Morristown exit (43) at around 7 PM and it started to rain heavily right after that.  Heavy rain continued for more than an hour and traffic was really slow with flooding on I-80 all the way east, and it was raining hard right to the Lincoln Tunnel and even in Manhattan, more than an hour later.  Couldn't really see outside, it was raining so hard. Heavy rain was still falling in Queens when I got there around 9 PM and it only got lighter when I got to Long Island around 9:30.  It briefly got heavy there at around a quarter to 10 when I was safely home but it ended before 11 PM.  Lots of lightning too.  

 

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...