IDA remnants-Moderate to isolated Major Impact (esp NJ-LI), general storm total 2-8" rainfall Wednesday-Thursday September 1-2 2021

[Intensewind002]

0.05” both in Lindenhurst and here in albany. I guess LI got dry slotted today?

[Brian5671]

1 minute ago, NJwx85 said:

All you need to look at now is the radar to see what's coming.

those bust calls will look silly by tomorrow am

[donsutherland1]

Through 3:56 pm, Harrisburg had picked up 4.75" of rain. That is the 2nd biggest daily rainfall on record in September and the 5th biggest daily rainfall overall. Heavy rain continued to fall.

In the larger scheme of things, the consistent guidance shown on the 9/1 0z and 9/1 12z HREF seems to be verifying quite well. The northern most guidance is falling short. Thus, much of the New York City and Newark areas remain on track for 3"-6" of rain with local amounts of near or above 8". The heaviest amounts will likely be somewhat north and west of both cities.

[LibertyBell]

16 minutes ago, donsutherland1 said:

Through 3:56 pm, Harrisburg had picked up 4.75" of rain. That is the 2nd biggest daily rainfall on record in September and the 5th biggest daily rainfall overall. Heavy rain continued to fall.

In the larger scheme of things, the consistent guidance shown on the 9/1 0z and 9/1 12z HREF seems to be verifying quite well. The northern most guidance is falling short. Thus, much of the New York City and Newark areas remain on track for 3"-6" of rain with local amounts of near or above 8". The heaviest amounts will likely be somewhat north and west of both cities.

Lee Goldberg just told people to shelter in place and don't go anywhere tonight.  They should shut down all roads and highways to make sure everyone stays home and we don't need to have any water rescues like we did last time.  No one should be allowed outside tonight period.

[Brian5671]

2 minutes ago, LibertyBell said:

Lee Goldberg just told people to shelter in place and don't go anywhere tonight.  They should shut down all roads and highways to make sure everyone stays home and we don't need to have any water rescues like we did last time.  No one should be allowed outside tonight period.

the good news is that this is after rush hour and not during the day....

[donsutherland1]

6 minutes ago, LibertyBell said:

Lee Goldberg just told people to shelter in place and don't go anywhere tonight.  They should shut down all roads and highways to make sure everyone stays home and we don't need to have any water rescues like we did last time.  No one should be allowed outside tonight period.

I agree. It’s going to be intense.

[LibertyBell]

5 minutes ago, Brian5671 said:

the good news is that this is after rush hour and not during the day....

Yes and it will be long over by the time we wake up tomorrow morning and the sun will be out

[LibertyBell]

1 minute ago, donsutherland1 said:

I agree. It’s going to be intense.

The wind is picking up too.  I saw that there's an isolated risk of tornadoes tonight for the entire area.

 

[donsutherland1]

Just now, LibertyBell said:

The wind is picking up too.  I saw that there's an isolated risk of tornadoes tonight for the entire area.

 

Yes. That is true. Central and southern NJ could be at elevated risk for tornadoes.

[sferic]

Sprinkler system app set to off for next 5 days. Never had Long island grass this green on Sept 1st

[SnowGoose69]

No changes to my thoughts.  Best rains will be west of Queens/Brooklyn/LI but still will see maybe 3-5 inches...I think S shore of LI less.  Winds across DE/Delmarva/SE NJ in warm sector despite sunshine and 925 winds of 50kts only gusting low 30s.  I still think with the Ambrose funnelling effect SW Nassau back to JFK could see gusts 02-04Z 35-40 but way less as you go E and more inland into LI

[Tatamy]

4 hours ago, donsutherland1 said:

10-15. Orographic enhancement likely contributes.

The placement of the precip max just south of Allentown corresponds with South Mountain.  That is the ridge that I78 weaves in and around in that vicinity.

[donsutherland1]

1 minute ago, Tatamy said:

The placement of the precip max just south of Allentown corresponds with South Mountain.  That is the ridge that I78 weaves in and around in that vicinity.

Thanks. That’s great information.

[LibertyBell]

26 minutes ago, donsutherland1 said:

Yes. That is true. Central and southern NJ could be at elevated risk for tornadoes.

They're talking about extending the Tornado Watch to include NYC and Long Island and extending it in duration too.  We could all be at a 10% risk of tornadoes tonight.

 

[Tatamy]

Multiple tornado warnings currently up in the Mt Holly WFO including Philadelphia.

[NJwx85]

Unloading here in Mahwah

[Cfa]

0.09” so far.

Also can’t recall the last time we were under a Tornado Watch, they’re so rare that even Tornado Warnings occur with greater frequency.

[NJwx85]

Tornado Watch

TORNADO WATCH OUTLINE UPDATE FOR WT 484
NWS STORM PREDICTION CENTER NORMAN OK
620 PM EDT WED SEP 1 2021

TORNADO WATCH 484 IS IN EFFECT UNTIL 100 AM EDT FOR THE
 FOLLOWING LOCATIONS

NYC005-047-059-061-081-085-087-103-119-020500-
/O.NEW.KWNS.TO.A.0484.210901T2220Z-210902T0500Z/

NY
.    NEW YORK COUNTIES INCLUDED ARE

BRONX                KINGS               NASSAU
NEW YORK             QUEENS              RICHMOND
ROCKLAND             SUFFOLK             WESTCHESTER
$$

 

[NJwx85]

 

 

---

 

Tornado Watch

TORNADO WATCH OUTLINE UPDATE FOR WT 484
NWS STORM PREDICTION CENTER NORMAN OK
620 PM EDT WED SEP 1 2021

TORNADO WATCH 484 IS IN EFFECT UNTIL 100 AM EDT FOR THE
 FOLLOWING LOCATIONS

NJC003-013-017-031-039-020500-
/O.NEW.KWNS.TO.A.0484.210901T2220Z-210902T0500Z/

NJ
.    NEW JERSEY COUNTIES INCLUDED ARE

BERGEN               ESSEX               HUDSON
PASSAIC              UNION
$$

 

[Brian5671]

here too:

TORNADO WATCH OUTLINE UPDATE FOR WT 484
NWS STORM PREDICTION CENTER NORMAN OK
620 PM EDT WED SEP 1 2021

TORNADO WATCH 484 IS IN EFFECT UNTIL 100 AM EDT FOR THE
 FOLLOWING LOCATIONS

CTC001-007-009-011-020500-
/O.NEW.KWNS.TO.A.0484.210901T2220Z-210902T0500Z/

CT
.    CONNECTICUT COUNTIES INCLUDED ARE

FAIRFIELD            MIDDLESEX           NEW HAVEN
NEW LONDON

[NJwx85]

You heard it here first:

 

[NJwx85]

@Allsnow still going with an inch for NYC?

[NortheastPAWx]

Don't think it's time to call disaster for NYC just yet. The best stuff is still west and radar movement is more N than E.

There's another dyslot in S NJ headed for the city.

[Neblizzard]

4 minutes ago, NortheastPAWx said:

Don't think it's time to call disaster for NYC just yet. The best stuff is still west and radar movement is more N than E.

There's another dyslot in S NJ headed for the city.

That’s pivoting east, NYC will not dry slot 

[BxEngine]

Obs thread is pinned guys

[forkyfork]

12 hours ago, qg_omega said:

NYC could see less than one inch total

[wdrag]

Will update this wrap-up post around 10A with more data.

 

Prelim:  CoCoRaHS data as of 720A, and reports possibly delayed where no power. The red is the max wsw-ene axis near I95 which favors SPC HREF and GFS modeled axis as best forecast, along with ENS.  The 10"s were possible.  Will detail the data when i can later on today, by which time you'll have many NWS lists. 

Added Radar-sensor combined. Appears to be 1/2-1" too low for yesterday.

Also added yesterdays 12z/1 SPC HREF showing general 5" swath just nw of NYC but also look at the max for same time period showing the spotting of 10-15" across NNJ to s CT. 

Finally some perspective: These amounts have occurred in the recent decade and will again, but over the identical areas as yesterday--- possibly not,  but close.  We can go back to the historic tropical data base into the mid 1950s when I was a kid floating paper boats down the rain swollen streets in Newton NJ in 1955 (Connie-Diane in an 8 day period of early August).  Yesterdays problem was in part antecedent conditions but I think mostly that 80% of the rain fell in less than 3 hours. NO URBAN SYSTEM can handle that unless budget allocations change and there is too much else to care for. Finally: misuse of data is too much drama. For instance: Unprecedented use of the term Flood EMERGENCY.  NWS implemented that I think it was 2017-18. Not a very long period of record.  

Tentatively: I'll review further but I will log this as a moderate event except major where 8"+ and deaths.  The MAJOR 8+ was much more extensive than I had capability of confidently predicting as well as over NYC.  (Not much flooding here in Wantage despite 4+".) 

The TOR added spice but this was mainly a heavy rain event with gusty winds 40-60 MPH causing the uproots, branch breakage-power outages. 

 

Added NYS Mesonet just after initial post. 

[Brian5671]

23 hours ago, qg_omega said:

Euro may have the rare victory here

BUST

[qg_omega]

2 minutes ago, Brian5671 said:

BUST

Euro was terrible!

[wdrag]

CoCoRaHS data as of 9A, and some reports possibly delayed where no power. The red is the max wsw-ene axis near I95 which favors SPC HREF and GFS modeled axis as best forecast, along with EPS GEFS swath primary 2+ rainfall.  The 10"s were possible.  

Added Radar-sensor combined. Appears to be 1/2-1" too low for yesterday.

Also added yesterdays 12z/1 SPC HREF showing general 5" swath just nw of NYC but also look at the max for same time period showing the spotting of 10-15" across NNJ to s CT.  CLICK MAPS for greater clarity of each. 

Finally some perspective: These amounts have occurred in the recent decade and will again, but over the identical areas as yesterday--- possibly not,  but close.  We can go back to the historic tropical data base into the mid 1950s when I was a kid floating toy boats down the rain swollen streets in Newton NJ in 1955 (Connie-Diane in an 8 day period of early August).  Yesterdays problem was in part antecedent conditions but I think mostly, that 80% of the rain fell in less than 3 hours. NO URBAN SYSTEM can handle that unless budget allocations change and there is too much else to care for. Finally: misuse of data is too much drama. For instance: Unprecedented use of the term Flood EMERGENCY.  NWS implemented that I think it was 2017-18. Not a very long period of record.  I also think the same on recurrence interval.  We simply don't have reliable data. 

Tentatively: I will log this as a moderate event on the edges BUT major where 8"+ and deaths which is near and just north of I95 corridor.  The MAJOR 8+ was much more extensive than I had capability of confidently predicting including over NYC.  (Not much flooding here in Wantage Sussex County NJ despite 4+". Have a few road closure due to wind related downed branches) 

The TOR added spice but this was mainly a heavy rain event with gusty winds 40-60 MPH causing the uproots, branch breakage-power outages.