Another big Sept rain event between roughly midnight Friday morning and midnight Sunday morning (bulk 9/29-30/2023)

[NJwx85]

3 minutes ago, bluewave said:

The HREF out output looks more like something we see with a tropical system. The mean would be significant enough. But that max potential would really be tough for any locales than can even come within a few inches of that. 
 

 

This is a tropical system. It's what is leftover from Ophelia that is fueling this.

[Stormlover74]

Hrrr still favoring LI

[jm1220]

Just now, Stormlover74 said:

Hrrr still favoring LI

It moved a little west from 12z but yes still a huge drenching. The inverted trough and upper air dynamics will focus the very moist flow coming in from the east, where that axis sets up will get walloped. And over time it’s expected to pivot around so even though not all of us will get 10”, many will probably get 3-4”. 

[Doorman]

big bump upward  ATM

 

[Allsnow]

4 minutes ago, Stormlover74 said:

Hrrr still favoring LI

Map ? 

[Brian5671]

1 minute ago, Allsnow said:

Map ? 

through 30 hrs

[bluewave]

9 minutes ago, NJwx85 said:

This is a tropical system. It's what is leftover from Ophelia that is fueling this.

I just mean so long after the landfall on Saturday. This may be one of the most delayed post tropical remnant systems that we have had.

[jm1220]

1 minute ago, Brian5671 said:

through 30 hrs

And it’s still raining then. 

[Brian5671]

2 minutes ago, jm1220 said:

And it’s still raining then. 

I'll post the full run soon but it may show 20 inches somewhere...

[wdrag]

Smattering of 0.01-.02 se NYS and NJ so far since midday including Wantage NJ.

Global models not changing too much on amounts...general 1-3 spot 4.

 

Blend of Models, 13z/28 version, finally hammered NYC/e NJ etc with 4-7" but this takes into account the the mesoscale models. Those mesoscale continue bullish, though I think shifting east to favor more LI/CT, NYC/Hud River and extreme e NJ... their amounts seem so high for a cooler surface temp/dewpoint. 

My guess is the RRFS is too far west with BOM near NYC and the HRRR SPC HREF more CT/LI eastern NJ/NYC seem to me more probable, at least at this juncture, but could still shift a bit.

 

I added SPC HREF chance of 3" in 6 hrs ending 18z/29 (grey-20% chance), and its overall 48 hour mean and max.  These are big numbers...  but for me disturbing that the globals including SREF are considerably less.  

 

Click for clarity.

 

 

 

[Rtd208]

I have to give @wdragkudos for seeing this storm potential early on. 

[STORMANLI]

-RA intermittent from 245pm on

[Maureen]

34 minutes ago, Rtd208 said:

Not in all cases but usually in these potential high end flood events NE NJ and the NYC metro are where the heaviest rainfall amounts and the most serious flooding occur. We'll see if that is the case this time around.

As you know we flood here in Carteret with a lot less. We had damage and issues from Sandy of course, but Irene was far worse for us with regard to the flooding. And the ground around here is quite saturated already!

[Rtd208]

2 minutes ago, Maureen said:

As you know we flood here in Carteret with a lot less. We had damage and issues from Sandy of course, but Irene was far worse for us with regard to the flooding. And the ground around here is quite saturated already!

Ida was by far the worst I have ever seen this town flood and I have been here for a long time and have seen many flood events over the years here.

[jm1220]

8 minutes ago, Rtd208 said:

I have to give @wdragkudos for seeing this storm potential early on. 

Absolutely. Kudos to @wdrag. I was hoping he was wrong but here we are.  

[Stormlover74]

14 minutes ago, Allsnow said:

Map ? 

Driving. By the way it's already pouring in monmouth on 18

[Doorman]

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1154 AM EDT Thu Sep 28 2023

Day 1
Valid 16Z Thu Sep 28 2023 - 12Z Fri Sep 29 2023

...A SLIGHT RISK OF EXCESSIVE RAINFALL IS IN EFFECT OVER PORTIONS
OF THE MID-ATLANTIC AND NORTHEAST...


...16Z Update...

In coordination with the local WFO offices in Mount Holly and
Upton, have upgraded the D1 ERO to a Slight Risk given the trends
in short term guidance in terms of placement and magnitude of
heavy rainfall this evening. General synoptic scale pattern
remains fairly similar to previous forecast package, but more
emphasis on heavy rain potential has arose given the signals on
the latest ensemble means and deterministic QPF distribution. 12z
HREF neighborhood probabilities of >1" and >2" totals across
northern and central NJ, as well as the NYC metro into the
southern Catskills was sufficient to upgrade the area to the SLGT
risk. There is still some discrepancy on the exact placement of
the heaviest QPF footprint, however the highly anomalous u-vector
wind fields across northern NJ and adjacent areas are all
prevalent across all guidance which would generate a robust
upslope component typically found in these types of heavy rain
events. Convective potential is still on the low side, but
non-zero given the theta-E advection regime likely overnight into
early tomorrow morning as indicated by all deterministic, global
or hi-res base. Total QPF between 1-2" with locally as high as 4"
are being depicted within the HREF blended mean QPF which only
lends credence to the higher potential with the SLGT. Main areas
of concern will be the higher terrain in NNJ and southern NY
state, as well as the urban areas in-of NYC/Newark/Jersey City.

https://www.wpc.ncep.noaa.gov/index.shtml#page=ero

 

 

[Big Jims Videos]

First soaking rain band just moved through the Ocean County beaches.  Second one incoming. 

[Dan76]

3 minutes ago, jm1220 said:

Absolutely. Kudos to @wdrag. I was hoping he was wrong but here we are.  

Did well here too

 

 

[Allsnow]

Just now, Big Jims Videos said:

First soaking rain band just moved through the Ocean County beaches.  Second one incoming. 

Here it comes!

[Maureen]

4 minutes ago, Rtd208 said:

Ida was by far the worst I have ever seen this town flood and I have been here for a long time and have seen many flood events over the years here.

Oh yes, Ida was crazy! No doubt the OEM is keeping a close eye on this event as well. 

[NJwx85]

18z NAM is East lol

[Rtd208]

[Big Jims Videos]

Chatting with some of our mets the concern is growing here in NJ.  Will probably have to double up on the rain gear for the morning shows tomorrow.  

No panic bells and alarms just YET but this evening's newscasts will certainly have a different tone than this morning.  

[brooklynwx99]

7 minutes ago, NJwx85 said:

18z NAM is East lol

still really bad, just in a different spot than 12z. still going too

[Brian5671]

8 minutes ago, NJwx85 said:

18z NAM is East lol

Western CT JP this run--will likely come down to a now cast

[Brian5671]

3K NAM looks nothing like the 12K-has an area of 26 inches off the NJ coast...

[brooklynwx99]

NAM has 7-8" just E of TTN... still very significant. it's clear that this system is going to lead to major issues somewhere. NE NJ / Monmouth / NYC is favored, but it's still up in the air

[winterwx21]

5 minutes ago, Brian5671 said:

3K NAM looks nothing like the 12K

Yeah 3km is suddlenly much less bullish on anyone in the tri-state getting huge amounts. Keeps the extremely heavy stuff to the southeast off the coast. As many have pointed out, this is the type of event that is incredibly hard to predict. We won't know until tomorrow what area will get under the extremely heavy band. Hopefully it will miss like 3km NAM shows, but who knows. 

[cardinalland]

if the 12k nam is right i might have to buy a boat