Post-Tropical Ida (Cat 4 hurricane @ Landfall @12:55pm EDT, 40 mph, 998 mb, 28 mph NE) - possible area flood impact, tornadoes, and severe weather

[jhotdog]

8.6 Souderton. Back edge close

[Chadzachadam]

The schuylkill has totally flooded onto Kelly Drive here in East Falls. We got around 5” but nothing severe, hope the river doesn’t rise too much higher..

[Hurricane Agnes]

WPC 11 pm update (the rainstorm has strengthened to 40 mph, with pressure at 998  mb, and is now zipping along at 28 mph to the NE) -

Quote

000
WTNT34 KWNH 020235
TCPAT4

BULLETIN
Post-Tropical Cyclone Ida Advisory Number  28
NWS Weather Prediction Center College Park MD   AL092021
1100 PM EDT Wed Sep 01 2021

...POST-TROPICAL CYCLONE IDA CONTINUES TO BRING WIDESPREAD HEAVY
RAINFALL AND AREAS OF LIFE THREATENING FLASH FLOODING ALONG AND
NEAR TRACK...
...AN ENHANCED RISK FOR TORNADOES WILL PERSIST ACROSS NORTHEAST NEW
JERSEY, SOUTHERN NEW YORK, AND FAR SOUTHERN NEW ENGLAND THROUGH THE
PRE-DAWN HOURS THURSDAY...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...40.5N 74.3W
ABOUT 190 MI...300 KM ENE OF HAGERSTOWN MARYLAND
ABOUT 140 MI...225 KM E OF HARRISBURG PENNSYLVANIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NE OR 55 DEGREES AT 28 MPH...44 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
Flood and Flash Flood Watches remain in effect for northern
portions of the Mid-Atlantic Region into southern New York and
southern New England.

Tornado Watches are in effect for portions of southern Connecticut,
northern New Jersey, and southern New York.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM EDT (0300 UTC), the center of Post-Tropical Cyclone Ida
was located near latitude 40.5 North, longitude 74.3 West. The
post-tropical cyclone is moving toward the northeast near 28 mph (44
km/h), and this motion is expected to continue overnight. 

Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Little change in strength is forecast during the next 24 hours.

The estimated minimum central pressure is 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: Post-Tropical Cyclone Ida will produce the following
rainfall totals:

Northern Mid Atlantic to Southern New England: 3 to 8 inches with
isolated higher amounts through Thursday.

Significant and life-threatening flash flooding is likely from the
Mid-Atlantic into southern New England, especially across highly
urbanized metropolitan areas and areas of steep terrain. Widespread
moderate and major river flooding impacts are forecast from eastern
West Virginia and western Maryland into southern Pennsylvania and
New Jersey, particularly in the Monongahela, Potomac, Susquehanna,
Delaware, lower Hudson and Coastal Connecticut river basins.

Widespread minor to isolated major river flooding is occurring or
forecast from the Lower Mississippi Valley into far western Alabama
and northeast Georgia. Some rivers will remain elevated into next
week.

For the latest rainfall reports and wind gusts associated with
Post-Tropical Cyclone Ida, see the companion storm summary at
WBCSCCNS4 with the WMO header of ACUS44 KWBC or at the following
link:

www.wpc.ncep.noaa.gov/discussions/nfdscc4.html

TORNADOES: The threat for a few tornadoes will continue across the
northern Mid Atlantic into far southern New England through the
remainder of tonight.


NEXT ADVISORY
-------------
Next complete advisory at 500 AM EDT.

$$
Forecaster Hurley

FORECAST POSITIONS AND MAX WINDS

INIT  02/0300Z 40.5N  74.3W   35 KT  40 MPH...POST-TROP/EXTRATROP
 12H  02/1200Z 42.3N  70.1W   35 KT  40 MPH...POST-TROP/EXTRATROP
 24H  03/0000Z 45.3N  64.9W   40 KT  45 MPH...POST-TROP/EXTRATROP

 

[Hurricane Agnes]

Just now, Chadzachadam said:

The schuylkill has totally flooded onto Kelly Drive here in East Falls. We got around 5” but nothing severe, hope the river doesn’t rise too much higher..

There is still rain coming down to the west and the river has already flooded way out of its banks in Norristown, so expect it to get a bit higher down there.

Back edge is coming soon and has finally stopped (at least with the measurable) here so far.  Currently at 5.33" for the event so far (0.56" round 1 and 4.77" for round 2).  Currently breezy, overcast, misty and 63 with dp 62.

[Hurricane Agnes]

Latest Mt. Holly tweet -

 

[Chadzachadam]

4 minutes ago, Hurricane Agnes said:

There is still rain coming down to the west and the river has already flooded way out of its banks in Norristown, so expect it to get a bit higher down there.

Back edge is coming soon and has finally stopped (at least with the measurable) here so far.  Currently at 5.33" for the event so far (0.56" round 1 and 4.77" for round 2).  Currently breezy, overcast, misty and 63 with dp 62.

Yep, just checked and it looks like NWS is projecting another 5ft of rise which would bring the river right to my doorstep tomorrow morning

[The Iceman]

Back edge will probably be through around midnight but looks like the heavy stuff has just about ended. 5.6" on the event, may see another .1 or .2 before it's over, don't think we'll hit 6. Hope I can get to work in Trenton tomorrow or hope Murphy closes the state. Can't believe the Delaware river is already flooding, won't be surprised if it crests higher than predicted. 

[Hurricane Agnes]

2 minutes ago, Chadzachadam said:

Yep, just checked and it looks like NWS is projecting another 5ft of rise which would bring the river right to my doorstep tomorrow morning

Ugh.

I remember when the river flooded pretty badly after the 1996 blizzard when the temp suddenly warmed and then there was some heavy rain.  The muddy water lines were clearly visible on the huge plowed snow banks along Kelly Drive near the Falls Bridge and the water had come all the way up and over Ridge Ave. and had probably reached partially up the hills where Calumet or Midvale come down.

[JTA66]

8.60"...it won't stop raining here.

[CoolHandMike]

I like this site to monitor flood gauges around our region:

https://water.weather.gov/ahps2/index.php?wfo=phi

You can zoom in and hover over each point for a quick snapshot or click on them for detailed historical data.

[Hurricane Agnes]

4 minutes ago, The Iceman said:

Back edge will probably be through around midnight but looks like the heavy stuff has just about ended. 5.6" on the event, may see another .1 or .2 before it's over, don't think we'll hit 6. Hope I can get to work in Trenton tomorrow or hope Murphy closes the state. Can't believe the Delaware river is already flooding, won't be surprised if it crests higher than predicted. 

KYW had an alert thingy (I have their audacy app) about Murphy having declared a state of emergency and had called out the National Guard.

 

[hazwoper]

57 minutes ago, Moderately Unstable said:

It would be quite surprising, and unprecedented, to see an EF5, given their rarity here--iirc the strongest Philly area tornado was an EF4 that hit the north broad part of town coming down from Norristown over a century ago. But that radar signature was definitely something else. I stopped what I was doing at work and remarked to a coworker, "this is the strongest tornadic signature I may have ever seen around here"--I am not at all shocked by your report. Certainly seemed EF3+ based on the debris sig and definitely based on the videos. Not something you expect to see in the Philly area. Last year we had a couple strong ish ones from Isias EF2 level...but tonight was just shocking. 

I will add with that line earlier tonight it felt like everything was rotating to some extent at some point. I went outside a couple of times and in addition to the ground scraping LCLs there was just so much non linear motion on everything. It seems rather clear that there must have been some local enhancement of the low level wind field to cause this degree of widespread and significant damage. It will be interesting to read the storm reports when they come out....honestly I just hope no one died. When I saw that sig earlier that was my first thought. Not something something I'd want to be in. 

The sky when that initial push with all the rotation in Bucks County was something to behold.  I’ve seen anytime it!  Rotation everywhere!

[Hurricane Agnes]

The Delaware at Washington Crossing is flooding.

I also got a light blip of measurable rain and am now at 5.34" for the day.

[hazwoper]

17 minutes ago, The Iceman said:

Back edge will probably be through around midnight but looks like the heavy stuff has just about ended. 5.6" on the event, may see another .1 or .2 before it's over, don't think we'll hit 6. Hope I can get to work in Trenton tomorrow or hope Murphy closes the state. Can't believe the Delaware river is already flooding, won't be surprised if it crests higher than predicted. 

Crazy and honestly worse than even I expected.  I don’t have a gauge, but looking at surrounding reports I have to be over 9” here.  Amazing system!

[Chadzachadam]

18 minutes ago, Hurricane Agnes said:

Ugh.

I remember when the river flooded pretty badly after the 1996 blizzard when the temp suddenly warmed and then there was some heavy rain.  The muddy water lines were clearly visible on the huge plowed snow banks along Kelly Drive near the Falls Bridge and the water had come all the way up and over Ridge Ave. and had probably reached partially up the hills where Calumet or Midvale come down.

Yikes, that would be crazy to see. Looks like a beautiful day tomorrow, hope I can actually get out my front door to enjoy it

[Hurricane Agnes]

Schuylkill at 30th St. right at flood stage downtown.

[RedSky]

Neshaminy Creek is 6" from it's record of 23'. Floyd?

 

 

[Kevin Reilly]

4.59” here in Media Delaware County we got lucky in regards to the tornadoes that easily could have been here feeling fortunate prayers of support to those that were affected by this unprecedented weather event flooding and tornadoes. 

[Hurricane Agnes]

1 minute ago, Chadzachadam said:

Yikes, that would be crazy to see. Looks like a beautiful day tomorrow, hope I can actually get out my front door to enjoy it

The wildest thing though was that there was some huge tree trunk that had washed down the river with the currents that literally got wedged near the top of one of the stone arches of one of the (I think) railroad bridges that goes over the river near there.  It was literally wedged straight across and it stayed up there for almost a year before someone finally removed it.  There used to be pics of it on the internet years ago but I haven't been able to find one recently.

[Kevin Reilly]

1 minute ago, RedSky said:

Neshaminy Creek is 6" from it's record of 23'. Floyd?

 

 

Well guess the HRE model you talked about was right Floyd 2.0. Just an incredible day! 

[Hurricane Agnes]

2 minutes ago, RedSky said:

Neshaminy Creek is 6" from it's record of 23'. Floyd?

 

 

Mt. Holly had posted a Climatology section in the AFD earlier this afternoon.  I think it is safe to say that several sites including PHL broke a record for today!

Quote

&&

.CLIMATE...
Record Maximum Daily Rainfall Records for:

           9/1                 9/2
Site  Record/Year         Record/Year
ABE     4.06/1952           1.63/2006
ACY     2.18/2006           2.40/1951
55N     2.35/2006           1.43/2017
PHL     1.80/1952           1.89/2013
ILG     1.73/1952           2.95/1910
RDG     3.50/1952           2.24/2006
TTN     3.84/1940           2.05/2006
MPO     4.54/1952           2.30/1926
GED     6.22/2002           2.47/1998

&&

 

[RedSky]

3 minutes ago, Hurricane Agnes said:

Mt. Holly had posted a Climatology section in the AFD earlier this afternoon.  I think it is safe to say that several sites including PHL broke a record for today!

 

1000 year rains now, none of that 100 year garbage anymore

 

[Hurricane Agnes]

6 minutes ago, RedSky said:

1000 year rains now, none of that 100 year garbage anymore

 

The 100 year ones are annual though, so there's that.

[RedSky]

Everybody check your trees in the morning

https://www.upi.com/Odd_News/2021/09/01/Hurricane-Ida-St-Bernard-Parish-Louisiana-cow-tree/5231630517311/

 

[Hurricane Agnes]

56 minutes ago, The Iceman said:

Back edge will probably be through around midnight but looks like the heavy stuff has just about ended. 5.6" on the event, may see another .1 or .2 before it's over, don't think we'll hit 6. Hope I can get to work in Trenton tomorrow or hope Murphy closes the state. Can't believe the Delaware river is already flooding, won't be surprised if it crests higher than predicted. 

Here is the latest - 3 hour delayed (for state workers) so appears the state will be open but the rivers haven't all crested yet so stay tuned because that might change.

 

[Hurricane Agnes]

Was still getting on and off rain and finished up with 5.41" for the day (since it is now past midnight).  Any additional will make it a 2-day event.  There's still a little back edge left so maybe a couple hundredths more might be added on if that.

Currently overcast and 63 with dp 63.

[mattinpa]

Power just went out for a few minutes. Back on now so perhaps they were working on it. 

[Rtd208]

Picked up 9.60" of rain for the day yesterday. 

0.13" of rain since midnight. 

Storm Total 9.73"

[Hurricane Agnes]

No further rain overnight so still at 5.41" for the event.

Currently 62 with dp 57.

[Hurricane Agnes]

Flooding at rivers and creeks around the area are going through extreme flooding.