Our next weekend rain event
Latest WPC forecast for our area is broadly 2-3” with locally higher amounts possible. This seems quite reasonable to me.
sprout said:
Thank you. I may as well revise my weekend plans now...
should be noted the brunt of this will be Friday through Saturday
The Weather Prediction Center has upped their probability of flash flooding for our area to moderate risk. Where the heaviest rain falls will be a function of where any localized bands may develop — a detail that likely won’t be known until the rain starts falling. Be prepared for anywhere from 2-4 inches of rain with potentially higher amounts possible.
This is really starting to look more and more ominous. I think flooding should be considered more of an expectation than a concern.
A very good tweet thread about this: https://x.com/weatherprof/status/1707581903312683177?s=46&t=-gCsEJhafaBrK4uno8C3Eg
Fri Sept 29th
FLOD ADVISORY and FLOOD WATCH
There is a strong signal in the models and on the radar for heavy rain this morning and likely to continue into this afternoon. Total rain today could be 3 - 5 inches.
A system is setting up this morning that is very likely to pump water into our area all day, with thunderstorms likely. A band of very heavy rain is likely to set up somewhere in the metro area, and in that area we could have multiple hours of 1 inch or more per hour rainfall. This could cause local field and street flooding, and small streams to jump their banks. See details of NWS Watch and Advisory in comments. Make sure to have your phone set to receive emergency warnings in case of local flooding.
Showers tomorrow morning, then clearing.
Graphics below include one example of model output this morning showing possible extent of heavy rain and also the NWS official forecast. This gives an idea of the range in the raw data and a possible spread of heaviest rain.
Flood Watch
Flood Watch
National Weather Service New York NY
414 AM EDT Fri Sep 29 2023
CTZ005-006-009-010-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179-
291615-
/O.CON.KOKX.FA.A.0010.000000T0000Z-230930T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Northern New Haven-Southern Fairfield-Southern
New Haven-Western Passaic-Eastern Passaic-Hudson-Western Bergen-
Eastern Bergen-Western Essex-Eastern Essex-Western Union-Eastern
Union-Orange-Putnam-Rockland-Northern Westchester-Southern
Westchester-New York (Manhattan)-Bronx-Richmond (Staten Island)-
Kings (Brooklyn)-Northwest Suffolk-Northeast Suffolk-Southwest
Suffolk-Southeast Suffolk-Northern Queens-Northern Nassau-
Southern Queens-Southern Nassau-
414 AM EDT Fri Sep 29 2023
...FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...
* WHAT...Scattered to Numerous Instances of Flash flooding Likely.
Locally Considerable Flash Flooding is Possible.
* WHERE...Portions of southern Connecticut, including the following
areas, Northern Fairfield, Northern New Haven, Southern Fairfield
and Southern New Haven. Portions of northeast New Jersey,
including the following areas, Eastern Bergen, Eastern Essex,
Eastern Passaic, Eastern Union, Hudson, Western Bergen, Western
Essex, Western Passaic and Western Union. Portions of southeast
New York, including the following areas, Bronx, Kings (Brooklyn),
New York (Manhattan), Northeast Suffolk, Northern Nassau, Northern
Queens, Northern Westchester, Northwest Suffolk, Orange, Putnam,
Richmond (Staten Island), Rockland, Southeast Suffolk, Southern
Nassau, Southern Queens, Southern Westchester and Southwest
Suffolk.
* WHEN...Through late tonight.
* IMPACTS...Excessive runoff will likely result in scattered to
numerous instances of flash flooding in urban and poor drainage
areas. Locally considerable flash flooding is possible where axis
of heaviest rain develops and sits for several hours. If this
heavier rainfall axis develops over the flashy river and stream
basins of northeastern NJ, Lower Hudson Valley, and southwestern
CT, moderate flood stages could be exceeded.
* ADDITIONAL DETAILS...
- A widespread 3 to 5 inches of rain is expected, with
localized amounts of 5 to 7 inches possible.
-Rainfall rates of 1 to 2"/hr likely in heaviest rainfall
axis, with rates in excess of 2"/hr possible.
-Flooding will be exacerbated in coastal areas where heavy
rainfall coincides with this morning and and evening high
tides.
-The exact axis of excessive rainfall is still uncertain, but
those in the watch areas should prepare for the potential of
considerable flooding.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.
&&
$
NV
Flood Advisory
Flood Advisory
National Weather Service New York NY
708 AM EDT Fri Sep 29 2023
NJC013-017-039-NYC047-061-085-291300-
/O.NEW.KOKX.FA.Y.0202.230929T1108Z-230929T1300Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Essex NJ-Hudson NJ-Union NJ-Kings (Brooklyn) NY-New York
(Manhattan) NY-Richmond (Staten Island) NY-
708 AM EDT Fri Sep 29 2023
...FLOOD ADVISORY IN EFFECT UNTIL 9 AM EDT THIS MORNING...
* WHAT...Flooding caused by excessive rainfall is expected.
* WHERE...Portions of northeast New Jersey, including the following
counties, Essex, Hudson and Union. Portions of southeast New York,
including the following counties, Kings (Brooklyn), New York
(Manhattan) and Richmond (Staten Island).
* WHEN...Until 900 AM EDT.
* IMPACTS...Minor flooding in low-lying and poor drainage areas.
Overflowing poor drainage areas. Ponding of water in urban or
other areas is occurring or is imminent.
* ADDITIONAL DETAILS...
- At 708 AM EDT, Doppler radar indicated heavy rain due to
thunderstorms. Minor flooding is ongoing or expected to begin
shortly in the advisory area. Between 0.5 and 1 inch of rain
has fallen.
- Additional rainfall amounts of 1 to 2 inches are expected
over the area. This additional rain will result in minor
flooding.
- Some locations that will experience flooding include...
Newark, Jersey City, Elizabeth, Flatbush, Bayonne, Hoboken,
Linden, Orange, Coney Island, Harrison, Todt Hill, The
Verrazano Narrows Bridge, Huguenot, Bay Ridge, Lower East
Side, Union City, East Village, SoHo, Port Richmond and
Kearny.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
Where is the best source for actual rain totals in Maplewood/South Orange?
wow:
Emergency in nyc pic.twitter.com/oNl1idC937
— EveryThing Plus ULTRA (@EveryTPlusULTRA) September 29, 2023
weatherunderground.com Several personal weather stations in each town, most reporting precipitation accumulation live. Interesting how much measured rainfall can vary within the 2 towns. This a.m., station near Maplecrest received considerably more around 6a than the other stations.
Looks like we're on the edge of the system and most of the heavy storms are east of us.
jamie said:
Looks like we're on the edge of the system and most of the heavy storms are east of us.
This is likely true though I’d remain ready for more. Wouldn’t take much to get a fresh pulse further west.
This is incredibly bizarre. 8" of rain in NYC with massive flooding, and nothing but a steady rain here in SO.
It really hasn't been much around here. The sun sorta came out this afternoon too.
DanDietrich said:
This is incredibly bizarre. 8" of rain in NYC with massive flooding, and nothing but a steady rain here in SO.
MAPSO got quite lucky here; the deformation/frontal boundary set up over NYC/LI rather than another 20 miles inland. Parts of Long Island saw a 1 in 200+ year rain event yesterday.
I'd like to see a map of NY before development to see how swamps and waterways coincide with flooded areas. That E.23rd st area has flooded for as long as I can remember.
The Viele map is an often-referenced one.
Link to that map, and a few others, at http://www.codex99.com/cartography/109.html
link to jpg of the map, from the referenced site:
http://www.codex99.com/cartography/images/nyc/viele_lg.jpg
Pretty reasonable chance the entire area sees 2+ inches of rain tomorrow. Locally higher totals — some areas reaching 4+— also possible.
We may have lucked out a bit here as model guidance appears to have substantially overplayed its hand. The setup today is quite similar to last week, however rain totals likely won’t approach expectations. Still could see another 1-2 inches, but highly doubtful we approach anything much higher.
Thank you, max, wxnut, pvw... anyone else I missed.
We just spent 12 days in France without even a sprinkle. The air is so thick here you could practically chew it.
KarenMarlowe said:
Thank you, max, wxnut, pvw... anyone else I missed.
We just spent 12 days in France without even a sprinkle. The air is so thick here you could practically chew it.
The humidity the past couple of weeks has been crazy. My dehumidifier is working overtime.
Some pretty good signal coming out of the both the deterministic and probabilistic guidance for another potentially heavy rain event this late this week and coming weekend. It’s probably a good time to make sure the gutters and storm drains are clean again.