ALL WATCHES AND WARNINGS HAVE ENDED. Flash Flood WARNING, Severe Thunderstorm Watch until 11 pm tonight, Flood Watch Today, Tuesday 8/6 thru 8/7

Mon Aug 5th

Wet week ahead as heat wave tempers

Today, Monday, hot but not quite as humid, high near 90⁰ and a slight chance of rain.

Tuesday and Wednesday, wet. Warm but not hot, likely rain starting Tuesday afternoon and persisting into Wednesday morning. This is not likely to be the short monsoon downpours of the last couple of days but more likely a steady soak.

The late week forecast is complicated by disagreement in the models on the track of the remnants of Tropical Storm Debbie. At this point the best I can do is to say, expect some rain sometime Thursday through Saturday. At this time I do not expect this to be heavy flooding event, but the ground is likely to be saturated and in both model scenarios there is the potential for a couple of inches additional rain.

I'll keep you posted

Some wild localized variability in the rainfall yesterday

My gauge is the one showing 1.01 inches on the Essex/Union border

Tuesday Aug 6th

Warm, humid, rain

Today will be warm and humid, with a high near 90⁰ and a heat index in the mid 90⁰s. Rain is likely from this afternoon and through tonight, and could be heavy at times as a front moves into the area and stalls. Exactly where the front stalls, and for how long, is a matter in some dispute among the computer models, so exact location of the heavier rain is a bit of a crap shoot. Thunderstorms are possible as well. Rain could continue Wednesday, though thunderstorms are less likely.

The NWS has issued a Flood Watch for the entire area for this afternoon through Wednesday morning.

Thursday rain and possibly a thundstorm in the afternoon as a (non Debby) front pulls tropical moisture into the area. Breezy and warm.

The effects of the remnants of hurricane Debby are still unclear. I would expect more than one wave of rain is possible, as there is an indication that we could see a PRE event Friday. PRE is an acronym for Predecessor Rain Event and refers to a rain system that occers before a storm, is caused by the storm, but is not the actual storm. The models are showing a potential of up to 4 inches of rain possible between the PRE and the storm remnants over 48+ hours. If the high end pans out, expect some small stream flooding along with road ponding and minor field flooding. The remnants of Debby are most likely to arrive Saturday as a rain event, breezy but without damaging winds, but at this time storm track and timing are still unclear.

Note that this is not Ida-level rain. This might be 4 inches in 48 hours. Ida was 8 inches in 18 hours.

I will keep updating daily as things become clearer.

Flood Watch
National Weather Service New York NY
357 AM EDT Tue Aug 6 2024

CTZ005>012-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179-062100-
/O.CON.KOKX.FA.A.0009.240806T1800Z-240807T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northern Fairfield-Northern New Haven-Northern Middlesex-Northern
New London-Southern Fairfield-Southern New Haven-Southern
Middlesex-Southern New London-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-
357 AM EDT Tue Aug 6 2024

...FLOOD WATCH REMAINS IN EFFECT FROM 2 PM EDT THIS AFTERNOON
THROUGH WEDNESDAY MORNING...

* WHAT...Flooding caused by excessive rainfall continues to be
  possible.

* WHERE...Portions of southern Connecticut, including the following
  areas, Northern Fairfield, Northern Middlesex, Northern New Haven,
  Northern New London, Southern Fairfield, Southern Middlesex,
  Southern New Haven and Southern New London, 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, and 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...From 2 PM EDT this afternoon through Wednesday morning.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Creeks and streams may rise out of their banks. Flooding may occur
  in poor drainage and urban areas. Extensive street flooding and
  flooding of creeks and rivers are possible.

* ADDITIONAL DETAILS...
  - - Heavy rainfall results in the potential for flooding. While
    much of the flooding is expected to be localized, significant
    flooding is possible due to rainfall rates of 1 to 2 inches
    per hour. Especially along fast responding rivers and
    streams, and in more urbanized locations.
  - http://www.weather.gov/safety/flood
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood
Warnings. Those living in areas prone to flooding should be prepared
to take action should flooding develop.

&&

Tuesday afternoon, Aug 6th

Severe Thunderstorm Watch until 11 pm tonight

Flood Watch tonight and tomorrow

Thunderstorms forming to the south of the area now will track north and them train through for several hours. Heavy rain likely, possibly two or more inches by Wednesday morning. Right now, these storms are throwing a lot of lightning, too. The NWS is concerned about a slight chance of strong gusts that I don't really see but they are better at this than I am so take their word for it. Be alert for road ponding and small stream overflow

Flash Flood Statement
National Weather Service New York NY
638 PM EDT Tue Aug 6 2024

NJC003-013-017-031-039-070045-
/O.CON.KOKX.FF.W.0015.000000T0000Z-240807T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bergen NJ-Essex NJ-Hudson NJ-Passaic NJ-Union NJ-
638 PM EDT Tue Aug 6 2024

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM EDT THIS
EVENING FOR SOUTH CENTRAL BERGEN, ESSEX, HUDSON, EASTERN PASSAIC AND
CENTRAL UNION COUNTIES...

At 638 PM EDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1.5 and 2.5 inches of rain have
fallen. The expected rainfall rate is 0.75 to 1.5 inches in 1 hour.
Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Newark, Paterson, Passaic, Bloomfield, Orange, Paramus, Summit,
  Lyndhurst, Millburn, Rutherford, Secaucus, Harrison, Caldwell,
  Kearny, Fairfield, Union, Teterboro, Clifton, East Orange and
  Irvington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Move to higher ground now. Act quickly to protect your life.

Be aware of your surroundings and do not drive on flooded roads.

Stay away or be swept away. River banks and culverts can become
unstable and unsafe.

Please report observed flooding to local emergency services or law
enforcement and request they pass this information to the National
Weather Service when you can do so safely.

&&

LAT...LON 4066 7440 4067 7440 4066 7442 4072 7440
      4075 7436 4076 7438 4080 7436 4082 7433
      4086 7432 4087 7434 4091 7433 4090 7428
      4090 7427 4092 7427 4092 7428 4093 7429
      4096 7406 4072 7405 4062 7442

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL RATE...0.75-1.5 INCHES IN 1 HOUR

So, is this drizzle hurricane related or is it just a warmup for the main event?

My rain gauge is showing around 3.5 inches so far.

tjohn said:

So, is this drizzle hurricane related or is it just a warmup for the main event?

My rain gauge is showing around 3.5 inches so far.

It’s the appetizer before the PRE event on Friday….when Debby does Jersey 

My street has horrible drainage and water seepage issues. Not sure if we're getting through this one unscathed. 

Holy rain, Batman!

seems like a lot of rain for a pre-event.  but when is the real rain coming and how much ???  

Wednesday, Aug 7th

A slightly abbreviated report

I'm going to stick to the short term this morning and do a deeper weekend analysis later this afternoon. Debby is coming into focus and I would like a little more time with the data.

There are no active watches or warnings.

Today, cooler, high in the low 70⁰s (likely already reached) as temps likely to fall a little. Slight chance of a light shower or two decreasing during the day. Breezy. Thursday, similar profile with a slightly higher chance of showers in the afternoon.

Yesterday, highly localized heavy rain of up to 4 inches fell in the MAPSO area causing road ponding as well as small stream and field flooding.

The East Branch of the Rahway River ('the Brook' in the valley) crested at 7.66 feet at 8:30pm last night, 1.5 feet above flood stage. Flooding was reported at several locations throughout the local area, including near the train station and on Rt 124 (Springfield Ave) near Home Depot. This morning the river has returned to its banks and is well below flood stage.

Thanks, Max!