Alert archive / Rhode Island / Flash Flood Warnings in 2021

Flash Flood Warning 30, NWS Boston/Norton, MA

September 1, 20215 counties in Rhode Island

NWS Boston/Norton, MA issued this flash flood warning at Sep 1, 2021, 10:17 PM EDT for 5 counties in Rhode Island. It was in force for 9 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 1, 2021, 10:17 PM EDT (02:17 UTC)
Expired
Sep 2, 2021, 7:45 AM EDT
In force
9 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 40 km from the middle of the area, began a volume at 02:17 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Sep 2, 5:53 AM EDTHEAVY RAIN 5.1Greene, RI

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 2.3 hours before the alert went out and 150 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2021-09-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2021-09-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 279 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
123 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
512 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
279 m²/s²
0-3 km storm-relative helicity
456 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

217 
WGUS51 KBOX 020217
FFWBOX
RIC001-003-005-007-009-021015-
/O.NEW.KBOX.FF.W.0030.210902T0217Z-210902T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
1017 PM EDT Wed Sep 1 2021

The National Weather Service in Norton has issued a

* Flash Flood Warning for...
  Northeastern Bristol County in Rhode Island...
  Kent County in Rhode Island...
  Northeastern Newport County in Rhode Island...
  Providence County in Rhode Island...
  Washington County in Rhode Island...

* Until 615 AM EDT Thursday.

* At 1017 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. Additional rainfall amounts of 2 to 5 inches are 
  possible in the warned area. 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...
  Providence, Warwick, Cranston, Pawtucket, East Providence, 
  Woonsocket, Coventry, Cumberland, North Providence, South 
  Kingstown, West Warwick, Johnston, North Attleborough, North 
  Kingstown, Bristol, Attleboro, Westerly, Smithfield, Lincoln and 
  Central Falls.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4131 7189 4142 7180 4201 7180 4202 7138
      4180 7134 4172 7123 4171 7123 4173 7126
      4164 7127 4176 7129 4173 7129 4171 7130
      4182 7141 4167 7137 4159 7113 4150 7112
      4159 7120 4170 7145 4166 7141 4136 7148

FLASH FLOOD...RADAR INDICATED

$$

Frank
1 follow-up statement
913 
WGUS51 KBOX 020938
FFWBOX
RIC001-003-005-007-009-021145-
/O.EXT.KBOX.FF.W.0030.000000T0000Z-210902T1145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
538 AM EDT Thu Sep 2 2021

The National Weather Service in Norton has extended the

* Flash Flood Warning for...
  Northeastern Bristol County in Rhode Island...
  Kent County in Rhode Island...
  Northeastern Newport County in Rhode Island...
  Providence County in Rhode Island...
  Washington County in Rhode Island...

* Until 745 AM EDT.

* At 538 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 3 and 6 inches of rain have fallen. The heavy 
  rain should exit the region through 7 am, but runoff will continue 
  to result in Flash flooding and significant urban flooding.

  HAZARD...Flash flooding caused by heavy rain.

  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...
  Providence, Warwick, Cranston, Pawtucket, East Providence, 
  Woonsocket, Coventry, Cumberland, North Providence, South 
  Kingstown, West Warwick, Johnston, North Attleborough, North 
  Kingstown, Bristol, Attleboro, Westerly, Smithfield, Lincoln and 
  Central Falls.

Numerous roads are flooded and impassable. Even though the heavy 
rain will be exiting the region by 7 am roads will continue to be 
flooded and impassable into the morning commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4131 7189 4142 7180 4201 7180 4202 7138
      4180 7134 4172 7123 4171 7123 4173 7126
      4164 7127 4176 7129 4173 7129 4171 7130
      4182 7141 4167 7137 4159 7113 4150 7112
      4159 7120 4170 7145 4166 7141 4136 7148

FLASH FLOOD...RADAR INDICATED

$$

Frank

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 10:32 PM EDTFlash Flood WarningBOXBristol, Newport, Providence10 hr
Sep 2, 2:34 AM EDTFlash Flood Warning Considerable damage threatBOXBristol, Kent, Newport, Providence, Washington6 hr
Sep 2, 5:10 AM EDTRiver Flood WarningBOXKent, Providence18 hr
Sep 2, 7:04 AM EDTAreal Flood WarningBOXProvidence11 hr
Sep 2, 7:43 AM EDTAreal Flood WarningBOXBristol, Kent, Newport, Providence, Washington6 hr
Sep 2, 8:20 AM EDTRiver Flood WarningBOXWashington43 hr
Sep 2, 8:20 AM EDTRiver Flood WarningBOXProvidence32 hr
Sep 2, 8:20 AM EDTRiver Flood WarningBOXWashington53 hr
Sep 2, 1:42 PM EDTAreal Flood WarningBOXBristol, Kent, Newport, Providence, Washington6 hr

Nearby

Flash Flood Warnings in Rhode Island, 2021Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.