Alert archive / Massachusetts / Flash Flood Warnings in 2018

Flash Flood Warning 31, NWS Boston/Norton, MA

September 18, 20186 counties in Massachusetts; Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island

NWS Boston/Norton, MA issued this flash flood warning at Sep 18, 2018, 11:23 AM EDT for 6 counties in Massachusetts; Northeastern Connecticut Planning Region, Connecticut; Providence County, Rhode Island. It was in force for 4 hr. 16 reports 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 18, 2018, 11:23 AM EDT (15:23 UTC)
Expired
Sep 18, 2018, 3:15 PM EDT
In force
4 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Northeastern Connecticut Planning Region, CT, Bristol County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Providence County, RI

The radar

The Boston radar (KBOX), 43 km from the middle of the area, began a volume at 15:27 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 18, 11:40 AM EDTFLASH FLOODUxbridge, MAROUTE 122 AT HAZEL STREET FLOODED
Sep 18, 11:44 AM EDTFLASH FLOODBellingham, MAMONIQUE DRIVE FLOODED AND IMPASSABLE
Sep 18, 11:44 AM EDTFLASH FLOODMilford, MANORTH BOW STREET FLOODED AND IMPASSABLE
Sep 18, 11:50 AM EDTFLASH FLOODQuincy, MAARTERY AT GREENLEAF STREET CLOSED DUE TO FLOODING
Sep 18, 12:18 PM EDTFLASH FLOODWeymouth, MAGREENVILLE AVE IS FLOODED AND IMPASSABLE
Sep 18, 12:35 PM EDTFLASH FLOODBellingham, MACAROLINE DRIVE IS FLOODED AND IMPASSABLE. WATER UP TO CAR BUMPER.
Sep 18, 12:38 PM EDTFLASH FLOODNorwood, MAROUTE 1 AT PLEASANT STREET IS CLOSED DUE TO FLOODING
Sep 18, 12:48 PM EDTFLASH FLOODNorfolk, MAHOLBROOK STREET IN AREA OF ROUTE 115 FLOODED AND IMPASSABLE
Sep 18, 1:08 PM EDTFLASH FLOODRandolph, MAHIGHLAND AVE, WARREN STREET, AND DIAUTO DRIVE FLOODED AND IMPASSABLE
Sep 18, 1:38 PM EDTFLASH FLOODNorfolk, MADEDHAM STREET BY VILLAGE GREEN NURSERIES FLOODED AND IMPASSABLE
Sep 18, 1:42 PM EDTFLASH FLOODCohasset, MAROUTE 3A SOUTHBOUND FLOODED WITH TWO FEET OF WATER
Sep 18, 1:42 PM EDTFLASH FLOODFranklin, MAFLOODING INTO THE LOBBY AT DEAN COLLEGE
Sep 18, 1:48 PM EDTFLASH FLOODBrockton, MASECTIONS OF OAK HILL WAY ARE FLOODED AND IMPASSABLE
Sep 18, 2:03 PM EDTFLASH FLOODNorwood, MADEAN STREET AT KERRY PLACE FLOODED AND IMPASSABLE
Sep 18, 2:29 PM EDTFLASH FLOODBurrillville, RIHOUSE ON WALLUM LAKE ROAD FLOODING
Sep 18, 2:42 PM EDTHEAVY RAIN 1.16East Killingly, CT

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

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 3.4 hours before the alert went out and 144 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, Chatham, MA at 12:00Z on 2018-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 165 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, Chatham, MA at 12:00Z on 2018-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 square meters per square second.193958Sfc1 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
165 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

413 
WGUS51 KBOX 181523
FFWBOX
CTC013-015-MAC005-017-021-023-025-027-RIC007-181915-
/O.NEW.KBOX.FF.W.0031.180918T1523Z-180918T1915Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
1123 AM EDT TUE SEP 18 2018

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  Windham County in northern Connecticut...
  Northeastern Tolland County in northern Connecticut...
  Southeastern Worcester County in central Massachusetts...
  Norfolk County in eastern Massachusetts...
  Southern Suffolk County in eastern Massachusetts...
  South central Middlesex County in northeastern Massachusetts...
  Northern Plymouth County in southeastern Massachusetts...
  Northwestern Bristol County in southeastern Massachusetts...
  Providence County in Rhode Island...

* Until 315 PM EDT.

* At 1120 AM EDT Doppler radar indicated showers and thunderstorms 
  producing very heavy rain within the warned area. Flash flooding 
  is expected to begin shortly.

* As of 1120 AM, the heaviest rainfall extended from extreme 
  northeast Connecticut into far northwest Rhode Island, 
  northeastward into the Boston corridor. Rainfall rates in this 
  area were as high as 2 to 5 inches per hour. This band may shift 
  to the south over the next couple of hours. 

* Some locations that will experience flooding include...
  Boston, Brockton, Quincy, Pawtucket, Taunton, Weymouth, Woonsocket,
  Braintree, Cumberland, Randolph, North Providence, Franklin,
  Johnston, North Attleborough, Norwood, Milford, Milton, Stoughton,
  Bridgewater and Windham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning means that flooding will occur quickly, and
could be life threatening for those who try to drive through flooded
roads or underpasses. Find alternate routes. Those near small streams
need to get to higher ground immediately.

&&

LAT...LON 4172 7224 4202 7226 4202 7172 4218 7174
      4229 7096 4234 7088 4205 7065 4168 7220

$$

NMB

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 7:54 AM EDTSpecial Weather StatementBOXFranklin, Hampshire81 min
Sep 18, 8:21 AM EDTSpecial Weather StatementBOXNorfolk54 min
Sep 18, 8:52 AM EDTFlash Flood WarningBOXFranklin, Hampshire, Middlesex, Worcester4 hr
Sep 18, 9:09 AM EDTSpecial Weather StatementBOXHampden, Worcester36 min
Sep 18, 9:32 AM EDTSpecial Weather StatementBOXEssex, Middlesex88 min
Sep 18, 9:50 AM EDTSpecial Weather StatementBOXHampden, Worcester85 min
Sep 18, 10:12 AM EDTSpecial Weather StatementBOXEssex48 min
Sep 18, 10:17 AM EDTFlash Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk, Worcester4 hr
Sep 18, 10:34 AM EDTSpecial Weather StatementBOXEssex41 min
Sep 18, 10:45 AM EDTSevere Thunderstorm WarningBOXEssex, Middlesex30 min
Sep 18, 10:56 AM EDTSpecial Marine WarningBOX64 min
Sep 18, 10:58 AM EDTFlash Flood WarningBOXHampden, Hampshire, Worcester4 hr
Sep 18, 11:00 AM EDTTornado WarningBOXEssex15 min
Sep 18, 11:07 AM EDTRiver Flood WarningBOXWorcester9 hr
Sep 18, 11:09 AM EDTSpecial Marine WarningBOX66 min
Sep 18, 11:58 AM EDTSpecial Marine WarningBOX62 min
Sep 18, 12:20 PM EDTSpecial Marine WarningBOX25 min
Sep 18, 12:32 PM EDTAreal Flood WarningBOXFranklin, Hampshire, Middlesex, Worcester4 hr
Sep 18, 12:49 PM EDTSpecial Marine WarningBOX86 min
Sep 18, 12:58 PM EDTSpecial Weather StatementBOXPlymouth62 min
Sep 18, 1:10 PM EDTSpecial Marine WarningBOX80 min
Sep 18, 1:31 PM EDTFlash Flood WarningBOXBristol, Plymouth4 hr
Sep 18, 2:01 PM EDTAreal Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk, Worcester4 hr
Sep 18, 2:07 PM EDTSpecial Weather StatementBOXBristol, Plymouth38 min
Sep 18, 2:27 PM EDTSevere Thunderstorm WarningBOXBarnstable, Plymouth33 min
Sep 18, 2:31 PM EDTSpecial Marine WarningBOX44 min
Sep 18, 2:59 PM EDTSpecial Marine WarningBOX46 min
Sep 18, 3:04 PM EDTSevere Thunderstorm WarningBOXBarnstable41 min
Sep 18, 3:05 PM EDTFlash Flood WarningBOXBarnstable115 min
Sep 18, 3:14 PM EDTAreal Flood WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester3 hr
Sep 18, 3:22 PM EDTSpecial Marine WarningBOX53 min
Sep 18, 3:59 PM EDTSpecial Marine WarningBOX46 min
Sep 18, 4:01 PM EDTSmall Craft AdvisoryBOX60 hr
Sep 18, 12:36 PM EDTSpecial Weather StatementBOX39 min
Sep 18, 11:22 AM EDTSpecial Weather StatementBOXProvidence53 min
Sep 18, 12:07 PM EDTSpecial Weather StatementBOXProvidence23 min

Nearby

Flash Flood Warnings in Massachusetts, 2018Flash Flood Warnings in Connecticut, 2018Flash Flood Warnings in Rhode Island, 2018Every flash flood warning in 2018

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.