Alert archive / Massachusetts / Flash Flood Warnings in 2018

Flash Flood Warning 29, NWS Boston/Norton, MA

September 18, 20185 counties in Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Sep 18, 2018, 10:17 AM EDT for 5 counties in Massachusetts. It was in force for 4 hr. 35 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, 10:17 AM EDT (14:17 UTC)
Expired
Sep 18, 2018, 2:15 PM EDT
In force
4 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Essex County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 73 km from the middle of the area, began a volume at 14:19 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, 10:20 AM EDTHEAVY RAIN 2Dracut, MA
Sep 18, 10:21 AM EDTHEAVY RAIN 3.13Pepperell, MA
Sep 18, 10:23 AM EDTFLASH FLOODWorcester, MABRIDGE IS FLOODING OUT AT ROUTE 20 AT GRAFTON STREET.
Sep 18, 10:32 AM EDTFLASH FLOODShrewsbury, MAMAPLE AVE AT ROUTE 9 FLOODED AND IMPASSABLE
Sep 18, 10:41 AM EDTFLASH FLOODAndover, MABEACON STREET IN FRONT OF WEST ELEMENTARY SCHOOL FLOODED
Sep 18, 10:42 AM EDTHEAVY RAIN 1.58Lexington, MA
Sep 18, 10:43 AM EDTFLASH FLOODLawrence, MAANDOVER AT CLIFTON STREET INTERSECTION FLOODED AND IMPASSABLE
Sep 18, 10:45 AM EDTFLASH FLOODSudbury, MAROUTE 20 AT MASSASOIT NEAR MILLBROOK ROAD IS COMPLETELY FLOODED AND IMPASSABLE
Sep 18, 10:53 AM EDTFLASH FLOODMarlborough, MACAR STUCK IN FLOOD WATERS AT FARM ROAD AT CLARK DRIVE
Sep 18, 10:55 AM EDTFLASH FLOODLawrence, MAMARKET STREET FROM MERRIMACK TO PARKER STREET IN THE AREA OF THE UNDERPASS CLOSED DUE TO FLOODING
Sep 18, 10:59 AM EDTFLASH FLOODNewton, MASECTION OF BEACON STREET IN THE AREA OF 85 BEACON STREET CLOSED DUE TO FLOODING
Sep 18, 11:00 AM EDTFLASH FLOODDanvers, MASIGNIFICANT STREET FLOODING ON ROUTE 62 AT THE MIDDLETON/DANVERS LINE ABOUT 1 FOOT DEEP
Sep 18, 11:00 AM EDTFLASH FLOODWaltham, MAAREA OF 840 WINTER STREET IS FLOODED AND IMPASSABLE
Sep 18, 11:03 AM EDTFLASH FLOODLynnfield, MACAR STUCK IN FLOOD WATERS AT MAIN STREET AT LOWELL STREET
Sep 18, 11:03 AM EDTFLASH FLOODWaltham, MALEXINGTON STREET PRIOR TO RIVER FOREST FLOODED AND IMPASSABLE
Sep 18, 11:03 AM EDTFLASH FLOODWaltham, MAWINTER STREET BY DUFFYS POND IS FLOODED AND IMPASSABLE. CAR STUCK IN FLOOD WATERS.
Sep 18, 11:05 AM EDTFLASH FLOODWaltham, MACAR STUCK IN FLOOD WATERS UNDER THE RAILROAD UNDERPASS ON PROSPECT STREET. WATER UP TO WHEEL WELL.
Sep 18, 11:06 AM EDTFLASH FLOODDanvers, MASECTION OF ROUTE 114 IN BOTH DIRECTIONS ARE FLOODED AND IMPASSABLE
Sep 18, 11:07 AM EDTFLASH FLOODArlington, MAHAMILTON ROAD AT LAKE HILL FLOODED AND IMPASSABLE
Sep 18, 11:08 AM EDTFLASH FLOODHamilton, MAWALNUT STREET AND RAILROAD AVE FLOODED AND IMPASSABLE
Sep 18, 11:08 AM EDTFLASH FLOODWatertown, MAROAD FLOODED AT 103 SUMMER STREET
Sep 18, 11:40 AM EDTFLASH FLOODChelsea, MAVERNON ROAD CLOSED DUE TO FLOODING
Sep 18, 11:40 AM EDTFLASH FLOODMalden, MAROUTE 60 EASTERN AVE FLOODED AND IMPASSABLE. ROAD CLOSED.
Sep 18, 11:40 AM EDTFLASH FLOODMiddleton, MABELLEVIEW AVE GARAGE FLOODED
Sep 18, 11:44 AM EDTFLASH FLOODChelsea, MARIGHT LANE OF ROUTE 16 IS FLOODED AND IMPASSABLE BY EAGLE HEIGHTS ACADEMY
Sep 18, 11:57 AM EDTHEAVY RAIN 2.64Westborough, MA
Sep 18, 12:00 PM EDTFLASH FLOODLynn, MABENNETT STREET FLOODED AND IMPASSABLE WITH THREE TO FOUR FEET OF STANDING WATER
Sep 18, 12:00 PM EDTFLASH FLOODMiddleton, MAVILLAGE ROAD FLOODED AND IMPASSABLE
Sep 18, 12:00 PM EDTFLASH FLOODRevere, MAROUTE 1 NORTHBOUND NEAR ROUTE 16 EXIT IS FLOODED
Sep 18, 12:56 PM EDTFLASH FLOODCambridge, MALONGFELLOW BRIDGE AND MEMORIAL DRIVE CLOSED IN BOTH DIRECTIONS DUE TO FLOODING
Sep 18, 1:04 PM EDTHEAVY RAIN 3.41Pepperell, MA
Sep 18, 1:30 PM EDTHEAVY RAIN 1.9Wakefield, MA
Sep 18, 1:36 PM EDTFLASH FLOODShrewsbury, MAFLORAL STREET FLOODED AND IMPASSABLE
Sep 18, 2:10 PM EDTHEAVY RAIN 1.5Salem, MA
Sep 18, 2:20 PM EDTHEAVY RAIN 2.47Chelmsford, MA

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, 2.3 hours before the alert went out and 138 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.

275 
WGUS51 KBOX 181417
FFWBOX
MAC009-017-021-025-027-181815-
/O.NEW.KBOX.FF.W.0029.180918T1417Z-180918T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
1017 AM EDT TUE SEP 18 2018

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  Southeastern Worcester County in central Massachusetts...
  North central Norfolk County in eastern Massachusetts...
  Suffolk County in eastern Massachusetts...
  Essex County in northeastern Massachusetts...
  Middlesex County in northeastern Massachusetts...

* Until 215 PM EDT.

* At 1015 AM EDT Doppler radar indicated a swath of heavy rain 
  moving across the warned area. Rainfall rates of up to 1 to 3 
  inches per hour were occurring. Flash flooding is expected to 
  begin shortly. This includes rapid ponding of water in urban poor 
  drainage areas. 

* Some locations that will experience flooding include...
  Boston, Worcester, Lowell, Cambridge, Quincy, Lynn, Nashua, Newton,
  Lawrence, Somerville, Framingham, Haverhill, Waltham, Malden,
  Brookline, Medford, Revere, Peabody, Methuen and Arlington.

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 4287 7082 4281 7087 4280 7078 4269 7074
      4270 7062 4265 7056 4241 7090 4242 7096
      4235 7094 4235 7087 4229 7097 4216 7188
      4233 7194 4240 7162 4271 7163 4270 7129
      4274 7118 4281 7116 4281 7107 4289 7091

$$

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, 10:34 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, 11:23 AM EDTFlash Flood WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester4 hr
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

Nearby

Flash Flood Warnings in Massachusetts, 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.