Alert archive / Massachusetts / Flash Flood Warnings in 2011

Flash Flood Warning 9, NWS Boston/Norton, MA

August 27, 20114 counties in Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Aug 27, 2011, 3:15 PM EDT for 4 counties in Massachusetts. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 27, 2011, 3:15 PM EDT (19:15 UTC)
Expired
Aug 27, 2011, 6:15 PM EDT
In force
3 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

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

The radar

The Boston radar (KBOX), 44 km from the middle of the area, began a volume at 19:18 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.

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 7.3 hours before the alert went out and 125 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 2011-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 125 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 2011-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 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
125 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
721 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

135 
WGUS51 KBOX 271915
FFWBOX
MAC017-021-025-027-272215-
/O.NEW.KBOX.FF.W.0009.110827T1915Z-110827T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
315 PM EDT SAT AUG 27 2011

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN WORCESTER COUNTY IN CENTRAL MASSACHUSETTS...
  THIS INCLUDES THE CITY OF MILFORD...
  WESTERN NORFOLK COUNTY IN EASTERN MASSACHUSETTS...
  THIS INCLUDES THE CITIES OF...FRANKLIN...BROOKLINE...
  SUFFOLK COUNTY IN EASTERN MASSACHUSETTS...
  THIS INCLUDES THE CITY OF BOSTON...
  SOUTHERN MIDDLESEX COUNTY IN SOUTHEAST MASSACHUSETTS...
  THIS INCLUDES THE CITIES OF...WALTHAM...SOMERVILLE...NEWTON...
  FRAMINGHAM...CAMBRIDGE...

* UNTIL 615 PM EDT

* AT 307 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  FLASH FLOODING FROM RAINS ASSOCIATED WITH HURRICANE IRENE OVER THE 
  WARNED AREA. RAINFALL RATES OVER 2 INCHES AN HOUR HAVE BEEN        
  REPORTED BY AUTOMATED RAIN GAGES AND RADAR ESTIMATES WITH HEAVIER 
  BANDS OF RAIN.  

FLASH FLOODING OF SMALL STREAMS AND URBAN AREAS IS OCCURRING OR
IMMINENT. THOSE NEAR STREAMS AND CREEKS...OR IN AREAS PRONE TO
FLOODING SHOULD MOVE TO HIGHER GROUND IMMEDIATELY. AVOID FLOODED
ROADS. THE WATER MAY BE TOO DEEP TO ALLOW VEHICLES TO CROSS SAFELY...
OR THE ROADWAY MAY BE UNDERMINED. TURN AROUND...DONT DROWN!

&&

LAT...LON 4252 7104 4247 7105 4243 7101 4244 7096
      4241 7098 4236 7096 4232 7101 4232 7103
      4231 7103 4202 7138 4202 7183 4223 7173
      4259 7136

$$

SIPPRELL
2 follow-up statements
726 
WGUS71 KBOX 272024
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
424 PM EDT SAT AUG 27 2011

MAC017-021-025-027-272215-
/O.CON.KBOX.FF.W.0009.000000T0000Z-110827T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MIDDLESEX MA-WORCESTER MA-NORFOLK MA-SUFFOLK MA-
424 PM EDT SAT AUG 27 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM EDT FOR
SUFFOLK...WESTERN NORFOLK...SOUTHEASTERN WORCESTER AND SOUTHERN
MIDDLESEX COUNTIES...

AT 410 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE RAINS ASSOCIATED WITH HURRICANE IRENE PRODUCING FLASH 
FLOODING OVER THE WARNED AREA. RADAR RAINFALL RATE ESTIMATES OF 2 TO 
3 INCHES AN HOUR WERE BEING OBSERVED ACROSS SOUTHERN PORTIONS OF 
MIDDLESEX...NORTHERN AND WESTERN NORFOLK...AND SUFFOLK COUNTY 
MASSACHUSETTS.   

REPORTS HAVE BEEN RECEIVED FROM SOUTHEAST WORCESTER COUNTY 
MASSACHUSETTS OF RAINFALL TOTALS THUS FAR OF 2 TO 2.5 INCHES...WITH 
MUCH OF THAT FALLING WITHIN THE PAST HOUR. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WOBURN...
WINTHROP...WINCHESTER...WESTON...WAYLAND...WATERTOWN...WALTHAM...
WAKEFIELD...SUDBURY...STOW...STONEHAM...SOMERVILLE...REVERE...
MELROSE...MEDFORD...MAYNARD...MARLBOROUGH...MALDEN...LINCOLN...
LEXINGTON...EVERETT...CONCORD...CHELSEA...CARLISLE...CAMBRIDGE...
BURLINGTON...BILLERICA...BELMONT...BEDFORD...ARLINGTON AND ACTON

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4252 7104 4247 7105 4243 7101 4244 7096
      4241 7098 4236 7096 4232 7101 4232 7103
      4231 7103 4202 7138 4202 7183 4223 7173
      4259 7136

$$

SIPPRELL
340 
WGUS71 KBOX 272212
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
612 PM EDT SAT AUG 27 2011

MAC017-021-025-027-272221-
/O.EXP.KBOX.FF.W.0009.000000T0000Z-110827T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MIDDLESEX MA-WORCESTER MA-NORFOLK MA-SUFFOLK MA-
612 PM EDT SAT AUG 27 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 615 PM EDT FOR SUFFOLK...
WESTERN NORFOLK...SOUTHEASTERN WORCESTER AND SOUTHERN MIDDLESEX
COUNTIES...

HEAVY RAINS HAVE MOVED NORTHWARD AND OUT OF THE WARNED AREA. 

LAT...LON 4252 7104 4247 7105 4243 7101 4244 7096
      4241 7098 4236 7096 4232 7101 4232 7103
      4231 7103 4202 7138 4202 7183 4223 7173
      4259 7136

$$

SIPPRELL

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 2:22 PM EDTAreal Flood AdvisoryBOXEssex, Middlesex, Norfolk, Suffolk, Worcester4 hr

Nearby

Flash Flood Warnings in Massachusetts, 2011Every flash flood warning in 2011

Sources

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