Alert archive / Massachusetts / Flash Flood Warnings in 2014

Flash Flood Warning 6, NWS Boston/Norton, MA

May 27, 20144 counties in Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at May 27, 2014, 10:36 PM EDT for 4 counties in Massachusetts. It was in force for 114 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 27, 2014, 10:36 PM EDT (02:36 UTC)
Expired
May 28, 2014, 12:30 AM EDT
In force
114 min
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

The radar

The Boston radar (KBOX), 45 km from the middle of the area, began a volume at 02:35 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 00:00Z, 2.6 hours before the alert went out and 113 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 00:00Z on 2014-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2014-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 249 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
529 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
249 m²/s²
0-3 km storm-relative helicity
375 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.

775 
WGUS51 KBOX 280236
FFWBOX
MAC009-017-021-025-280430-
/O.NEW.KBOX.FF.W.0006.140528T0236Z-140528T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
1036 PM EDT TUE MAY 27 2014

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SUFFOLK COUNTY IN EASTERN MASSACHUSETTS...
  SOUTHEASTERN MIDDLESEX COUNTY IN NORTHEAST MASSACHUSETTS...
  NORTHEASTERN NORFOLK COUNTY IN EASTERN MASSACHUSETTS...
  SOUTH CENTRAL ESSEX COUNTY IN NORTHEAST MASSACHUSETTS...

* UNTIL 1230 AM EDT

* AT 1034 PM EDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING 
  HEAVY RAIN ACROSS AREAS JUST WEST OF BOSTON INCLUDING SUDBURY AND 
  WAYLAND. UP TO ONE TO TWO INCHES OF RAIN HAS ALREADY FALLEN WITH 
  THIS AREA OF STORMS. EXPECT THAT THIS HEAVY RAINFALL WILL CONTINUE 
  AS THE STORM MOVES INTO THE BOSTON METRO AREA...RESULTING IN URBAN 
  FLASH FLOODING.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BOSTON...CAMBRIDGE...QUINCY...LYNN...NEWTON...SOMERVILLE...
  FRAMINGHAM...WALTHAM...MALDEN...BROOKLINE...MEDFORD...WEYMOUTH...
  REVERE...ARLINGTON...EVERETT...SALEM...WOBURN...BRAINTREE...
  CHELSEA...NATICK...RANDOLPH...WATERTOWN...LEXINGTON...NEEDHAM...
  NORWOOD...WELLESLEY...MILTON...MELROSE...STOUGHTON AND SAUGUS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RAPID AND POTENTIALLY LIFE THREATENING FLOODING OF STREETS AND
UNDERPASSES IS IMMINENT. DO NOT DRIVE THROUGH FLOODED ROADS AND FIND
ALTERNATE ROUTES.

A FLASH FLOOD WARNING IS ISSUED FOR RAPID AND POTENTIALLY LIFE
THREATENING FLOODING. IN URBAN AREAS AVOID FLOODED ROADS AND OBEY
ROAD CLOSURES. THOSE NEAR SMALL STREAMS MUST HEAD FOR HIGHER GROUND
IMMEDIATELY.

&&

LAT...LON 4246 7094 4242 7091 4242 7099 4237 7097
      4234 7087 4236 7096 4233 7094 4229 7102
      4227 7099 4227 7095 4230 7096 4233 7089
      4226 7092 4210 7107 4230 7144 4249 7127
      4249 7086

$$

RLG
1 follow-up statement
060 
WGUS71 KBOX 280337
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
1137 PM EDT TUE MAY 27 2014

MAC009-280346-
/O.CAN.KBOX.FF.W.0006.000000T0000Z-140528T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ESSEX MA-
1137 PM EDT TUE MAY 27 2014

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL ESSEX COUNTY IS
CANCELLED...

THE HEAVY RAIN HAS ENDED...AND FLOODING IS NO LONGER EXPECTED TO POSE
A THREAT. PLEASE CONTINUE TO HEED ALL ROAD CLOSURES.

LAT...LON 4226 7092 4210 7107 4230 7144 4242 7126
      4232 7096 4229 7102 4227 7099 4227 7095
      4230 7096 4230 7090

$$

MAC017-021-025-280430-
/O.CON.KBOX.FF.W.0006.000000T0000Z-140528T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUFFOLK MA-MIDDLESEX MA-NORFOLK MA-
1137 PM EDT TUE MAY 27 2014

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM EDT FOR
SUFFOLK...SOUTHEASTERN MIDDLESEX AND NORTHEASTERN NORFOLK COUNTIES...

AT 1136 PM EDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA. UP TO TWO INCHES OF RAIN HAVE 
ALREADY FALLEN. HEAVIEST RAINFALL IS OCCURRING ACROSS THE 
NATICK...WESTWOOD...NORWOOD...AND CANTON AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RAPID AND POTENTIALLY LIFE THREATENING FLOODING OF STREETS AND
UNDERPASSES IS IMMINENT. DO NOT DRIVE THROUGH FLOODED ROADS AND FIND
ALTERNATE ROUTES.

A FLASH FLOOD WARNING IS ISSUED FOR RAPID AND POTENTIALLY LIFE
THREATENING FLOODING. IN URBAN AREAS AVOID FLOODED ROADS AND OBEY
ROAD CLOSURES. THOSE NEAR SMALL STREAMS MUST HEAD FOR HIGHER GROUND
IMMEDIATELY.

&&

LAT...LON 4226 7092 4210 7107 4230 7144 4242 7126
      4232 7096 4229 7102 4227 7099 4227 7095
      4230 7096 4230 7090

$$

RLG

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 10:39 PM EDTAreal Flood AdvisoryBOXMiddlesex, Worcester2 hr

Nearby

Flash Flood Warnings in Massachusetts, 2014Every flash flood warning in 2014

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.