Alert archive / Massachusetts / Flash Flood Warnings in 2012

Flash Flood Warning 18, NWS Boston/Norton, MA

August 10, 2012Essex County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Aug 10, 2012, 5:55 PM EDT for Essex County, Massachusetts. It was in force for 3 hr. 2 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
Aug 10, 2012, 5:55 PM EDT (21:55 UTC)
Expired
Aug 10, 2012, 8:46 PM EDT
In force
3 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

County Essex County, MA

The radar

The Boston radar (KBOX), 78 km from the middle of the area, began a volume at 21:57 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
Aug 10, 7:04 PM EDTFLOODLynn, MACOMMERCIAL STREET UNDERPASS FLOODED AND IMPASSABLE.
Aug 10, 7:25 PM EDTFLOODLynn, MANAHANT CIRCLE FLOODED WITH 1 FOOT OF WATER.

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, 9.9 hours before the alert went out and 133 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 2012-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 424 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Chatham, MA at 12:00Z on 2012-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
424 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
475 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
77 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.

756 
WGUS51 KBOX 102155
FFWBOX
MAC009-110200-
/O.NEW.KBOX.FF.W.0018.120810T2155Z-120811T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
555 PM EDT FRI AUG 10 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ESSEX COUNTY IN EASTERN MASSACHUSETTS...

* UNTIL 1000 PM EDT

* AT 548 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  ONE HOUR RAINFALL RATES OF 1 TO 2 INCHES FROM A LINE OF            
  THUNDERSTORMS MOVING NORTH ACROSS OVER THE WARNED AREA. ALREADY    
  REPORTS HAVE BEEN RECEIVED OF ROADS BECOMING INUNDATED WITH        
  SEVERAL INCHES OF WATER IN A VERY SHORT PERIOD OF TIME

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 4287 7081 4270 7077 4266 7069 4270 7063
      4264 7057 4250 7081 4254 7085 4253 7084
      4254 7085 4248 7082 4244 7093 4242 7091
      4246 7104 4258 7103 4265 7125 4274 7125
      4274 7119 4282 7116 4289 7090

$$

SIPPRELL
1 follow-up statement
780 
WGUS71 KBOX 110046
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
846 PM EDT FRI AUG 10 2012

MAC009-110055-
/O.CAN.KBOX.FF.W.0018.000000T0000Z-120811T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ESSEX MA-
846 PM EDT FRI AUG 10 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR ESSEX COUNTY...

A TORNADO WATCH REMAINS IN EFFECT UNTIL 900 PM EDT.

LAT...LON 4287 7081 4270 7077 4266 7069 4270 7063
      4264 7057 4250 7081 4254 7085 4253 7084
      4254 7085 4248 7082 4244 7093 4242 7091
      4246 7104 4258 7103 4265 7125 4274 7125
      4274 7119 4282 7116 4289 7090

$$

WTB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 4:31 AM EDTSmall Craft AdvisoryBOX3 days
Aug 10, 10:57 AM EDTSpecial Weather StatementBOXHampshire63 min
Aug 10, 11:07 AM EDTSpecial Weather StatementBOXHampshire53 min
Aug 10, 11:35 AM EDTSpecial Weather StatementBOXHampden55 min
Aug 10, 11:40 AM EDTSpecial Weather StatementBOXFranklin65 min
Aug 10, 11:45 AM EDTSpecial Weather StatementBOXFranklin60 min
Aug 10, 11:52 AM EDTAreal Flood AdvisoryBOXFranklin, Hampden, Hampshire6 hr
Aug 10, 12:29 PM EDTSpecial Weather StatementBOXHampshire61 min
Aug 10, 1:15 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire30 min
Aug 10, 2:29 PM EDTSpecial Weather StatementBOXWorcester61 min
Aug 10, 3:13 PM EDTSpecial Marine WarningBOX92 min
Aug 10, 3:36 PM EDTAreal Flood AdvisoryBOXBristol, Hampden, Hampshire, Middlesex, Norfolk, Plymouth and 2 more2 hr
Aug 10, 4:45 PM EDTSpecial Marine WarningBOX30 min
Aug 10, 4:45 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester45 min
Aug 10, 5:00 PM EDTTornado WarningBOXHampden, Hampshire45 min
Aug 10, 5:03 PM EDTSpecial Marine WarningBOX87 min
Aug 10, 5:09 PM EDTFlash Flood WarningBOXBristol, Plymouth3 hr
Aug 10, 5:16 PM EDTSevere Thunderstorm WarningBOXBristol, Plymouth59 min
Aug 10, 5:20 PM EDTSpecial Marine WarningBOX25 min
Aug 10, 5:27 PM EDTFlash Flood WarningBOXFranklin, Hampden, Hampshire, Middlesex, Norfolk, Suffolk and 1 more3 hr
Aug 10, 5:31 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester44 min
Aug 10, 5:33 PM EDTSevere Thunderstorm WarningBOXBristol27 min
Aug 10, 5:45 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester45 min
Aug 10, 5:47 PM EDTSpecial Weather StatementBOXMiddlesex43 min
Aug 10, 6:08 PM EDTSpecial Marine WarningBOX52 min
Aug 10, 6:23 PM EDTSevere Thunderstorm WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk37 min
Aug 10, 6:46 PM EDTSpecial Weather StatementBOXBristol44 min
Aug 10, 7:45 PM EDTSpecial Marine WarningBOX30 min

Nearby

Flash Flood Warnings in Massachusetts, 2012Every flash flood warning in 2012

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.