Alert archive / Massachusetts / Flash Flood Warnings in 2017

Flash Flood Warning 3, NWS Boston/Norton, MA

July 7, 2017Barnstable County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Jul 7, 2017, 1:37 PM EDT for Barnstable County, Massachusetts. It was in force for 3 hr. 12 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
Jul 7, 2017, 1:37 PM EDT (17:37 UTC)
Expired
Jul 7, 2017, 4:17 PM EDT
In force
3 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

County Barnstable County, MA

The radar

The Boston radar (KBOX), 63 km from the middle of the area, began a volume at 17:38 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
Jul 7, 1:43 PM EDTFLASH FLOODFalmouth, MAMAIN STREET BY DUNKIN DONUTS FLOODED UP TO VECHICLES HOODS
Jul 7, 1:48 PM EDTFLOODFalmouth, MAMAIN STREET RTE 28 CLOSED DUE TO SIGNIFICANT STREET FLOODING
Jul 7, 1:48 PM EDTFLOODFalmouth, MAMAIN STREET RTE 28 CLOSED DUE TO SIGNIICANT STREET FLOODING
Jul 7, 1:57 PM EDTFLASH FLOODFalmouth, MAPALMER ROAD FLOODED AND IMPASSABLE
Jul 7, 2:17 PM EDTFLASH FLOODWest Barnstable, MAHALF OF CEDAR STREET IS FLOODED AMD WASHED OUIT
Jul 7, 2:25 PM EDTFLASH FLOODSandwich, MAHILLSIDE ROAD AND WEST CROSSFIELD FLOODED AND IMPASSABLE
Jul 7, 2:35 PM EDTFLASH FLOODSandwich, MAMUDSLIDE FROM A CONSTRUCTION AREA FLOWING ONTO ACADEMY ROAD
Jul 7, 2:38 PM EDTFLASH FLOODMashpee, MA12 INCHES OF STANDING WATER ON MALLWAY STREET
Jul 7, 2:43 PM EDTFLASH FLOODOsterville, MAOAK RIDGE ROAD IS FLOODED AND IMPASSABLE.
Jul 7, 2:49 PM EDTFLASH FLOODSandwich, MACAR STUCK IN FLOOD WATERS ON SPINNAKER STREET
Jul 7, 3:04 PM EDTFLASH FLOODWest Barnstable, MAPARKING LOT FLOODED AT CAPE COD COMMUNITY COLLEGE
Jul 7, 3:38 PM EDTFLASH FLOODSandwich, MACOTUIT ROAD AND PIMILCO POND ROAD FLOODED AND IMPASSABLE

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, 5.6 hours before the alert went out and 49 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 2017-07-07Temperature 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 12:00Z on 2017-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1054 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

438 
WGUS51 KBOX 071737
FFWBOX
MAC001-071930-
/O.NEW.KBOX.FF.W.0003.170707T1737Z-170707T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Taunton MA
137 PM EDT FRI JUL 7 2017

The National Weather Service in Taunton has issued a

* Flash Flood Warning for...
  Southwestern Barnstable County in southeastern Massachusetts...

* Until 330 PM EDT

* At 136 PM EDT, Doppler radar indicated heavy rain across the warned
  area. Up to one inch of rain has already fallen. Flash flooding is 
  expected to begin shortly with an additional 1 to 2 inches of rain 
  within the next hour.

* Some locations that will experience flooding include...
  Barnstable, Falmouth, Sandwich, Bourne, Mashpee and Gosnold. 

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 4161 7033 4159 7043 4154 7047 4154 7059
      4151 7065 4151 7068 4150 7071 4152 7073
      4158 7065 4163 7067 4170 7067 4178 7048
      4174 7031

$$

Frank
3 follow-up statements
505 
WGUS71 KBOX 071749
FFSBOX

Flash Flood Statement
National Weather Service Taunton MA
149 PM EDT FRI JUL 7 2017

MAC001-071930-
/O.CON.KBOX.FF.W.0003.000000T0000Z-170707T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Barnstable MA-
149 PM EDT FRI JUL 7 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM EDT FOR
SOUTHWESTERN BARNSTABLE COUNTY...

At 145 PM EDT, trained weather spotters reported flash flooding 
occurring in Falmouth.  Many roads were experiencing significant 
flooding, especially along portions of Main Street.  Some roads were 
impassable and in certain instances water was up to the hoods of 
vehicles.  Up to two inches of rain have already fallen. Flash
flooding is already occurring.  Do not drive through flooded 
roadways, this is a serious situation.

Some locations that will experience flooding include...
Barnstable, Falmouth, Sandwich, Bourne, Mashpee and Gosnold. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4161 7033 4159 7043 4154 7047 4154 7059
      4151 7065 4151 7068 4150 7071 4152 7073
      4158 7065 4163 7067 4170 7067 4178 7048
      4174 7031

$$

Frank
679 
WGUS51 KBOX 071901
FFWBOX
MAC001-072130-
/O.EXT.KBOX.FF.W.0003.000000T0000Z-170707T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Taunton MA
301 PM EDT FRI JUL 7 2017

The National Weather Service in Taunton has extended the

* Flash Flood Warning for...
  Southwestern Barnstable County in southeastern Massachusetts...

* Until 530 PM EDT

* At 256 PM EDT, Doppler radar indicated that the worst of the 
  torrential rain has shifted east of the Falmouth, Sandwich and 
  Mashpee areas. However, widespread rain was still occurring with 
  bands of heavier showers persisting.  Flash flooding was still in 
  progress from the 2 to 4.50 inches of rain that has occurred in 
  the last two hours.  Therefore, the flash flood warning has been 
  extended as many roads are flooded and impassable.  Travel is 
  highly discouraged.
  
* Some locations that will experience flooding include...
  Barnstable, Falmouth, Sandwich, Bourne, Mashpee and Gosnold. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4161 7033 4159 7043 4154 7047 4154 7059
      4151 7065 4151 7068 4150 7071 4152 7073
      4158 7065 4163 7067 4170 7067 4178 7048
      4174 7031

$$

Frank
989 
WGUS71 KBOX 072017
FFSBOX

Flash Flood Statement
National Weather Service Taunton MA
417 PM EDT FRI JUL 7 2017

MAC001-072025-
/O.CAN.KBOX.FF.W.0003.000000T0000Z-170707T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Barnstable MA-
417 PM EDT FRI JUL 7 2017

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN BARNSTABLE COUNTY IS
CANCELLED...

The heavy rain has ended and additional flooding is not expected. 
However, the 2 to 4.50 inches of the rain that fell earlier today 
resulted in signficant flash flooding.  Some roadways are still 
closed and motorists are urged not to drive through flooded areas.

LAT...LON 4161 7033 4159 7043 4154 7047 4154 7059
      4151 7065 4151 7068 4150 7071 4152 7073
      4158 7065 4163 7067 4170 7067 4178 7048
      4174 7031

$$

Frank

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 12:05 PM EDTSpecial Marine WarningBOX25 min
Jul 7, 12:29 PM EDTSpecial Marine WarningBOX31 min
Jul 7, 12:37 PM EDTAreal Flood AdvisoryBOXBarnstable, Bristol, Dukes, Plymouth113 min
Jul 7, 1:17 PM EDTAreal Flood WarningBOXBarnstable118 min
Jul 7, 2:16 PM EDTAreal Flood AdvisoryBOXBarnstable119 min
Jul 7, 2:25 PM EDTFlash Flood WarningBOXBarnstable2 hr
Jul 7, 2:43 PM EDTSpecial Weather StatementBOXBarnstable47 min
Jul 7, 3:14 PM EDTAreal Flood WarningBOXBarnstable2 hr
Jul 7, 3:42 PM EDTSpecial Marine WarningBOX63 min
Jul 7, 3:46 PM EDTSpecial Marine WarningBOX59 min
Jul 7, 4:25 PM EDTAreal Flood AdvisoryBOXBarnstable110 min

Nearby

Flash Flood Warnings in Massachusetts, 2017Every flash flood warning in 2017

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.