Alert archive / Massachusetts / Flash Flood Warnings in 2017

Flash Flood Warning 19, NWS Boston/Norton, MA

August 2, 2017Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Aug 2, 2017, 4:08 PM EDT for Middlesex County, Worcester County, Massachusetts. It was in force for 3 hr. 3 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 2, 2017, 4:08 PM EDT (20:08 UTC)
Expired
Aug 2, 2017, 7:15 PM EDT
In force
3 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Middlesex County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 89 km from the middle of the area, began a volume at 20:11 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 2, 4:33 PM EDTFLOODWestminster, MASIGNIFICANT STREET FLOODING AND DEBRIS IN ROAD REDUCING TRAVEL TO ONE LANE
Aug 2, 4:33 PM EDTFLOODWestminster, MASIGNIFICANT STREET FLOODING AND DEBRIS IN ROAD REDUCING TRAVEL TO ONE LANE ON SOUTH ASH STREET
Aug 2, 5:08 PM EDTFLOODFitchburg, MA2 FEET OF WATER ON ROUTE 31

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 8.1 hours before the alert went out and 172 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, Albany, NY at 12:00Z on 2017-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 312 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, Albany, NY at 12:00Z on 2017-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 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
312 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1098 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

113 
WGUS51 KBOX 022008
FFWBOX
MAC017-027-022315-
/O.NEW.KBOX.FF.W.0019.170802T2008Z-170802T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Taunton MA
408 PM EDT WED AUG 2 2017

The National Weather Service in Taunton has issued a

* Flash Flood Warning for...
  Northeastern Worcester County in central Massachusetts...
  Northwestern Middlesex County in northeastern Massachusetts...

* Until 715 PM EDT

* At 407 PM EDT, Doppler radar indicated thunderstorms producing 
  torrential rain in north central Massachusetts. Flash flooding is 
  expected to begin shortly, including rapid inundation of roads and 
  underpasses.

* Some locations that will experience flooding include...
  Leominster, Fitchburg, Gardner, Pepperell, Groton, Lunenburg,
  Townsend, Ayer, Westminster, Shirley, Harvard, Ashburnham and
  Ashby.

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 4269 7158 4269 7194 4253 7195 4253 7159

$$

JWD
2 follow-up statements
345 
WGUS71 KBOX 022111
FFSBOX

Flash Flood Statement
National Weather Service Taunton MA
511 PM EDT WED AUG 2 2017

MAC017-027-022315-
/O.CON.KBOX.FF.W.0019.000000T0000Z-170802T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Worcester MA-Middlesex MA-
511 PM EDT WED AUG 2 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT FOR
NORTHEASTERN WORCESTER AND NORTHWESTERN MIDDLESEX COUNTIES...

At 509 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain across parts of north central Massachusetts. Over two inches of 
rain have already fallen in parts of the area. A spotter reported 
two feet of water on Route 31 in North Fitchburg.

Although the rain has begun to lessen in intensity, additional 
flooding of roads and underpasses can be expected. Do not drive 
through flooded roads!

Some locations that will experience flooding include...
Leominster, Fitchburg, Gardner, Pepperell, Groton, Lunenburg,
Townsend, Ayer, Westminster, Shirley, Harvard, Ashburnham and Ashby.

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 4269 7158 4269 7194 4253 7195 4253 7159

$$

JWD
494 
WGUS71 KBOX 022159
FFSBOX

Flash Flood Statement
National Weather Service Taunton MA
559 PM EDT WED AUG 2 2017

MAC017-027-022209-
/O.CAN.KBOX.FF.W.0019.000000T0000Z-170802T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Worcester MA-Middlesex MA-
559 PM EDT WED AUG 2 2017

...THE FLASH FLOOD WARNING FOR NORTHEASTERN WORCESTER AND
NORTHWESTERN MIDDLESEX COUNTIES IS CANCELLED...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed any remaining road closures and 
avoid flooded roadways.

&&

LAT...LON 4269 7158 4269 7194 4253 7195 4253 7159

$$

JWD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 11:55 AM EDTFlash Flood WatchBOXEssex, Franklin, Hampden, Hampshire, Middlesex, Norfolk and 2 more8 hr
Aug 2, 1:00 PM EDTSpecial Weather StatementBOXWorcester30 min
Aug 2, 2:00 PM EDTSpecial Weather StatementBOXNorfolk45 min
Aug 2, 2:05 PM EDTFlash Flood WarningBOXNorfolk3 hr
Aug 2, 2:12 PM EDTSpecial Weather StatementBOXHampshire33 min
Aug 2, 2:13 PM EDTFlash Flood WarningBOXFranklin, Hampshire3 hr
Aug 2, 2:16 PM EDTSpecial Weather StatementBOXSuffolk29 min
Aug 2, 2:21 PM EDTSpecial Marine WarningBOX39 min
Aug 2, 2:22 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire38 min
Aug 2, 2:24 PM EDTFlash Flood WarningBOXHampden, Hampshire3 hr
Aug 2, 2:26 PM EDTSevere Thunderstorm WarningBOXSuffolk34 min
Aug 2, 2:29 PM EDTFlash Flood WarningBOXSuffolk3 hr
Aug 2, 2:34 PM EDTSpecial Weather StatementBOXEssex, Middlesex41 min
Aug 2, 2:37 PM EDTSpecial Weather StatementBOXPlymouth38 min
Aug 2, 2:42 PM EDTFlash Flood WarningBOXMiddlesex3 hr
Aug 2, 2:46 PM EDTSpecial Marine WarningBOX59 min
Aug 2, 2:50 PM EDTSpecial Marine WarningBOX40 min
Aug 2, 2:52 PM EDTSevere Thunderstorm WarningBOXMiddlesex38 min
Aug 2, 2:57 PM EDTSpecial Weather StatementBOXEssex48 min
Aug 2, 3:01 PM EDTSpecial Weather StatementBOXWorcester44 min
Aug 2, 3:02 PM EDTSpecial Weather StatementBOXHampden43 min
Aug 2, 3:10 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire50 min
Aug 2, 3:13 PM EDTSpecial Weather StatementBOXEssex47 min
Aug 2, 3:29 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Worcester32 min
Aug 2, 3:33 PM EDTSevere Thunderstorm WarningBOXMiddlesex29 min
Aug 2, 3:44 PM EDTSpecial Weather StatementBOXMiddlesex46 min
Aug 2, 3:50 PM EDTSpecial Marine WarningBOX55 min
Aug 2, 3:54 PM EDTSpecial Weather StatementBOXSuffolk51 min
Aug 2, 4:00 PM EDTSevere Thunderstorm WarningBOXWorcester45 min
Aug 2, 4:11 PM EDTSpecial Weather StatementBOXSuffolk49 min
Aug 2, 4:42 PM EDTSpecial Marine WarningBOX63 min
Aug 2, 4:43 PM EDTSpecial Weather StatementBOXSuffolk32 min
Aug 2, 4:48 PM EDTSevere Thunderstorm WarningBOXWorcester31 min
Aug 2, 4:56 PM EDTAreal Flood WarningBOXPlymouth2 hr
Aug 2, 5:04 PM EDTSpecial Weather StatementBOXSuffolk41 min
Aug 2, 5:09 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester38 min
Aug 2, 5:17 PM EDTFlash Flood WarningBOXMiddlesex, Norfolk, Worcester118 min
Aug 2, 5:26 PM EDTFlash Flood WarningBOXSuffolk2 hr
Aug 2, 5:43 PM EDTSpecial Marine WarningBOX62 min
Aug 2, 6:15 PM EDTSpecial Weather StatementBOXNorfolk45 min
Aug 2, 6:36 PM EDTSpecial Weather StatementBOXNorfolk39 min
Aug 2, 6:44 PM EDTFlash Flood WarningBOXNorfolk, Suffolk2 hr

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.