Alert archive / Massachusetts / Flash Flood Warnings in 2020

Flash Flood Warning 2, NWS Boston/Norton, MA

June 28, 2020Norfolk County, Plymouth County, Suffolk County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Jun 28, 2020, 3:03 PM EDT for Norfolk County, Plymouth County, Suffolk County, Massachusetts. It was in force for 117 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
Jun 28, 2020, 3:03 PM EDT (19:03 UTC)
Expired
Jun 28, 2020, 5:00 PM EDT
In force
117 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Norfolk County, MA, Plymouth County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 39 km from the middle of the area, began a volume at 19:05 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, 7.1 hours before the alert went out and 102 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 2020-06-28Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Chatham, MA at 12:00Z on 2020-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.193958Sfc1 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
926 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

924 
WGUS51 KBOX 281903
FFWBOX
MAC021-023-025-282100-
/O.NEW.KBOX.FF.W.0002.200628T1903Z-200628T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
303 PM EDT Sun Jun 28 2020

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  South central Suffolk County in eastern Massachusetts...
  Northeastern Norfolk County in eastern Massachusetts...
  Northwestern Plymouth County in southeastern Massachusetts...

* Until 500 PM EDT.

* At 303 PM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  Boston, Brockton, Quincy, Weymouth, Braintree, Randolph, Milton,
  Hingham, Scituate, Rockland, Abington, Hanover, Holbrook, Norwell,
  Hull, Cohasset and Avon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4226 7086 4224 7077 4225 7077 4220 7071
      4211 7102 4228 7111 4230 7101 4228 7102
      4226 7097 4230 7093 4225 7096 4227 7093
      4225 7088 4228 7090 4228 7088 4230 7092
      4231 7089

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 28, 12:51 PM EDTSpecial Weather StatementBOXMiddlesex39 min
Jun 28, 1:10 PM EDTSpecial Weather StatementBOXHampshire50 min
Jun 28, 1:19 PM EDTSpecial Weather StatementBOXSuffolk41 min
Jun 28, 1:26 PM EDTSevere Thunderstorm WarningBOXEssex, Middlesex, Norfolk, Plymouth, Suffolk64 min
Jun 28, 1:31 PM EDTSpecial Marine WarningBOX89 min
Jun 28, 1:39 PM EDTSpecial Weather StatementBOXFranklin51 min
Jun 28, 1:42 PM EDTSpecial Weather StatementBOXFranklin63 min
Jun 28, 1:49 PM EDTAreal Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk116 min
Jun 28, 1:58 PM EDTFlash Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk3 hr
Jun 28, 2:23 PM EDTAreal Flood WarningBOXFranklin, Hampshire2 hr
Jun 28, 2:32 PM EDTSpecial Weather StatementBOXSuffolk58 min
Jun 28, 2:45 PM EDTSpecial Weather StatementBOXHampden45 min
Jun 28, 2:50 PM EDTSpecial Weather StatementBOXEssex55 min
Jun 28, 3:02 PM EDTSevere Thunderstorm WarningBOXPlymouth35 min
Jun 28, 3:07 PM EDTSpecial Marine WarningBOX83 min
Jun 28, 3:13 PM EDTSpecial Weather StatementBOXNorfolk47 min
Jun 28, 3:16 PM EDTSevere Thunderstorm WarningBOXFranklin, Hampden, Hampshire, Worcester59 min
Jun 28, 3:47 PM EDTSpecial Weather StatementBOXMiddlesex43 min
Jun 28, 4:02 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Plymouth, Suffolk58 min
Jun 28, 4:11 PM EDTAreal Flood WarningBOXMiddlesex, Norfolk, Suffolk55 min
Jun 28, 4:39 PM EDTSevere Thunderstorm WarningBOXMiddlesex, Norfolk, Worcester51 min
Jun 28, 4:46 PM EDTSpecial Weather StatementBOXHampden44 min
Jun 28, 4:58 PM EDTSevere Thunderstorm WarningBOXBristol, Norfolk, Plymouth, Worcester62 min
Jun 28, 5:02 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester58 min
Jun 28, 5:04 PM EDTFlash Flood Warning EmergencyBOXBristol, Middlesex, Norfolk, Plymouth, Worcester116 min
Jun 28, 5:05 PM EDTSevere Thunderstorm WarningBOXNorfolk, Worcester55 min
Jun 28, 5:17 PM EDTSpecial Weather StatementBOXFranklin, Hampshire58 min
Jun 28, 5:28 PM EDTSpecial Weather StatementBOXNantucket62 min
Jun 28, 5:34 PM EDTFlash Flood WarningBOXWorcester108 min
Jun 28, 6:00 PM EDTRiver Flood WarningBOXNorfolk, Suffolk2 hr
Jun 28, 6:04 PM EDTSevere Thunderstorm WarningBOXBristol, Norfolk, Worcester56 min
Jun 28, 6:20 PM EDTSpecial Weather StatementBOXHampshire40 min
Jun 28, 6:23 PM EDTFlash Flood WarningBOXWorcester83 min
Jun 28, 6:35 PM EDTSpecial Weather StatementBOXNorfolk55 min
Jun 28, 6:56 PM EDTAreal Flood WarningBOXBristol, Middlesex, Norfolk, Worcester2 hr
Jun 28, 6:59 PM EDTSpecial Weather StatementBOXWorcester61 min
Jun 28, 7:01 PM EDTSpecial Weather StatementBOXBristol44 min
Jun 28, 7:20 PM EDTAreal Flood WarningBOXWorcester115 min

Nearby

Flash Flood Warnings in Massachusetts, 2020Every flash flood warning in 2020

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.