Alert archive / Massachusetts / Flash Flood Warnings in 2020

Flash Flood Warning 8, NWS Boston/Norton, MA

July 13, 2020Essex County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Jul 13, 2020, 3:31 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
Jul 13, 2020, 3:31 PM EDT (19:31 UTC)
Expired
Jul 13, 2020, 6:30 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), 92 km from the middle of the area, began a volume at 19:34 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 13, 3:42 PM EDTFLOODNewburyport, MASTREET FLOODING ON NORTHERN BLVD ON PLUM ISLAND.
Jul 13, 3:44 PM EDTFLOODNewburyport, MAFLOODING ALONG PLUM ISLAND BLVD.

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

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 7.5 hours before the alert went out and 135 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, Gray, ME at 12:00Z on 2020-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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, Gray, ME at 12:00Z on 2020-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
17 J/kg
Mixed-layer CIN
-117 J/kg
Mixed-layer LCL
1349 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

148 
WGUS51 KBOX 131931
FFWBOX
MAC009-132230-
/O.NEW.KBOX.FF.W.0008.200713T1931Z-200713T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
331 PM EDT Mon Jul 13 2020

The National Weather Service in Boston/Norton has issued a

* Flash Flood Warning for...
  Northwestern Essex County in northeastern Massachusetts...

* Until 630 PM EDT.

* At 329 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across northeast Massachusetts. Flash flooding is 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

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

* Some locations that will experience flooding include...
  Lawrence, Haverhill, Methuen, Andover, North Andover, Newburyport,
  Amesbury, Ipswich, Salisbury, Georgetown, Boxford, Newbury,
  Groveland, Topsfield, Rowley and West Newbury.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Rapid flooding of urban areas, highways, streets and underpasses as 
well as small streams is expected. Do not drive through flooded 
roads!

&&

LAT...LON 4283 7081 4281 7087 4280 7083 4282 7082
      4271 7078 4271 7079 4277 7082 4272 7082
      4270 7080 4271 7082 4270 7083 4262 7115
      4269 7123 4286 7086 4287 7082

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

JWD
3 follow-up statements
025 
WGUS71 KBOX 132003
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
403 PM EDT Mon Jul 13 2020

MAC009-132230-
/O.CON.KBOX.FF.W.0008.000000T0000Z-200713T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Essex MA-
403 PM EDT Mon Jul 13 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT FOR
NORTHWESTERN ESSEX COUNTY...

At 358 PM EDT, Doppler radar indicated thunderstorms producing heavy 
rain from Andover to Georgetown and Newburyport, which were moving 
northeast and over the same areas.

A spotter in North Andover reported 1.22 inches of rain in less than 
one hour, and another spotter in Andover reported 1 inch of rain in 
about 30 minutes.

Flooding has already been reported on Plum Island where roads were 
becoming impassable.

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...
Lawrence, Haverhill, Methuen, Andover, North Andover, Newburyport,
Amesbury, Ipswich, Salisbury, Georgetown, Boxford, Newbury,
Groveland, Topsfield, Rowley and West Newbury.

PRECAUTIONARY/PREPAREDNESS ACTIONS...
Do not drive through flooded roads! Your vehicle can easily become 
stranded.

&&

LAT...LON 4283 7081 4281 7087 4280 7083 4282 7082
      4271 7078 4271 7079 4277 7082 4272 7082
      4270 7080 4271 7082 4270 7083 4262 7115
      4269 7123 4286 7086 4287 7082

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

JWD
686 
WGUS71 KBOX 132058
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
458 PM EDT Mon Jul 13 2020

MAC009-132230-
/O.CON.KBOX.FF.W.0008.000000T0000Z-200713T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Essex MA-
458 PM EDT Mon Jul 13 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM EDT FOR
NORTHWESTERN ESSEX COUNTY...

At 455 PM EDT, Doppler radar indicated thunderstorms have move to 
the coast, but new storms were forming near Westford and Chelmsford, 
and will move through the area before 6 PM, and may cause additional 
flooding.

Significant flooding has been reported on Plum Island and in Ipswich.

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...
Lawrence, Haverhill, Methuen, Andover, North Andover, Newburyport,
Amesbury, Ipswich, Salisbury, Georgetown, Boxford, Newbury,
Groveland, Topsfield, Rowley and West Newbury.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roads. Your vehicle can easily become 
stranded.

&&

LAT...LON 4283 7081 4281 7087 4280 7083 4282 7082
      4271 7078 4271 7079 4277 7082 4272 7082
      4270 7080 4271 7082 4270 7083 4262 7115
      4269 7123 4286 7086 4287 7082

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

JWD
344 
WGUS71 KBOX 132222
FFSBOX

Flash Flood Statement
National Weather Service Boston/Norton MA
622 PM EDT Mon Jul 13 2020

MAC009-132230-
/O.EXP.KBOX.FF.W.0008.000000T0000Z-200713T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Essex MA-
622 PM EDT Mon Jul 13 2020

...THE FLASH FLOOD WARNING FOR NORTHWESTERN ESSEX COUNTY WILL EXPIRE
AT 630 PM EDT...

Thunderstorms with heavy rain have ended in northeast Massachusetts. 

Any flooding will ease this evening, but continue to avoid any 
flooded roadways.

&&

LAT...LON 4283 7081 4281 7087 4280 7083 4282 7082
      4271 7078 4271 7079 4277 7082 4272 7082
      4270 7080 4271 7082 4270 7083 4262 7115
      4269 7123 4286 7086 4287 7082

$$

JWD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 1:17 PM EDTSpecial Weather StatementBOXHampden43 min
Jul 13, 2:23 PM EDTSpecial Weather StatementBOXEssex37 min
Jul 13, 2:44 PM EDTSevere Thunderstorm WarningBOXEssex61 min
Jul 13, 2:46 PM EDTSpecial Marine WarningBOX29 min
Jul 13, 3:03 PM EDTSpecial Weather StatementBOXMiddlesex42 min
Jul 13, 3:46 PM EDTSpecial Weather StatementBOXEssex59 min
Jul 13, 4:52 PM EDTSpecial Weather StatementBOXMiddlesex38 min
Jul 13, 5:39 PM EDTSpecial Weather StatementBOXEssex, Middlesex81 min
Jul 13, 5:44 PM EDTSpecial Weather StatementBOXHampshire46 min
Jul 13, 5:46 PM EDTSpecial Weather StatementBOXHampden44 min
Jul 13, 6:01 PM EDTSpecial Weather StatementBOXBristol44 min
Jul 13, 6:19 PM EDTSevere Thunderstorm WarningBOXHampden, Hampshire, Worcester56 min
Jul 13, 7:06 PM EDTSevere Thunderstorm WarningBOXHampden, Worcester54 min
Jul 13, 7:41 PM EDTSpecial Weather StatementBOXMiddlesex34 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.