Alert archive / Massachusetts / Flash Flood Warnings in 2013

Flash Flood Warning 37, NWS Boston/Norton, MA

July 23, 20134 counties in Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Jul 23, 2013, 4:40 PM EDT for 4 counties in Massachusetts. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 23, 2013, 4:40 PM EDT (20:40 UTC)
Expired: Jul 23, 2013, 6:45 PM EDT
In force: 2 hr
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

Counties Essex County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA

The radar

The Boston radar (KBOX), 42 km from the middle of the area, began a volume at 20:43 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, 8.7 hours before the alert went out and 114 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 757 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 498 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

395 
WGUS51 KBOX 232040
FFWBOX
MAC009-017-021-025-232245-
/O.NEW.KBOX.FF.W.0037.130723T2040Z-130723T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
440 PM EDT TUE JUL 23 2013

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN MIDDLESEX COUNTY IN NORTHEAST MASSACHUSETTS...
  SUFFOLK COUNTY IN EASTERN MASSACHUSETTS...
  NORTHERN NORFOLK COUNTY IN EASTERN MASSACHUSETTS...
  EXTREME SOUTH CENTRAL ESSEX COUNTY IN NORTHEAST MASSACHUSETTS...

* UNTIL 645 PM EDT

* AT 435 PM EDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA.  FLASH FLOODING IS EXPECTED TO
  BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  BOSTON...CAMBRIDGE...NEWTON...SOMERVILLE...BROOKLINE...WESTON... 
  REVERE...EVERETT...CHELSEA...WATERTOWN...NEEDHAM... 
  DEDHAM...WINTHROP...WEST ROXBURY...HYDE PARK...SOUTH 
  BOSTON...JAMAICA PLAIN...ALLSTON...EAST BOSTON...FOREST 
  HILLS...MATTAPAN...BRIGHTON...DORCHESTER...CHARLESTOWN AND 
  ROSLINDALE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.  MOVE TO HIGHER GROUND.

&&

LAT...LON 4236 7098 4233 7094 4233 7096 4231 7096
      4231 7097 4230 7100 4229 7102 4228 7102
      4219 7131 4235 7139 4244 7097 4241 7099
      4233 7093

$$

MD

2 follow-up statements

480 
WGUS71 KBOX 232149
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
549 PM EDT TUE JUL 23 2013

MAC009-017-021-025-232245-
/O.CON.KBOX.FF.W.0037.000000T0000Z-130723T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MIDDLESEX MA-SUFFOLK MA-NORFOLK MA-ESSEX MA-
549 PM EDT TUE JUL 23 2013

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM EDT FOR
SOUTHEASTERN MIDDLESEX...SUFFOLK...NORTHERN NORFOLK AND EXTREME SOUTH
CENTRAL ESSEX COUNTIES...

AT 547 PM EDT...THE BULK OF THE HEAVY RAIN HAS ENDED ACROSS THE 
BOSTON METRO...HOWEVER SPOTTERS...LAW ENFORCEMENT...AND SEVERAL 
PUBLIC REPORTS CONTINUE TO INDICATE THAT DEEP PONDING OF WATER ON 
ROADWAYS CONTINUES.  PLEASE CONTINUE TO HEED ROAD CLOSURES.

SOME LOCATIONS THAT MAY CONTINUE TO EXPERIENCE FLOODING INCLUDE... 
BOSTON...CAMBRIDGE...NEWTON...SOMERVILLE...BROOKLINE...WESTON... 
REVERE...EVERETT...CHELSEA...WATERTOWN...NEEDHAM...WELLESLEY... 
DEDHAM...WINTHROP...NATICK...DOVER...WEST ROXBURY...HYDE 
PARK...SOUTH BOSTON...JAMAICA PLAIN...ALLSTON...EAST BOSTON...FOREST 
HILLS... MATTAPAN...BRIGHTON...DORCHESTER...CHARLESTOWN AND 
ROSLINDALE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RUNOFF FROM HEAVY RAINFALL HAS CAUSED FLOODING OF SMALL CREEKS AND 
STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL 
AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.  MOVE TO HIGHER GROUND.

&&

LAT...LON 4236 7098 4233 7094 4233 7096 4231 7096
      4231 7097 4230 7100 4229 7102 4228 7102
      4219 7131 4235 7139 4244 7097 4241 7099
      4233 7093

$$

MD

387 
WGUS71 KBOX 232237
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
637 PM EDT TUE JUL 23 2013

MAC009-017-021-025-232245-
/O.EXP.KBOX.FF.W.0037.000000T0000Z-130723T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MIDDLESEX MA-SUFFOLK MA-NORFOLK MA-ESSEX MA-
637 PM EDT TUE JUL 23 2013

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN MIDDLESEX...SUFFOLK...
NORTHERN NORFOLK AND EXTREME SOUTH CENTRAL ESSEX COUNTIES WILL EXPIRE
AT 645 PM EDT...

THUNDERSTORMS WITH HEAVY RAIN HAVE ENDED...AND FLASH FLOODING IS NO 
LONGER EXPECTED. HOWEVER...IT MAY TAKE A FEW HOURS FOR EARLIER 
FLOODING TO SUBSIDE. DRIVERS SHOULD REMAIN ALERT FOR FLOODED ROADS.

&&

LAT...LON 4236 7098 4233 7094 4233 7096 4231 7096
      4231 7097 4230 7100 4229 7102 4228 7102
      4219 7131 4235 7139 4244 7097 4241 7099
      4233 7093

$$

JWD

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 10:31 PM EDT	Areal Flood Advisory	BOX	Franklin, Hampshire	3 hr
Jul 23, 1:14 AM EDT	Flash Flood Warning	BOX	Franklin, Hampshire	2 hr
Jul 23, 4:12 AM EDT	Flash Flood Watch	BOX	Bristol, Essex, Franklin, Hampden, Hampshire, Middlesex and 4 more	15 hr
Jul 23, 5:40 AM EDT	Areal Flood Advisory	BOX	Franklin, Hampshire	3 hr
Jul 23, 6:15 AM EDT	Flash Flood Warning	BOX	Franklin	2 hr
Jul 23, 6:47 AM EDT	Areal Flood Advisory	BOX	Franklin, Worcester	3 hr
Jul 23, 10:22 AM EDT	Areal Flood Advisory	BOX	Franklin, Hampden, Hampshire, Worcester	113 min
Jul 23, 11:37 AM EDT	Areal Flood Advisory	BOX	Middlesex, Worcester	113 min
Jul 23, 12:43 PM EDT	Areal Flood Advisory	BOX	Essex, Middlesex, Norfolk, Plymouth, Suffolk	2 hr
Jul 23, 12:52 PM EDT	Special Weather Statement	BOX	Essex	38 min
Jul 23, 12:56 PM EDT	Flash Flood Warning	BOX	Middlesex, Norfolk, Suffolk	2 hr
Jul 23, 1:12 PM EDT	Flash Flood Warning	BOX	Middlesex, Norfolk	2 hr
Jul 23, 1:25 PM EDT	Severe Thunderstorm Warning	BOX	Norfolk, Suffolk	65 min
Jul 23, 1:26 PM EDT	Areal Flood Advisory	BOX	Essex, Norfolk, Plymouth, Suffolk	2 hr
Jul 23, 1:36 PM EDT	Special Marine Warning	BOX		54 min
Jul 23, 1:40 PM EDT	Special Weather Statement	BOX	Essex	50 min
Jul 23, 2:31 PM EDT	Areal Flood Advisory	BOX	Hampden, Hampshire, Worcester	119 min
Jul 23, 2:56 PM EDT	Special Weather Statement	BOX	Essex, Middlesex, Worcester	64 min
Jul 23, 3:13 PM EDT	Areal Flood Advisory	BOX	Essex, Middlesex, Worcester	2 hr
Jul 23, 3:34 PM EDT	Special Weather Statement	BOX	Essex, Middlesex	56 min
Jul 23, 3:38 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	52 min
Jul 23, 3:45 PM EDT	Special Marine Warning	BOX		90 min
Jul 23, 3:58 PM EDT	Areal Flood Advisory	BOX	Essex, Middlesex	2 hr
Jul 23, 4:15 PM EDT	Areal Flood Advisory	BOX	Essex, Middlesex, Norfolk, Plymouth, Suffolk, Worcester	2 hr
Jul 23, 4:20 PM EDT	Special Weather Statement	BOX	Suffolk	40 min
Jul 23, 5:00 PM EDT	Flash Flood Warning	BOX	Bristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester	2 hr
Jul 23, 5:10 PM EDT	Special Weather Statement	BOX	Bristol	50 min

Nearby

Flash Flood Warnings in Massachusetts, 2013 Every flash flood warning in 2013

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.