Alert archive / Massachusetts / Flash Flood Warnings in 2012

Flash Flood Warning 6, NWS Boston/Norton, MA

July 18, 2012Middlesex County, Norfolk County, Suffolk County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Jul 18, 2012, 5:24 PM EDT for Middlesex County, Norfolk County, Suffolk County, Massachusetts. It was in force for 78 min. 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 18, 2012, 5:24 PM EDT (21:24 UTC)
Expired: Jul 18, 2012, 6:42 PM EDT
In force: 78 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

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

The radar

The Boston radar (KBOX), 38 km from the middle of the area, began a volume at 21:27 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

Time	Report	Where	Remark
Jul 18, 5:26 PM EDT	FLOOD	Newton, MA	20 FOOT STRECH OF BEACON STREET UNDER 1 FOOT OF WATER
Jul 18, 5:31 PM EDT	FLOOD	Natick, MA	1 FOOT OF WATER ON SPEEN STREET NEAR ROUTE 9

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, 9.4 hours before the alert went out and 122 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: 1521 J/kg
Mixed-layer CIN: -208 J/kg
Mixed-layer LCL: 1597 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

193 
WGUS51 KBOX 182124
FFWBOX
MAC017-021-025-190030-
/O.NEW.KBOX.FF.W.0006.120718T2124Z-120719T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
ISSUED BY NATIONAL WEATHER SERVICE NEW YORK NY
524 PM EDT WED JUL 18 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN MIDDLESEX COUNTY IN EASTERN MASSACHUSETTS...
  SUFFOLK COUNTY IN EASTERN MASSACHUSETTS...
  NORTHERN NORFOLK COUNTY IN EASTERN MASSACHUSETTS...

* UNTIL 830 PM EDT...

* AT 519 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH 
  FLOODING FROM THUNDERSTORMS OVER THE WARNED AREA.

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.

&&

LAT...LON 4221 7095 4217 7148 4220 7157 4227 7157
      4227 7152 4230 7149 4233 7150 4233 7152
      4243 7096 4240 7098 4234 7095 4234 7101
      4230 7104 4231 7102 4232 7095 4228 7101
      4227 7095

$$

JST

1 follow-up statement

314 
WGUS71 KBOX 182242
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
ISSUED BY NATIONAL WEATHER SERVICE NEW YORK NY
642 PM EDT WED JUL 18 2012

MAC017-021-025-182250-
/O.CAN.KBOX.FF.W.0006.000000T0000Z-120719T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORFOLK MA-SUFFOLK MA-MIDDLESEX MA-
642 PM EDT WED JUL 18 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN
MIDDLESEX...SUFFOLK AND NORTHERN NORFOLK COUNTIES...

THE HEAVY RAIN HAS ENDED FOR THE EVENING. 

LAT...LON 4221 7095 4217 7148 4220 7157 4227 7157
      4227 7152 4230 7149 4233 7150 4233 7152
      4243 7096 4240 7098 4234 7095 4234 7101
      4230 7104 4231 7102 4232 7095 4228 7101
      4227 7095

$$

JST

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:23 PM EDT	Special Weather Statement	BOX	Essex	67 min
Jul 18, 12:37 PM EDT	Special Weather Statement	BOX	Middlesex	53 min
Jul 18, 12:41 PM EDT	Heat Advisory	BOX	Bristol, Essex, Franklin, Hampden, Hampshire, Middlesex and 2 more	6 hr
Jul 18, 12:54 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex	66 min
Jul 18, 1:21 PM EDT	Special Marine Warning	BOX		84 min
Jul 18, 1:29 PM EDT	Flash Flood Warning	BOX	Essex, Middlesex	98 min
Jul 18, 1:43 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	36 min
Jul 18, 1:45 PM EDT	Special Marine Warning	BOX		60 min
Jul 18, 1:50 PM EDT	Special Weather Statement	BOX	Hampden	40 min
Jul 18, 2:04 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Hampshire, Worcester	56 min
Jul 18, 2:04 PM EDT	Tornado Warning	BOX	Essex, Suffolk	12 min
Jul 18, 2:21 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Suffolk	39 min
Jul 18, 2:21 PM EDT	Severe Thunderstorm Warning	BOX	Hampden	54 min
Jul 18, 2:24 PM EDT	Flash Flood Warning	BOX	Hampden, Worcester	3 hr
Jul 18, 2:30 PM EDT	Special Marine Warning	BOX		90 min
Jul 18, 2:39 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester	51 min
Jul 18, 2:44 PM EDT	Severe Thunderstorm Warning	BOX	Hampden, Norfolk, Worcester	61 min
Jul 18, 3:09 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Norfolk, Worcester	51 min
Jul 18, 3:46 PM EDT	Severe Thunderstorm Warning	BOX	Barnstable, Bristol, Norfolk, Plymouth	59 min
Jul 18, 4:04 PM EDT	Special Marine Warning	BOX		56 min
Jul 18, 4:25 PM EDT	Special Marine Warning	BOX		80 min
Jul 18, 4:42 PM EDT	Severe Thunderstorm Warning	BOX	Barnstable, Plymouth	36 min
Jul 18, 5:08 PM EDT	Special Weather Statement	BOX	Norfolk, Suffolk	52 min
Jul 18, 5:27 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Norfolk, Plymouth, Suffolk	48 min
Jul 18, 5:30 PM EDT	Special Marine Warning	BOX		54 min
Jul 18, 6:08 PM EDT	Special Marine Warning	BOX		67 min
Jul 18, 6:27 PM EDT	Special Weather Statement	BOX	Essex	33 min

Nearby

Flash Flood Warnings in Massachusetts, 2012 Every flash flood warning in 2012

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.