Alert archive / Massachusetts / Flash Flood Warnings in 2017

Flash Flood Warning 31, NWS Boston/Norton, MA

October 30, 2017Middlesex County, Norfolk County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Oct 30, 2017, 2:26 AM EDT for Middlesex County, Norfolk County, Worcester 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: Oct 30, 2017, 2:26 AM EDT (06:26 UTC)
Expired: Oct 30, 2017, 5:30 AM EDT
In force: 3 hr
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

Counties Middlesex County, MA, Norfolk County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 62 km from the middle of the area, began a volume at 06:31 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
Oct 30, 2:44 AM EDT	FLOOD	Uxbridge, MA	Williams Street flooded.
Oct 30, 4:00 AM EDT	FLOOD	Fitchburg, MA	John Fitch Highway flooded

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 00:00Z, 6.4 hours before the alert went out and 157 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 822 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 190 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

013 
WGUS51 KBOX 300626
FFWBOX
MAC017-021-027-300930-
/O.NEW.KBOX.FF.W.0031.171030T0626Z-171030T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Taunton MA
226 AM EDT MON OCT 30 2017

The National Weather Service in Taunton has issued a

* Flash Flood Warning for...
  Eastern Worcester County in central Massachusetts...
  Southwestern Norfolk County in eastern Massachusetts...
  Central Middlesex County in northeastern Massachusetts...

* Until 530 AM EDT

* At 225 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. 2 to 3 inches of rain have already fallen. Flash 
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Worcester, Framingham, Leominster, Fitchburg, Marlborough,
  Shrewsbury, Natick, Franklin, Milford, Westford, Acton, Hudson,
  Westborough, Grafton, Concord, Sudbury, Holden, Webster, Ashland
  and Bellingham.

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 4263 7142 4202 7138 4205 7189 4265 7187

$$

Frank

1 follow-up statement

414 
WGUS71 KBOX 300750
FFSBOX

Flash Flood Statement
National Weather Service Taunton MA
350 AM EDT MON OCT 30 2017

MAC017-021-027-300759-
/O.CAN.KBOX.FF.W.0031.000000T0000Z-171030T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Worcester MA-Norfolk MA-Middlesex MA-
350 AM EDT MON OCT 30 2017

...THE FLASH FLOOD WARNING FOR EASTERN WORCESTER...SOUTHWESTERN
NORFOLK AND CENTRAL MIDDLESEX COUNTIES IS CANCELLED...

The heavy rain has ended and Flash Flooding is no longer expected to 
pose a threat. However, earlier heavy rain and continued runoff may 
result in some continued street and small stream flooding for the 
next few hours.  Do not drive through flooded roadways.

LAT...LON 4263 7142 4202 7138 4205 7189 4265 7187

$$

Frank

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 29, 8:30 PM EDT	Areal Flood Warning	BOX	Franklin, Hampden, Hampshire	10 hr
Oct 29, 10:05 PM EDT	Areal Flood Warning	BOX	Bristol	6 hr
Oct 29, 11:04 PM EDT	Areal Flood Warning	BOX	Franklin, Hampden, Hampshire, Middlesex, Norfolk, Worcester	6 hr
Oct 29, 11:43 PM EDT	Special Weather Statement	BOX	Dukes, Nantucket	77 min
Oct 30, 12:24 AM EDT	Areal Flood Warning	BOX	Bristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk	3 hr
Oct 30, 2:16 AM EDT	River Flood Warning	BOX	Worcester	23 hr
Oct 30, 2:40 AM EDT	Areal Flood Warning	BOX	Barnstable, Dukes, Nantucket	4 hr
Oct 30, 3:05 AM EDT	Flash Flood Warning	BOX	Bristol	115 min
Oct 30, 3:58 AM EDT	Areal Flood Warning	BOX	Bristol	3 hr
Oct 30, 4:07 AM EDT	Gale Warning	BOX		16 hr
Oct 30, 4:08 AM EDT	Areal Flood Warning	BOX	Bristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk	112 min
Oct 30, 4:15 AM EDT	Wind Advisory	BOX	Barnstable, Bristol, Dukes, Essex, Franklin, Hampden and 7 more	13 hr
Oct 30, 4:21 AM EDT	Areal Flood Warning	BOX	Middlesex, Norfolk, Worcester	3 hr
Oct 30, 6:07 AM EDT	Storm Warning	BOX		7 hr
Oct 30, 9:01 AM EDT	River Flood Warning	BOX	Worcester	12 hr
Oct 30, 7:43 PM EDT	Small Craft Advisory	BOX		30 hr

Nearby

Flash Flood Warnings in Massachusetts, 2017 Every 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.