Alert archive / Massachusetts / Flash Flood Warnings in 2014

Flash Flood Warning 42, NWS Boston/Norton, MA

August 13, 2014Hillsborough County, New Hampshire; Middlesex County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Aug 13, 2014, 5:00 PM EDT for Hillsborough County, New Hampshire; Middlesex County, Worcester County, Massachusetts. It was in force for 4 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
Aug 13, 2014, 5:00 PM EDT (21:00 UTC)
Expired
Aug 13, 2014, 9:00 PM EDT
In force
4 hr
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Flood severity
None

Counties Middlesex County, MA, Worcester County, MA, Hillsborough County, NH

The radar

The Boston radar (KBOX), 107 km from the middle of the area, began a volume at 21:02 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

Gray, ME (KGYX), launched 12:00Z, 9.0 hours before the alert went out and 148 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 2014-08-13Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Gray, ME at 12:00Z on 2014-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 119 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
1245 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
119 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

034 
WGUS51 KBOX 132100
FFWBOX
MAC017-027-NHC011-140100-
/O.NEW.KBOX.FF.W.0042.140813T2100Z-140814T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
500 PM EDT WED AUG 13 2014

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN WORCESTER COUNTY IN CENTRAL MASSACHUSETTS...
  NORTH CENTRAL MIDDLESEX COUNTY IN NORTHEAST MASSACHUSETTS...
  EASTERN HILLSBOROUGH COUNTY IN SOUTHERN NEW HAMPSHIRE...

* UNTIL 900 PM EDT

* AT 454 PM EDT...DOPPLER RADAR INDICATED HEAVY RAIN APPROACHING THE 
  WARNED AREA. THE BAND OF HEAVY RAIN IS EXPECTED TO CROSS THROUGH 
  THE MANCHESTER TO NASHUA CORRIDOR IN NH...SOUTHWARD THROUGH 
  MIDDLESEX COUNTY MA...BETWEEN 5 AND 7 PM. THE POTENTIAL EXISTS FOR 
  RAINFALL RATES OF 1 TO 2 INCHES PER HOUR DURING THIS TIMEFRAME.  
  AS A RESULT...THERE IS A THREAT FOR FLASH FLOODING. THE MAIN 
  THREAT IS FOR RAPID URBAN AND POOR DRAINAGE INUNDATION...THOUGH 
  SOME SMALL STREAMS MAY APPROACH BANKFULL LEVELS.  

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  MANCHESTER...LOWELL...NASHUA...METHUEN...BILLERICA...CHELMSFORD...
  LEXINGTON...DRACUT...TEWKSBURY...MERRIMACK...HUDSON...WESTFORD...
  ACTON...CONCORD...SUDBURY...GOFFSTOWN...MILFORD...CLINTON...
  BEDFORD...PELHAM...PEPPERELL...TYNGSBOROUGH...AMHERST...GROTON...
  MAYNARD...LUNENBURG...TOWNSEND...LITTLETON...WEARE AND LITCHFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RAPID FLOODING OF STREETS AND UNDERPASSES IS IMMINENT. DO NOT DRIVE 
THROUGH FLOODED ROADS AND FIND ALTERNATE ROUTES.

&&

LAT...LON 4305 7164 4307 7153 4305 7151 4304 7145
      4302 7145 4301 7139 4294 7137 4293 7145
      4284 7143 4283 7143 4282 7138 4277 7135
      4274 7125 4243 7124 4238 7169 4313 7167

$$

NMB
1 follow-up statement
260 
WGUS71 KBOX 132342
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
742 PM EDT WED AUG 13 2014

MAC017-027-NHC011-132347-
/O.CAN.KBOX.FF.W.0042.000000T0000Z-140814T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WORCESTER MA-MIDDLESEX MA-HILLSBOROUGH NH-
742 PM EDT WED AUG 13 2014

...THE FLASH FLOOD WARNING FOR NORTHEASTERN WORCESTER...NORTH CENTRAL
MIDDLESEX AND EASTERN HILLSBOROUGH COUNTIES IS CANCELLED...

THE HEAVY RAIN THAT CROSSED THROUGH THE MANCHESTER TO NASHUA 
CORRIDOR AND NORTH CENTRAL MASSACHUSETTS HAS DIMINISHED AND MOVED TO 
THE EAST...AND THE THREAT OF FLASH FLOODING HAS SUBSIDED.  AS A 
RESULT...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR THE AREA 
HAS BEEN CANCELED. 

MINOR PONDING OF WATER IN LOW LYING AND POOR DRAINAGE AREAS MAY 
LINGER IN SOME AREAS THIS EVENING.

LAT...LON 4305 7164 4307 7153 4305 7151 4304 7145
      4302 7145 4301 7139 4294 7137 4293 7145
      4284 7143 4283 7143 4282 7138 4277 7135
      4274 7125 4243 7124 4238 7169 4313 7167

$$

NMB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 2:56 PM EDTFlash Flood WarningBOXCheshire, Hillsborough4 hr
Aug 13, 8:58 AM EDTAreal Flood AdvisoryBOXWorcester2 hr
Aug 13, 10:33 AM EDTCoastal Flood AdvisoryBOXBarnstable, Essex, Nantucket, Norfolk, Plymouth, Suffolk5 hr
Aug 13, 10:59 AM EDTAreal Flood AdvisoryBOXBristol, Middlesex, Norfolk, Worcester4 hr
Aug 13, 11:24 AM EDTFlash Flood WarningBOXBristol, Norfolk, Worcester4 hr
Aug 13, 12:43 PM EDTAreal Flood AdvisoryBOXFranklin, Hampden, Hampshire2 hr
Aug 13, 1:30 PM EDTFlash Flood WarningBOXHampden, Hampshire4 hr
Aug 13, 1:59 PM EDTFlash Flood WarningBOXFranklin, Hampshire4 hr
Aug 13, 3:46 PM EDTFlash Flood WarningBOXFranklin, Hampshire, Middlesex, Worcester4 hr
Aug 13, 4:23 PM EDTSevere Thunderstorm WarningBOXWorcester32 min
Aug 13, 4:28 PM EDTSpecial Marine WarningBOX62 min
Aug 13, 6:16 PM EDTAreal Flood AdvisoryBOXEssex, Middlesex119 min

Nearby

Flash Flood Warnings in Massachusetts, 2014Flash Flood Warnings in New Hampshire, 2014Every flash flood warning in 2014

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.