Alert archive / Massachusetts / Flash Flood Warnings in 2024

Flash Flood Warning 13, NWS Boston/Norton, MA

August 15, 2024Barnstable County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Aug 15, 2024, 2:46 PM EDT for Barnstable County, Massachusetts. It was in force for 3 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 15, 2024, 2:46 PM EDT (18:46 UTC)
Expired: Aug 15, 2024, 5:45 PM EDT
In force: 3 hr
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

County Barnstable County, MA

The radar

The Boston radar (KBOX), 50 km from the middle of the area, began a volume at 18:49 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

Brookhaven, NY (KOKX), launched 12:00Z, 6.8 hours before the alert went out and 210 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: 157 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 1556 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 51 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

868 
WGUS51 KBOX 151846
FFWBOX
MAC001-152145-
/O.NEW.KBOX.FF.W.0013.240815T1846Z-240815T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Boston/Norton MA
246 PM EDT Thu Aug 15 2024

The National Weather Service in Norton has issued a

* Flash Flood Warning for...
  West Central Barnstable County in southeastern Massachusetts...

* Until 545 PM EDT.

* At 246 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 3 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Plymouth, Falmouth, Wareham, Sandwich and Bourne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 4171 7066 4172 7064 4173 7064 4175 7068
      4175 7066 4175 7065 4174 7064 4176 7063
      4181 7054 4176 7048 4165 7053 4161 7057
      4161 7065 4173 7068

FLASH FLOOD...RADAR INDICATED

$$

KS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 15, 3:11 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Worcester	64 min
Aug 15, 3:26 PM EDT	Special Marine Warning	BOX		64 min
Aug 15, 3:42 PM EDT	Severe Thunderstorm Warning	BOX	Essex, Middlesex, Norfolk, Plymouth, Suffolk, Worcester	48 min
Aug 15, 3:55 PM EDT	Severe Thunderstorm Warning	BOX	Barnstable, Plymouth	50 min
Aug 15, 4:03 PM EDT	Severe Thunderstorm Warning	BOX	Bristol	27 min
Aug 15, 4:03 PM EDT	Severe Thunderstorm Warning	BOX	Middlesex, Worcester	42 min
Aug 15, 4:04 PM EDT	Special Marine Warning	BOX		56 min
Aug 15, 4:12 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Middlesex, Norfolk, Plymouth, Suffolk	48 min
Aug 15, 4:31 PM EDT	Special Marine Warning	BOX		44 min
Aug 15, 4:37 PM EDT	Flash Flood Warning	BOX	Norfolk, Plymouth	2 hr
Aug 15, 4:44 PM EDT	Severe Thunderstorm Warning	BOX	Bristol, Plymouth	61 min
Aug 15, 5:06 PM EDT	Severe Thunderstorm Warning	BOX	Bristol	39 min
Aug 15, 5:09 PM EDT	Special Marine Warning	BOX		51 min
Aug 15, 5:18 PM EDT	Flash Flood Warning	BOX	Bristol	108 min
Aug 15, 5:23 PM EDT	Severe Thunderstorm Warning	BOX	Barnstable, Plymouth	39 min
Aug 15, 5:25 PM EDT	Special Marine Warning	BOX		50 min
Aug 15, 5:34 PM EDT	Severe Thunderstorm Warning	BOX	Hampden	30 min
Aug 15, 5:39 PM EDT	Special Marine Warning	BOX		66 min
Aug 15, 6:16 PM EDT	Special Marine Warning	BOX		59 min

Nearby

Flash Flood Warnings in Massachusetts, 2024 Every flash flood warning in 2024

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.