Alert archive / Massachusetts / Special Weather Statements in 2021

Special Weather Statement, NWS Boston/Norton, MA

October 25, 2021Barnstable County, Massachusetts

NWS Boston/Norton, MA issued this special weather statement at Oct 25, 2021, 9:49 PM EDT for Barnstable County, Massachusetts. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Oct 25, 2021, 9:49 PM EDT (01:49 UTC)
Expired
Oct 25, 2021, 10:30 PM EDT
In force
41 min
Issued by
NWS Boston/Norton, MA
Hail
0.00 in
Wind
30

County Barnstable County, MA

The radar

The Boston radar (KBOX), 88 km from the middle of the area, began a volume at 01:51 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 00:00Z, 1.8 hours before the alert went out and 245 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, Brookhaven, NY at 00:00Z on 2021-10-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 544 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2021-10-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 square meters per square second.1939587897Sfc1 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
544 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
758 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted.

386 
WWUS81 KBOX 260149
SPSBOX

Special Weather Statement
National Weather Service Boston/Norton MA
949 PM EDT Mon Oct 25 2021
 
MAZ022-260230-
Barnstable MA-
949 PM EDT Mon Oct 25 2021

...An area of thunderstorms will impact portions of southeastern 
Barnstable County through 1030 PM EDT...

At 949 PM EDT, Doppler radar was tracking thunderstorms over 
Yarmouth, or near Barnstable, moving north at 20 mph.

HAZARD...Heavy rainfall and frequent lightning. 

SOURCE...Radar indicated.

IMPACT...Heavy rainfall may cause flooding of roads and ponding of 
         water in low lying areas.

Locations impacted include...
Barnstable, Brewster, Yarmouth, Dennis, Harwich, Chatham, Orleans,
Eastham and Hyannis.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. For your
safety, go indoors or to your vehicle.

Turn around, don't drown when encountering flooded roads.

&&

LAT...LON 4161 6998 4166 6997 4165 7026 4163 7024
      4161 7026 4164 7035 4161 7042 4174 7037
      4171 7026 4179 7002 4184 7000 4179 6993
      4171 6993
TIME...MOT...LOC 0145Z 200DEG 18KT 4168 7025 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...<30 MPH

$$

BL

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 25, 10:18 PM EDTSpecial Weather StatementBOXBarnstable42 min
Oct 25, 11:24 PM EDTSpecial Weather StatementBOXBristol, Plymouth81 min

Nearby

Special Weather Statements in Massachusetts, 2021Every special weather statement in 2021

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.