Alert archive / Massachusetts / Tornado Warnings in 2018

Tornado Warning 11, NWS Boston/Norton, MA

September 18, 2018Essex County, Massachusetts

NWS Boston/Norton, MA issued this tornado warning at Sep 18, 2018, 11:00 AM EDT for Essex County, Massachusetts. It was in force for 15 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
Sep 18, 2018, 11:00 AM EDT (15:00 UTC)
Expired
Sep 18, 2018, 11:15 AM EDT
In force
15 min
Issued by
NWS Boston/Norton, MA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Essex County, MA

The radar

The Boston radar (KBOX), 66 km from the middle of the area, began a volume at 15:03 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

Chatham, MA (KCHH), launched 12:00Z, 3.0 hours before the alert went out and 117 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, Chatham, MA at 12:00Z on 2018-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 165 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, Chatham, MA at 12:00Z on 2018-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 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
165 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

569 
WFUS51 KBOX 181500
TORBOX
MAC009-181515-
/O.NEW.KBOX.TO.W.0011.180918T1500Z-180918T1515Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Boston/Norton MA
1100 AM EDT TUE SEP 18 2018

The National Weather Service in Boston/Norton has issued a

* Tornado Warning for...
  South central Essex County in northeastern Massachusetts...

* Until 1115 AM EDT.
    
* At 1100 AM EDT, a severe thunderstorm capable of producing a
  tornado was located over Salem, moving east at 20 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Marblehead around 1110 AM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4256 7079 4252 7078 4248 7081 4247 7082
      4246 7085 4246 7094 4251 7093
TIME...MOT...LOC 1500Z 250DEG 17KT 4249 7091 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

JWD
1 follow-up statement
901 
WWUS51 KBOX 181511
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
1111 AM EDT TUE SEP 18 2018

MAC009-181520-
/O.EXP.KBOX.TO.W.0011.000000T0000Z-180918T1515Z/
Essex MA-
1111 AM EDT TUE SEP 18 2018

...THE TORNADO WARNING FOR SOUTH CENTRAL ESSEX COUNTY WILL EXPIRE AT
1115 AM EDT...
        
The storm which prompted the warning has moved off the coast. 
Therefore, the warning will be allowed to expire.

As of 1110 AM, there has been no confirmation of a tornado.

&&

LAT...LON 4256 7079 4252 7078 4248 7081 4247 7082
      4246 7085 4246 7094 4251 7093
TIME...MOT...LOC 1510Z 250DEG 17KT 4250 7086 

$$

JWD

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 7:54 AM EDTSpecial Weather StatementBOXFranklin, Hampshire81 min
Sep 18, 8:21 AM EDTSpecial Weather StatementBOXNorfolk54 min
Sep 18, 8:52 AM EDTFlash Flood WarningBOXFranklin, Hampshire, Middlesex, Worcester4 hr
Sep 18, 9:09 AM EDTSpecial Weather StatementBOXHampden, Worcester36 min
Sep 18, 9:32 AM EDTSpecial Weather StatementBOXEssex, Middlesex88 min
Sep 18, 9:50 AM EDTSpecial Weather StatementBOXHampden, Worcester85 min
Sep 18, 10:12 AM EDTSpecial Weather StatementBOXEssex48 min
Sep 18, 10:17 AM EDTFlash Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk, Worcester4 hr
Sep 18, 10:34 AM EDTSpecial Weather StatementBOXEssex41 min
Sep 18, 10:45 AM EDTSevere Thunderstorm WarningBOXEssex, Middlesex30 min
Sep 18, 10:56 AM EDTSpecial Marine WarningBOX64 min
Sep 18, 10:58 AM EDTFlash Flood WarningBOXHampden, Hampshire, Worcester4 hr
Sep 18, 11:07 AM EDTRiver Flood WarningBOXWorcester9 hr
Sep 18, 11:09 AM EDTSpecial Marine WarningBOX66 min
Sep 18, 11:23 AM EDTFlash Flood WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester4 hr
Sep 18, 11:58 AM EDTSpecial Marine WarningBOX62 min
Sep 18, 12:20 PM EDTSpecial Marine WarningBOX25 min
Sep 18, 12:32 PM EDTAreal Flood WarningBOXFranklin, Hampshire, Middlesex, Worcester4 hr
Sep 18, 12:49 PM EDTSpecial Marine WarningBOX86 min
Sep 18, 12:58 PM EDTSpecial Weather StatementBOXPlymouth62 min
Sep 18, 1:10 PM EDTSpecial Marine WarningBOX80 min
Sep 18, 1:31 PM EDTFlash Flood WarningBOXBristol, Plymouth4 hr
Sep 18, 2:01 PM EDTAreal Flood WarningBOXEssex, Middlesex, Norfolk, Suffolk, Worcester4 hr
Sep 18, 2:07 PM EDTSpecial Weather StatementBOXBristol, Plymouth38 min
Sep 18, 2:27 PM EDTSevere Thunderstorm WarningBOXBarnstable, Plymouth33 min
Sep 18, 2:31 PM EDTSpecial Marine WarningBOX44 min
Sep 18, 2:59 PM EDTSpecial Marine WarningBOX46 min
Sep 18, 3:04 PM EDTSevere Thunderstorm WarningBOXBarnstable41 min
Sep 18, 3:05 PM EDTFlash Flood WarningBOXBarnstable115 min
Sep 18, 3:14 PM EDTAreal Flood WarningBOXBristol, Middlesex, Norfolk, Plymouth, Suffolk, Worcester3 hr
Sep 18, 3:22 PM EDTSpecial Marine WarningBOX53 min
Sep 18, 3:59 PM EDTSpecial Marine WarningBOX46 min
Sep 18, 4:01 PM EDTSmall Craft AdvisoryBOX60 hr

Nearby

Tornado Warnings in Massachusetts, 2018Every tornado warning in 2018Tornadoes in 2018

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.