Alert archive / Massachusetts / Flash Flood Warnings in 1993

Flash Flood Warning 2, NWS Boston/Norton, MA

April 1, 1993Essex County, Middlesex County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Apr 1, 1993, 10:55 AM EST for Essex County, Middlesex County, Massachusetts. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Apr 1, 1993, 10:55 AM EST (15:55 UTC)
Expired
Apr 1, 1993, 6:00 PM EST
In force
7 hr
Issued by
NWS Boston/Norton, MA
Area
Whole counties

Counties Essex County, MA, Middlesex County, MA

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 3.9 hours before the alert went out and 138 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 1993-04-01Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Chatham, MA at 12:00Z on 1993-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
313 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.

000 
TTAA00 KBOS 011600 COR
FFWBOS
MAC017-009-012300-

BULLETIN - EBS ACTIVATION REQUESTED
FLOOD WARNING...CORRECTED TO BE FLOOD...NOT FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BOSTON MA
1055 AM EST THU APR 1 1993

THE NATIONAL WEATHER SERVICE IN BOSTON HAS ISSUED A
FLOOD WARNING EFFECTIVE UNTIL  600 PM EST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN EAST MASSACHUSETTS

   ...MIDDLESEX COUNTY

IN NORTHEAST MASSACHUSETTS

   ...ESSEX COUNTY

PRIOR RAIN AND SNOWMELT HAVE BROUGHT MANY STREAMS IN MIDDLESEX AND
ESSEX COUNTIES TO NEAR BANKFUL...AND IN SOME INSTANCES SUCH AS THE
SHAWSHEEN RIVER...OVER BANKFUL IN SOME LOCATIONS. AT 1055 AM...RADAR
INDICATED A LARGE AREA OF MODERATE TO HEAVY RAIN MOVING INTO MIDDLESEX
AND ESSEX COUNTIES.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND*.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 1, 5:47 PM ESTFlash Flood WarningBOXBristol118 min
Apr 1, 5:55 PM ESTFlash Flood WarningBOXEssex, Middlesex6 hr
Apr 1, 5:55 PM ESTFlash Flood WarningBOXNorfolk6 hr
Apr 1, 6:10 PM ESTFlash Flood WarningBOXPlymouth2 hr

Nearby

Flash Flood Warnings in Massachusetts, 1993Every flash flood warning in 1993

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.