Alert archive / New Hampshire / Flash Flood Warnings in 1998

Flash Flood Warning 61, NWS Boston/Norton, MA

July 17, 1998Cheshire County, New Hampshire

NWS Boston/Norton, MA issued this flash flood warning at Jul 17, 1998, 4:26 PM EDT for Cheshire County, New Hampshire. 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 counties it named.

The facts

Issued
Jul 17, 1998, 4:26 PM EDT (20:26 UTC)
Expired
Jul 17, 1998, 7:25 PM EDT
In force
3 hr
Issued by
NWS Boston/Norton, MA
Area
Whole counties

County Cheshire County, NH

The radar

The Boston radar (KBOX), 141 km from the middle of the area, began a volume at 20:46 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

Albany, NY (KALY), launched 12:00Z, 8.4 hours before the alert went out and 131 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, Albany, NY at 12:00Z on 1998-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 542 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, Albany, NY at 12:00Z on 1998-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.19395878Sfc1 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
542 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
712 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBOS 172025
FFWBOS
NHC005-172325-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
426 PM EDT FRI JUL 17 1998

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN CHESHIRE COUNTY IN SOUTHWESTERN NEW HAMPSHIRE

* UNTIL 725 PM EDT

* AT 420 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A THUNDERSTORM WITH VERY HEAVY RAIN OVER WESTMORELAND AND
WALPOLE...MOVING SLOWLY NORTHEAST.

* IN WALPOLE...RADAR INDICATED BETWEEN 3.5 AND 4 INCHES OF RAIN HAD
  FALLEN SINCE 130 PM.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT. IT IS
IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO RIVERS AND STREAM.
EVEN THE SMALLEST STREAMS CAN BECOME KILLERS IN TORRENTIAL RAINS.

JN/WTB

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jul 17, 12:50 PM EDT, 3 hours 36 minutes before
MAZ002>006-008>012-CTZ002>004-NHZ011>012-180200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BOSTON MA
1250 PM EDT FRI JUL 17 1998

...A FEW STRONG THUNDERSTORMS ARE POSSIBLE IN SOUTHERN NEW ENGLAND
THIS AFTERNOON AND EVENING...

SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING WILL LIKELY
CONTAIN VERY HEAVY DOWNPOURS WITH STREET FLOODING A POSSIBILITY.
A FEW THUNDERSTORMS MAY ALSO CONTAIN LOCALLY STRONG WINDS AND
HAIL.   THE THUNDERSTORMS SHOULD BE MOST NUMEROUS BETWEEN 4 PM
AND 8 PM.

THE AREAS MOST SUSCEPTIBLE TO SEVERE THUNDERSTORMS EXTENDS FROM
PROVIDENCE RHODE ISLAND NORTHEAST TO BOSTON AND ALL POINTS NORTH
AND WEST.

A COLD FRONT MOVING INTO THE WARM HUMID AIR MASS OVER NEW ENGLAND
IS RESPONSIBLE FOR THE THUNDERSTORMS.  BESIDES THE POTENTIAL RISK
FROM TORRENTIAL DOWNPOURS...DAMAGING WIND GUSTS AND HAIL...OUTDOOR
ENTHUSIASTS SHOULD BE READY TO SEEK SHELTER FROM LIGHTNING IF A
STORM IS SIGHTED.

SKYWARN AMATEUR RADIO OPERATORS ARE REQUESTED TO BE PREPARED FOR
POSSIBLE ACTIVATION THIS AFTERNOON.

STAY TUNED TO NOAA WEATHER RADIO AND YOUR LOCAL MEDIA FOR ANY
ADDITIONAL STATEMENTS...WATCHES AND WARNINGS.

LJC/JN

Nearby

Flash Flood Warnings in New Hampshire, 1998Every flash flood warning in 1998

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.