Alert archive / New Hampshire / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 643

August 3, 20004 states

The Storm Prediction Center issued this severe thunderstorm watch at Aug 3, 2000, 1:45 PM EDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Aug 3, 2000, 1:45 PM EDT (17:45 UTC)
Expired: Aug 3, 2000, 7:00 PM EDT
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA, Franklin County, ME, Oxford County, ME, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH, Essex County, VT

The radar

The Portland,ME radar (KGYX), 142 km from the middle of the area, began a volume at 17:43 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.

Warnings issued inside it

6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Aug 3, 2:14 PM EDT	Severe Thunderstorm Warning	GYX	Coos	46 min
Aug 3, 2:21 PM EDT	Severe Thunderstorm Warning	BOX	Cheshire	24 min
Aug 3, 2:38 PM EDT	Severe Thunderstorm Warning	GYX	Franklin, Oxford	52 min
Aug 3, 3:41 PM EDT	Severe Thunderstorm Warning	BOX	Hillsborough	34 min
Aug 3, 5:03 PM EDT	Severe Thunderstorm Warning	BOX	Franklin	42 min
Aug 3, 6:31 PM EDT	Severe Thunderstorm Warning	BOX	Franklin	39 min

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 5.8 hours before the alert went out and 142 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: 628 J/kg
Mixed-layer CIN: -93 J/kg
Mixed-layer LCL: 852 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

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

544 
WWUS9 KMKC 031717
SEL3  

SEL3  
MKC WW 031712
MAZ000-MEZ000-NHZ000-032300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 643
STORM PREDICTION CENTER NORMAN OK
112 PM EDT THU AUG 3 2000

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   MASSACHUSETTS                      
   WESTERN MAINE                              
   NEW HAMPSHIRE                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 145 PM UNTIL 700
PM EDT.

HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 40 STATUTE MILES
EAST AND WEST OF A LINE FROM 20 MILES SOUTHWEST OF WORCESTER
MASSACHUSETTS TO 35 MILES NORTH NORTHEAST OF BERLIN NEW HAMPSHIRE.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 642...

DISCUSSION...THUNDERSTORMS ARE INCREASING OVER HIGHER TERRAIN VT/NH
AND WILL INTENSIFY INTO VERY MOIST AND UNSTABLE AIRMASS EWD.  SHEAR
ADEQUATE FOR STORMS TO DEVELOP INTO MULTICELL CLUSTERS/SHORT LINES
ENHANCING WIND DAMAGE POTENTIAL.


AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. 
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550.  MEAN STORM MOTION
VECTOR 25030.


...HALES

450,0700 420,0712 420,0725 450,0714

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 3, 12:00 PM EDT	Severe Thunderstorm Watch	SPC	Berkshire	5 hr

Nearby

Severe Thunderstorm Watches in New Hampshire, 2000 Severe Thunderstorm Watches in Massachusetts, 2000 Severe Thunderstorm Watches in Maine, 2000 Every severe thunderstorm watch in 2000

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.