Alert archive / Massachusetts / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 765
The Storm Prediction Center issued this severe thunderstorm watch at Aug 20, 2004, 1:05 PM EDT for 6 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 20, 2004, 1:05 PM EDT (17:05 UTC)
- Expired
- Aug 20, 2004, 7:00 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 28 counties
Berkshire County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, York County, ME, Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Albany County, NY, Columbia County, NY, Dutchess County, NY, Greene County, NY, Orange County, NY, Putnam County, NY, Rensselaer County, NY, Schenectady County, NY, Ulster County, NY, Providence County, RI, Bennington County, VT, Windham County, VT
The radar
The Albany radar (KENX), 95 km from the middle of the area, began a volume at 17:06 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
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 1:59 PM EDT | Severe Thunderstorm Warning | BOX | Worcester | 31 min |
| Aug 20, 2:07 PM EDT | Tornado Warning | BOX | Worcester | 23 min |
| Aug 20, 2:28 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Worcester | 32 min |
| Aug 20, 2:58 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Worcester | 47 min |
| Aug 20, 3:25 PM EDT | Severe Thunderstorm Warning | BOX | Essex, Middlesex | 50 min |
| Aug 20, 4:02 PM EDT | Severe Thunderstorm Warning | ALY | Dutchess | 43 min |
| Aug 20, 4:05 PM EDT | Tornado Warning | GYX | York | 25 min |
| Aug 20, 4:24 PM EDT | Severe Thunderstorm Warning | ALY | Ulster | 66 min |
| Aug 20, 4:29 PM EDT | Severe Thunderstorm Warning | BOX | Essex, Middlesex | 46 min |
| Aug 20, 4:33 PM EDT | Severe Thunderstorm Warning | BOX | Franklin, Hampshire | 27 min |
| Aug 20, 5:02 PM EDT | Severe Thunderstorm Warning | OKX | Orange | 43 min |
| Aug 20, 5:17 PM EDT | Severe Thunderstorm Warning | ALY | Albany | 58 min |
| Aug 20, 6:03 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Worcester | 42 min |
| Aug 20, 6:23 PM EDT | Severe Thunderstorm Warning | ALY | Berkshire | 52 min |
| Aug 20, 6:41 PM EDT | Severe Thunderstorm Warning | BOX | Middlesex, Norfolk, Suffolk | 49 min |
| Aug 20, 6:54 PM EDT | Severe Thunderstorm Warning | ALY | Albany | 36 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 5.1 hours before the alert went out and 78 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.
- Mixed-layer CAPE
- 244 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 569 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 77 m²/s²
- 0-3 km storm-relative helicity
- 142 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 11:56 AM EDT | Mesoscale Discussion | SPC | 2 hr | |
| Aug 20, 3:41 PM EDT | Mesoscale Discussion | SPC | 2 hr | |
| Aug 20, 6:10 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr | |
| Aug 20, 2:05 PM EDT | Severe Thunderstorm Watch | SPC | Sullivan | 5 hr |
Nearby
Severe Thunderstorm Watches in Massachusetts, 2004Severe Thunderstorm Watches in New York, 2004Severe Thunderstorm Watches in New Hampshire, 2004Every severe thunderstorm watch in 2004
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.