Alert archive / Massachusetts / Mesoscale Discussions in 2018
Mesoscale Discussion 425
The Storm Prediction Center issued this mesoscale discussion at May 15, 2018, 1:58 PM EDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 15, 2018, 1:58 PM EDT (17:58 UTC)
- Expired
- May 15, 2018, 4:00 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 95%
All 22 counties
Bristol County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Suffolk County, MA, Worcester County, MA, York County, ME, Belknap County, NH, Cheshire County, NH, Hillsborough County, NH, Merrimack County, NH, Rockingham County, NH, Strafford County, NH, Sullivan County, NH, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI
The radar
The Boston radar (KBOX), 77 km from the middle of the area, began a volume at 17:58 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Chatham, MA (KCHH), launched 12:00Z, 6.0 hours before the alert went out and 168 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 884 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 8 m²/s²
- 0-3 km storm-relative helicity
- 54 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 11:43 AM EDT | Mesoscale Discussion | SPC | 3 hr | |
| May 15, 1:03 PM EDT | Tornado Watch | SPC | Northwest Hills Planning Region | 4 hr |
| May 15, 1:46 PM EDT | Severe Thunderstorm Watch | SPC | Greater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region | 9 hr |
| May 15, 2:23 PM EDT | Tornado Watch | SPC | Capitol Planning Region, Northeastern Connecticut Planning Region | 4 hr |
| May 15, 2:38 PM EDT | Mesoscale Discussion | SPC | 2 hr | |
| May 15, 3:33 PM EDT | Mesoscale Discussion | SPC | 117 min | |
| May 15, 2:26 PM EDT | Severe Thunderstorm Watch | SPC | Bristol, Essex, Middlesex, Norfolk, Plymouth, Suffolk | 5 hr |
Nearby
Mesoscale Discussions in Massachusetts, 2018Mesoscale Discussions in New Hampshire, 2018Mesoscale Discussions in Rhode Island, 2018Every mesoscale discussion 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.