Alert archive / Massachusetts / Mesoscale Discussions in 2017

Mesoscale Discussion 167

February 9, 20175 states

The Storm Prediction Center issued this mesoscale discussion at Feb 9, 2017, 11:05 AM EST for 5 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 9, 2017, 11:05 AM EST (16:05 UTC)
Expired
Feb 9, 2017, 3:00 PM EST
In force
4 hr
Issued by
the Storm Prediction Center

Counties Bristol County, MA, Essex County, MA, Hampden County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Cumberland County, ME, Lincoln County, ME, Sagadahoc County, ME, York County, ME, Rockingham County, NH, Strafford County, NH, Suffolk County, NY, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Boston radar (KBOX), 41 km from the middle of the area, began a volume at 16:06 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 4.1 hours before the alert went out and 180 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, Brookhaven, NY at 12:00Z on 2017-02-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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, Brookhaven, NY at 12:00Z on 2017-02-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 600 square meters per square second.1939587897117136156Sfc1 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
1 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
460 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
600 m²/s²
0-3 km storm-relative helicity
1118 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 9, 4:55 AM ESTMesoscale DiscussionSPC6 hr
Feb 9, 3:20 PM ESTMesoscale DiscussionSPC6 hr

Nearby

Mesoscale Discussions in Massachusetts, 2017Mesoscale Discussions in Connecticut, 2017Mesoscale Discussions in Rhode Island, 2017Every mesoscale discussion in 2017

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.