Alert archive / Vermont / Mesoscale Discussions in 2018

Mesoscale Discussion 970

June 30, 2018Coos County, Grafton County, Sullivan County, New Hampshire; 4 counties in New York; 12 counties in Vermont

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2018, 10:10 PM EDT for Coos County, Grafton County, Sullivan County, New Hampshire; 4 counties in New York; 12 counties in Vermont. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 30, 2018, 10:10 PM EDT (02:10 UTC)
Expired
Jul 1, 2018, 12:15 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Coos County, NH, Grafton County, NH, Sullivan County, NH, Clinton County, NY, Essex County, NY, Franklin County, NY, St. Lawrence County, NY, Addison County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Franklin County, VT, Grand Isle County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windsor County, VT

The radar

The Burlington radar (KCXX), 24 km from the middle of the area, began a volume at 02:10 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 00:00Z, 2.2 hours before the alert went out and 188 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 00:00Z on 2018-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 729 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 00:00Z on 2018-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.193958Sfc1 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
729 J/kg
Mixed-layer CIN
-151 J/kg
Mixed-layer LCL
1929 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

536 
ACUS11 KWNS 010210
SWOMCD
SPC MCD 010210 
MEZ000-NHZ000-VTZ000-NYZ000-010415-

Mesoscale Discussion 0970
NWS Storm Prediction Center Norman OK
0910 PM CDT Sat Jun 30 2018

Areas affected...Northern New York...northern and central
Vermont...northern and central New Hampshire,

Concerning...Severe potential...Watch possible 

Valid 010210Z - 010415Z

Probability of Watch Issuance...40 percent

SUMMARY...Isolated storms may move across the discussion area over
the next few hours. Storms that can mature may produce isolated,
marginally severe hail/wind gusts.

DISCUSSION...Buoyancy is decreasing across northern New England and
the boundary layer is beginning to stabilize. Nonetheless, large
scale ascent is glancing the area and sparse convection has
initiated within the last hour. Deep-layer and low-level
speed/directional shear highly favor updraft organization for any
storms that may sustain themselves in the next few hours. 

Given the waning instability and increasing inhibition, marginally
severe hail/damaging winds will likely be the primary threats with
these storms. Given low confidence in greater storm coverage, a WW
issuance may not be needed at this time, though convective trends
will continue to be monitored.

..Squitieri/Gleason/Thompson.. 07/01/2018

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GYX...BTV...ALY...

LAT...LON   44397578 44737539 44947487 44967408 44987284 45007184
            44737104 44367090 43917125 43457186 43277243 43687396
            44057497 44397578

Nearby

Mesoscale Discussions in Vermont, 2018Mesoscale Discussions in New York, 2018Mesoscale Discussions in New Hampshire, 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.