Alert archive / Maine / Mesoscale Discussions in 2016

Mesoscale Discussion 841

June 7, 20164 counties in Maine

The Storm Prediction Center issued this mesoscale discussion at Jun 7, 2016, 3:56 PM EDT for 4 counties in Maine. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Jun 7, 2016, 3:56 PM EDT (19:56 UTC)
Expired
Jun 7, 2016, 5:00 PM EDT
In force
64 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Androscoggin County, ME, Cumberland County, ME, Kennebec County, ME, Oxford County, ME

The radar

The Portland,ME radar (KGYX), 30 km from the middle of the area, began a volume at 19:56 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

Gray, ME (KGYX), launched 12:00Z, 7.9 hours before the alert went out and 30 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, Gray, ME at 12:00Z on 2016-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Gray, ME at 12:00Z on 2016-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1903 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
194 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

813 
ACUS11 KWNS 071956
SWOMCD
SPC MCD 071956 
MEZ000-NHZ000-072100-

MESOSCALE DISCUSSION 0841
NWS STORM PREDICTION CENTER NORMAN OK
0256 PM CDT TUE JUN 07 2016

AREAS AFFECTED...SRN AND S-CNTRL MAINE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 071956Z - 072100Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A LOCALIZED MARGINAL HAIL/ISOLATED DAMAGING WIND THREAT
WILL LIKELY REMAIN CONFINED TO NEAR AND WEST OF AN OUTFLOW BOUNDARY
AND TO THE WEST OF A SEA BREEZE FRONT.  A SEVERE THUNDERSTORM WATCH
APPEARS UNNECESSARY AT THIS TIME.

DISCUSSION...RADAR IMAGERY DURING THE PAST HOUR HAD SHOWN A PAIR OF
MARGINAL SUPERCELLS ACROSS SRN AND S-CNTRL MAINE.  SURFACE
OBSERVATIONS AND RADAR IMAGERY INDICATE A SEA BREEZE FRONT IS MOVING
INLAND ACROSS SRN COASTAL MAINE AND AN ARCING OUTFLOW/DIFFERENTIAL
HEATING ZONE IS LOCATED ROUGHLY FROM 25 MI SE AUG TO 40 MI N AUG. 
THE AIRMASS NEAR AND W OF THESE BOUNDARIES IN THE WARM SECTOR IS
SUPPORTIVE OF A LOCALIZED SEVERE THREAT GIVEN THE MARGINAL BUOYANCY
COUPLED WITH SHEAR CONDUCIVE FOR WEAK UPDRAFT ROTATION. 
HOWEVER...THE SMALL SPATIOTEMPORAL WINDOW FOR A STRONG/LOCALIZED
SEVERE RISK WILL LIKELY PRECLUDE THE ISSUANCE OF A SEVERE
THUNDERSTORM WATCH ACROSS NEW ENGLAND.

..SMITH/DIAL.. 06/07/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CAR...GYX...

LAT...LON   43647102 44747069 45126961 44406935 43367052 43647102

Nearby

Mesoscale Discussions in Maine, 2016Every mesoscale discussion in 2016

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.