Alert archive / New York / Mesoscale Discussions in 2016

Mesoscale Discussion 1685

September 14, 20166 states

The Storm Prediction Center issued this mesoscale discussion at Sep 14, 2016, 1:33 PM EDT for 6 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Sep 14, 2016, 1:33 PM EDT (17:33 UTC)
Expired
Sep 14, 2016, 3:00 PM EDT
In force
87 min
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 25 counties

Berkshire County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Cheshire County, NH, Sussex County, NJ, Albany County, NY, Columbia County, NY, Dutchess County, NY, Greene County, NY, Orange County, NY, Putnam County, NY, Rensselaer County, NY, Sullivan County, NY, Ulster County, NY, Lackawanna County, PA, Luzerne County, PA, Monroe County, PA, Pike County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, Bennington County, VT, Windham County, VT

The radar

The Albany radar (KENX), 55 km from the middle of the area, began a volume at 17:34 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, 5.6 hours before the alert went out and 166 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 2016-09-14Temperature 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, Brookhaven, NY at 12:00Z on 2016-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 162 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
972 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
162 m²/s²
0-3 km storm-relative helicity
164 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

260 
ACUS11 KWNS 141733
SWOMCD
SPC MCD 141733 
NHZ000-MAZ000-CTZ000-VTZ000-NYZ000-NJZ000-PAZ000-141900-

MESOSCALE DISCUSSION 1685
NWS STORM PREDICTION CENTER NORMAN OK
1233 PM CDT WED SEP 14 2016

AREAS AFFECTED...NERN PA...SERN NY...SRN VT...NWRN CT...WRN
MA...SWRN NH

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 141733Z - 141900Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...ISOLATED STRONG/DAMAGING GUSTS MAY OCCUR WITH STORMS
FORMING ALONG A COLD FRONT THIS AFTERNOON.  A SEVERE THUNDERSTORM
WATCH DOES NOT APPEAR NECESSARY.

DISCUSSION...VISIBLE SATELLITE IMAGERY REVEALS DEEPENING CONVECTION
ALONG A SURFACE COLD FRONT ACROSS NERN PA...ALONG THE SRN FRINGE OF
THE INFLUENCE OF A DIFFUSE LEAD SHORTWAVE TROUGH PRECEDING THE MAIN
WAVE OVER THE SAINT LAWRENCE VALLEY.  STRONG SURFACE HEATING WILL
CONTINUE AHEAD OF THE FRONT FROM ERN PA INTO SRN NEW ENGLAND...WHERE
A NARROW CORRIDOR OF WEAK-MODERATE BUOYANCY WILL SUPPORT
THUNDERSTORM DEVELOPMENT.  THOUGH MIDLEVEL LAPSE RATES WILL BE POOR
AND BUOYANCY SOMEWHAT LIMITED...DEEP-LAYER SPEED SHEAR AND STRAIGHT
HODOGRAPH STRUCTURES WILL BE SUFFICIENT FOR SPLITTING STORMS WITH
SUPERCELL STRUCTURE.  WLY MIDLEVEL FLOW OF 30-50 KT AND WEAK
INVERTED-V STRUCTURES IN THE LOW LEVELS WITH 20-30 F
TEMPERATURE-DEWPOINT SPREADS MAY FAVOR ISOLATED STRONG/DAMAGING
OUTFLOW WINDS WITH THE STRONGEST STORMS.  OVERALL STORM COVERAGE
SHOULD REMAIN RATHER ISOLATED...WHICH COMBINED WITH THE MODEST
BUOYANCY AND POOR MIDLEVEL LAPSE RATES SUGGESTS ONLY A MARGINAL
SEVERE RISK.

..THOMPSON/GRAMS.. 09/14/2016

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

ATTN...WFO...GYX...BOX...OKX...ALY...PHI...BGM...CTP...

LAT...LON   42197236 41837268 41197420 40967571 41217696 41497711
            41677636 42087512 42517424 43217274 43217225 42987199
            42597198 42197236

Nearby

Mesoscale Discussions in New York, 2016Mesoscale Discussions in Pennsylvania, 2016Mesoscale Discussions in Massachusetts, 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.