Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 937

May 28, 2012Sussex County, New Jersey; 12 counties in New York; 5 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 28, 2012, 11:19 AM EDT for Sussex County, New Jersey; 12 counties in New York; 5 counties in Pennsylvania. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
May 28, 2012, 11:19 AM EDT (15:19 UTC)
Expired
May 28, 2012, 12:15 PM EDT
In force
56 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Sussex County, NJ, Broome County, NY, Chenango County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Greene County, NY, Orange County, NY, Otsego County, NY, Putnam County, NY, Rockland County, NY, Sullivan County, NY, Ulster County, NY, Lackawanna County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA

The radar

The Albany radar (KENX), 93 km from the middle of the area, began a volume at 15:19 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, 3.3 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 2012-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 659 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 2012-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
659 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
812 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
80 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

510 
ACUS11 KWNS 281520
SWOMCD
SPC MCD 281519
CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-281615-

MESOSCALE DISCUSSION 0937
NWS STORM PREDICTION CENTER NORMAN OK
1019 AM CDT MON MAY 28 2012

AREAS AFFECTED...S CNTRL AND SERN NY...NERN PA...NRN NJ...SRN NEW
ENGLAND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 281519Z - 281615Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...POORLY ORGANIZED MCS OVER CNTRL NY MAY BECOME MORE
ORGANIZED AND CONTINUE TO PROGRESS ESEWD. SMALL BOWING SEGMENTS AND
SUPERCELLS WITHIN THE BROADER CIRCULATION WILL BE CAPABLE OF DMGG
WINDS AND LARGE HAIL LATER THIS AFTERNOON.

DISCUSSION...A WEAK UPPER WAVE OBSERVED ON 15Z WV IMAGERY OVER W
CNTRL NY APPEARS TO HAVE EMANATED FROM SRN MN 24 HRS AGO. THE SUBTLE
WAVE HAS PROVIDED SUFFICIENT FORCING FOR ASCENT FOR THE DEVELOPMENT
OF A CURRENTLY ELEVATED COMPLEX OF STORMS...NOW ORIENTED ACROSS
CNTRL NY. 15Z SURFACE ANALYSIS PLACES A WAVY STATIONARY FRONT FROM
SRN NEW ENGLAND TO APPROXIMATELY BUFFALO...AND SHOULD SERVE AS A
FOCUS FOR CONVECTIVE DEVELOPMENT/SUSTENANCE THIS AFTERNOON. WITH THE
PERSISTENCE OF A BROADER ERN UPPER RIDGE...WELL ABOVE NORMAL HIGH
TEMPERATURES FORECAST IN THE UPPER 80S TO LOWER 90S F AND A
LINGERING MOIST AIR MASS /CHARACTERIZED BY DEW POINTS IN THE MID TO
UPPER 60S F/ WILL ERODE REMAINING CONVECTIVE INHIBITION AND
CONTRIBUTE TO MODERATE INSTABILITY. MODEL FORECASTS SUGGEST NEAR
SURFACE-BASED CONVECTION IS POSSIBLE IN THE 17-18Z PERIOD...WITH A
SUBSEQUENT INCREASE IN DMGG WIND POTENTIAL LATER THIS AFTERNOON AS
LOW-LEVEL LAPSE RATES CONTINUE TO STEEPEN. THE 12Z BUFFALO SOUNDING
REFLECTS AN EWD ADVECTION OF THE EML...WITH STEEP MID-LEVEL LAPSE
RATES NEAR 7 C/KM. WITH STRONGER MID-LEVEL WINDS AROUND THE
PERIPHERY OF THE RIDGE...OCCASIONALLY ROTATING STORMS AND
SEMI-ORGANIZED BOWING SEGMENTS CAPABLE OF LARGE HAIL AND DMGG WINDS
WILL BE POSSIBLE AS SURFACE-BASED STORMS DEVELOP LATER TODAY.

..HURLBUT/CARBIN.. 05/28/2012

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

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

LAT...LON   42767507 42257338 41607289 41297326 41067416 40957508
            41657623 42287616 42767507

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 2:25 PM EDTMesoscale DiscussionSPC65 min
May 28, 8:09 AM EDTMesoscale DiscussionSPCCayuga, Fulton, Herkimer, Madison, Montgomery, Oneida and 3 more96 min

Nearby

Mesoscale Discussions in New York, 2012Mesoscale Discussions in Pennsylvania, 2012Mesoscale Discussions in Connecticut, 2012Every mesoscale discussion in 2012

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.