Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 1966

September 18, 201212 counties in New York

The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2012, 2:10 PM EDT for 12 counties in New York. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Sep 18, 2012, 2:10 PM EDT (18:10 UTC)
Expired
Sep 18, 2012, 3:45 PM EDT
In force
95 min
Issued by
the Storm Prediction Center
Chance of a watch
60%

Counties Clinton County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Saratoga County, NY, St. Lawrence County, NY, Warren County, NY, Washington County, NY

The radar

The Ft Drum radar (KTYX), 76 km from the middle of the area, began a volume at 18:10 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 6.2 hours before the alert went out and 143 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 12:00Z on 2012-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 12:00Z on 2012-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 251 square meters per square second.1939587897Sfc1 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
2 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
572 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
251 m²/s²
0-3 km storm-relative helicity
226 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

743 
ACUS11 KWNS 181810
SWOMCD
SPC MCD 181810 
NYZ000-181945-

MESOSCALE DISCUSSION 1966
NWS STORM PREDICTION CENTER NORMAN OK
0110 PM CDT TUE SEP 18 2012

AREAS AFFECTED...NERN NY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 181810Z - 181945Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...CONVECTIVE TRENDS WILL BE MONITORED...AND THE ISSUANCE OF
A TORNADO WATCH IS POSSIBLE.

DISCUSSION...FORCING FOR ASCENT ALONG A PRE-FRONTAL CONFLUENCE AXIS
HAS SUPPORTED THE DEVELOPMENT OF A NARROW...LOW-TOPPED SQUALL LINE
THAT EXTENDS FROM THE EAST END OF LAKE ONTARIO INTO S-CNTRL NY.
WHILE PRECIPITATION IS LIMITING THE DEGREE OF BOUNDARY-LAYER
DESTABILIZATION...CONTINUED NWD TRANSPORT OF RICHER LOW-LEVEL
MOISTURE/WARMER AIR SHOULD SUPPORT MODEST DESTABILIZATION AHEAD OF
THE LINE. AND WITH 52 KT OF 0-1-KM BULK SHEAR PER BURLINGTON VERMONT
VWP DATA...WHICH ALSO INDICATE A LARGE/CURVED LOW-LEVEL
HODOGRAPH...EMBEDDED MESOVORTICES/LEWP STRUCTURES WITH SVR WINDS AND
TORNADOES WILL BE OF CONCERN. AS SUCH...THE AREA WILL BE MONITORED
FOR THE POTENTIAL DEEPENING/STRENGTHENING OF THE CONVECTIVE LINE
SUPPORTING THE ISSUANCE OF A TORNADO WATCH.

..COHEN/MEAD.. 09/18/2012

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

ATTN...WFO...BTV...ALY...BGM...BUF...

LAT...LON   43187342 42907400 43007458 43417486 43447561 43527613
            43927626 44247596 44607537 44867487 44917363 44187346
            43187342

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 18, 11:14 AM EDTMesoscale DiscussionSPCBronx, Dutchess, Kings, Nassau, New York, Orange and 5 more91 min
Sep 18, 11:19 AM EDTMesoscale DiscussionSPCAlbany, Broome, Chenango, Delaware, Fulton, Greene and 8 more86 min
Sep 18, 12:10 PM EDTTornado WatchSPCBronx, Kings, New York, Orange, Queens, Richmond and 2 more9 hr
Sep 18, 12:57 PM EDTMesoscale DiscussionSPCAlbany, Broome, Chemung, Chenango, Columbia, Cortland and 11 more93 min
Sep 18, 1:21 PM EDTTornado WatchSPCBroome, Chenango, Cortland, Delaware, Madison, Oneida and 4 more5 hr
Sep 18, 1:56 PM EDTMesoscale DiscussionSPCKings, New York, Orange, Richmond, Rockland64 min
Sep 18, 3:26 PM EDTMesoscale DiscussionSPCAlbany, Columbia, Dutchess, Essex, Franklin, Fulton and 11 more34 min
Sep 18, 3:38 PM EDTTornado WatchSPCAlbany, Columbia, Dutchess, Fulton, Greene, Hamilton and 13 more8 hr
Sep 18, 4:21 PM EDTMesoscale DiscussionSPCAlbany, Bronx, Chenango, Columbia, Delaware, Dutchess and 24 more114 min
Sep 18, 6:08 PM EDTMesoscale DiscussionSPCBronx, Kings, New York, Queens, Richmond67 min
Sep 18, 7:42 PM EDTMesoscale DiscussionSPCBronx, Kings, Nassau, Putnam, Queens, Suffolk and 1 more63 min

Nearby

Mesoscale Discussions in New York, 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.