Alert archive / New York / Mesoscale Discussions in 2012

Mesoscale Discussion 1345

July 1, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 6:22 PM EDT for 4 states. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Jul 1, 2012, 6:22 PM EDT (22:22 UTC)
Expired
Jul 1, 2012, 7:45 PM EDT
In force
83 min
Issued by
the Storm Prediction Center

Counties Bristol County, MA, Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Middlesex County, NJ, Morris County, NJ, Union County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Queens County, NY, Richmond County, NY, Suffolk County, NY, Westchester County, NY, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI

The radar

The Brookhaven radar (KOKX), 54 km from the middle of the area, began a volume at 22:24 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, 10.4 hours before the alert went out and 54 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 2012-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 254 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 2012-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
254 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1757 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
40 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.

618 
ACUS11 KWNS 012222
SWOMCD
SPC MCD 012222 
MAZ000-RIZ000-CTZ000-NYZ000-NJZ000-012345-

MESOSCALE DISCUSSION 1345
NWS STORM PREDICTION CENTER NORMAN OK
0522 PM CDT SUN JUL 01 2012

AREAS AFFECTED...NERN NJ...FAR SERN NY...SRN CT...RI...SERN MA

CONCERNING...SEVERE THUNDERSTORM WATCH 444...

VALID 012222Z - 012345Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 444
CONTINUES.

SUMMARY...THE THREAT FOR SVR STORMS CONTINUES ACROSS WW 444...WITH
ANY REMAINING SVR THREAT TRANSITIONING TOWARD/OFF THE COAST.
REMAINING VALID PARTS OF THE WW SHOULD BE ALLOWED TO EXPIRE BY THE
SCHEDULED EXPIRATION TIME OF 00Z.

DISCUSSION...THE SVR THREAT IS DECREASING IN SPATIAL EXTENT...AS
DRIER AIR IN THE WAKE OF A PRE-FRONTAL WIND-SHIFT AXIS MAKES
ADDITIONAL PROGRESS TOWARD THE COAST. WITH MLCAPE VALUES OF 500-1750
J/KG IN ADVANCE OF THE WIND-SHIFT AXIS AMIDST MID-LEVEL WLY FLOW
AROUND 35 KT PER UPTON NY VWP DATA -- OFFERING MODEST DEEP SHEAR --
ISOLATED TO SCATTERED ORGANIZED/MULTICELL STORMS WILL CONTINUE TO
TRANSITION TO AND OFF THE COAST FROM LONG ISLAND TOWARD SERN MA
DURING THE NEXT HOUR OR SO. AS NOCTURNAL STABILIZATION
INCREASES...AND DRIER AIR CONTINUES TO FILTER INTO THE REGION...THE
SVR THREAT IS EXPECTED TO HAVE SUBSIDED BY THE 00Z SCHEDULED
EXPIRATION TIME.

..COHEN.. 07/01/2012

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

ATTN...WFO...BOX...OKX...PHI...

LAT...LON   41517061 40927196 40267383 40397453 40867455 41617292
            41897187 41987082 41517061

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 12:11 PM EDTMesoscale DiscussionSPC64 min
Jul 1, 1:35 PM EDTSevere Thunderstorm WatchSPCGreater Bridgeport Planning Region, Capitol Planning Region, Northwest Hills Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region and 1 more6 hr
Jul 1, 3:25 PM EDTMesoscale DiscussionSPC95 min

Nearby

Mesoscale Discussions in New York, 2012Mesoscale Discussions in Connecticut, 2012Mesoscale Discussions in New Jersey, 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.