Alert archive / New York / Mesoscale Discussions in 2009

Mesoscale Discussion 1713

July 29, 20097 states

The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2009, 5:05 PM EDT for 7 states. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Jul 29, 2009, 5:05 PM EDT (21:05 UTC)
Expired
Jul 29, 2009, 6:00 PM EDT
In force
55 min
Issued by
the Storm Prediction Center
All 87 counties

Kent County, DE, New Castle County, DE, Berkshire County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Baltimore County, MD, Caroline County, MD, Cecil County, MD, Harford County, MD, Kent County, MD, Queen Anne's County, MD, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Bronx County, NY, Broome County, NY, Chenango County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Fulton County, NY, Greene County, NY, Kings County, NY, Montgomery County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Otsego County, NY, Putnam County, NY, Queens County, NY, Rensselaer County, NY, Richmond County, NY, Rockland County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Westchester County, NY, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Dauphin County, PA, Delaware County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, York County, PA, Bennington County, VT, Windham County, VT

The radar

The Albany radar (KENX), 135 km from the middle of the area, began a volume at 21:06 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, 9.1 hours before the alert went out and 144 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 2009-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 594 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 2009-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
594 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
646 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 12:22 PM EDTMesoscale DiscussionSPC23 min
Jul 29, 12:49 PM EDTSevere Thunderstorm WatchSPCGreater Bridgeport Planning Region, Capitol Planning Region, Northwest Hills Planning Region, Naugatuck Valley Planning Region8 hr
Jul 29, 2:22 PM EDTMesoscale DiscussionSPC23 min
Jul 29, 7:14 PM EDTMesoscale DiscussionSPC61 min
Jul 29, 1:32 PM EDTMesoscale DiscussionSPCKent, Sussex28 min

Nearby

Mesoscale Discussions in New York, 2009Mesoscale Discussions in Pennsylvania, 2009Mesoscale Discussions in New Jersey, 2009Every mesoscale discussion in 2009

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.