Alert archive / New York / Mesoscale Discussions in 2004

Mesoscale Discussion 739

May 18, 200434 counties in New York; 7 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 18, 2004, 1:04 PM EDT for 34 counties in New York; 7 counties in Pennsylvania. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
May 18, 2004, 1:04 PM EDT (17:04 UTC)
Expired
May 18, 2004, 2:00 PM EDT
In force
56 min
Issued by
the Storm Prediction Center
All 41 counties

Albany County, NY, Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Clinton County, NY, Cortland County, NY, Delaware County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Lewis County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Oswego County, NY, Otsego County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Sullivan County, NY, Tioga County, NY, Tompkins County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Yates County, NY, Bradford County, PA, Lackawanna County, PA, Luzerne County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA

The radar

The Binghamton radar (KBGM), 80 km from the middle of the area, began a volume at 17:06 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 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, 5.1 hours before the alert went out and 137 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 2004-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 2004-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 201 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
6 J/kg
Mixed-layer CIN
-326 J/kg
Mixed-layer LCL
662 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
201 m²/s²
0-3 km storm-relative helicity
186 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.

972 
ACUS11 KWNS 181704
SWOMCD
SPC MCD 181704 
VTZ000-NYZ000-PAZ000-181800-

MESOSCALE DISCUSSION 0739
NWS STORM PREDICTION CENTER NORMAN OK
1204 PM CDT TUE MAY 18 2004

AREAS AFFECTED...CENTRAL/ERN NY INTO NERN PA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 181704Z - 181800Z

WW MAY BE NEEDED IN THE NEXT HOUR OR SO.

CONVECTION IS INTENSIFYING ACROSS CENTRAL AND WRN NY OVER HIGHER
TERRAIN AND INVOF LAKE BREEZES AS LARGE SCALE ASCENT INCREASES AHEAD
OF APPROACHING UPPER TROUGH.  AFTERNOON HEATING IS NOW SUPPORTING
1500-2000 J/KG SBCAPES OVER THIS REGION.  GIVEN STRENGTH OF SHEAR
OVER THIS REGION /I.E. 0-6 KM SHEAR FROM 40-50 KT/ ...SEVERE THREAT
IS INCREASING. AS STORMS INCREASE...THEY SHOULD EVOLVE INTO
SUPERCELLS AND SMALL LINES/BOW ECHOES THIS AFTERNOON AND CONTINUE
INTO THE EARLY EVENING...AHEAD OF APPROACHING COLD FRONT.

..EVANS.. 05/18/2004

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

ATTN...WFO...BTV...ALY...PHI...BGM...BUF...CTP...

42357758 43697665 44967365 43497335 42037373 40877593

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 18, 12:54 PM EDTMesoscale DiscussionSPCCattaraugus66 min
May 18, 1:50 PM EDTSevere Thunderstorm WatchSPCAlbany, Allegany, Broome, Cattaraugus, Cayuga, Chemung and 39 more8 hr
May 18, 2:54 PM EDTMesoscale DiscussionSPCBronx, Dutchess, Kings, New York, Orange, Putnam and 3 more96 min
May 18, 4:38 PM EDTMesoscale DiscussionSPCAlbany, Chenango, Cortland, Fulton, Greene, Madison and 7 more2 hr
May 18, 6:24 PM EDTMesoscale DiscussionSPCAlbany, Broome, Cayuga, Chemung, Chenango, Columbia and 22 more2 hr
May 18, 1:45 PM EDTSevere Thunderstorm WatchSPCAllegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 6 more6 hr
May 18, 7:09 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Fayette, Greene and 3 more96 min
May 18, 7:49 PM EDTMesoscale DiscussionSPCChester, Delaware, Lancaster, Montgomery, Philadelphia, York2 hr

Nearby

Mesoscale Discussions in New York, 2004Mesoscale Discussions in Pennsylvania, 2004Every mesoscale discussion in 2004

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.