Alert archive / New York / Tornado Watches in 2003

Tornado Watch 934

September 27, 200312 counties in New York; Erie County, Pennsylvania

The Storm Prediction Center issued this tornado watch at Sep 27, 2003, 2:35 AM EDT for 12 counties in New York; Erie County, Pennsylvania. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Sep 27, 2003, 2:35 AM EDT (06:35 UTC)
Expired
Sep 27, 2003, 8:00 AM EDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Allegany County, NY, Cattaraugus County, NY, Chautauqua County, NY, Erie County, NY, Genesee County, NY, Livingston County, NY, Monroe County, NY, Niagara County, NY, Ontario County, NY, Orleans County, NY, Wayne County, NY, Wyoming County, NY, Erie County, PA

The radar

The Buffalo radar (KBUF), 41 km from the middle of the area, began a volume at 06:36 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.

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 6.6 hours before the alert went out and 39 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, Buffalo Intl Airport, NY at 00:00Z on 2003-09-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Buffalo Intl Airport, NY at 00:00Z on 2003-09-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1576 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
248 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.

000 
WWUS20 KWNS 270635
SEL4  
SPC WW 270635
NYZ000-LOZ000-LEZ000-271200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 934 
NWS STORM PREDICTION CENTER NORMAN OK 
235 AM EDT SAT SEP 27 2003

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       WESTERN NEW YORK
       LAKE ONTARIO
       LAKE ERIE

EFFECTIVE THIS SATURDAY MORNING FROM 235 AM UNTIL 800 AM EDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 60 STATUTE MILES EAST AND WEST
OF A LINE FROM 25 MILES NORTH NORTHWEST OF ROCHESTER NEW YORK TO
15 MILES SOUTHEAST OF JAMESTOWN NEW YORK.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.


OTHER WATCH INFORMATION...CONTINUE...WW 933...


DISCUSSION...ENVIRONMENT OVER WRN NY CONTINUES TO BECOME MORE
FAVORABLE FOR WIND DAMAGE AND/OR ISOLATED TORNADOES AS BROKEN SQUALL
LINE PROGRESSES EWD ACROSS LAKE ERIE.  TEMPERATURES HAVE WARMED A
FEW DEGREES AT THE SURFACE SUGGESTING SOME MIXING IS OCCURRING
WITHIN THE BOUNDARY LAYER  AND CAP IS WEAKENING.  IN
ADDITION...STRONGEST PRESSURE FALLS AND LOWER 60F SURFACE DEW POINTS
HAVE SPREAD NWD INTO THE REGION.  GIVEN THE EXTREME SHEAR WITH 0-1
KM SHEAR IN EXCESS OF 35 KT...EMBEDDED BRIEF SUPERCELLS OR SMALL
SCALE BOW ECHOES CAN BE EXPECTED AS STORMS MOVE ACROSS WRN NY EARLY
THIS MORNING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 350.
MEAN STORM MOTION VECTOR 24040.


...EVANS

432,0763 415,0775 415,0801 432,0790

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 27, 1:58 AM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Cayuga, Erie, Genesee, Livingston and 9 more62 min
Sep 27, 6:39 AM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Erie, Livingston, Wyoming96 min
Sep 27, 2:22 PM EDTMesoscale DiscussionSPCBroome, Cayuga, Chemung, Ontario, Schuyler, Seneca and 4 more113 min
Sep 27, 4:05 PM EDTSevere Thunderstorm WatchSPCCayuga, Chemung, Cortland, Onondaga, Ontario, Schuyler and 6 more5 hr
Sep 27, 6:52 PM EDTMesoscale DiscussionSPCCayuga, Ontario, Schuyler, Seneca, Steuben, Wayne and 1 more53 min
Sep 27, 12:06 AM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Crawford, Lawrence and 3 more84 min
Sep 27, 12:40 AM EDTTornado WatchSPCBeaver, Butler, Crawford, Forest, Lawrence, Mercer and 2 more5 hr
Sep 27, 3:37 AM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Cambria, Cameron and 17 more113 min
Sep 27, 5:15 AM EDTMesoscale DiscussionSPCBeaver, Crawford, Lawrence, Mercer, Venango, Warren60 min

Nearby

Tornado Watches in New York, 2003Tornado Watches in Pennsylvania, 2003Every tornado watch in 2003

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.