Alert archive / New York / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 87, NWS Buffalo, NY

August 20, 2009Orleans County, New York

NWS Buffalo, NY issued this severe thunderstorm warning at Aug 20, 2009, 8:31 PM EDT for Orleans County, New York. It was in force for 59 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 20, 2009, 8:31 PM EDT (00:31 UTC)
Expired: Aug 20, 2009, 9:30 PM EDT
In force: 59 min
Issued by: NWS Buffalo, NY
Area: Storm-based polygon

County Orleans County, NY

The radar

The Buffalo radar (KBUF), 55 km from the middle of the area, began a volume at 00:32 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 20, 6:54 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 0.5 hours before the alert went out and 55 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 828 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 1273 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 232 m²/s²
0-3 km storm-relative helicity: 306 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 6.5

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KBUF 210031
SVRBUF
NYC073-210130-
/O.NEW.KBUF.SV.W.0087.090821T0031Z-090821T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BUFFALO NY
831 PM EDT THU AUG 20 2009

THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ORLEANS COUNTY IN WESTERN NEW YORK

* UNTIL 930 PM EDT

* AT 828 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS
  IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE       
  EXTENDING FROM 8 MILES NORTHEAST OF NIAGARA FALLS TO AMHERST TO    
  KENMORE...AND MOVING NORTHEAST AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  MEDINA BY 905 PM EDT...
  POINT BREEZE BY 915 PM EDT...
  ALBION BY 920 PM EDT...
  KENDALL BY 930 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE ARE DANGEROUS STORMS. IF YOU ARE IN THE PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS AND DEADLY CLOUD TO GROUND LIGHTNING. 
PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY INSIDE A STRONG 
BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 200 AM EDT FRIDAY
MORNING FOR WESTERN NEW YORK.

&&

LAT...LON 4337 7847 4337 7845 4338 7838 4337 7824
      4338 7800 4337 7799 4325 7799 4313 7828
      4313 7847
TIME...MOT...LOC 0030Z 235DEG 41KT 4320 7891 4307 7876
          4295 7883

$$

ZAFF

2 follow-up statements

000 
WWUS51 KBUF 210115
SVSBUF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
915 PM EDT THU AUG 20 2009

NYC073-210130-
/O.CON.KBUF.SV.W.0087.000000T0000Z-090821T0130Z/
ORLEANS NY-
915 PM EDT THU AUG 20 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR ORLEANS COUNTY...

AT 914 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE 
EXTENDING FROM POINT BREEZE TO ALBION...MOVING NORTHEAST AT 50 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  ALBION BY 920 PM EDT...
  KENDALL BY 930 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE ARE DANGEROUS STORMS THAT HAVE A HISTORY OF PRODUCING WIND 
DAMAGE ACROSS WESTERN NEW YORK. IF YOU ARE IN THE PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS...AND DEADLY CLOUD TO GROUND 
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY 
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT 
TONIGHT FOR WESTERN NEW YORK.

&&

LAT...LON 4314 7846 4337 7847 4338 7800 4337 7799
      4325 7799 4313 7828 4313 7847
TIME...MOT...LOC 0114Z 236DEG 43KT 4343 7820 4337 7814
          4324 7826

$$

HITCHCOCK

000 
WWUS51 KBUF 210130
SVSBUF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE BUFFALO NY
930 PM EDT THU AUG 20 2009

NYC073-210140-
/O.EXP.KBUF.SV.W.0087.000000T0000Z-090821T0130Z/
ORLEANS NY-
930 PM EDT THU AUG 20 2009

...THE SEVERE THUNDERSTORM WARNING FOR ORLEANS COUNTY HAS EXPIRED...

AT 930 PM EDT NATIONAL WEATHER SERVICE RADAR SHOWED THAT THE SEVERE 
THUNDERSTORM THAT PROMPTED THE WARNING HAD EXITED THE WARNED AREA 
AND WEAKENED...THUS THE WARNING HAS BEEN ALLOWED TO EXPIRE.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT 
TONIGHT FOR WESTERN NEW YORK.

LAT...LON 4314 7846 4337 7847 4338 7800 4337 7799
      4325 7799 4313 7828 4313 7847
TIME...MOT...LOC 0115Z 236DEG 43KT 4343 7818 4337 7812
          4324 7825

$$

HITCHCOCK

The office that day

Everything else NWS Buffalo, NY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 20, 8:31 PM EDT	Special Marine Warning	BUF		44 min
Aug 20, 8:52 PM EDT	Areal Flood Advisory	BUF	Allegany, Cattaraugus, Chautauqua, Erie, Genesee, Niagara and 2 more	3 hr
Aug 20, 8:59 PM EDT	Severe Thunderstorm Warning	BUF	Cattaraugus, Chautauqua	61 min
Aug 20, 9:16 PM EDT	Special Marine Warning	BUF		89 min
Aug 20, 9:52 PM EDT	Severe Thunderstorm Warning	BUF	Allegany, Cattaraugus	53 min
Aug 20, 10:04 PM EDT	Severe Thunderstorm Warning	BUF	Genesee, Monroe, Orleans	56 min
Aug 20, 10:06 PM EDT	Severe Thunderstorm Warning	BUF	Allegany	54 min
Aug 20, 10:19 PM EDT	Special Marine Warning	BUF		86 min
Aug 20, 10:25 PM EDT	Tornado Warning	BUF	Allegany	35 min
Aug 20, 11:28 PM EDT	Special Marine Warning	BUF		92 min

Nearby

Severe Thunderstorm Warnings in New York, 2009 Every severe thunderstorm warning 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.