Winter '09 / '10 - Snow Storm #1 - Blizzard Conditions

Blizzard conditions were observed at Islip...NY between 10:30 PM EST...19-DEC-09 through almost 2 AM EST...20-DEC-09.

Three conditions are needed for a blizzard:

1 - Visibility frequently less than 1/4 SM (< 1320')...

2 - Sustained wind speed or frequent gusts of 30 KTs (35 MPH) or higher...and

3 - Restricted visibility and high-wind conditions observed for at least three hours.

Note the METAR reports of SNINCR 3/xx (three inches-per-hour followed by the amount on the ground...rounded to closest whole number) in the 0456z...0556z...and 0656z observations (Sunday midnight - 3 AM EST)

SPECI KISP 200328Z 36017G27KT 1/8SM +SN BLSN FZFG VV001 M04/M07 A2955 RMK AO2 PK WND 01030/0300 P0001 $

METAR KISP 200356Z 36020G30KT 1/8SM +SN BLSN FZFG VV001 M04/M07 A2952 RMK AO2 PK WND 36031/0330 SLP998 SNINCR 1/7 P0001 T10441067 $

METAR KISP 200456Z 36019G30KT 1/16SM +SN BLSN FZFG VV001 M04/M07 A2949 RMK AO2 PK WND 01034/0441 SLP987 SNINCR 3/10 P0003 T10441067 410111050 $

METAR KISP 200556Z 36020G35KT 1/8SM +SN BLSN FZFG VV001 M04/M07 A2948 RMK AO2 PK WND 35035/0554 SLP985 931114 4/013 SNINCR 3/13 P0002 60013 T10441067 11039 21050 56023 $

METAR KISP 200656Z 35021G32KT 1/8SM +SN BLSN FZFG VV001 M04/M07 A2950 RMK AO2 PK WND 36032/0649 SLP989 SNINCR 3/15 P0003 T10441067 $

METAR KISP 200756Z 35016G22KT 1/4SM +SN FZFG BLSN VV002 M04/M07 A2953 RMK AO2 PK WND 36030/0717 SLP999 SNINCR 2/17 P0003 T10441067 $
 
Blizzards are wind storms where visibility is restricted by falling or blowing snow.
 
Blizzards defined here and here.