|
TYPE OF ISSUANCE
|
WHEN ISSUED FOR SOUTHERN NEW ENGLAND
|
| WINTER WEATHER ADVISORY |
When the following expected in the next
24-36 hours: Any accretion of freezing rain or freezing drizzle on
road surfaces
Blowing/drifting snow occasionally reducing visibility
to <= 1/4 mile
Snow or snow and sleet combination:
3, 4, or 5 inches averaged over a CT, MA, RI forecast
zone in 12 hours.
4 or 5 inches averaged over a NH forecast zone in 12
hours
|
| WINTER STORM WARNING |
When the following expected in the next
24-36 hours: 1/2 inch accretion of freezing rain in any zone
Snow or snow and sleet combination: 6 inches
averaged over a forecast zone in 12 hours
8 inches averaged over a CT, MA, RI forecast zone in
24 hours.
9 inches averaged over a NH forecast zone in 24 hours
|
| BLIZZARD WARNING |
At least 3 hours, falling and/or blowing
snow frequently reduces visibility to < 1/4 mile AND sustained
winds or frequent gusts >= 35 mph |
| WIND CHILL ADVISORY |
Wind chill index between -15F and -24F for
at least 3 hours using only the sustained wind (except -20F to -29F
southern NH) |
| WIND CHILL WARNING |
Wind chill index<= -25F for at least
3 hours using only sustained wind (except -30F southern NH) |
| WIND ADVISORY |
Sustained winds 31-39 mph (27-34 kts) for
at least 1 hour; OR any gusts to 46-57 mph (40-49 kts) |
| HIGH WIND WARNING |
Sustained winds 40-73 mph (>= for at
least 1 hour; OR any gusts >= 58 mph (>= 50 kts) |
| INLAND HIGH WIND WARNING FOR
HURRICANE FORCE WINDS |
Sustained winds >= 74
mph |
| DENSE FOG ADVISORY |
Widespread visibility <= 1/4 mile
for at least 3 hours |
| SMALL CRAFT ADVISORY |
Sustained wind 25-33 knots AND/OR Seas
>= 5 feet within 12 hours |
| GALE WARNING |
Sustained wind 34-47 knots within 24 hours
from a non-tropical system |
| STORM WARNING |
Sustained wind >= 48 knots within 24
hours from a non-tropical system |
| TROPICAL STORM WARNING |
Sustained winds of 39-73 mph (34-63 knots)
within 24 hours |
| HURRICANE WARNING |
Sustained winds >= 74 mph (64 knots)
within 24 hours; implies dangerous storm surge |
| SPECIAL MARINE WARNING |
Brief/sudden occurrence of sustained wind
or frequent gusts >= 34 knots, usually associated with
thunderstorms; also issued for waterspouts |
| SEVERE THUNDERSTORM WARNING |
Thunderstorms with wind gusts >= 58
mph AND/OR hail >= 3/4" in diameter |
| TORNADO WARNING |
Likelihood of a tornado within the given
area based on radar or actual sighting; usually accompanied by
conditions indicated above for "Severe Thunderstorm Warning" |
| FLASH FLOOD WARNING |
A flood that occurs within a few hours of
heavy rainfall, a dam or levee failure, or water released from an ice jam |
| FLOOD WARNING |
Expected inundation of a normally dry area
near a stream or other watercourse; OR unusually severe ponding
of water expected |
| RIVER FLOOD WARNING |
Expected flooding of main stem rivers (such
as the Merrimack, Charles, Connecticut, etc.) |
| COASTAL FLOOD WARNING |
Widespread coastal flooding expected
within 12 hours; more than just typical overwash |