New Hampshire, 2020

Winter Storm in New Hampshire, April 9 to 10, 2020

April 9 to 10, 2020 · NWS GYX · 2 events in 2 counties and zones

An upper low pressure ejected out of the Southwest and reached the East Coast by the 9th. A strong jet streak exiting the Mid Atlantic coast with a coupled jet to the north helped initiate intense secondary cyclogenesis along the New England coast.

Where it happened

Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS GYX wrote it up.

An upper low pressure ejected out of the Southwest and reached the East Coast by the 9th. A strong jet streak exiting the Mid Atlantic coast with a coupled jet to the north helped initiate intense secondary cyclogenesis along the New England coast. Pressures in the center of the storm fell over 30 mb in 24 hours by the time it reached peak intensity near Penobscot Bay on the 10th. This storm spread snow over interior areas with rain at the coast. By the afternoon of the 9th rain flipped to heavy, wet snow generally along a north of a line from the White Mountains to Portland, Maine. Rainfall amounts were around 1 inch south of there.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Gray, ME wrote its last area forecast discussion before the first event at Apr 8, 6:01 PM EST, 15 hours 59 minutes earlier.

Area forecast discussion, Apr 8, 6:01 PM EST, 15 hours 59 minutes before
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Hazardous weather outlook, Apr 8, 3:11 PM EST, 18 hours 49 minutes before
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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 winter storm. Local standard time, as filed.

Winter Storm, Northern Coos

When
April 9, 10:00 AM EST to April 10, 7:00 AM EST
Where
Northern Coos forecast zone
Reported by
Trained Spotter
Coordinates
44.690, -71.305 (the zone’s center; the record gives no point)

Precipitation overspread northern Coos County during the morning of the 9th as mostly rain at the lower elevations, and some snow in the mountains. Temperatures gradually cooled into the upper 30s, but by late afternoon heavier precipitation moved in, temperatures fell to the lower 30s, and rain changed to snow. Snow continued moderate to heavy at times into the very early morning hours of the 10th. As low pressure pulled away significant upslope snow showers continued into the morning of the 10th. Snow totals ranged from around an inch along the Connecticut River bordering Vermont to 10 inches near First Connecticut Lake.

Winter Storm, Southern Coos

When
April 9, 10:00 AM EST to April 10, 7:00 AM EST
Where
Southern Coos forecast zone
Reported by
Trained Spotter
Coordinates
44.690, -71.305 (the zone’s center; the record gives no point)

Precipitation overspread southern Coos County during the morning of the 9th as mostly rain at the lower elevations, and some snow in the mountains. Temperatures gradually cooled into the upper 30s, but by late afternoon heavier precipitation moved in, temperatures fell to the lower 30s, and rain changed to snow. Snow continued moderate to heavy at times into the very early morning hours of the 10th. As low pressure pulled away significant upslope snow showers continued into the morning of the 10th. Snow totals ranged from around an inch along the Connecticut River bordering Vermont to 11 inches in the White Mountains.

What these are

Winter Storm
A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in New Hampshire in 2020Every state in 2020This day in weather historyWarnings in New Hampshire, April 2020

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 878417, 878418.