Alert archive / New Hampshire / Flash Flood Warnings in 2021
Flash Flood Warning 6, NWS Gray, ME
NWS Gray, ME issued this flash flood warning at Jul 17, 2021, 7:45 PM EDT for Cheshire County, Hillsborough County, New Hampshire. It was in force for 3 hr. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 17, 2021, 7:45 PM EDT (23:45 UTC)
- Expired
- Jul 17, 2021, 10:45 PM EDT
- In force
- 3 hr
- Issued by
- NWS Gray, ME
- Area
- Storm-based polygon
- Flood severity
- None
Counties Cheshire County, NH, Hillsborough County, NH
The radar
The Boston radar (KBOX), 128 km from the middle of the area, began a volume at 23:45 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 17, 8:00 PM EDT | HEAVY RAIN 0.97 | 2 Se Keene, NH | OBSERVER REPORTED 0.97 INCHES OF RAIN IN 1 HOUR AND SEVERAL INCHES OF WATER ON VALLEY ST. |
| Jul 17, 9:00 PM EDT | FLASH FLOOD | 1 Ssw Dublin, NH | LAW ENFORCEMENT REPORTED THAT MAIN STREET IN DUBLIN NEAR DUBLIN POND IS FLOODED WITH SEVERAL FEET OF WATER COVERING THE ROAD AND THAT VEHICLES ARE STALLED OUT. |
| Jul 17, 9:17 PM EDT | FLASH FLOOD | 2 Ese Keene, NH | LAW ENFORCEMENT REPORTED THAT A PORTION OF ROXBURY STREET IN KEENE HAS BEEN WASHED OUT DUE TO FLASH FLOODING. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 11.8 hours before the alert went out and 137 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 958 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 83 m²/s²
- 0-3 km storm-relative helicity
- 163 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
708
WGUS51 KGYX 172345
FFWGYX
NHC005-011-180245-
/O.NEW.KGYX.FF.W.0006.210717T2345Z-210718T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Gray ME
745 PM EDT Sat Jul 17 2021
The National Weather Service in Gray has issued a
* Flash Flood Warning for...
Southeastern Cheshire County in southern New Hampshire...
Southwestern Hillsborough County in southern New Hampshire...
* Until 1045 PM EDT.
* At 745 PM EDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Up to 2
inches of rain have fallen. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Keene, Jaffrey, Swanzey, Peterborough, Rindge, Winchester,
Marlborough, Fitzwilliam, Greenfield, and Lyndeborough.
This includes the following Rec locations...
Mount Monadnock, North Pack Monadnock.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.
&&
LAT...LON 4273 7240 4298 7238 4295 7180 4271 7181
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
Tubbs1 follow-up statement
654
WGUS71 KGYX 180136
FFSGYX
Flash Flood Statement
National Weather Service Gray ME
936 PM EDT Sat Jul 17 2021
NHC005-011-180245-
/O.CON.KGYX.FF.W.0006.000000T0000Z-210718T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cheshire NH-Hillsborough NH-
936 PM EDT Sat Jul 17 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT THIS
EVENING FOR SOUTHEASTERN CHESHIRESOUTHWESTERN HILLSBOROUGH
COUNTIES...
At 936 PM EDT, local law enforcement reported multiple streets
flooded across Keene and Jaffrey. Up to 3 inches of rain have
fallen. Although rainfall rates have decreased, additional runoff is
still expected.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Law enforcement reported.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Keene, Jaffrey, Swanzey, Peterborough, Rindge, Winchester,
Marlborough, Fitzwilliam, Greenfield, and Lyndeborough.
This includes the following Rec locations...
Mount Monadnock, North Pack Monadnock.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.
&&
LAT...LON 4273 7240 4298 7238 4295 7180 4271 7181
FLASH FLOOD...OBSERVED
$$
TubbsNearby
Flash Flood Warnings in New Hampshire, 2021Every flash flood warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.