Alert archive / New Hampshire / Flash Flood Warnings in 2021
Flash Flood Warning 8, NWS Gray, ME
NWS Gray, ME issued this flash flood warning at Jul 18, 2021, 12:01 AM EDT for Cheshire County, Hillsborough County, New Hampshire. It was in force for 4 hr. 4 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 18, 2021, 12:01 AM EDT (04:01 UTC)
- Expired
- Jul 18, 2021, 4:00 AM EDT
- In force
- 4 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), 143 km from the middle of the area, began a volume at 04:05 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 18, 12:40 AM EDT | FLASH FLOOD | 2 Wnw Peterborough, NH | MEDIA FOOTAGE OF OLD TOWN ROAD IN PETERBOROUGH WASHED OUT ON BOTH SIDES. TIME ESTIMATED BY RADAR. |
| Jul 18, 1:00 AM EDT | FLASH FLOOD | Fitzwilliam, NH | MULTIPLE ROAD WASHOUTS CAUSED BY FLASH FLOODING. TIME ESTIMATED BY RADAR. |
| Jul 18, 1:00 AM EDT | FLASH FLOOD | Richmond, NH | EMERGENCY MANAGER DIRECTOR REPORTS MULTIPLE IMPASSABLE ROADS DUE TO WASHOUTS. |
| Jul 18, 2:00 AM EDT | FLASH FLOOD | 2 Ssw Peterborough, NH | CORRECTS PREVIOUS FLASH FLOOD REPORT FROM 2 SSW PETERBOROUGH. OLD TOWN ROAD AND OLD JAFFREY ROAD IN PETERBOROUGH CLOSED DUE TO WASHOUTS CAUSED BY FLASH FLOODING. TIME ESTIMATED BY RADAR. |
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 00:00Z, 4.0 hours before the alert went out and 125 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
- 30 J/kg
- Mixed-layer CIN
- -90 J/kg
- Mixed-layer LCL
- 630 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 163 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
149
WGUS51 KGYX 180401
FFWGYX
NHC005-011-180800-
/O.NEW.KGYX.FF.W.0008.210718T0401Z-210718T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Gray ME
1201 AM EDT Sun Jul 18 2021
The National Weather Service in Gray Maine has issued a
* Flash Flood Warning for...
Southeastern Cheshire County in southern New Hampshire...
Southwestern Hillsborough County in southern New Hampshire...
* Until 400 AM EDT.
* At 1201 AM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Up to two inches of rain have
already fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar indicated.
IMPACT...Flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other
drainage and low lying areas.
* Some locations that will experience flooding include...
Keene, Jaffrey, Swanzey, Peterborough, Winchester, Greenfield,
Dublin, Richmond, Harrisville, Nelson, Marlborough, Rindge, New
Ipswich, Sharon, Roxbury, Fitzwilliam, Troy, Temple, Hancock and
Sullivan.
Additional rainfall amounts of 1 to 2 inches are possible in the
warned area.
This also includes...
Mount Monadnock and North Pack Monadnock.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 4295 7184 4272 7187 4273 7241 4301 7227
FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR
$$
ARNOTT1 follow-up statement
315
WGUS51 KGYX 180415
FFWGYX
NHC005-011-180715-
/O.NEW.KGYX.FF.W.0008.210718T0415Z-210718T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Gray ME
Issued by National Weather Service Caribou ME
1215 AM EDT Sun Jul 18 2021
The National Weather Service in Gray has issued a
* Flash Flood Warning for...
Southern Cheshire County in southern New Hampshire...
Southwestern Hillsborough County in southern New Hampshire...
* Until 315 AM EDT.
* At 1215 AM EDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 2 and 4 inches of rain
have fallen. Additional rainfall amounts of 1 to 2 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Keene, Jaffrey, Swanzey, Peterborough, Rindge, Winchester,
Marlborough, Fitzwilliam, Greenfield, and Lyndeborough.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4294 7242 4293 7241 4295 7241 4294 7240
4294 7238 4294 7183 4271 7187 4273 7244
4291 7251 4291 7250
FLASH FLOOD...RADAR INDICATED
$$
TD/VJNThe office that day
Everything else NWS Gray, ME issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 17, 10:42 PM EDT | Areal Flood Warning | GYX | Cheshire, Hillsborough | 3 hr |
| Jul 17, 11:03 PM EDT | Special Weather Statement | GYX | Hillsborough | 42 min |
| Jul 18, 3:55 AM EDT | Areal Flood Advisory | GYX | Cheshire, Hillsborough | 2 hr |
| Jul 18, 5:56 AM EDT | Special Weather Statement | GYX | Rockingham | 34 min |
| Jul 18, 6:26 AM EDT | Areal Flood Warning | GYX | Cheshire, Hillsborough | 6 hr |
| Jul 18, 6:34 AM EDT | Special Weather Statement | GYX | Rockingham | 26 min |
| Jul 18, 7:59 AM EDT | Areal Flood Advisory | GYX | Belknap, Carroll, Rockingham, Strafford | 3 hr |
| Jul 18, 3:00 PM EDT | Areal Flood Warning | GYX | Cheshire | 30 hr |
Nearby
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.