Alert archive / New Hampshire / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS Gray, ME

July 1, 2017Carroll County, Coos County, Grafton County, New Hampshire

NWS Gray, ME issued this flash flood warning at Jul 1, 2017, 9:34 PM EDT for Carroll County, Coos County, Grafton County, New Hampshire. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 1, 2017, 9:34 PM EDT (01:34 UTC)
Expired
Jul 2, 2017, 12:30 AM EDT
In force
3 hr
Issued by
NWS Gray, ME
Area
Storm-based polygon
Flood severity
None

Counties Carroll County, NH, Coos County, NH, Grafton County, NH

The radar

The Portland,ME radar (KGYX), 99 km from the middle of the area, began a volume at 01:35 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.

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 1.6 hours before the alert went out and 247 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.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 00:00Z on 2017-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 844 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 00:00Z on 2017-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
844 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
760 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

324 
WGUS51 KGYX 020134
FFWGYX
NHC003-007-009-020430-
/O.NEW.KGYX.FF.W.0013.170702T0134Z-170702T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Gray ME
934 PM EDT SAT JUL 1 2017

The National Weather Service in Gray Maine has issued a

* Flash Flood Warning for...
  Southeastern Coos County in northern New Hampshire...
  Eastern Grafton County in northern New Hampshire...
  Northern Carroll County in northern New Hampshire...

* Until 1230 AM EDT

* At 933 PM EDT, Doppler radar indicated another round of 
  thunderstorms producing heavy rain across the warned area. Up to 
  three inches of rain have already fallen. Additional Flash 
  flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Conway, Bethlehem, Lincoln, Plymouth, Holderness, Ashland,
  Franconia, Woodstock, Pinkham Notch, Mount Washington, Sandwich,
  Carroll, Gorham, Bartlett, Jackson, Albany, Hebron, Chatham, Easton
  and Ellsworth.

This includes Interstate 93 between mile markers 79 and 111.
 
This also includes...
  Crawford Notch State Park, Franconia Notch, Cannon Mountain, North
Twin Mountain, and Franconia Ridge.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

Campers should be particularly aware of where they are relative to 
rivers and streams. Rivers may rise rapidly. 

&&

LAT...LON 4416 7176 4441 7102 4408 7100 4369 7177

$$

MBC

The office that day

Everything else NWS Gray, ME issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 8:01 PM EDTSpecial Weather StatementGYXCheshire59 min
Jul 1, 9:45 PM EDTRiver Flood WarningGYXGrafton24 hr
Jul 1, 11:58 PM EDTRiver Flood WarningGYXGrafton9 hr
Jul 2, 1:20 AM EDTRiver Flood WarningGYXCarroll16 hr
Jul 2, 3:24 PM EDTBeach Hazards StatementGYXRockingham30 hr

Nearby

Flash Flood Warnings in New Hampshire, 2017Every flash flood warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.