Alert archive / New Hampshire / Flash Flood Warnings in 2012

Flash Flood Warning 23, NWS Boston/Norton, MA

August 16, 2012Hillsborough County, New Hampshire

NWS Boston/Norton, MA issued this flash flood warning at Aug 16, 2012, 4:14 AM EDT for Hillsborough County, New Hampshire. It was in force for 2 hr. 2 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: Aug 16, 2012, 4:14 AM EDT (08:14 UTC)
Expired: Aug 16, 2012, 6:15 AM EDT
In force: 2 hr
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

County Hillsborough County, NH

The radar

The Boston radar (KBOX), 116 km from the middle of the area, began a volume at 08:15 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
Aug 16, 4:15 AM EDT	FLASH FLOOD	Manchester, NH	LOCAL LAW INFORCEMENT REPORT 2 TO 3 FEET OF WATER ON CHESTNUT STREET.
Aug 16, 4:25 AM EDT	FLASH FLOOD	Manchester, NH	LOCAL POLICE REPORT CAR STUCK IN FLOOD WATERS AT THE INTERSECTION OF CONNECTING ROAD AND CANDIA ROAD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Gray, ME (KGYX), launched 00:00Z, 8.2 hours before the alert went out and 141 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 572 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 742 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 47 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

131 
WGUS51 KBOX 160814
FFWBOX
NHC011-161015-
/O.NEW.KBOX.FF.W.0023.120816T0814Z-120816T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
414 AM EDT THU AUG 16 2012

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL HILLSBOROUGH COUNTY IN SOUTHERN NEW HAMPSHIRE...
  THIS INCLUDES THE CITY OF MANCHESTER...

* UNTIL 615 AM EDT

* AT 410 AM EDT...LOCAL POLICE REPORTED FLASH FLOODING FROM A 
THUNDERSTORM OVER THE WARNED AREA.  PORTIONS OF CHESTNUT STREET IN 
MANCHESTER WAS REPORTED TO BE UNDER TWO TO THREE FEET OF WATER.

FLASH FLOODING OF SMALL STREAMS AND URBAN AREAS IS OCCURRING OR
IMMINENT. THOSE NEAR STREAMS AND CREEKS...OR IN AREAS PRONE TO
FLOODING SHOULD MOVE TO HIGHER GROUND IMMEDIATELY. AVOID FLOODED
ROADS. THE WATER MAY BE TOO DEEP TO ALLOW VEHICLES TO CROSS SAFELY...
OR THE ROADWAY MAY BE UNDERMINED. TURN AROUND...DONT DROWN!

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. ACT QUICKLY. MOVE TO HIGHER GROUND TO ESCAPE
FLOOD WATERS. DO NOT STAY IN LOW LYING AREAS. DRIVERS SHOULD BE ALERT
FOR FLOODED ROADS AND FIND AN ALTERNATE ROUTE. TURN AROUND...DONT
DROWN!

&&

LAT...LON 4305 7150 4304 7148 4305 7146 4302 7144
      4301 7139 4294 7137 4293 7144 4284 7143
      4283 7138 4282 7138 4285 7157 4307 7158
      4307 7152

$$

MD

1 follow-up statement

391 
WGUS71 KBOX 161011
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
611 AM EDT THU AUG 16 2012

NHC011-161021-
/O.EXP.KBOX.FF.W.0023.000000T0000Z-120816T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HILLSBOROUGH NH-
611 AM EDT THU AUG 16 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 615 AM EDT FOR EAST CENTRAL
HILLSBOROUGH COUNTY...

LAT...LON 4305 7150 4304 7148 4305 7146 4302 7144
      4301 7139 4294 7137 4293 7144 4284 7143
      4283 7138 4282 7138 4285 7157 4307 7158
      4307 7152

$$

MD

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 16, 3:40 AM EDT	Areal Flood Advisory	BOX	Cheshire, Hillsborough	3 hr

Nearby

Flash Flood Warnings in New Hampshire, 2012 Every flash flood warning in 2012

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.