Alert archive / Louisiana / Flash Flood Watches in 2015

Flash Flood Watch 2, NWS New Orleans, LA

April 12, 201513 parishes in Louisiana; Pearl River County, Mississippi

NWS New Orleans, LA issued this flash flood watch at Apr 12, 2015, 3:37 PM CDT for 13 parishes in Louisiana; Pearl River County, Mississippi. It was in force for 6 days.

The area

The counties it named.

The facts

Issued: Apr 12, 2015, 3:37 PM CDT (20:37 UTC)
Expired: Apr 18, 2015, 3:46 PM CDT
In force: 6 days
Issued by: NWS New Orleans, LA
Flood severity: None

Counties Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Pearl River County, MS

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.6 hours before the alert went out and 237 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: 322 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 639 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS New Orleans, LA wrote its last area forecast discussion before this flash flood watch went out at Apr 12, 1:25 PM CDT, 2 hours 12 minutes earlier.

Area forecast discussion, Apr 12, 1:25 PM CDT, 2 hours 12 minutes before

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Hazardous weather outlook, Apr 12, 11:51 AM CDT, 3 hours 46 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 12, 11:45 AM CDT	River Flood Warning	LIX	Tangipahoa	7 days
Apr 12, 3:41 PM CDT	Special Marine Warning	LIX		34 min
Apr 12, 4:43 PM CDT	Special Marine Warning	LIX		32 min
Apr 12, 5:14 PM CDT	Special Marine Warning	LIX		31 min
Apr 12, 5:25 PM CDT	Special Marine Warning	LIX		35 min
Apr 12, 6:11 PM CDT	Special Marine Warning	LIX		19 min
Apr 12, 6:32 PM CDT	Special Marine Warning	LIX		28 min
Apr 12, 5:17 PM CDT	Special Weather Statement	LIX	Harrison	28 min
Apr 12, 6:20 PM CDT	Special Weather Statement	LIX	Harrison	25 min

Nearby

Flash Flood Watches in Louisiana, 2015 Flash Flood Watches in Mississippi, 2015 Every flash flood watch in 2015

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.