Alert archive / New York / Flash Flood Warnings in 1986

Flash Flood Warning 1, NWS New York, NY

July 30, 1986Rockland County, New York

NWS New York, NY issued this flash flood warning at Jul 30, 1986, 1:48 PM EDT for Rockland County, New York. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Jul 30, 1986, 1:48 PM EDT (17:48 UTC)
Expired
Jul 30, 1986, 4:00 PM EDT
In force
2 hr
Issued by
NWS New York, NY
Area
Whole counties

County Rockland County, NY

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Atlantic City In, NJ (KACY), launched 12:00Z, 5.8 hours before the alert went out and 194 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, Atlantic City In, NJ at 12:00Z on 1986-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 577 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Atlantic City In, NJ at 12:00Z on 1986-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -31 square meters per square second.193958Sfc1 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
577 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
683 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-31 m²/s²
0-3 km storm-relative helicity
-14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

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

In the hours before

Special weather statement, Jul 30, 1:20 PM EDT, 28 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW YORK NY
100 PM EDT WEDNESDAY JULY 30 1986

...DO NOT USE AFTER 230 PM EDT...

WEATHER SERVICE RADAR SHOWED SOME VERY HEAVY THUNDERSTORMS IN NASSAU
COUNTY ON LONG ISLAND WITH VERY LITTLE MOVEMENT. THERE ARE HEAVY
DOWNPOURS AND LOCAL FLOODING OF STREETS AND HIGHWAYS MAY CAUSE SERIUS
PROBLEMS IF TORRENTIAL RAINS CONTINUE OVER ONE LOCATION FOR A PERIOD
OF TIME. DANGEROUS LIGHTNING IS ALSO POSSIBLE WITH THESE STORMS.
VERY HEAVY THUNDERSTORMS WERE ALSO OVER THE OCEAN FROM 40 MILES
SOUTHWEST OF MARTHAS VINEYARD TO NEAR NANTUCKET. THEY WERE MOVING
NORTHEAST AT 25 MILES AN HOUR.
OTHER SHOWERS AND THUNDERSTORMS WERE SCATTERED FROM9 NORTHERN NEW JERSEY
ACROSS THE HUDSON VALLEY INTO NEW ENGLAND.
END/TCM

Nearby

Flash Flood Warnings in New York, 1986Every flash flood warning in 1986

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.