Alert archive / Pennsylvania / Flash Flood Warnings in 1990

Flash Flood Warning 1, NWS State College, PA

May 16, 1990Montour County, Pennsylvania

NWS State College, PA issued this flash flood warning at May 16, 1990, 8:18 PM EDT for Montour County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: May 16, 1990, 8:18 PM EDT (00:18 UTC)
Expired: May 16, 1990, 11:15 PM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Whole counties

County Montour County, PA

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

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.3 hours before the alert went out and 240 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: 730 J/kg
Mixed-layer CIN: -73 J/kg
Mixed-layer LCL: 1337 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 287 m²/s²
0-3 km storm-relative helicity: 312 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KHAR 170019 RRB
FFWHAR
PAC093-170315-
 
BULLETIN - EBS ACTIVATION REQUESTED
SMALL STREAM AND URBAN FLOOD WARNING
NATIONAL WEATHER SERVICE HARRISBURG PA
818 PM EDT WED MAY 16 1990
 
THE NATIONAL WEATHER SERVICE IN HARRISBURG HAS ISSUED A
SMALL STREAM AND URBAN FLOOD WARNING EFFECTIVE UNTIL 1115 PM EDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN CENTRAL PENNSYLVANIA
          ...MONTOUR
 
FLOODING OF SOME STREAMS AND HIGHWAYS HAS BEEN REPORTED THROUGHOUT
PORTIONS OF THE COUNTY.
 
RADAR WAS SHOWING SOME HEAVY THUNDERSTORMS MOVING EAST ACROSS THE AREA
AT AROUND 30 MILES AN HOUR.
 
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

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, May 16, 7:28 PM EDT, 50 minutes before

PAZ009-170200-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
725 PM  EDT  WED MAY 16 1990

    ...HEAVY THUNDERSTORMS DEVELOPING IN WESTERN PORTIONS OF LOWER
       SUSQUEHANNA VALLEY...

AT 720 PM EDT THE HARRISBURG WEATHER RADAR WAS OBSERVINGA HEAVY THUNDERSTORM
IN SOUTHERN FRANKLIN COUNTY..JUST TO THE WEST OF WAYNESBORO AND ANOTHER
IN NORTHERN FRNAKLIN COUNTY...ABOUT 15 MILES SOUTWEST OF NEWVILLE.

THESE STORMS WERE MOVING TO THE EAST AT AROUND 30 MILES AN HOUR AND WILL
PRODUCE HEAVY DOWNPOURS...GUSTY WINDS AND POSSIBLE SMALL HAIL.
RESIDENTS OF FRANKLIN COUNTY SHOULD BE ALERT FOR PASSAGE OF THESE STORMS
UNTIL AROUND 745 PM THIS EVENING. AT THERE PRESENT MOVEMENT THESE
STORMS
WILL BE ENTERING WESTERN ADAMS AND CUMBERLAND COUNTIES SHORTLY.

CURLL WSO HARRISBURG

Special weather statement, May 16, 7:57 PM EDT, 21 minutes before

PAZ009-170200-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HARRISBURG PA.
755 PM  EDT  WED MAY 16 1990

        ....HEAVY THUNDERSTORMS ALONG THE MASON-DIXON LINE....

AT 750 PM EDT THE HARRISBURG WEATHER RADAR WAS OBSERVING A SMALL CLUSTER
OF HEAVY THUNDERSTORMS ALONG THE MASON-DIXON LINE IN EXTREME EASTERN
PORTIONS OF FRANKLIN COUNTY AND WESTERN PORTIONS OF ADAMS COUNTY.

THESE STORMS WERE MOVING TO THE EAST AT AROUND 35 MILES AN HOUR AND 3WILL
PRODUCE HEAVY DOWNPOURS...GUSTY WINDS AND POSSIBLE SMALL HAIL.
RESIDENTS OF SOUTHERN ADAMS COUNTY SHOULD BE ALERT FOR THE PASSAGE OF
THESE STORMS UNTIL AT LEAST 830 PM EDT THIS WEDNESDAY EVENING.

CURLL WSO HARRISBURG

The office that day

Everything else NWS State College, PA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 17, 2:07 PM EDT	Severe Thunderstorm Warning	CTP	Tioga	38 min
May 17, 2:22 PM EDT	Severe Thunderstorm Warning	CTP	Lycoming	38 min
May 17, 2:52 PM EDT	Severe Thunderstorm Warning	CTP	Sullivan	38 min
May 17, 2:55 PM EDT	Severe Thunderstorm Warning	CTP	Lycoming	35 min

Nearby

Flash Flood Warnings in Pennsylvania, 1990 Every flash flood warning in 1990

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.