Alert archive / Pennsylvania / Flash Flood Warnings in 1993

Flash Flood Warning 40, NWS State College, PA

August 11, 1993Adams County, York County, Pennsylvania

NWS State College, PA issued this flash flood warning at Aug 11, 1993, 7:13 PM EDT for Adams County, York County, Pennsylvania. It was in force for 32 min.

The area

The counties it named.

The facts

Issued
Aug 11, 1993, 7:13 PM EDT (23:13 UTC)
Expired
Aug 11, 1993, 7:45 PM EDT
In force
32 min
Issued by
NWS State College, PA
Area
Whole counties

Counties Adams County, PA, York County, PA

The radar

The Sterling radar (KLWX), 111 km from the middle of the area, began a volume at 23:17 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.2 hours before the alert went out and 111 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, Washington/Dulle, VA at 12:00Z on 1993-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 1993-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
67 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, Aug 11, 6:40 PM EDT, 33 minutes before
PAZ007-008-014-120000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
640 PM EDT WED AUG 11 1993

...THUNDERSTORMS MOVING THROUGH NORTHCENTRAL PENNSYLVANIA...

...RADAR INFORMATION...
AT 640 PM EDT NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SHOWERS AND THUNDERSTORMS EXTENDING FROM ELMIRA NEW YORK TO HILLSGROVE
TO LAIRDSVILLE...THEN SOUTHWEST TO LEWISBURG AND SELINSGROVE.  THE
STRONGEST THUNDERSTORMS WERE IN A LINE FROM SONESTOWN IN SULLIVAN
COUNTY TO HUGHESVILLE TO WATSONTOWN AND MIFFLINBURG.  OTHER STRONG
THUNDERSTORMS WERE OVER SOUTHERN SNYDER COUNTY AND SOUTH OF BERWICK IN
COLUMBIA COUNTY.  THE SHOWERS AND THUNDERSTORMS WERE MOVING SLOWLY
SOUTHEAST AT AROUND 15 MPH.  A SPOTTER FROM THE WILLIAMSPORT AREA
REPORTED PEA SIZE HAIL FROM THESE THUNDERSTORMS.  ALSO...OVER ONE INCH
OF RAIN /1.12/ FELL HERE AT THE WILLIAMSPORT LYCOMING COUNTY AIRPORT
IN ONE-HALF AN HOUR.  THE SHOWERS AND THUNDERSTORMS WILL CONTINUE
MOVING ACROSS EASTERN TIOGA...LYCOMING AND CLINTON COUNTIES THROUGH
730 PM EDT...THEN MOVE THROUGH BRADFORD AND SULLIVAN COUNTIES BETWEEN
700 AND 900 PM EDT.

THE THUNDERSTORMS WILL CONTAIN HEAVY RAINS...AND POSSIBLY SOME HAIL.
ALL THUNDERSTORMS CONTAIN DEADLY LIGHTNING.

...SAFETY INFORMATION...
IF THREATENING WEATHER APPROACHES MOVE INDOORS.  STAY AWAY FROM
WINDOWS AND DO NOT USE ELECTRICAL APPLIANCES WHILE THUNDERSTORMS ARE
IN THE AREA.  BE CAREFUL IF DRIVING IN HEAVY DOWNPOURS...THE RAIN CAN
REDUCE VISIBILITIES TO NEAR ZERO AT TIMES.  SLOW DOWN AND USE YOUR
HEADLIGHTS IN ANY DOWNPOURS.

TG
Special weather statement, Aug 11, 6:40 PM EDT, 33 minutes before
PAZ007-008-014-120000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
640 PM EDT WED AUG 11 1993

...THUNDERSTORMS MOVING THROUGH NORTHCENTRAL PENNSYLVANIA...

...RADAR INFORMATION...
AT 640 PM EDT NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SHOWERS AND THUNDERSTORMS EXTENDING FROM ELMIRA NEW YORK TO HILLSGROVE
TO LAIRDSVILLE...THEN SOUTHWEST TO LEWISBURG AND SELINSGROVE.  THE
STRONGEST THUNDERSTORMS WERE IN A LINE FROM SONESTOWN IN SULLIVAN
COUNTY TO HUGHESVILLE TO WATSONTOWN AND MIFFLINBURG.  OTHER STRONG
THUNDERSTORMS WERE OVER SOUTHERN SNYDER COUNTY AND SOUTH OF BERWICK IN
COLUMBIA COUNTY.  THE SHOWERS AND THUNDERSTORMS WERE MOVING SLOWLY
SOUTHEAST AT AROUND 15 MPH.  A SPOTTER FROM THE WILLIAMSPORT AREA
REPORTED PEA SIZE HAIL FROM THESE THUNDERSTORMS.  ALSO...OVER ONE INCH
OF RAIN /1.12/ FELL HERE AT THE WILLIAMSPORT LYCOMING COUNTY AIRPORT
IN ONE-HALF AN HOUR.  THE SHOWERS AND THUNDERSTORMS WILL CONTINUE
MOVING ACROSS EASTERN TIOGA...LYCOMING AND CLINTON COUNTIES THROUGH
730 PM EDT...THEN MOVE THROUGH BRADFORD AND SULLIVAN COUNTIES BETWEEN
700 AND 900 PM EDT.

THE THUNDERSTORMS WILL CONTAIN HEAVY RAINS...AND POSSIBLY SOME HAIL.
ALL THUNDERSTORMS CONTAIN DEADLY LIGHTNING.

...SAFETY INFORMATION...
IF THREATENING WEATHER APPROACHES MOVE INDOORS.  STAY AWAY FROM
WINDOWS AND DO NOT USE ELECTRICAL APPLIANCES WHILE THUNDERSTORMS ARE
IN THE AREA.  BE CAREFUL IF DRIVING IN HEAVY DOWNPOURS...THE RAIN CAN
REDUCE VISIBILITIES TO NEAR ZERO AT TIMES.  SLOW DOWN AND USE YOUR
HEADLIGHTS IN ANY DOWNPOURS.

TG
Special weather statement, Aug 11, 6:55 PM EDT, 18 minutes before
PAZ006-008-009-013-014-120100-

SEVERE WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HARRISBURG PA
655 PM EDT WED AUG 11 1993
...SEVERE WEATHER INFORMATION...
A SEVERE THUNDERSTORM WARNING CONTINUES IN EFFECT UNTIL 700 PM FOR ADAMS
COUNTY.  AT 650 PM A SPOTTER REPORTED DIME SIZED HAIL 5 MILES NORTHWEST OF
EAST BERLIN IN NORTHEAST ADAMS COUNTY.

...WATCH INFORMATION...
A FLASH FLOOD WATCH IS IN EFFECT FOR SOUTH CENTRAL PENNSYLVANIA AND THE
SOUTH CENTRAL MOUNTAINS.  THE FOLLOWING COUNTIES ARE INCLUDED IN THE WATCH:
BEDFORD...BLAIR...CENTRE...MIFFLIN...JUNIATA...FULTON...FRANKLIN...AND
HUNTINGDON.

...RADAR INFORMATION...
AT 630 PM HARRISBURG RADAR SHOWED AN AREA OF SCATTERED SHOWERS AND THUNDERSTORMSACROSS CENTRAL AND EASTERN PENNSYLVANIA...WESTERN MARYLAND...NORTHEAST WEST
VIRGINIA...AND NORTHERN VIRGINIA.  THE STRONGEST STORM WAS OVER NORTHEAST ADAMS
COUNTY.  THE SHOWERS AND THUNDERSTORMS WERE MOVING EAST-SOUTHEAST AT 15 MILE
AN HOUR.

...SAFETY INFORMATION...
A FLASH FLOOD WATCH MEANS FLOODING IS A POSSIBILITY...NOT A CERTAINTY.
BE PREPARED FOR QUICK ACTION IS A WARNING IS ISSUED OR FLOODING IS
OBSERVED.  DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE
ROADWAY.

WHEN A THUNDERSTORM THREATENS...TAKE COVER IMMEDIATELY.

MATUSIEWICZ
Special weather statement, Aug 11, 6:58 PM EDT, 15 minutes before
PAZ006-008-009-013-014-120100-

SEVERE WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HARRISBURG PA
655 PM EDT WED AUG 11 1993
...SEVERE WEATHER INFORMATION...
A SEVERE THUNDERSTORM WARNING CONTINUES IN EFFECT UNTIL 700 PM FOR ADAMS
COUNTY.  AT 650 PM A SPOTTER REPORTED DIME SIZED HAIL 5 MILES NORTHWEST OF
EAST BERLIN IN NORTHEAST ADAMS COUNTY.

...WATCH INFORMATION...
A FLASH FLOOD WATCH IS IN EFFECT FOR SOUTH CENTRAL PENNSYLVANIA AND THE
SOUTH CENTRAL MOUNTAINS.  THE FOLLOWING COUNTIES ARE INCLUDED IN THE WATCH:
BEDFORD...BLAIR...CENTRE...MIFFLIN...JUNIATA...FULTON...FRANKLIN...AND
HUNTINGDON.

...RADAR INFORMATION...
AT 630 PM HARRISBURG RADAR SHOWED AN AREA OF SCATTERED SHOWERS AND THUNDERSTORMSACROSS CENTRAL AND EASTERN PENNSYLVANIA...WESTERN MARYLAND...NORTHEAST WEST
VIRGINIA...AND NORTHERN VIRGINIA.  THE STRONGEST STORM WAS OVER NORTHEAST ADAMS
COUNTY.  THE SHOWERS AND THUNDERSTORMS WERE MOVING EAST-SOUTHEAST AT 15 MILE
AN HOUR.

...SAFETY INFORMATION...
A FLASH FLOOD WATCH MEANS FLOODING IS A POSSIBILITY...NOT A CERTAINTY.
BE PREPARED FOR QUICK ACTION IS A WARNING IS ISSUED OR FLOODING IS
OBSERVED.  DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE
ROADWAY.

WHEN A THUNDERSTORM THREATENS...TAKE COVER IMMEDIATELY.

MATUSIEWICZ
Special weather statement, Aug 11, 7:10 PM EDT, 3 minutes before
PAZ007-008-014-120030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
710 PM EDT WED AUG 11 1993

...THUNDERSTORMS MOVING THROUGH NORTHCENTRAL PENNSYLVANIA...

...RADAR INFORMATION...
AT 710 PM EDT NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SHOWERS AND THUNDERSTORMS EXTENDING FROM ELMIRA NEW YORK TO LAPORTE
AND BENTON...THEN SOUTHWEST TO SHAMOKIN AND HARRISBURG.  THE STRONGEST
THUNDERSTORMS WERE BETWEEN SONESTOWN HUGHESVILLE...BLOOMSBURG AND
BERWICK.  OTHER STRONG THUNDERSTORMS WERE BETWEEN LEWISBURG...SUNBURY
AND REBUCK IN THE MIDDLE SUSQUEHANNA VALLEY.  THE SHOWERS AND
THUNDERSTORMS WERE MOVING SLOWLY SOUTHEAST AT AROUND 15 MPH.  A
SPOTTER FROM THE WILLIAMSPORT AREA REPORTED PEA SIZE HAIL FROM THESE
THUNDERSTORMS.  ALSO...OVER ONE INCH OF RAIN /1.12/ FELL HERE AT THE
WILLIAMSPORT LYCOMING COUNTY AIRPORT IN ONE-HALF AN HOUR.  THE SHOWERS
AND THUNDERSTORMS WILL CONTINUE MOVING ACROSS EASTERN TIOGA AND
LYCOMING COUNTIES THROUGH 800 PM EDT...AND WILL BE MOVING THROUGH
BRADFORD AND SULLIVAN COUNTIES DURING THE NEXT 2 TO 3 HOURS.

THE THUNDERSTORMS WILL CONTAIN HEAVY RAINS...AND POSSIBLY SOME HAIL.
ALL THUNDERSTORMS CONTAIN DEADLY LIGHTNING.

...SAFETY INFORMATION...
IF THREATENING WEATHER APPROACHES MOVE INDOORS.  STAY AWAY FROM
WINDOWS AND DO NOT USE ELECTRICAL APPLIANCES WHILE THUNDERSTORMS ARE
IN THE AREA.  BE CAREFUL IF DRIVING IN HEAVY DOWNPOURS...THE RAIN CAN
REDUCE VISIBILITIES TO NEAR ZERO AT TIMES.  SLOW DOWN AND USE YOUR
HEADLIGHTS IN ANY DOWNPOURS.

TG
Special weather statement, Aug 11, 7:10 PM EDT, 3 minutes before
PAZ007-008-014-120030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILLIAMSPORT PA
710 PM EDT WED AUG 11 1993

...THUNDERSTORMS MOVING THROUGH NORTHCENTRAL PENNSYLVANIA...

...RADAR INFORMATION...
AT 710 PM EDT NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SHOWERS AND THUNDERSTORMS EXTENDING FROM ELMIRA NEW YORK TO LAPORTE
AND BENTON...THEN SOUTHWEST TO SHAMOKIN AND HARRISBURG.  THE STRONGEST
THUNDERSTORMS WERE BETWEEN SONESTOWN HUGHESVILLE...BLOOMSBURG AND
BERWICK.  OTHER STRONG THUNDERSTORMS WERE BETWEEN LEWISBURG...SUNBURY
AND REBUCK IN THE MIDDLE SUSQUEHANNA VALLEY.  THE SHOWERS AND
THUNDERSTORMS WERE MOVING SLOWLY SOUTHEAST AT AROUND 15 MPH.  A
SPOTTER FROM THE WILLIAMSPORT AREA REPORTED PEA SIZE HAIL FROM THESE
THUNDERSTORMS.  ALSO...OVER ONE INCH OF RAIN /1.12/ FELL HERE AT THE
WILLIAMSPORT LYCOMING COUNTY AIRPORT IN ONE-HALF AN HOUR.  THE SHOWERS
AND THUNDERSTORMS WILL CONTINUE MOVING ACROSS EASTERN TIOGA AND
LYCOMING COUNTIES THROUGH 800 PM EDT...AND WILL BE MOVING THROUGH
BRADFORD AND SULLIVAN COUNTIES DURING THE NEXT 2 TO 3 HOURS.

THE THUNDERSTORMS WILL CONTAIN HEAVY RAINS...AND POSSIBLY SOME HAIL.
ALL THUNDERSTORMS CONTAIN DEADLY LIGHTNING.

...SAFETY INFORMATION...
IF THREATENING WEATHER APPROACHES MOVE INDOORS.  STAY AWAY FROM
WINDOWS AND DO NOT USE ELECTRICAL APPLIANCES WHILE THUNDERSTORMS ARE
IN THE AREA.  BE CAREFUL IF DRIVING IN HEAVY DOWNPOURS...THE RAIN CAN
REDUCE VISIBILITIES TO NEAR ZERO AT TIMES.  SLOW DOWN AND USE YOUR
HEADLIGHTS IN ANY DOWNPOURS.

TG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 6:27 PM EDTSevere Thunderstorm WarningCTPAdams33 min
Aug 11, 7:13 PM EDTSevere Thunderstorm WarningCTPAdams, York32 min
Aug 11, 7:50 PM EDTFlash Flood WarningCTPAdams, York55 min
Aug 11, 7:50 PM EDTSevere Thunderstorm WarningCTPAdams, York55 min

Nearby

Flash Flood Warnings in Pennsylvania, 1993Every flash flood warning in 1993

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.