Alert archive / Pennsylvania / Flash Flood Warnings in 1998

Flash Flood Warning 54, NWS State College, PA

April 9, 1998Lancaster County, Pennsylvania

NWS State College, PA issued this flash flood warning at Apr 9, 1998, 10:00 PM EDT for Lancaster County, Pennsylvania. It was in force for 5 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 9, 1998, 10:00 PM EDT (02:00 UTC)
Expired
Apr 10, 1998, 2:30 AM EDT
In force
5 hr
Issued by
NWS State College, PA
Area
Whole counties

County Lancaster County, PA

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.0 hours before the alert went out and 157 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 00:00Z on 1998-04-10Temperature 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 00:00Z on 1998-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -162 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
809 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
-162 m²/s²
0-3 km storm-relative helicity
-130 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.

000 
TTAA00 KCTP 100202
FFWCTP
PAC071-100630-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1000 PM EDT THU APR 9 1998
 
THE NATIONAL WEATHER SERVICE IN STATE COLLEGE HAS ISSUED A
FLOOD WARNING EFFECTIVE UNTIL 230 AM EDT FOR PEOPLE IN THE
FOLLOWING LOCATIONS......
 
IN  PENNSYLVANIA
 
   ...LANCASTER COUNTY
 
ALTHOUGH RAIN HAS ENDED ACROSS THE COUNTY THIS EVENING...SMALL STREAMS
AND CREEKS CONTINUE TO RISE DUE TO RUNOFF FROM TODAY/S RAIN.  ADDITIONAL
RAIN IS FORECAST TO MOVE BACK INTO THE COUNTY OVERNIGHT.
 
STREAM GAUGES INDICATE THAT CHICKIES CREEK AT MANHEIM HAS RISEN TO NEAR
FLOOD STAGE OF 8 FEET.  THE CREEK WILL CONTINUE TO RISE AND CREST A FOOT
OR TWO OVER BANKFULL DURING THE NEXT SEVERAL HOURS.
 
STREAM GAGES ALSO INDICATE THAT COCALICO CREEK AT EPHRATA WAS RISING
RAPIDLY AND WILL LIKELY CREST AT OR SLIGHTLY ABOVE BANKFULL.
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS.  IF FLOODING IS OBSERVED...ACT QUICKLY.
MOVE UP TO ESCAPE FLOOD WATERS.  DO NOT STAY IN AREAS SUBJECT
TO FLOODING WHEN WATER BEGINS RISING.
 
JUNG

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.

NWS State College, PA wrote its last area forecast discussion before this flash flood warning went out at Apr 9, 9:30 PM EDT, 30 minutes earlier.

Area forecast discussion, Apr 9, 9:30 PM EDT, 30 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
930 PM EDT THU APR 9 1998...UPDATED

...ZONE SUGGESTIONS...

UPDATED FOR LAST MINUTE FLOOD WATCH RECONSIDERATIONS. WHILE THREAT
OF PRECIP MAY LAST A LITTLE LONGER THAN OLD ZONES INDICATED...THINK
THREAT OF HEAVY PRECIP WILL DWINDLE. HOWEVER LONGEVITY OF PRECIP OVER
NRN COUNTIES ARGUES FOR CONTINUATION OF FLOOD WATCH INTO WEE HOURS.
THINK SNOW OVER NRN SUSQ IS MAINLY AT HIGHER ELEVATIONS. SPOTTER
REPORTS SHOW CREEKS AND STREAMS RUNNING HIGH BUT NO FLOODING TO REPORT.

...DISCUSSION...

A STORM WITH A LITTLE BIT OF SOMETHING FOR EVERYONE. WE HAD PEA
SIZED HAIL REPORTED OUT OF THE AREA NORTH OF ALTOONA...HEAVY RAIN
OVER A WIDESPREAD PORTION OF THE CWA...AND EVEN 3 IN OF SNOW OVER
THE HIGH ELEVATIONS OF TIOGA COUNTY.

COMPLEX SYSTEM IS FINALLY SHOWING SIGNS OF MOVING AWAY AS CENTER
REDEVELOPS RAPIDLY ALONG COAST IN THE VICINITY OF THE DELMARVA.
SURFACE PRESSURES FALLING RESPECTABLY FOR APRIL...5 TO 7MB PER 3HR
...WITH THE CENTER OF THE LOW ALREADY DOWN NEAR 988MB. SATELLITE AND
REGIONAL RADAR PLOTS SHOW HUGE DEFORMATION ZONE ROTATING SLOWLY THRU
THE NERN PART OF OUR CWA. MESO ETA SHOWS STRONG FRONTOGENESIS BEING
FORCED IN DEFORMING UPPER FLOW AS SFC LOW ON COAST RAPIDLY BECOMES
DOMINANT FEATURE. MODELS REDISTRIBUTE UPPER TROF QUICKLY EAST IN
RESPONSE TO DEEPENING COASTAL CYCLONE AND THIS RESULTS IN
DEFORMATION ZONE SAGGING SOUTH THRU PA TONITE BEFORE WEAKENING EARLY
FRI. WHAT THIS MEANS IS THAT PRECIP MAY BE SLOW TO DWINDLE OVERNIGHT
AS BEST FORCING ELONGATES EAST-WEST AND SETTLES SOUTH BEFORE MOVING
AWAY. THE THREAT OF PRECIP WILL LIKELY STICK AROUND AS THE FORCING
WILL BE SLOW TO LEAVE...BUT PROGGED LOW LEVEL FLOW INDICATES WE LOSE
BEST EASTERLY FLOW...MOISTURE ADVECTION...JUST AFTER 06Z SO THINK
THREAT FOR HEAVY PRECIP WILL CONTINUE TO DWINDLE.

DRYING DOES LOOK PROMISING FOR FRIDAY AS SFC HIGH BUILDS IN FROM GR
LAKES AND LOW LEVEL FLOW COMES AROUND TO THE NORTH OR NORTHEAST.
STRONG HGHT RISES ALOFT REPLACE TROF AS RIDGE BUILDS QUICKLY INTO
THE REGION. DESPITE CURRENT TRENDS WHICH SUGGEST LITTLE TENDENCY FOR
DRY AIR IN SRN CANADA TO SETTLE SOUTH...AM CONFIDENT FRIDAY WILL SEE
IMPROVING CONDITIONS UNDER RAPIDLY REORIENTING FLOW.

MODEL SOUNDINGS SHOW FLOW THRU BOUNDARY LAYER SHIFTING TO NORTH OR
NORTHEAST. EVEN NORMALLY VERY MOIST ETA SHOWS SIG DRYING IN LOW
LEVELS GIVING EVEN MORE CONFIDENCE TO OPTIMISTIC OUTLOOK.

LA CORTE

Nearby

Flash Flood Warnings in Pennsylvania, 1998Every flash flood warning in 1998

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.