Alert archive / Pennsylvania / Flash Flood Warnings in 1998

Flash Flood Warning 48, NWS State College, PA

March 21, 1998Adams County, Cumberland County, Pennsylvania

NWS State College, PA issued this flash flood warning at Mar 21, 1998, 4:48 AM EST for Adams County, Cumberland 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
Mar 21, 1998, 4:48 AM EST (09:48 UTC)
Expired
Mar 21, 1998, 10:00 AM EST
In force
5 hr
Issued by
NWS State College, PA
Area
Whole counties

Counties Adams County, PA, Cumberland County, PA

The radar

The Sterling radar (KLWX), 118 km from the middle of the area, began a volume at 09:49 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 00:00Z, 9.8 hours before the alert went out and 120 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 1998-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 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 1998-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 255 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
2 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
448 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
255 m²/s²
0-3 km storm-relative helicity
420 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 210948
FFWCTP
PAC001-041-067-099-109-211500-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
448 AM EST SAT MAR 21 1998

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS EXTENDED THE
FLOOD WARNING EFFECTIVE UNTIL 10 AM EST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN SOUTH CENTRAL PENNSYLVANIA

   ...JUNIATA COUNTY
   ...PERRY COUNTY
   ...CUMBERLAND COUNTY
   ...ADAMS COUNTY

IN CENTRAL PENNSYLVANIA

   ...SNYDER COUNTY
 
A SWATH OF HEAVY RAINFALL HAS OCCURRED FROM WESTERN SNYDER AND
NORTHERN JUNIATA COUNTIES... SOUTH THROUGH PERRY AND CUMBERLAND
COUNTIES TO ADAMS COUNTIES. THE HEAVIEST RAIN FELL OVER
WESTERN PERRY COUNTY WHERE THE RADAR WAS ESTIMATING OVER 3 INCHES.
RAINFALL REPORTS RECEIVED FROM THIS AREA WERE RANGING GENERALLY FROM
1 TO 3 INCHES.

EVEN THOUGH THE HEAVY RAIN WAS OVER... RUNOFF FROM PREVIOUS
RAINFALL WILL CONTINUE TO CAUSE FLOODING PROBLEMS ON STREAMS...
CREEKS AND POOR DRAINAGE AREAS THROUGH SUNRISE.

A FEW REPORTS OF FLOODING AND HIGH WATER AS OF 430 AM...

IN ADAMS COUNTY... ROADS WERE REPORTED FLOODED IN THE CITIES OF
GETTYSBURG... BIGERLVILLE... CASHTOWN AND CARROLL VALLEY.

IN CUMBERLAND COUNTY... UNDERPASSES WERE FLOODED IN THE CAMP
HILL AND SHIPPENSBURG AREAS.

IN PERRY COUNTY... BIXLER'S RUN CREEK WAS REPORTED TO BE FLOODING.

OTHER STREAMS AND CREEKS IN THE WARNING AREA LIKELY WERE SEEING
FLOODING DUE TO THE HEAVY RAINFALL. MOST SMALLER STREAMS AND CREEKS
SHOULD BEGIN RECEDE AFTER SUNRISE.

RUNOFF FROM THE SMALLER STREAMS AND CREEKS WILL CAUSE SIGNIFICANT
RISES ON PENNS CREEK... CONODOGUINET CREEK AND SHERMANS CREEK. SOME
FLOODING IS POSSIBLE ON THESE LARGER CREEKS BY THIS EVENING.
6 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED
QUICKLY.  MOVE TO HIGHER GROUND.

NICOSIA
&

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 Mar 21, 3:27 AM EST, 1 hour 21 minutes earlier.

Area forecast discussion, Mar 21, 3:27 AM EST, 1 hour 21 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
310 AM EST FRI MAR 20 1998

...ALREADY COORD WITH PIT...PHL...BUF AND BGM CONCERNING EXPANDED
WINT STM WARNINGS THROUGH THE CENTRAL COUNTIES AND LAURELS...ALONG
WITH EXTENDED FLOOD WATCHES OVER THE SOUTH CENTRAL COUNTIES THROUGH
THIS MORNING...

...DISCUSSION...
MAJOR EARLY SPRING SNOWSTORM IN THE WORKS FOR THIS AFTERNOON AND
TONIGHT...FOLLOWING RATHER WIDESPREAD SMALL STREAM/POOR DRAINAGE
FLOODING OVER PARTS OF SCENT PA THIS MORNING.

995 MB SFC LOW CURRENTLY JUMPING THE COOL AIR WEDGE EAST OF THE
APPALACHIANS...AND REFORMING ALONG THE SE VIRGINIA COAST.

UPR BLYR TEMPS PROGGED TO DROP RAPIDLY VIA DYNAMIC COOLING FROM
SOUTHWEST TO NORTHEAST LATER THIS MORNING THROUGH THE AFTERNOON...
AS UPPER LOW SLOWLY APPROACHES FROM THE SOUTHWEST.

IN THE MEANTIME...SHALLOW SUBFREEZING LAYER CONTINUES TO FILTER
SOUTH ACROSS THE NORTHERN MOUNTAINS...LEADING TO A SEVERAL HOUR
PERIOD OF FREEZING RAIN/SLEET THROUGH 12 TO 14Z.

THE BLYR BECOMES COLD ENOUGH TO SUPPORT WET SNOW ACROSS ALL BUT THE
LOWER SUSQ AND EXTREME SOUTHCENTRAL COUNTIES BY MID AFTERNOON.
ETA APPEARS TO BEST HANDLE THIS RAPID TRANSITION TO A HEAVY WET SNOW
WITH THE MESO ETA 950-900 MB WINDS A BIT TOO EASTERLY THROUGH 18Z
(THUS LEADING TO A SOMEWHAT MILDER UPPER BLYR).

AS HAS BEEN TYPICAL WITH PAST STORMS THIS WINTER...AND APPEARS TO BE
A CONSISTENT MODEL DEFICIENCY WITH FULLY DEVELOPED EAST COAST STORMS...
QPF/SNOWFALL IS HIGHLY UNDERESTIMATED OUTSIDE THE PRIMARY AREA OF
WARM ADVECTION/ISENT LIFT IN THE LOW TO MID LEVELS.

I LIKE THE MESO ETA'S DEPICTION AND ORIENTATION OF THE PRECIP SHIELD
ACROSS THE CENTRAL AND ERN COUNTIES OF OUR CWA...BUT WOULD STILL
EXTEND THIS HIGHER QPF SHIELD APPROX 50 MILES FURTHER WEST WITHIN
REGION OF STG MID/UPPER LVL DEFORMATION LATE TODAY AND TONIGHT.

PER CALLS TO PHL AND PIT WILL UP SNOWFALL AMOUNTS ACROSS THE MTNS N
OF IPT TO MORE THAN 1 FOOT...AND GO WITH A GENERAL 6 TO 9 INCHES
FURTHER SOUTH AND WEST INTO THE LAURELS.

WILL GO WITH A WINT WEATHER ADVIS FOR THE LWR TERRAIN OF SCENT PA
...AND A FEW INCHES TWD DARK ACROSS THE LWR SUSQ.

SOME OF THE PROJECTED ACCUMS ACROSS THE NCENT MTNS MAY EVEN BE ON
THE CONSERVATIVE SIDE...CONSIDERING THE PERSISTENT DEEP EASTERLY
FLOW OFF THE ATLANTIC THROUGH THE LATE NIGHT HOURS TONIGHT.

WOULDN'T BE SURPRISED TO SEE LOCAL 2 FT AMOUNTS IN SULLIVAN...TIOGA
AND NRN LYCOMING COUNTIES OF OUR CWA BY SUNDAY MORNING.

LAMBERT

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 20, 9:54 PM ESTFlash Flood WarningCTPFranklin6 hr
Mar 20, 11:29 PM ESTFlash Flood WarningCTPCumberland, Perry6 hr
Mar 20, 11:29 PM ESTFlash Flood WarningCTPAdams6 hr
Mar 21, 12:28 AM ESTFlash Flood WarningCTPJuniata, Snyder6 hr
Mar 21, 3:14 AM ESTFlash Flood WarningCTPLancaster, York6 hr
Mar 21, 3:43 AM ESTFlash Flood WarningCTPFranklin6 hr
Mar 21, 4:48 AM ESTFlash Flood WarningCTPJuniata, Perry, Snyder5 hr
Mar 21, 9:40 AM ESTFlash Flood WarningCTPCumberland, Perry, York5 hr
Mar 21, 9:40 AM ESTFlash Flood WarningCTPLancaster5 hr
Mar 21, 9:53 AM ESTFlash Flood WarningCTPCumberland, Perry, York5 hr
Mar 21, 9:53 AM ESTFlash Flood WarningCTPLancaster5 hr
Mar 21, 11:42 AM ESTFlash Flood WarningCTPFranklin6 hr

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; radar from the NEXRAD Level II archive.