Alert archive / Pennsylvania / Flash Flood Warnings in 1999

Flash Flood Warning 65, NWS State College, PA

September 16, 1999Perry County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 16, 1999, 2:15 PM EDT for Perry County, Pennsylvania. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Sep 16, 1999, 2:15 PM EDT (18:15 UTC)
Expired
Sep 16, 1999, 9:00 PM EDT
In force
7 hr
Issued by
NWS State College, PA
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Perry County, PA

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.3 hours before the alert went out and 178 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 1999-09-16Temperature 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 1999-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
577 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
268 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 161816
FFWCTP
PAC001-041-043-071-075-099-107-133-170100-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
215 PM EDT THU SEP 16 1999

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS EXTENDED THE

* FLOOD WARNING FOR...
  YORK COUNTY.
  PERRY COUNTY.
  LEBANON COUNTY.
  DAUPHIN COUNTY.
  CUMBERLAND COUNTY.
  SCHUYLKILL COUNTY.
  ADAMS COUNTY.
  LANCASTER COUNTY.

* UNTIL 900 PM EDT.

* AT 200 PM EDT...HEAVY RAIN FROM HURRICANE FLOYD CONTINUED TO MOVE ACROSS 
THE LOWER SUSQUEHANNA VALLEY REGION. SPOTTER REPORTS AND RADAR ESTIMATES 
INDICATE OVER 5 INCHES OF RAIN HAS FALLEN IN SPOTS IN THE PAST 24 HOURS. 

* ADDITIONAL HEAVY RAIN WILL CONTINUE THROUGH THE REST OF THE AFTERNOON. THE 
RAIN WILL BEGIN TO TAPER OFF BY LATE AFTERNOON OR EARLY THIS EVENING. RAINFALL 
TOTALS OF 4 TO 6 INCHES WILL BE LIKELY ACROSS THE WARNING AREA...WITH LOCAL 
AMOUNTS UP TO 8 INCHES. EVEN AFTER THE RAIN ENDS...WATER WILL BE SLOW TO 
RECEEDE. 

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS AND 
STREAMS...HIGHWAYS...STREETS AND UNDERPASSES.  ROADS MAY BE CLOSED OR WASHED 
OUT IN SOME AREAS. 

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED. MOVE TO
HIGHER GROUND.

.END/ JUNG

LAT...LON 4021 7608 3977 7620 3977 7738 4031 7762
          4056 7714 4067 7657 4089 7617 4085 7606
          4075 7587 4050 76z49

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 Sep 16, 2:02 PM EDT, 13 minutes earlier.

Area forecast discussion, Sep 16, 2:02 PM EDT, 13 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
200 PM PM EDT THU SEP 16 1999

FOLLOWING FLOYD CLOSELY THIS AFTN. SYSTEM IN THE FIRST STAGES OF
BECOMING EXTRA TROPICAL. A COASTAL FRONT HAS DEVELOPED FROM NORTH
JERSEY SW THRU THE DELEWARE VALLEY...THEN N/S ACROSS THE CHEASEPEAKE.
THIS APPRS TO BE ENHANCING THE WIND SPEEDS OVR LANCASTER COUNTY AND
IS PROBABLY AIDING IN THE HEAVY RAIN TOTALS EAST OF THE SUSQUEHANNA.
RADAR AND WATER VAPOR LOOPS INDICATE A S/W EMBEDDED IN THE SYSTEM
MOVING INTO SCEN PA. THIS SHOULD SHUT THE R+ DOWN TO R-/R UNTIL
FLOYD PASSES. IFLOWS INDICATES CREEKS AND SMALL RIVERS AROUND
LANCASTER COUNTY ARE JUST BEGINNING TO OVERFLOW THEIR BANKS. WITH
ANOTHER FEW HOURS OF R+ B4 SETTLING BACK TO R-/R IT...APPRS FLOODING
WILL GET WORSE B4 IT GETS BETTER.

SIMILAR TO BOB BACK IN 91...WINDS ARE STRONGEST EAST OF THE CENTER
AND IN THE SW QUAD. IN THE NORTH AND NW SIDE OF THE STORM...WIND
SPEEDS ARE RUNNING 15 TO 25KTS. ALTHO LANCASTER ASOS IS GUSTING TO
34 KTS. HOW FAR INLAND THE DAMAGING WIND GETS AS THE CENTER PASSES
ATLANTIC CITY IS A GOOD QUESTION. IT WILL TAKE MUCH LESS WIND THAN
USUAL TO BRING SHALLOW ROOTED TREES DOWN...THE 4+ INCHES OF RAIN
HAVING SOFTENED THE GROUND MAKING LOCUST TREES AND SWAMP MAPLES
PARTICULARLY VULNERABLE. ONE THING IN OUR FAVOR IS THE DROUGHT DRIED
QUITE A FEW LEAVES OFF THE TREES...SO THERE ARE NOT AS MANY LEAVES
TO ACT AS SAILS.  WE DO NOT HAVE TO WORRY ABOUT STRONG ENOUGH WINDS
TO TOPPLE TREES IN OUR CWA UNTIL THE CENTER OF FLOYD GETS TO OUR
LATITUDE. THAT SHOULD BE SOMETIME LATE THIS AFTN OR EVENING. NHC HAS
FLOYD AS A 60KT T.S. JUST E OF TOMS RIVER NJ AT 00Z. FWCMDT IS
INTERESTING AT 00Z WITH NW WIND AT 43KTS. IF WE SEE INDICATIONS OF
THIS UPSTREAM...WE WILL UPGRADE THE SE COUNTIES TO A HWW.

ONCE FLOYD PASSES THIS EVE...THE RAIN WILL SHUT DOWN QUICKLY. THE
WIND WILL PROB BE A BIT SLOWER TO SUBSIDE AND AS MENTIONED ABOVE
...MAY REACH HIGH WIND WARNING CRITERIA AT PLACES LIKE MDT AND LNS.

FRI SHUD BE A BEAUTIFUL DAY WITH LOTS OF SUN AND A FEW SC OVR THE
MTNS. TEMPS IN THE 70S E OF THE MTNS AND IN THE 60S ON THE HI GRND.
DEWPTS WILL DROP INTO THE 40S EVEN IN THE LWR SUSQ.

HAVENT HAD A CHC TO LOOK MUCH FURTHER THAN THAT AND WILL ACCEPT
WHAT IS OUT.

IN THE EXTENDED...WILL PUT A CHC SHRS IN TUE BASED ON MRF.

.CTP...FFA FOR THE EASTERN THIRD OF THE CWA THRU THIS EVE.
       WIND ADVISORY FOR LWR SUSQ AND CUMB VALS THRU THIS EVE.

HEAD

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 9:00 AM EDTFlash Flood WarningCTPDauphin, Lebanon, Schuylkill6 hr
Sep 16, 9:00 AM EDTFlash Flood WarningCTPLancaster, York6 hr
Sep 16, 9:00 AM EDTFlash Flood WarningCTPAdams, Cumberland, Perry6 hr
Sep 16, 2:15 PM EDTFlash Flood WarningCTPAdams, Cumberland, Dauphin, Lancaster, York7 hr
Sep 16, 2:15 PM EDTFlash Flood WarningCTPLebanon, Schuylkill7 hr
Sep 16, 4:35 PM EDTFlash Flood WarningCTPColumbia, Lycoming, Montour, Northumberland, Union3 hr
Sep 16, 4:35 PM EDTFlash Flood WarningCTPSnyder3 hr
Sep 16, 7:30 PM EDTFlash Flood WarningCTPSnyder, Union90 min

Nearby

Flash Flood Warnings in Pennsylvania, 1999Every flash flood warning in 1999

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.