Alert archive / Pennsylvania / Flash Flood Warnings in 1995

Flash Flood Warning 74, NWS State College, PA

October 21, 1995Blair County, Pennsylvania

NWS State College, PA issued this flash flood warning at Oct 21, 1995, 4:55 AM EDT for Blair County, Pennsylvania. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Oct 21, 1995, 4:55 AM EDT (08:55 UTC)
Expired
Oct 21, 1995, 9:00 AM EDT
In force
4 hr
Issued by
NWS State College, PA
Area
Whole counties

County Blair County, PA

The radar

The State College radar (KCCX), 57 km from the middle of the area, began a volume at 08:59 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

Pittsburgh, PA (KPIT), launched 00:00Z, 8.9 hours before the alert went out and 148 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, Pittsburgh, PA at 00:00Z on 1995-10-21Temperature 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, Pittsburgh, PA at 00:00Z on 1995-10-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -280 square meters per square second.1939587897117Sfc1 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
631 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
-280 m²/s²
0-3 km storm-relative helicity
176 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 210856
FFWCTP
PAC013-211300-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
455 AM EDT SAT OCT 21 1995
 
THE NATIONAL WEATHER SERVICE IN STATE COLLEGE HAS ISSUED A
FLOOD WARNING EFFECTIVE UNTIL  900 AM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS......
 
IN  PENNSYLVANIA
 
   ...BLAIR COUNTY
 
AT 455 AM STATE COLLEGE DOPPLER RADAR SHOWED VERY HEAVY RAINS MOVING
NORTH INTO NORTHERN PORTION OF BLAIR COUNTY NEAR TYRONE. HEAVY RAINS
WILL CONTINUE THROUGH 6AM CAUSING FLOODING OF POOR DRAINAGE AREAS AND
PONDING OF WATER OVER ROADS.
 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CRROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.
 
LA CORTE/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 Oct 21, 2:37 AM EDT, 2 hours 18 minutes earlier.

Area forecast discussion, Oct 21, 2:37 AM EDT, 2 hours 18 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
235 AM EDT SAT OCT 21 1995

STRONG COLD FRONT FROM IPT SOUTH TO JUST WEST OF MDT AT 2AM.
LARGE AREA OF HEAVY RAIN OVER CNTRL PA AT THIS TIME IN RESPONSE
TO STRONG FRONTOGENETIC FORCING. NOSE OF 55+ KT LOW LEVEL JET NOW
PUSHING INTO SRN NY WITH CTRL PA IN LEFT ENTRANCE REGION OF LL
JET. STRONG AGEOSTROPHIC COMPONENT OF FLOW ACROSS LLJ MAKING FOR
INTENSE LOW LEVEL WIND AND MOISTURE CONVERGENCE OVER AREA. THIS
SITS NICELY UNDER STRONG DIVERGENCE ALOFT COURTESY OF NEGATIVE
TILT TROF AND STRONG EVACUATION OCCURRING DUE TO JET SPLITTING AS
IT MAKES TURN THRU TROF BASE. MARGINAL INSTABILITY CAUSING
EMBEDDED CONVECTION WHICH ISN'T HURTING SYSTEM'S PRECIP MAKING
ABILITY...SEEN SEVERAL FLASHES OF LTG OUT WINDOW HERE AT CTP.
EARLIER CONCERN WAS FOR POSSIBILITY OF SYSTEM TAPPING STRONG
WINDS JUST ABOVE BOUNDARY LAYER AND MIXING THEM DOWN IN
CONVECTION BUT THIS DOESN'T SEEM TO BE HAPPENING. INITIAL GUSTY
WINDS WITH FRONT HAVE CALMED DOWN SOMEWHAT AS WELL.

HAD 2.5" OF RAIN HERE AT CTP. RADAR INDICATING 3.9" IN ELK CTY.
CORRELATION BETWEEN RADAR AND GAGES KIND OF ERRATIC. SOME RADARA
ESTIMATES SEEM PRETTY CLOSE TO GAGES BUT OTHERS SHOWING BIG
DISCREPANCIES. WOULD THINK A SYSTEM LIKE THIS WOULD BE
UNDERCOOKED A BIT.

LA CORTE

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 20, 8:33 PM EDTSevere Thunderstorm WarningCTPClearfield, Elk57 min
Oct 21, 1:27 AM EDTFlash Flood WarningCTPClearfield, Elk4 hr
Oct 21, 4:22 AM EDTFlash Flood WarningCTPCentre, Clinton4 hr
Oct 21, 4:28 AM EDTFlash Flood WarningCTPLancaster, Lebanon, York4 hr
Oct 21, 4:34 AM EDTFlash Flood WarningCTPFranklin, Fulton, Huntingdon, Juniata, Mifflin4 hr
Oct 21, 4:40 AM EDTFlash Flood WarningCTPCameron, Potter4 hr
Oct 21, 4:40 AM EDTFlash Flood WarningCTPLycoming, Tioga4 hr
Oct 21, 5:11 AM EDTFlash Flood WarningCTPSnyder, Union4 hr
Oct 21, 5:38 AM EDTFlash Flood WarningCTPSchuylkill4 hr
Oct 21, 6:09 AM EDTFlash Flood WarningCTPAdams, Cumberland4 hr
Oct 21, 6:09 AM EDTFlash Flood WarningCTPDauphin, Perry4 hr
Oct 21, 6:15 AM EDTFlash Flood WarningCTPColumbia, Sullivan4 hr
Oct 21, 6:15 AM EDTFlash Flood WarningCTPMontour, Northumberland4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 1995Every flash flood warning in 1995

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.