Alert archive / Pennsylvania / Flash Flood Warnings in 1999

Flash Flood Warning 56, NWS State College, PA

September 7, 1999Tioga County, Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 7, 1999, 3:45 AM EDT for Tioga County, Pennsylvania. It was in force for 2 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 7, 1999, 3:45 AM EDT (07:45 UTC)
Expired
Sep 7, 1999, 6:00 AM EDT
In force
2 hr
Issued by
NWS State College, PA
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Tioga County, PA

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 7.8 hours before the alert went out and 172 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 1999-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 35 joules per kilogram.LCLLFCEL10008507005003002001001 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 1999-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 square meters per square second.1939Sfc1 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
35 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
617 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
142 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 070633
FFWCTP
PAC043-081-099-109-117-119-133-071000-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
225 AM EDT TUE SEP 7 1999

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  YORK COUNTY.
  PERRY COUNTY.
  DAUPHIN COUNTY.
  SNYDER COUNTY.
  UNION COUNTY.
  LYCOMING COUNTY.
  SOUTHERN TIOGA COUNTY.

* UNTIL 6 AM EDT.

* EMERGENCY MANAGEMENT OFFICIALS REPORT WIDESPREAD FLOODING PERRY... 
  UNION...DAUPHIN AND SNYDER COUNTIES. FLOODING IS ALSO              
  REPORTED IN YORK COUNTY.

VERY HEAVY RAIN CONTINUES TO FALL OVER THE AREA NORTH OF 
HARRISBURG...FROM ABOUT SAXTON UP THROUGH NORTHUMBERLAND...LEWISBURG 
AND WATSONTOWN. THE RAIN IS FALLING OVER AREAS WHERE VERY HEAVY RAIN 
HAS FALLEN ALREADY THIS EVENING...LEADING TO LOCALIZED FLASH FLOODING.

IN AREAS WHERE THE RAIN HAS TAPERED OFF...RUNOFF FROM THE EARLIER 
HEAVY RAINS WILL CONTINUE TO CAUSE FLOODING PROBLEMS FOR THE NEXT 
FEW HOURS.

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/ LA CORTE

LAT...LON 4108 7717 4086 7737 4071 7734 4065 7698
          4030 7766 4020 7760 4033 7692 4021 7686
          4006 7708 3994 7701 3974 7699 3974 7629
          4012 7672 4022 7660 4047 7669 4056 7655
          4068 7671 4064 7692 4095 7686 4116 7690
          4121 7656F 4162 7683 4156 7762

&

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 7, 3:45 AM EDT, 0 minutes earlier.

Area forecast discussion, Sep 7, 3:45 AM EDT, 0 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
345 AM EDT TUE SEP 7 1999

...WORK ZONES OUT AS PHLADMCTP...

IR IMAGERY AND SFC OBS INDICATING SFC LOW OVER NORTHWEST PA EARLY
THIS MORNING. MEANWHILE...LL JET PRODUCING FLOODING RAINS CONTINUES
TO SPIRAL NORTHEASTWARD. WILL DROP FLASH FLOOD WATCH FOR ALL BUT OUR
NORTHEAST ZONES...WHERE HEAVY RAIN CONTINUES TO FALL.  LATEST ETA
SUGGESTS THAT STEADY RAIN WILL LIFT NORTH OF ENTIRE CWA DURING THE
MID MORNING HOURS.  EXPECT PARTLY SUNNY SKIES TO DEVELOP FROM
SOUTHWEST TO NORTHEAST AS DRY SLOT WORKS UP INTO THE AREA.
HOWEVER...MODEL SOUNDINGS STILL SEEM UNSTABLE ENOUGH TO SUPPORT SCT
SHOWERS/TSRA THIS AFTERNOON.

TONIGHT...SECONDARY S/WV PROGGED TO SWING THROUGH THE AREA CUD BRING
A FEW MORE SHOWERS/TSRA DURING THE EVENING HOURS. THEN CLEARING
SKIES...LIGHT WINDS...AND RECENT RAINS WILL LIKELY COMBINE TO FORM
AREAS OF DENSE FOG TONIGHT.

WEDNESDAY...SUBSIDENCE BEHIND DEPARTING TROUGH WILL BRING PARTLY TO
MOSTLY SUNNY SKIES ON WEDNESDAY. 8H TEMPS AROUND 15C SUPPORT TEMPS
FROM THE U70S OVER THE MTNS TO THE M80S IN THE SUSQ VALL.

.CTP...FLASH FLOOD WATCH FOR PORTIONS OF THE MIDDLE SUSQUEHANNA
VALLEY AND NORTHERN MOUNTAINS THROUGH THIS MORNING.

FITZGERALD

In the hours before

Local storm report, Sep 6, 11:24 PM EDT, 4 hours 21 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1124 PM EDT MON SEP 06 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0500 PM    MARYSVILLE                PA   WIND DAMAGE
09/06/99   PERRY                          TREE DOWN BLOCKING RTE 850
Local storm report, Sep 6, 11:24 PM EDT, 4 hours 21 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1124 PM EDT MON SEP 06 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0500 PM    MARYSVILLE                PA   WIND DAMAGE
09/06/99   PERRY                          TREE DOWN BLOCKING RTE 850

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 9:07 PM EDTFlash Flood WarningCTPCumberland, Dauphin, Perry, York3 hr
Sep 6, 11:37 PM EDTFlash Flood WarningCTPLycoming, Snyder, Union3 hr
Sep 6, 11:47 PM EDTFlash Flood WarningCTPCumberland, Dauphin, York3 hr
Sep 6, 11:47 PM EDTFlash Flood WarningCTPPerry3 hr
Sep 7, 2:06 AM EDTFlash Flood WarningCTPNorthumberland3 hr
Sep 7, 2:25 AM EDTFlash Flood WarningCTPPerry, Snyder, Union4 hr
Sep 7, 2:25 AM EDTFlash Flood WarningCTPDauphin, York4 hr
Sep 7, 2:25 AM EDTFlash Flood WarningCTPLycoming4 hr

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.