Alert archive / Pennsylvania / Flash Flood Warnings in 1999

Flash Flood Warning 1, NWS State College, PA

January 18, 1999Lancaster County, Pennsylvania

NWS State College, PA issued this flash flood warning at Jan 18, 1999, 10:33 AM EST for Lancaster County, Pennsylvania. It was in force for 3 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
Jan 18, 1999, 10:33 AM EST (15:33 UTC)
Expired
Jan 18, 1999, 1:25 PM EST
In force
3 hr
Issued by
NWS State College, PA
Area
Whole counties

County Lancaster County, PA

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 3.6 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 12:00Z on 1999-01-18Temperature 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 1999-01-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 601 square meters per square second.1939587897Sfc1 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
408 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
601 m²/s²
0-3 km storm-relative helicity
602 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 181533
FFWCTP
PAC071-181825-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1033 AM EST MON JAN 18 1999

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* FLOOD WARNING FOR...
  LANCASTER COUNTY IN SOUTHEASTERN PENNSYLVANIA.

* UNTIL 125 PM EST.

* AT 1020 AM...DOPPLER RADAR FROM STATE COLLEGE SHOWED SCATTERED
  SHOWERS ACROSS THE REGION.

* SHOWERS...COUPLED WITH WARM TEMPERATURES AND SNOWMELT HAVE CAUSED
  SMALLER STREAMS AND CREEKS IN LANCASTER COUNTY TO RISE
  SIGNIFICANTLY. AT 1020 AM...MILL CREEK AT SMOKETOWN WAS 8.1 FEET
  AND RISING. FLOOD STAGE IS 8 FEET.

  PEQUEA CREEK AT PARADISE IS ALSO RISING. THE STAGE WAS 8.0 FEET
  WITH A FLOOD STAGE OF 10 FEET. IT IS EXPECTED THAT FLOODING AT
  PARADISE WILL ALSO OCCUR.

  COUNTY EMERGENCY MANAGEMENT REPORTS THAT ROUTE 772 IS CLOSED IN
  WEST EARL TOWNSHIP IN THE VILLAGE OF TALMAGE.

  ADDITIONAL FLOODING OF SMALL STREAMS...CREEKS AND PONDING OF
  WATER ON ROADS WILL BE POSSIBLE LATER TODAY AS MORE RAIN MOVES
  INTO THE AREA.

RESIDENTS OF LANCASTER COUNTY SHOULD USE CAUTION WHILE TRAVELING
TODAY...AS SOME ROADS AND LOW-LYING AREAS MAY BE COVERED BY
FLOODWATERS.

.END/ 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 Jan 18, 10:30 AM EST, 3 minutes earlier.

Area forecast discussion, Jan 18, 10:30 AM EST, 3 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1030 AM EST MON JAN 18 1999

...WORK ZONES OUT AT 930 AS PHLADMCTP...
...ZONES OUT BY 11 AM AS PHLZFPCTP...

UPPER LO...SEEN IN THE SATELLITE IMAGERY NEAR SOUTHERN LK
MICHIGAN...WILL PROGRESS NE TODAY. DARKENING IN WV IMAGERY OVER OHIO
VALLEY REVEALING THE VORT MAX THAT IS PROGGED TO MOVE INTO PA LATE
TODAY. REGIONAL RADAR LOOP SHOWING AN AREA OF MODERATE TO HEAVY RAIN
DEVELOPING ACROSS EASTERN OHIO IN ADVANCE OF THE SFC COLD FRONT.
RECENT LIGHTNING DATA SUGGESTING THAT THUNDER WILL BE CONFINED TO
EXTREME SE PA...WHERE INFLUX OF LL MOISTURE IS THE GREATEST. WILL
KEEP THE FFA GOING THROUGH THE AFTN BECAUSE MINOR FLOODING STILL
SEEMS LIKELY AS PRE-FRONTAL RAIN BAND MOVES THROUGH THIS AFTN. IN
FACT...SOME STREAMS IN LANCASTER CO ALREADY FLOODING IN RESPONSE TO
RAINS OVERNIGHT. ALSO...FLASH FLOOD THREAT EXISTS AS A RESULT OF
POSSIBLE ICE JAMS ALONG SMALLER RIVERS AND STREAMS. HAVE ADDED THE
CHANCE OF SNOW SHOWERS EXTREME NW FOR LATE THIS AFTN GIVEN LATEST
ETA SOUNDINGS.

.CTP...FLASH FLOOD WATCH THROUGH THIS AFTERNOON SOUTHERN HALF OF
CENTRAL PA. WILL RE-ISSUE PHLSPSCTP FOR CONVECTIVE OUTLOOK IN THE
LOWER SUSQ VALL.

FITZGERALD

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 18, 1:25 PM ESTFlash Flood WarningCTPLancaster4 hr
Jan 18, 1:33 PM ESTSevere Thunderstorm WarningCTPCentre, Huntingdon, Mifflin77 min
Jan 18, 1:33 PM ESTSevere Thunderstorm WarningCTPBedford, Franklin, Fulton77 min
Jan 18, 1:33 PM ESTSevere Thunderstorm WarningCTPBlair77 min
Jan 18, 2:19 PM ESTSevere Thunderstorm WarningCTPCumberland, Dauphin, Juniata, Northumberland, Perry, Snyder61 min
Jan 18, 2:19 PM ESTSevere Thunderstorm WarningCTPAdams, York61 min
Jan 18, 2:19 PM ESTSevere Thunderstorm WarningCTPUnion61 min
Jan 18, 2:28 PM ESTSevere Thunderstorm WarningCTPLycoming47 min
Jan 18, 3:03 PM ESTFlash Flood WarningCTPColumbia, Lycoming, Montour, Northumberland, Sullivan4 hr
Jan 18, 3:03 PM ESTFlash Flood WarningCTPLebanon, Schuylkill4 hr
Jan 18, 4:05 PM ESTFlash Flood WarningCTPLancaster3 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.