Alert archive / Pennsylvania / Areal Flood Warnings in 2011

Areal Flood Warning 8, NWS State College, PA

March 11, 201112 counties in Pennsylvania

NWS State College, PA issued this areal flood warning at Mar 11, 2011, 4:52 AM EST for 12 counties in Pennsylvania. It was in force for 8 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 11, 2011, 4:52 AM EST (09:52 UTC)
Expired
Mar 11, 2011, 12:45 PM EST
In force
8 hr
Issued by
NWS State College, PA
Area
Storm-based polygon
Flood severity
None

Counties Clinton County, PA, Columbia County, PA, Dauphin County, PA, Lancaster County, PA, Lebanon County, PA, Lycoming County, PA, Montour County, PA, Northumberland County, PA, Potter County, PA, Schuylkill County, PA, Sullivan County, PA, Tioga County, PA

The radar

The State College radar (KCCX), 100 km from the middle of the area, began a volume at 09:55 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, 9.9 hours before the alert went out and 233 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 2011-03-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 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 2011-03-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 256 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
123 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
457 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
256 m²/s²
0-3 km storm-relative helicity
309 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal 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 areal flood warning went out at Mar 11, 4:45 AM EST, 7 minutes earlier.

Area forecast discussion, Mar 11, 4:45 AM EST, 7 minutes before
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Hazardous weather outlook, Mar 11, 3:50 AM EST, 1 hour 2 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
350 AM EST FRI MAR 11 2011

PAZ006-011-012-018-019-025>028-034>037-041-042-045-046-049>053-
056>059-063>066-120900-
POTTER-CAMERON-NORTHERN CLINTON-NORTHERN CENTRE-SOUTHERN CENTRE-
BLAIR-HUNTINGDON-MIFFLIN-JUNIATA-BEDFORD-FULTON-FRANKLIN-TIOGA-
NORTHERN LYCOMING-SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-
SNYDER-MONTOUR-NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-
LEBANON-CUMBERLAND-ADAMS-YORK-LANCASTER-
350 AM EST FRI MAR 11 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

FLOODING WILL CONTINUE TO OCCUR ALONG NUMEROUS SMALLER STREAMS
AND CREEKS THIS MORNING. LARGER STREAMS AND RIVERS...ESPECIALLY
ACROSS THE SUSQUEHANNA VALLEY AND LOCATIONS TO THE EAST...WILL
CONTINUE TO RISE THROUGH TODAY AND INTO TONIGHT WITH MANY POINTS
CRESTING ABOVE FLOOD STAGE.

PERIODS OF SNOW WILL BRING LIGHT ACCUMULATIONS TO THE NORTHERN
MOUNTAINS INTO THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

MOST LARGER TRIBUTARIES IN THE SUSQUEHANNA RIVER BASIN WILL FALL
BELOW FLOOD STAGE BY DAYBREAK SATURDAY...WITH THE FLOOD CREST
WORKING ITS WAY SOUTH THROUGH THE WEST AND NORTH BRANCH OF THE
SUSQUEHANNA RIVER SATURDAY MORNING. THE FLOOD CREST WILL REACH
THE LOWER SUSQUEHANNA MAINSTEM FROM HARRISBURG TO MARIETTA SATURDAY
AFTERNOON AND EVENING.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE REQUESTED TO RELAY REPORTS OF STORM TOTAL
RAINFALL...AND FLOODING TO THE NATIONAL WEATHER SERVICE IN STATE
COLLEGE.

PAZ004-005-010-017-024-033-120900-
WARREN-MCKEAN-ELK-CLEARFIELD-CAMBRIA-SOMERSET-
350 AM EST FRI MAR 11 2011

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 PM EST THIS EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO
WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE
INFORMATION ABOUT THE FOLLOWING HAZARDS.

   WINTER WEATHER ADVISORY.

IN ADDITION...FLOODING WILL CONTINUE TO OCCUR ALONG SOME
SMALLER STREAMS AND CREEKS THROUGH THIS MORNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE REQUESTED TO REPORT SNOW ACCUMULATIONS TO
THE NATIONAL WEATHER SERVICE IN STATE COLLEGE.

LAMBERT

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 10, 7:24 PM ESTSpecial Weather StatementCTPAdams36 min
Mar 10, 7:55 PM ESTSpecial Weather StatementCTPCumberland, Dauphin, Lancaster, Lebanon, York65 min
Mar 10, 8:06 PM ESTRiver Flood WarningCTPWarren4 days
Mar 11, 12:22 AM ESTRiver Flood WarningCTPBlair, Huntingdon10 hr
Mar 11, 1:01 AM ESTWinter Weather AdvisoryCTPCambria, Clearfield, Elk, McKean, Somerset, Warren21 hr
Mar 11, 1:12 AM ESTRiver Flood WarningCTPClinton20 hr
Mar 11, 2:26 AM ESTAreal Flood WarningCTPAdams, Bedford, Blair, Cambria, Centre, Clearfield and 11 more8 hr
Mar 11, 4:27 AM ESTRiver Flood WarningCTPNorthumberland, Union35 hr
Mar 11, 4:27 AM ESTRiver Flood WarningCTPNorthumberland, Union37 hr
Mar 11, 7:35 AM ESTRiver Flood WarningCTPLycoming27 hr
Mar 11, 7:35 AM ESTRiver Flood WarningCTPLycoming, Northumberland, Union27 hr
Mar 11, 10:02 AM ESTRiver Flood WarningCTPLycoming6 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2011Every areal flood warning in 2011

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.