Alert archive / Pennsylvania / Areal Flood Advisories in 2017

Areal Flood Advisory 21, NWS State College, PA

May 28, 2017Somerset County, Pennsylvania

NWS State College, PA issued this areal flood advisory at May 28, 2017, 4:31 PM EDT for Somerset County, Pennsylvania. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
May 28, 2017, 4:31 PM EDT (20:31 UTC)
Expired
May 28, 2017, 7:30 PM EDT
In force
3 hr
Issued by
NWS State College, PA
Area
Storm-based polygon

County Somerset County, PA

The radar

The Pittsburgh radar (KPBZ), 119 km from the middle of the area, began a volume at 20:33 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 (KAGC), launched 12:00Z, 8.5 hours before the alert went out and 103 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 12:00Z on 2017-05-28Temperature 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 12:00Z on 2017-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.19395878Sfc1 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
948 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory 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 advisory went out at May 28, 3:27 PM EDT, 1 hour 4 minutes earlier.

Area forecast discussion, May 28, 3:27 PM EDT, 1 hour 4 minutes before
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Hazardous weather outlook, May 28, 11:28 AM EDT, 5 hours 3 minutes before
Hazardous Weather Outlook
National Weather Service State College PA
1128 AM EDT Sun May 28 2017

PAZ005-006-011-012-018-019-027-028-037-041-042-045-046-049>053-
056>059-063>066-291530-
McKean-Potter-Cameron-Northern Clinton-Northern Centre-
Southern Centre-Mifflin-Juniata-Tioga-Northern Lycoming-Sullivan-
Southern Clinton-Southern Lycoming-Union-Snyder-Montour-
Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-Cumberland-
Adams-York-Lancaster-
1128 AM EDT Sun May 28 2017

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ004-010-017-024>026-035-036-291530-
Warren-Elk-Clearfield-Cambria-Blair-Huntingdon-Fulton-Franklin-
1128 AM EDT Sun May 28 2017

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

Isolated severe thunderstorms with strong winds, hail and locally
heavy rainfall are possible this afternoon and evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ033-034-291530-
Somerset-Bedford-
1128 AM EDT Sun May 28 2017

...FLASH FLOOD WATCH IN EFFECT UNTIL 10 PM EDT THIS EVENING...

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Flash Flood Watch.

In addition, isolated severe thunderstorms with strong winds and
hail are possible this afternoon and evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

In the hours before

Special weather statement, May 28, 1:07 PM EDT, 3 hours 24 minutes before
Special Weather Statement
National Weather Service State College PA
107 PM EDT SUN MAY 28 2017

PAZ036-281730-
Franklin PA-
107 PM EDT SUN MAY 28 2017

...SPECIAL WEATHER STATEMENT...

At 105 PM EDT, Doppler radar indicated a strong thunderstorm over
Marion, moving northeast at 15 mph.

Brief wind gusts in excess of 40 mph are possible.

Locations impacted include...
Chambersburg, Marion, Guilford, Fayetteville, Williamson and Upton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in State College PA.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 3979 7777 3980 7782 3982 7786 3996 7763
      3989 7754
TIME...MOT...LOC 1705Z 237DEG 12KT 3986 7771

Lambert
Special weather statement, May 28, 3:37 PM EDT, 54 minutes before
Special Weather Statement
National Weather Service State College PA
337 PM EDT SUN MAY 28 2017

PAZ024-033-282030-
Somerset PA-Cambria PA-
337 PM EDT SUN MAY 28 2017

...STRONG THUNDERSTORMS WILL AFFECT PARTS OF Western SOMERSET AND
western CAMBRIA COUNTIES UNTIL 430 PM EDT...

At 331 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Vinco to 6 miles west of New Centerville.
Movement was northeast at 15 mph.

Torrential rain of over one inch per hour is expected and isolated
instances of up to dime size hail and brief wind gusts to around 40
mph are possible. The greatest threat for the heavy rain and hail
will be to the west of route 219.

Locations impacted include...
Belmont, Johnstown, Westmont, Somerset, Ebensburg, Nanty-Glo, Acosta,
Davidsville, Vinco, East Conemaugh, New Centerville, South Fork,
Belsano, Boswell, Ehrenfeld, Tire Hill, Daisytown, Dale, Geistown and
Jerome.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Minor flooding may develop. Do not drive into water covering the
roadway.

Turn around don't drown.

&&

LAT...LON 3990 7940 4006 7928 4012 7921 4011 7919
      4012 7917 4016 7916 4036 7900 4054 7890
      4056 7864 3995 7907 3985 7941
TIME...MOT...LOC 1931Z 243DEG 13KT 4045 7894 3993 7932

Lambert

The office that day

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

IssuedProductOfficeCountiesLasted
May 28, 6:49 AM EDTDense Fog AdvisoryCTPAdams, Bedford, Blair, Cambria, Centre, Clearfield and 12 more2 hr
May 28, 11:19 AM EDTFlash Flood WatchCTPBedford, Somerset11 hr
May 28, 1:07 PM EDTSpecial Weather StatementCTPFranklin23 min
May 28, 3:37 PM EDTSpecial Weather StatementCTPCambria53 min
May 28, 5:06 PM EDTFlash Flood WarningCTPSomerset3 hr
May 28, 5:12 PM EDTAreal Flood AdvisoryCTPMcKean, Warren3 hr
May 28, 6:55 PM EDTAreal Flood AdvisoryCTPBedford, Fulton110 min
May 28, 7:56 PM EDTAreal Flood WarningCTPSomerset3 hr

Nearby

Areal Flood Advisories in Pennsylvania, 2017Every areal flood advisory in 2017

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.