Alert archive / Pennsylvania / Flash Flood Watches in 2018

Flash Flood Watch 4, NWS State College, PA

June 1, 2018Adams County, Lancaster County, York County, Pennsylvania

NWS State College, PA issued this flash flood watch at Jun 1, 2018, 10:40 PM EDT for Adams County, Lancaster County, York County, Pennsylvania. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Jun 1, 2018, 10:40 PM EDT (02:40 UTC)
Expired: Jun 2, 2018, 5:11 AM EDT
In force: 7 hr
Issued by: NWS State College, PA
Flood severity: None

Counties Adams County, PA, Lancaster County, PA, York County, PA

The radar

The Sterling radar (KLWX), 126 km from the middle of the area, began a volume at 02:44 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, 2.7 hours before the alert went out and 125 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 678 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 1436 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 45 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch 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 watch went out at Jun 1, 10:30 PM EDT, 10 minutes earlier.

Area forecast discussion, Jun 1, 10:30 PM EDT, 10 minutes before

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Hazardous weather outlook, Jun 1, 5:42 AM EDT, 16 hours 58 minutes before

Hazardous Weather Outlook
National Weather Service State College PA
542 AM EDT Fri Jun 1 2018

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-020945-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin-
Juniata-Somerset-Bedford-Fulton-Franklin-Tioga-Northern Lycoming-
Sullivan-Southern Clinton-Southern Lycoming-Union-Snyder-Montour-
Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-Cumberland-
Adams-York-Lancaster-
542 AM EDT Fri Jun 1 2018

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Special weather statement, Jun 1, 6:41 PM EDT, 3 hours 59 minutes before

Special Weather Statement
National Weather Service State College PA
641 PM EDT FRI JUN 1 2018

PAZ027-012315-
Mifflin PA-
641 PM EDT FRI JUN 1 2018

...HEAVY RAIN NEAR BELLEVILLE...

At 638 PM EDT, Doppler radar indicated a strong thunderstorm between
Belleville and Allensville. The storm is nearly stationary. Nearly
two inches of rain has already fallen and very heavy rain is
expected to continue through 7 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4052 7783 4055 7784 4058 7783 4061 7779
      4062 7777 4065 7773 4060 7769 4048 7780
TIME...MOT...LOC 2238Z 317DEG 49KT 4054 7774

Dangelo

Special weather statement, Jun 1, 6:48 PM EDT, 3 hours 52 minutes before

Special Weather Statement
National Weather Service State College PA
648 PM EDT FRI JUN 1 2018

PAZ035-036-012330-
Fulton PA-Franklin PA-
648 PM EDT FRI JUN 1 2018

...HEAVY RAIN OVER MCCONNELSBURG AAND FORT LOUDON...

At 643 PM EDT, Doppler radar indicated a strong thunderstorm over
Fort Loudon, moving only very slowly to the south. This storm is
producing very heavy rainfall along route 30 between Chambersburg
and McConnellsburg.

Up to an inch and a half of rain has fallen over parts of Fulton
County already, and the heavy rain is expected to continue through
at least 715 PM EDT.

Locations impacted include... Saluvia, St. Thomas, Mercersburg,
Needmore, Harrisonville, Fort Littleton, Big Cove Tannery, Marion,
Sideling Hill Rest Area, Fort Loudon, McConnellsburg and Williamson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4012 7810 4006 7787 3997 7775 3982 7763
      3984 7819
TIME...MOT...LOC 2243Z 317DEG 48KT 3990 7791

Dangelo

Local storm report, Jun 1, 8:24 PM EDT, 2 hours 16 minutes before

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Local storm report, Jun 1, 8:55 PM EDT, 1 hour 45 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
855 PM EDT FRI JUN 01 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0750 PM     FLASH FLOOD      1 SW MCCONNELLSBURG     39.92N  78.01W
06/01/2018                   FULTON             PA   TRAINED SPOTTER

            GREAT (BIG) COVE CREEK OUT OF ITS BANKS FLOWING OVER
            BRIDGE AND ROAD ON CONFEDERATE ROAD.

&&

EVENT NUMBER CTP1801871

TYBURSKI

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 1, 9:39 PM EDT	Areal Flood Advisory	CTP	Adams	111 min
Jun 1, 11:38 PM EDT	Flash Flood Warning	CTP	Lancaster	3 hr
Jun 1, 11:53 PM EDT	Areal Flood Advisory	CTP	York	3 hr
Jun 2, 12:47 AM EDT	Flash Flood Warning	CTP	York	3 hr
Jun 2, 1:02 AM EDT	Areal Flood Advisory	CTP	Lancaster	3 hr
Jun 2, 2:29 AM EDT	Flash Flood Warning	CTP	Lancaster	3 hr
Jun 2, 5:40 AM EDT	Flash Flood Watch	CTP	Adams, Bedford, Franklin, Fulton, Lancaster, Somerset and 1 more	22 hr
Jun 2, 3:44 PM EDT	Areal Flood Advisory	CTP	Bedford, Somerset	2 hr
Jun 2, 5:38 PM EDT	Areal Flood Advisory	CTP	Lancaster, York	112 min
Jun 2, 6:07 PM EDT	Special Weather Statement	CTP	York	38 min
Jun 2, 7:10 PM EDT	Areal Flood Advisory	CTP	York	4 hr
Jun 2, 7:12 PM EDT	Special Weather Statement	CTP	York	33 min
Jun 2, 7:39 PM EDT	Flash Flood Warning	CTP	Lancaster, York	6 hr

Nearby

Flash Flood Watches in Pennsylvania, 2018 Every flash flood watch in 2018

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.