Alert archive / Pennsylvania / Flash Flood Watches in 2021

Flash Flood Watch 2, NWS State College, PA

July 11, 20214 counties in Pennsylvania

NWS State College, PA issued this flash flood watch at Jul 11, 2021, 4:42 PM EDT for 4 counties in Pennsylvania. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Jul 11, 2021, 4:42 PM EDT (20:42 UTC)
Expired
Jul 12, 2021, 1:19 AM EDT
In force
9 hr
Issued by
NWS State College, PA
Flood severity
None

Counties Columbia County, PA, Lycoming County, PA, Sullivan County, PA, Tioga County, PA

The radar

The Binghamton radar (KBGM), 112 km from the middle of the area, began a volume at 20:42 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 8.7 hours before the alert went out and 231 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, Buffalo Intl Airport, NY at 12:00Z on 2021-07-11Temperature 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, Buffalo Intl Airport, NY at 12:00Z on 2021-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 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
1367 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

793 
WGUS61 KCTP 112042
FFACTP

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service State College PA
442 PM EDT Sun Jul 11 2021

PAZ037-041-042-046-053-121200-
/O.NEW.KCTP.FF.A.0002.210711T2042Z-210712T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Columbia-
Including the cities of Wellsboro, Laporte, Trout Run, Williamsport, 
Bloomsburg, Mansfield, and Berwick
442 PM EDT Sun Jul 11 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH MONDAY MORNING...

The National Weather Service in State College has issued a

* Flash Flood Watch for a portion of central Pennsylvania, including 
  the following areas, Columbia, Northern Lycoming, Southern 
  Lycoming, Sullivan and Tioga.

* Through Monday morning.

* Heavy rain from training thunderstorms is expected this evening 
  through early Monday. Rainfall totals of 1 to 2 inches are likely 
  with the potential for 3 inches in some locations.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

Lambert/Gutierrez
1 follow-up statement
655 
WGUS61 KCTP 120519
FFACTP

Flood Watch
National Weather Service State College PA
119 AM EDT Mon Jul 12 2021

PAZ037-041-042-046-053-120630-
/O.CAN.KCTP.FF.A.0002.000000T0000Z-210712T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Columbia-
Including the cities of Wellsboro, Laporte, Trout Run, Williamsport, 
Bloomsburg, Mansfield, and Berwick
119 AM EDT Mon Jul 12 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of central Pennsylvania, 
including the following areas, Columbia, Northern Lycoming, Southern 
Lycoming, Sullivan and Tioga has been cancelled.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat overnight. Additional heavy rain is possible, but not 
likely this afternoon and evening.

$$

Dangelo

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 3:29 PM EDTSpecial Weather StatementCTPCameron31 min
Jul 11, 3:51 PM EDTSpecial Weather StatementCTPCambria39 min
Jul 11, 4:48 PM EDTSevere Thunderstorm WarningCTPCameron, Elk42 min
Jul 11, 4:51 PM EDTSevere Thunderstorm WarningCTPClearfield, Elk39 min
Jul 11, 4:59 PM EDTSpecial Weather StatementCTPBlair46 min
Jul 11, 5:06 PM EDTSpecial Weather StatementCTPSnyder39 min
Jul 11, 5:06 PM EDTSevere Thunderstorm WarningCTPBlair, Huntingdon24 min
Jul 11, 5:10 PM EDTTornado WarningCTPCameron, Elk24 min
Jul 11, 5:18 PM EDTSevere Thunderstorm WarningCTPElk46 min
Jul 11, 5:19 PM EDTSevere Thunderstorm WarningCTPCameron, Clearfield, Elk41 min
Jul 11, 5:25 PM EDTSevere Thunderstorm WarningCTPCambria, Somerset65 min
Jul 11, 5:30 PM EDTSevere Thunderstorm WarningCTPBlair, Centre, Clearfield, Huntingdon45 min
Jul 11, 5:37 PM EDTAreal Flood AdvisoryCTPCameron, Clearfield, Clinton, Elk, Potter2 hr
Jul 11, 5:52 PM EDTSpecial Weather StatementCTPBedford23 min
Jul 11, 5:55 PM EDTSevere Thunderstorm WarningCTPCameron, Centre, Clearfield, Clinton, Potter35 min
Jul 11, 6:03 PM EDTSevere Thunderstorm WarningCTPBedford, Blair, Cambria, Centre, Clearfield, Huntingdon and 1 more57 min
Jul 11, 6:16 PM EDTTornado WarningCTPCentre, Clinton29 min
Jul 11, 6:23 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton52 min
Jul 11, 6:35 PM EDTSpecial Weather StatementCTPSullivan25 min
Jul 11, 6:39 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton51 min
Jul 11, 6:48 PM EDTTornado WarningCTPCentre, Clinton27 min
Jul 11, 6:57 PM EDTSevere Thunderstorm WarningCTPBedford, Centre, Cumberland, Franklin, Fulton, Huntingdon and 3 more63 min
Jul 11, 7:02 PM EDTSevere Thunderstorm WarningCTPColumbia, Sullivan43 min
Jul 11, 7:25 PM EDTSevere Thunderstorm WarningCTPClinton50 min
Jul 11, 7:31 PM EDTSevere Thunderstorm WarningCTPCentre, Clinton, Juniata, Mifflin, Snyder, Union44 min
Jul 11, 7:39 PM EDTTornado WarningCTPClinton, Lycoming36 min
Jul 11, 7:48 PM EDTSpecial Weather StatementCTPSullivan27 min
Jul 11, 7:58 PM EDTSevere Thunderstorm WarningCTPBedford, Cumberland, Franklin, Fulton, Huntingdon, Juniata and 2 more62 min

Nearby

Flash Flood Watches in Pennsylvania, 2021Every flash flood watch in 2021

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.