Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 64, NWS Philadelphia/Mount Holly

August 11, 2018Northampton County, Pennsylvania; Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 11, 2018, 3:06 PM EDT for Northampton County, Pennsylvania; Warren County, New Jersey. It was in force for 4 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 11, 2018, 3:06 PM EDT (19:06 UTC)
Expired: Aug 11, 2018, 7:21 PM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Warren County, NJ, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 19:05 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.

What was reported inside it

Time	Report	Where	Remark
Aug 11, 4:02 PM EDT	FLASH FLOOD	Lower Saucon Twp, PA	WATER RESCUE IN LOWER SAUCON TWP WITH SEVERAL ROADS FLOODED AND CLOSED IN THE AREA.
Aug 11, 6:46 PM EDT	FLOOD	1 Nne Hellertown, PA	FLOODING ON RAUBSVILLE ROAD AND EASTON ROAD BETWEEN CHERRY LANE AND LOWER SAUCON ROAD. ALL LANES CLOSED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.1 hours before the alert went out and 203 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: 840 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 590 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

816 
WGUS51 KPHI 111906
FFWPHI
NJC041-PAC095-112200-
/O.NEW.KPHI.FF.W.0064.180811T1906Z-180811T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
306 PM EDT SAT AUG 11 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Northwestern Warren County in northwestern New Jersey...
  Northampton County in eastern Pennsylvania...

* Until 600 PM EDT.

* At 304 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across northern Northampton County and northwestern 
  Warren County. Rainfall rates over 2 inches per hour are possible, 
  and flash flooding is expected in the areas of heaviest rain. 

* Some locations that could experience flooding include...
  Easton, Bethlehem, Forks, Northampton, Wilson, Blairstown,
  Hellertown, Nazareth, Bangor, Pen Argyl, Wind Gap, Bath, Belvidere,
  Harmony, Walnutport, Hope, Belfast, West Easton, Tatamy and East
  Bangor.

LAT...LON 4100 7486 4075 7513 4072 7519 4068 7520
      4068 7517 4061 7520 4054 7533 4058 7541
      4063 7539 4067 7543 4066 7548 4074 7553
      4072 7556 4074 7559 4079 7561 4086 7529
      4093 7522 4097 7512 4100 7511 4109 7496

$$

jjm

3 follow-up statements

045 
WGUS71 KPHI 112149
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
549 PM EDT SAT AUG 11 2018

NJC041-PAC095-112200-
/O.CON.KPHI.FF.W.0064.000000T0000Z-180811T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren NJ-Northampton PA-
549 PM EDT SAT AUG 11 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM EDT FOR
SOUTHWESTERN WARREN AND SOUTHEASTERN NORTHAMPTON COUNTIES...

At 547 PM EDT, Doppler radar indicated additional rain moving into 
the area from the north. While this rain is not as heavy as the rain 
which fell earlier today, flooding is still ongoing in a few 
locations so the flash flood warning will remain in effect.

Some locations that may be experiencing flooding include...
Easton, Bethlehem, Forks, Wilson, Hellertown, Harmony, West Easton,
Glendon, Old Orchard, Lehigh University, Phillipsburg, Fountain Hill,
Freemansburg and Palmer Heights.

LAT...LON 4072 7519 4068 7520 4068 7517 4061 7520
      4054 7533 4058 7541 4063 7539 4077 7518
      4075 7513

$$

jjm

781 
WGUS51 KPHI 112151
FFWPHI
NJC041-PAC095-120100-
/O.EXT.KPHI.FF.W.0064.000000T0000Z-180812T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
551 PM EDT SAT AUG 11 2018

The National Weather Service in Mount Holly NJ has extended the

* Flash Flood Warning for...
  Southwestern Warren County in northwestern New Jersey...
  Southeastern Northampton County in eastern Pennsylvania...

* Until 900 PM EDT.

* At 550 PM EDT, Doppler radar indicated additional rain moving into 
  the area from the north. While this rain is not as heavy as the 
  rain which fell earlier today, flooding is still ongoing in a few 
  locations so the flash flood warning will remain in effect. 

* Some locations that could experience flooding include...
  Easton, Bethlehem, Forks, Wilson, Hellertown, Harmony, West Easton,
  Glendon, Old Orchard, Lehigh University, Phillipsburg, Fountain
  Hill, Freemansburg and Palmer Heights.

LAT...LON 4072 7519 4068 7520 4068 7517 4061 7520
      4054 7533 4058 7541 4063 7539 4077 7518
      4075 7513

$$

JJM

508 
WGUS71 KPHI 112321
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
721 PM EDT SAT AUG 11 2018

NJC041-PAC095-112329-
/O.CAN.KPHI.FF.W.0064.000000T0000Z-180812T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren NJ-Northampton PA-
721 PM EDT SAT AUG 11 2018

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN WARREN AND SOUTHEASTERN
NORTHAMPTON COUNTIES IS CANCELLED...

A flash flood warning issued at 718 PM EDT replaces this warning, so 
it has been cancelled.

LAT...LON 4072 7519 4068 7520 4068 7517 4061 7520
      4054 7533 4058 7541 4063 7539 4077 7518
      4075 7513

$$

jjm

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 11, 2:25 AM EDT	Special Weather Statement	PHI	Berks	65 min
Aug 11, 3:24 AM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	20 hr
Aug 11, 3:26 AM EDT	Special Weather Statement	PHI	Berks	64 min
Aug 11, 4:17 AM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Aug 11, 4:26 AM EDT	Coastal Flood Advisory	PHI	Bucks, Delaware, Philadelphia	24 hr
Aug 11, 5:19 AM EDT	Flash Flood Warning	PHI	Berks	3 hr
Aug 11, 5:27 AM EDT	Areal Flood Advisory	PHI	Northampton	4 hr
Aug 11, 6:06 AM EDT	Areal Flood Advisory	PHI	Bucks, Northampton	6 hr
Aug 11, 6:31 AM EDT	Areal Flood Advisory	PHI	Bucks	7 hr
Aug 11, 12:16 PM EDT	Special Weather Statement	PHI	Chester	29 min
Aug 11, 12:48 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Aug 11, 1:20 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	3 hr
Aug 11, 1:33 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	4 hr
Aug 11, 1:40 PM EDT	Flash Flood Warning	PHI	Chester	4 hr
Aug 11, 1:48 PM EDT	Flash Flood Warning	PHI	Delaware, Philadelphia	4 hr
Aug 11, 1:51 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	39 min
Aug 11, 2:00 PM EDT	Flash Flood Warning	PHI	Bucks, Lehigh, Northampton	9 hr
Aug 11, 2:14 PM EDT	Flash Flood Warning	PHI	Bucks	3 hr
Aug 11, 2:26 PM EDT	Special Weather Statement	PHI	Bucks, Philadelphia	34 min
Aug 11, 2:42 PM EDT	Special Weather Statement	PHI	Bucks	33 min
Aug 11, 3:50 PM EDT	Areal Flood Advisory	PHI	Berks, Montgomery	115 min
Aug 11, 4:19 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Aug 11, 4:19 PM EDT	Severe Thunderstorm Warning	PHI	Chester	29 min
Aug 11, 4:47 PM EDT	Special Weather Statement	PHI	Montgomery	28 min
Aug 11, 4:52 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh	2 hr
Aug 11, 5:36 PM EDT	Areal Flood Warning	PHI	Bucks	4 hr
Aug 11, 5:58 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	5 hr
Aug 11, 6:13 PM EDT	Special Weather Statement	PHI	Chester	32 min
Aug 11, 7:16 AM EDT	Flash Flood Warning	PHI	Middlesex, Somerset	4 hr
Aug 11, 10:49 AM EDT	Areal Flood Advisory	PHI	Middlesex, Somerset	3 hr
Aug 11, 11:29 AM EDT	Areal Flood Advisory	PHI	Atlantic	4 hr
Aug 11, 11:46 AM EDT	Special Marine Warning	PHI		119 min
Aug 11, 11:55 AM EDT	Special Weather Statement	PHI	Burlington	35 min
Aug 11, 12:27 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Ocean	4 hr
Aug 11, 12:39 PM EDT	Special Weather Statement	PHI	Ocean	36 min
Aug 11, 12:55 PM EDT	Special Marine Warning	PHI		65 min
Aug 11, 1:07 PM EDT	Flash Flood Warning	PHI	Atlantic, Cape May	4 hr
Aug 11, 1:26 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 1:42 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 2:05 PM EDT	Special Weather Statement	PHI	Cape May	25 min
Aug 11, 2:06 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	3 hr
Aug 11, 2:19 PM EDT	Special Marine Warning	PHI		86 min
Aug 11, 2:20 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland	3 hr
Aug 11, 2:30 PM EDT	Flash Flood Warning	PHI	Hunterdon, Morris, Warren	3 hr
Aug 11, 2:46 PM EDT	Flash Flood Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	3 hr
Aug 11, 2:58 PM EDT	Special Weather Statement	PHI	Cumberland	47 min
Aug 11, 3:13 PM EDT	Special Weather Statement	PHI	Hunterdon	47 min
Aug 11, 3:23 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex	3 hr
Aug 11, 3:24 PM EDT	Special Weather Statement	PHI	Atlantic, Cumberland	51 min
Aug 11, 3:32 PM EDT	Flash Flood Warning	PHI	Atlantic	3 hr
Aug 11, 3:47 PM EDT	Flash Flood Warning	PHI	Morris	3 hr
Aug 11, 4:11 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 4:28 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 5:00 PM EDT	Areal Flood Advisory	PHI	Gloucester, Salem	3 hr
Aug 11, 5:26 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Warren	4 hr
Aug 11, 6:11 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 6:12 PM EDT	Flash Flood Warning	PHI	Salem	3 hr
Aug 11, 7:35 PM EDT	Areal Flood Advisory	PHI	Atlantic, Cumberland	3 hr
Aug 11, 7:46 PM EDT	River Flood Warning	PHI	Essex, Morris, Passaic	4 days

Nearby

Flash Flood Warnings in Pennsylvania, 2018 Flash Flood Warnings in New Jersey, 2018 Every flash flood warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.