Alert archive / Pennsylvania / Flash Flood Warnings in 2018

Flash Flood Warning 60, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 11, 2018, 2:00 PM EDT for Warren County, New Jersey; Bucks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 9 hr. 9 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, 2:00 PM EDT (18:00 UTC)
Expired: Aug 11, 2018, 10:30 PM EDT
In force: 9 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Warren County, NJ, Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 98 km from the middle of the area, began a volume at 18:02 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, 3:00 PM EDT	FLASH FLOOD	Milford Twp, PA	WIDESPREAD FLOODING AND FLASH FLOODING ONGOING IN NORTHWESTERN BUCKS COUNTY. NUMEROUS ROADS AND BRIDGES FLOODED OR WASHED OUT BY FAST MOVING FLOOD WATERS. SOME RESIDENTS ARE BEING EVACUATED AWAY FROM QUICKLY RISING CREEKS AND STREAMS.
Aug 11, 3:25 PM EDT	FLASH FLOOD	1 Ne Lower Milford Twp, PA	LANDSLIDE ON I-476 WESTBOUND. ALL WESTBOUND LANES CLOSED.
Aug 11, 3:30 PM EDT	FLASH FLOOD	Milford Square, PA	VIDEO FOOTAGE OF SWIFTLY FLOWING WATER TWO TO THREE FEET DEEP INUNDATING ALLENTOWN ROAD NEAR AND NORTH OF STATE ROUTE 663. TIME APPROXIMATED BY RADAR.
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, 4:10 PM EDT	FLOOD	Upper Saucon Twp, PA	NUMEROUS REPORTS OF FLOODING ACROSS UPPER SAUCON TWP, COOPERSBURG, AND LOWER MILFORD TWP WITHIN THE LAST HOUR.
Aug 11, 4:20 PM EDT	HEAVY RAIN 2.91	Springtown, PA	OBSERVED RAINFALL SINCE 7AM EDT. THIS IS IN ADDITION TO 1.14 INCHES THAT FELL BEFORE 7AM EDT. VALUE CORRECTED FROM PREVIOUS LSR.
Aug 11, 4:20 PM EDT	HEAVY RAIN 3.91	Springtown, PA	OBSERVED RAINFALL SINCE 7AM EDT. THIS IS IN ADDITION TO 1.14 INCHES THAT FELL BEFORE 7AM EDT.
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.
Aug 11, 9:41 PM EDT	FLOOD	Saucon Valley Terrace, PA	FLOODING ON HICKORY HILL ROAD...SIEDERSVILLE ROAD...AND FRIEDENSVILLE ROAD BETWEEN MOUNTAIN DRIVE AND MAIN STREET IN BETHLEHEM. 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, 6.0 hours before the alert went out and 200 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.

609 
WGUS51 KPHI 111800
FFWPHI
NJC041-PAC017-077-095-112030-
/O.NEW.KPHI.FF.W.0060.180811T1800Z-180811T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly NJ has issued a

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

* Until 430 PM EDT.

* At 157 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the southern Lehigh Valley around the Allentown, 
  Bethlehem, and Easton areas. Rain was falling at a rate of one to 
  two inches per hours in a few spots. This will cause flash 
  flooding in the urban areas.
  
* Some locations that could experience flooding include...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Quakertown, Wilson,
  Hellertown, Alpha, Ferndale, West Easton, Bloomsbury, Riegelsville,
  Glendon, Pleasant Valley, Zionsville, Lehigh University,
  Springtown, Old Orchard and Phillipsburg.

Additional rainfall amounts of 1 to 2 inches is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Do not drive through flooded roadways...the water may be deeper than 
you think.

&&

LAT...LON 4064 7510 4062 7516 4059 7519 4057 7519
      4057 7516 4058 7515 4058 7512 4056 7510
      4037 7540 4050 7561 4075 7519

$$

jjm

3 follow-up statements

877 
WGUS51 KPHI 112014
FFWPHI
NJC041-PAC017-077-095-112330-
/O.EXT.KPHI.FF.W.0060.000000T0000Z-180811T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
414 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 Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Southeastern Northampton County in eastern Pennsylvania...

* Until 730 PM EDT.

* At 412 PM EDT, Doppler radar indicated rain...some of it heavy, 
  moving into the area from the northwest. With the area already wet 
  from previous rain, renewed flooding is a possibility. The flash 
  flood warning issued earlier for this area has therefore been 
  extended until 730 PM EDT.

* Some locations that could experience flooding include...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Quakertown, Wilson,
  Hellertown, Alpha, Ferndale, West Easton, Bloomsbury, Riegelsville,
  Glendon, Pleasant Valley, Zionsville, Lehigh University,
  Springtown, Old Orchard and Phillipsburg.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

LAT...LON 4064 7510 4062 7516 4059 7519 4057 7519
      4057 7516 4058 7515 4058 7512 4056 7510
      4037 7540 4050 7561 4075 7519

$$

JJM

315 
WGUS71 KPHI 112254
FFSPHI

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

NJC041-PAC017-077-095-112330-
/O.CON.KPHI.FF.W.0060.000000T0000Z-180811T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Warren NJ-Lehigh PA-Bucks PA-Northampton PA-
654 PM EDT SAT AUG 11 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM EDT FOR
SOUTHWESTERN WARREN...SOUTHEASTERN LEHIGH...NORTHWESTERN BUCKS AND
SOUTHEASTERN NORTHAMPTON COUNTIES...

While the heavy rain has moved out of the area, flooding continues 
in parts of northern Bucks County and southern Lehigh County. The 
flash flood warning remains in effect.  

Numerous roads and bridges remain flooded or washed out by fast 
moving water.


LAT...LON 4064 7510 4062 7516 4059 7519 4057 7519
      4057 7516 4058 7515 4058 7512 4056 7510
      4037 7540 4050 7561 4075 7519

$$

JJM

667 
WGUS51 KPHI 112318
FFWPHI
NJC041-PAC017-077-095-120230-
/O.EXT.KPHI.FF.W.0060.000000T0000Z-180812T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
718 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 Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Southeastern Northampton County in eastern Pennsylvania...

* Until 1030 PM EDT.

* At 714 PM EDT, Doppler radar indicated heavy rain has moved out of 
  the area. However, flooding continues in various locations within 
  the warned area as a result of earlier heavy rain. A raingage in 
  Springtown recorded over 4 inches of rain since early this 
  morning.

The Flash Flood Warning will remain in effect until significant 
flooding has ended.

LAT...LON 4064 7510 4062 7516 4059 7519 4057 7519
      4057 7516 4058 7515 4058 7512 4056 7510
      4037 7540 4050 7561 4075 7519

$$

jjm

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 3:24 AM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Hunterdon and 9 more	20 hr
Aug 11, 4:26 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more	24 hr
Aug 11, 5:27 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Warren	4 hr
Aug 11, 6:06 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Warren	6 hr
Aug 11, 6:31 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	7 hr
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, 1:51 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	39 min
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, 3:06 PM EDT	Flash Flood Warning	PHI	Warren	4 hr
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, 5:36 PM EDT	Areal Flood Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	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
Aug 11, 2:25 AM EDT	Special Weather Statement	PHI	Berks	65 min
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, 5:19 AM EDT	Flash Flood Warning	PHI	Berks	3 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, 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, 5:58 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

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.