Alert archive / Pennsylvania / Flash Flood Warnings in 2019

Flash Flood Warning 4, NWS Philadelphia/Mount Holly

May 19, 20194 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 19, 2019, 11:15 PM EDT for 4 counties in Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 19, 2019, 11:15 PM EDT (03:15 UTC)
Expired: May 20, 2019, 2:15 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Binghamton radar (KBGM), 144 km from the middle of the area, began a volume at 03:18 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

Brookhaven, NY (KOKX), launched 00:00Z, 3.3 hours before the alert went out and 235 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: 61 J/kg
Mixed-layer CIN: -284 J/kg
Mixed-layer LCL: 581 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 147 m²/s²
0-3 km storm-relative helicity: 224 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

201 
WGUS51 KPHI 200315
FFWPHI
PAC025-077-089-095-200615-
/O.NEW.KPHI.FF.W.0004.190520T0315Z-190520T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1115 PM EDT Sun May 19 2019

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Lehigh County in eastern Pennsylvania...
  Carbon County in northeastern Pennsylvania...
  Southwestern Monroe County in northeastern Pennsylvania...
  Central Northampton County in eastern Pennsylvania...

* Until 215 AM EDT.

* At 1113 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across Carbon and western Lehigh Counties, with 
  rainfall rates over one inch per hour. These thunderstorms are 
  expected to move east through the midnight hour. Flash flooding is 
  expected in the areas of heaviest rain.

* Some locations that could experience flooding include...
  Allentown, Lehighton, Northampton, Nazareth, Palmerton, Bangor, Jim
  Thorpe, Slatington, Pen Argyl, Nesquehoning, Wind Gap, Bath,
  Weatherly, Walnutport, Belfast, East Bangor, Stormville, Neffs,
  Coffeetown and Lake Harmony.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4088 7509 4052 7565 4068 7589 4074 7576
      4083 7590 4091 7599 4098 7582 4101 7573
      4103 7574 4105 7577 4112 7566 4112 7564
      4118 7557

$$

jjm

The office that day

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

Issued	Product	Office	Counties	Lasted
May 19, 8:14 PM EDT	Special Weather Statement	PHI	Lehigh	46 min
May 19, 8:35 PM EDT	Tornado Warning	PHI	Berks	25 min
May 19, 8:37 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Montgomery	38 min
May 19, 8:43 PM EDT	Flash Flood Warning	PHI	Berks	3 hr
May 19, 9:09 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	51 min
May 19, 9:29 PM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	4 hr
May 19, 9:46 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Montgomery, Northampton	44 min
May 19, 10:27 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	48 min
May 19, 10:34 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	3 hr
May 19, 10:48 PM EDT	Flash Flood Warning	PHI	Berks	117 min
May 19, 11:00 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	60 min
May 19, 11:41 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	53 min
May 19, 11:54 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh, Northampton	39 min
May 20, 12:57 AM EDT	Areal Flood Advisory	PHI	Berks	3 hr
May 20, 1:21 AM EDT	Areal Flood Advisory	PHI	Berks, Montgomery	3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2019 Every flash flood warning in 2019

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.