Alert archive / Pennsylvania / Flash Flood Warnings in 2015

Flash Flood Warning 5, NWS Philadelphia/Mount Holly

May 31, 2015Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 31, 2015, 7:46 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 4 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 31, 2015, 7:46 PM EDT (23:46 UTC)
Expired: Jun 1, 2015, 12:15 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 144 km from the middle of the area, began a volume at 23:48 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 12:00Z, 11.8 hours before the alert went out and 228 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: 42 J/kg
Mixed-layer CIN: -162 J/kg
Mixed-layer LCL: 1212 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

314 
WGUS51 KPHI 312346
FFWPHI
PAC011-077-010415-
/O.NEW.KPHI.FF.W.0005.150531T2346Z-150601T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
746 PM EDT SUN MAY 31 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 1215 AM EDT
    
* AT 745 PM EDT...DOPPLER RADAR INDICATED A THUNDERSTORM PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. UP TO TWO INCHES OF RAIN HAVE 
  ALREADY FALLEN. ANOTHER WAVE OF VERY HEAVY RAIN IS ABOUT TO 
  ENTER BERKS COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4049 7642 4051 7638 4052 7625 4057 7602
      4065 7598 4070 7583 4078 7567 4078 7562
      4074 7559 4072 7556 4073 7553 4066 7548
      4067 7543 4066 7542 4028 7609

$$

1 follow-up statement

676 
WGUS71 KPHI 010249
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1049 PM EDT SUN MAY 31 2015

PAC011-077-010415-
/O.CON.KPHI.FF.W.0005.000000T0000Z-150601T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LEHIGH PA-BERKS PA-
1049 PM EDT SUN MAY 31 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 AM EDT FOR
LEHIGH AND CENTRAL BERKS COUNTIES...

AT 1045 PM EDT...DOPPLER RADAR INDICATED CLUSTERS OF THUNDERSTORMS 
PRODUCING HEAVY RAIN MOVING ACROSS PORTIONS OF THE WARNED AREA.  

THE WARNING CONTINUES THROUGH ITS EXPIRATION TIME OF 1215 AM FOR THE 
POSSIBILITY OF FLASH FLOODING...IF THE STORMS CAN REPEATEDLY MOVE 
OVER THE SAME COMMUNITIES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4049 7642 4051 7638 4052 7625 4057 7602
      4065 7598 4070 7583 4078 7567 4078 7562
      4074 7559 4072 7556 4073 7553 4066 7548
      4067 7543 4066 7542 4028 7609

$$

DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
May 30, 8:19 PM EDT	Special Weather Statement	PHI	Carbon	56 min
May 30, 8:46 PM EDT	Special Weather Statement	PHI	Lebanon	29 min
May 30, 9:03 PM EDT	Areal Flood Advisory	PHI	Berks	3 hr
May 30, 9:11 PM EDT	Special Weather Statement	PHI	Lebanon	64 min
May 30, 9:20 PM EDT	Special Weather Statement	PHI	Carbon	55 min
May 30, 9:36 PM EDT	Areal Flood Advisory	PHI	Carbon	3 hr
May 31, 1:00 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	45 min
May 31, 1:11 PM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Lehigh, Monroe, Northampton	13 hr
May 31, 4:33 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	42 min
May 31, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	63 min
May 31, 5:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks	37 min
May 31, 5:42 PM EDT	Flash Flood Warning	PHI	Carbon, Monroe	6 hr
May 31, 7:08 PM EDT	Special Weather Statement	PHI	Lehigh	82 min
May 31, 7:27 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	5 hr
May 31, 7:48 PM EDT	Severe Thunderstorm Warning	PHI	Berks	35 min
May 31, 7:57 PM EDT	Areal Flood Advisory	PHI	Lehigh, Northampton	6 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2015 Every flash flood warning in 2015

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.