Alert archive / Pennsylvania / Flash Flood Warnings in 2010

Flash Flood Warning 2, NWS Philadelphia/Mount Holly

May 27, 2010Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 27, 2010, 2:30 PM EDT for Northampton County, Pennsylvania. It was in force for 33 min. 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 27, 2010, 2:30 PM EDT (18:30 UTC)
Expired
May 27, 2010, 3:03 PM EDT
In force
33 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Northampton County, PA

The radar

The Philadelphia radar (KDIX), 116 km from the middle of the area, began a volume at 18:31 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.5 hours before the alert went out and 172 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, Phillips Aaf/Abe, MD at 12:00Z on 2010-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 759 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phillips Aaf/Abe, MD at 12:00Z on 2010-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -74 square meters per square second.1939Sfc1 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
759 J/kg
Mixed-layer CIN
-227 J/kg
Mixed-layer LCL
1358 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-74 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

209 
WGUS51 KPHI 271830
FFWPHI
PAC095-272030-
/O.NEW.KPHI.FF.W.0002.100527T1830Z-100527T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
230 PM EDT THU MAY 27 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 430 PM EDT

* AT 227 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
THAT FLASH FLOODING MAY BE OCCURRING FROM A SLOW MOVING THUNDERSTORM 
OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PORTLAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES  ARE POSSIBLE IN THE 
WARNED AREA.

&&

LAT...LON 4091 7508 4086 7505 4084 7510 4082 7509
      4079 7510 4077 7513 4078 7516 4074 7520
      4073 7519 4072 7522 4088 7528 4094 7518
      4096 7515

$$

PO
1 follow-up statement
562 
WGUS71 KPHI 271903
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
303 PM EDT THU MAY 27 2010

PAC095-271912-
/O.CAN.KPHI.FF.W.0002.000000T0000Z-100527T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORTHAMPTON PA-
303 PM EDT THU MAY 27 2010

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHEASTERN
NORTHAMPTON COUNTY...

THE THUNDERSTORM THAT HAS PRODUCED VERY HEAVY RAINS ACROSS THE 
NORTHEAST PART OF NORTHAMPTON COUNTY HAS WEAKENED. THE THREAT FOR 
FLASH FLOODING HAS PASSED. LOCAL STREAMS AND CREEKS WILL CONTINUE TO 
RUN HIGH FOR THE NEXT FEW HOURS.  

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 4091 7508 4086 7505 4084 7510 4082 7509
      4079 7510 4077 7513 4078 7516 4074 7520
      4073 7519 4072 7522 4088 7528 4094 7518
      4096 7515

$$

PO

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 2:00 PM EDTSevere Thunderstorm WarningPHIBucks, Monroe, Northampton60 min
May 27, 2:45 PM EDTSpecial Weather StatementPHIChester60 min
May 27, 3:19 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton41 min
May 27, 4:53 PM EDTSpecial Weather StatementPHIBucks, Montgomery52 min
May 27, 5:11 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Northampton64 min
May 27, 5:36 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton54 min
May 27, 5:44 PM EDTSpecial Weather StatementPHIDelaware, Montgomery61 min
May 27, 5:53 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery37 min
May 27, 6:05 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery25 min
May 27, 6:20 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Lehigh, Montgomery55 min
May 27, 6:35 PM EDTSpecial Weather StatementPHINorthampton55 min
May 27, 7:12 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Delaware, Montgomery48 min
May 27, 7:25 PM EDTSpecial Weather StatementPHIMontgomery65 min
May 27, 7:40 PM EDTSpecial Weather StatementPHIBucks65 min
May 27, 7:44 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery3 hr
May 27, 7:56 PM EDTSevere Thunderstorm WarningPHIChester, Delaware34 min

Nearby

Flash Flood Warnings in Pennsylvania, 2010Every flash flood warning in 2010

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.