Alert archive / Pennsylvania / Flash Flood Warnings in 1999

Flash Flood Warning 5, NWS Philadelphia/Mount Holly

January 9, 1999Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jan 9, 1999, 1:40 PM EST 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 counties it named.

The facts

Issued
Jan 9, 1999, 1:40 PM EST (18:40 UTC)
Expired
Jan 9, 1999, 6:00 PM EST
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 131 km from the middle of the area, began a volume at 18:44 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, 6.7 hours before the alert went out and 223 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, Washington/Dulle, VA at 12:00Z on 1999-01-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 1999-01-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 302 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
407 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
302 m²/s²
0-3 km storm-relative helicity
310 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.

000 
TTAA00 KPHL 091840
FFWPHL
PAC011-077-092300-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
140 PM EST SAT JAN 9 1999

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLOOD WARNING FOR...
  NORTHERN BERKS COUNTY IN PENNSYLVANIA
  NORTHWESTERN LEHIGH COUNTY IN PENNSYLVANIA

* UNTIL 600 PM EST

HEAVY RAIN HAS FALLEN ACROSS NORTHERN BERKS COUNTY TODAY.
EMERGENCY MANAGEMENT REPORTED THAT THE MILL CREEK WAS ABOUT TO FLOOD
IN MAXATAWNY TOWNSHIP.  OTHER CREEKS WERE ALSO RISING AND NEAR
BANKFULL IN RICHMOND TOWNSHIP WITH WATER ALREADY ON A COUPLE OF
ROADWAYS. SIMILAR AMOUNTS HAVE ALSO FALLEN IN NORTHWESTERN LEHIGH
COUNTY. WHILE THE HEAVIEST RAIN HAS MOVED THROUGH THE AREA...
ADDITIONAL RISES AND SMALL STREAM FLOODING ARE LIKELY AS THE RAIN
DRAINS INTO THE STREAMS.

AREA RESIDENTS SHOULD MONITOR FLOOD CONDITIONS... AND BE PREPARED
TO MOVE TO HIGHER GROUND... SHOULD FLOOD WATERS THREATEN. IF
FLOODING IS OBSERVED... ACT QUICKLY. MOVE TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

ANY LEFTOVER WATER ON ROADWAYS WILL FREEZE AS TEMPERATURES DROP
TONIGHT.

TFG

Nearby

Flash Flood Warnings in Pennsylvania, 1999Every flash flood warning in 1999

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.