Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 37, NWS Philadelphia/Mount Holly

June 7, 1999Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 7, 1999, 8:09 PM EDT for Berks County, Pennsylvania. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 7, 1999, 8:09 PM EDT (00:09 UTC)
Expired
Jun 7, 1999, 8:40 PM EDT
In force
31 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 139 km from the middle of the area, began a volume at 00:12 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 00:00Z, 0.2 hours before the alert went out and 206 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 00:00Z on 1999-06-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1850 joules per kilogram.LCLEL10008507005003002001001 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, Washington/Dulle, VA at 00:00Z on 1999-06-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
1850 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
1787 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
11 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.

817 
WUUS1 KPHL 080010 RRA
SVRPHL

PAC011-080040-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
809 PM EDT MON JUN 7 1999

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BERKS COUNTY IN PENNSYLVANIA.

* UNTIL 840 PM EDT.

* AT 808 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM IN THE VICINITY OF BERNVILLE... MOVING EAST
  AT 15 MPH.

* THE SEVERE THUNDERSTORM IS EXPECTED TO BE NEAR...
  BERNVILLE AT 808 PM EDT.

THIS IS A DANGEROUS STORM. MOVE INSIDE A STRONG BUILDING AND DO
NOT STAND NEAR WINDOWS. FOR YOUR PROTECTION MOVE TO AN INTERIOR
ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.

FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER
RADIO...YOUR LOCAL RADIO OR TELEVISION STATIONS...OR YOUR CABLE
TELEVISION OUTLET.

.END
JM/JE

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jun 7, 4:45 PM EDT, 3 hours 24 minutes before
PAZ067>071-NJZ015-017>019-DEZ001-090300-

SPECIAL WEATHER STATEMENT...EXCESSIVE HEAT WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
445 PM EDT MON JUN 7 1999

...AN EXCESSIVE HEAT WARNING FOR HIGHLY URBANIZED AREAS OF THE
DELAWARE VALLEY REMAINS IN EFFECT THROUGH TUESDAY...

THIS AFTERNOON...HEAT INDICES IN THE WARNING AREA GENERALLY PEAKED
NEAR 105. TONIGHT WON/T BRING ALOT OF RELIEF...AS IT WILL BE WARM
AND MUGGY. FOR TOMORROW...ALTHOUGH DEWPOINTS WILL GRADUALLY BEGIN TO
FALL IN THE AFTERNOON...TEMPERATURES IN THE MID TO UPPER 90S WILL
ONCE AGAIN CAUSE HEAT INDICES TO REACH AROUND 100. THE HEAT INDEX IS
A MEASURE OF THE COMBINED EFFECTS OF HIGH HEAT AND HUMIDITY ON THE
HUMAN BODY.

PEOPLE IN URBANIZED AREAS THROUGHOUT THE PHILADELPHIA METROPOLITAN
REGION SHOULD SEEK AIR-CONDITIONED RELIEF WHERE POSSIBLE.
OTHERWISE MAINTAIN PROPER AIR CIRCULATION BY KEEPING WINDOWS OPEN
AND BY USING FANS.

IF YOU HAVE OUTDOOR WORK PLANNED FOR TOMORROW WHICH CAN/T BE
POSTPONED...TRY TO FINISH IT IN THE MORNING. ALSO...REGARDLESS OF
WHEN TOMORROW YOU WORK OUTDOORS...WEAR LOOSE-FITTING...LIGHT COLORED
CLOTHING. TAKE FREQUENT BREAKS IN THE SHADE. TRY TO DRINK PLENTY OF
WATER OR OTHER NON-ALCOHOLIC BEVERAGES. DON/T WAIT UNTIL YOU FEEL
THIRSTY.

ALSO...KEEP AN EYE ON ELDERLY FRIENDS AND RELATIVES SINCE THEY ARE
THE MOST SUSCEPTIBLE TO HEAT-INDUCED ILLNESSES. PETS ALSO SUFFER
DURING THESE HOT SPELLS. MAKE SURE TO GIVE THEM AMPLE WATER AND
ACCESS TO SHADE. DON/T LEAVE ANYONE...ANY PERSON OR ANY PET...IN A
PARKED AUTOMOBILE FOR ANY LENGTH OF TIME.

FURTHER STATEMENTS WILL BE ISSUED THROUGH TUESDAY BY THE NATIONAL
WEATHER SERVICE IN MOUNT HOLLY NJ.  FOR THE LATEST INFORMATION ON
THIS HOT SPELL PLEASE STAY TUNED TO NOAA WEATHER RADIO...YOUR LOCAL
RADIO OR TV STATIONS...OR YOUR CABLE TV OUTLET.  WEATHER INFORMATION
MAY ALSO BE FOUND ON THE NWS MOUNT HOLLY INTERNET HOME PAGE AT
WWW.NWS.NOAA.GOV/ER/PHI.

MPD
Special weather statement, Jun 7, 4:45 PM EDT, 3 hours 24 minutes before
PAZ067>071-NJZ015-017>019-DEZ001-090300-

SPECIAL WEATHER STATEMENT...EXCESSIVE HEAT WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
445 PM EDT MON JUN 7 1999

...AN EXCESSIVE HEAT WARNING FOR HIGHLY URBANIZED AREAS OF THE
DELAWARE VALLEY REMAINS IN EFFECT THROUGH TUESDAY...

THIS AFTERNOON...HEAT INDICES IN THE WARNING AREA GENERALLY PEAKED
NEAR 105. TONIGHT WON/T BRING ALOT OF RELIEF...AS IT WILL BE WARM
AND MUGGY. FOR TOMORROW...ALTHOUGH DEWPOINTS WILL GRADUALLY BEGIN TO
FALL IN THE AFTERNOON...TEMPERATURES IN THE MID TO UPPER 90S WILL
ONCE AGAIN CAUSE HEAT INDICES TO REACH AROUND 100. THE HEAT INDEX IS
A MEASURE OF THE COMBINED EFFECTS OF HIGH HEAT AND HUMIDITY ON THE
HUMAN BODY.

PEOPLE IN URBANIZED AREAS THROUGHOUT THE PHILADELPHIA METROPOLITAN
REGION SHOULD SEEK AIR-CONDITIONED RELIEF WHERE POSSIBLE.
OTHERWISE MAINTAIN PROPER AIR CIRCULATION BY KEEPING WINDOWS OPEN
AND BY USING FANS.

IF YOU HAVE OUTDOOR WORK PLANNED FOR TOMORROW WHICH CAN/T BE
POSTPONED...TRY TO FINISH IT IN THE MORNING. ALSO...REGARDLESS OF
WHEN TOMORROW YOU WORK OUTDOORS...WEAR LOOSE-FITTING...LIGHT COLORED
CLOTHING. TAKE FREQUENT BREAKS IN THE SHADE. TRY TO DRINK PLENTY OF
WATER OR OTHER NON-ALCOHOLIC BEVERAGES. DON/T WAIT UNTIL YOU FEEL
THIRSTY.

ALSO...KEEP AN EYE ON ELDERLY FRIENDS AND RELATIVES SINCE THEY ARE
THE MOST SUSCEPTIBLE TO HEAT-INDUCED ILLNESSES. PETS ALSO SUFFER
DURING THESE HOT SPELLS. MAKE SURE TO GIVE THEM AMPLE WATER AND
ACCESS TO SHADE. DON/T LEAVE ANYONE...ANY PERSON OR ANY PET...IN A
PARKED AUTOMOBILE FOR ANY LENGTH OF TIME.

FURTHER STATEMENTS WILL BE ISSUED THROUGH TUESDAY BY THE NATIONAL
WEATHER SERVICE IN MOUNT HOLLY NJ.  FOR THE LATEST INFORMATION ON
THIS HOT SPELL PLEASE STAY TUNED TO NOAA WEATHER RADIO...YOUR LOCAL
RADIO OR TV STATIONS...OR YOUR CABLE TV OUTLET.  WEATHER INFORMATION
MAY ALSO BE FOUND ON THE NWS MOUNT HOLLY INTERNET HOME PAGE AT
WWW.NWS.NOAA.GOV/ER/PHI.

MPD

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1999Every severe thunderstorm 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.