Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 183, NWS State College, PA

September 6, 1999Cambria County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Sep 6, 1999, 3:27 PM EDT for Cambria County, Pennsylvania. It was in force for 48 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
Sep 6, 1999, 3:27 PM EDT (19:27 UTC)
Expired
Sep 6, 1999, 4:15 PM EDT
In force
48 min
Issued by
NWS State College, PA
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Cambria County, PA

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 7.5 hours before the alert went out and 118 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, Pittsburgh, PA at 12:00Z on 1999-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 460 joules per kilogram.LCLLFCEL10008507005003002001001 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, Pittsburgh, PA at 12:00Z on 1999-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
460 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
725 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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.

NWS State College, PA wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 6, 2:50 PM EDT, 37 minutes earlier.

Area forecast discussion, Sep 6, 2:50 PM EDT, 37 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
250 PM EDT MON SEP 6 1999

A FEW THUNDERSTORMS BEGINNING TO SHOW ROTATION...SO MAY HAVE TO CUT
THIS A LITTLE SHORT.

NOT QUITE THE WASHOUT IT APPEARED IT WOULD BE TODAY...BUT RAIN IS
DEFINITELY ON THE WAY.  DRY SLOT HUNG TOUGH ACROSS THE NORTHERN HALF
OF PA THIS AFTERNOON.  BUT DENNIS REMNANTS TAPPING INTO A DEEP MOIST
TONGUE EXTENDING FROM S PA TO THE CAROLINA COAST.  THIS MOIST TONGUE
WILL SPREAD OVER CENTRAL PA TONIGHT BRINGING CATEGORICAL POPS FOR
MOST.

WITH THE EFFICIENCY OF TROPICAL SYSTEMS FOR PRODUCING RAIN...ADDED
TO UPSLOPE SOUTHEASTERLY FLOW...THE REGION COULD SEE RAINFALL TOTALS
REACH FFG VALUES (2-4 IN 3 HOURS).  WILL EXTEND FLASH FLOOD WATCH
TO INCLUDE ALL OF CENTRAL PA THROUGH TUESDAY MORNING.  FEEL THERE IS
REASONABLE POTENTIAL FOR MOISTURE TO WRAP WESTWARD AROUND THE CENTER
OF CIRCULATION (LIKE CURRENTLY IN THE SOUTHWEST) AS REMNANTS DRIFT
NORTH-NORTHEAST...SO WILL INCLUDE ALL NORTHERN COUNTIES NOW AS WELL.

SYSTEM MOVES INTO SOUTH CENTRAL NY STATE LATE TOMORROW MORNING...
AIDED BY A PUSH FROM A TROUGH MOVING ACROSS THE MIDWEST. CATEGORICAL
RAIN FOR NORTHEASTERN PORTIONS WHILE TAPERING TO SHOWERS ELSEWHERE.
OVERNIGHT SHIFT WILL HAVE TO ADDRESS WHETHER TO EXTEND THE FLASH
FLOOD WATCH IN THE NE TOMORROW.

TROUGH SLOWLY TRAVERSES PA TUE NIGHT INTO WED.  MIGHT BE ABLE TO
SCRAPE UP A 30 POP FOR THOSE PERIODS...BUT WILL LEAVE DRY FOR NOW.

TEMPS ABOVE GUIDANCE TONIGHT AND TOMORROW NIGHT WITH DAYTIME HIGHS
CLOSE TO FAN/FWC.

.CTP...FLASH FLOOD WATCH FOR ALL OF CENTRAL PA THROUGH TUESDAY MORNING.

RXR

The office that day

Everything else NWS State College, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 6, 2:37 PM EDTSevere Thunderstorm WarningCTPCambria53 min
Sep 6, 2:45 PM EDTSevere Thunderstorm WarningCTPBedford60 min
Sep 6, 3:01 PM EDTFlash Flood WarningCTPFranklin, Fulton3 hr
Sep 6, 3:01 PM EDTFlash Flood WarningCTPBedford, Cambria, Somerset3 hr
Sep 6, 3:56 PM EDTSevere Thunderstorm WarningCTPLancaster, York64 min
Sep 6, 4:17 PM EDTFlash Flood WarningCTPLancaster, York3 hr
Sep 6, 4:32 PM EDTSevere Thunderstorm WarningCTPDauphin, Perry58 min

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.