Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 166, NWS State College, PA

August 14, 1999Lancaster County, York County, Pennsylvania

NWS State College, PA issued this severe thunderstorm warning at Aug 14, 1999, 1:49 PM EDT for Lancaster County, York County, Pennsylvania. It was in force for 56 min. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Aug 14, 1999, 1:49 PM EDT (17:49 UTC)
Expired: Aug 14, 1999, 2:45 PM EDT
In force: 56 min
Issued by: NWS State College, PA
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Lancaster County, PA, York County, PA

What was reported inside it

Time	Report	Where	Remark
Aug 14, 2:00 PM EDT	Hail 0.75	Manchester, PA	Dime size hail.
Aug 14, 2:10 PM EDT	Hail 0.75	Newberrytown, PA	Dime size hail.
Aug 14, 2:20 PM EDT	Thunderstorm Wind	Mt Joy, PA	Trees down across areas south of Mt. Joy.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.8 hours before the alert went out and 139 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: 379 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 930 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -56 m²/s²
0-3 km storm-relative helicity: 22 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -1.8

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 Aug 13, 3:25 PM EDT, 22 hours 24 minutes earlier.

Area forecast discussion, Aug 13, 3:25 PM EDT, 22 hours 24 minutes before

CENTRAL PENNSYLVANIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
325 PM EDT FRI AUG 13 1999

LINES OF SCATTERED TSRA NOW FORMING BACK IN W PA AND OHIO. WILL
PROBABLY SEE SOME ACTIVITY FIRE AND COME INTO WEST PA THIS EVENING
THEN WEAKEN BEFORE REACHING CENTRAL PA. MOST MODELS INITIALIZED TOO
WET...BUT LAST FEW RUNS OF MM5 HAVE BEEN CLOSER TO REALITY. WILL
LOWER POPS FOR TONIGHT TO CHC AND WORD AS MAINLY EVENING
THUNDERSTORMS.

SATURDAY WILL FEATURE MORE WIDESPREAD PRECIP AS SW TROF AXIS AND
VORT MOVE THRU...WITH MODEL SOUNDINGS INDICATING PLENTY OF DEEP
MOISTURE AND INSTABILTY TO BE TAPPED. WIND PROFILES ALSO SUGGEST SVR
POTENTIAL. WILL HAVE LIKELY POPS ALL ZONES. HEAVY RAIN AND POTENTIAL
FOR SVR WILL MAKE FOR AN INTERESTING DAY.

MOST SIG PRECIP SHUD BE EAST OF CTP CWA BY SAT EVE...WITH SHRA
LINGERING THRU OVERNIGHT PERIOD IN EAST ZONES. THINGS DRY OUT FOR
SUN...WITH MODERATING TEMPS INTO MIDWEEK.

.CTP...NONE.

OSTUNO/ SCALIO

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 8:08 PM EDT	Severe Thunderstorm Warning	CTP	Huntingdon, Juniata, Northumberland, Perry, Snyder	67 min
Aug 13, 8:08 PM EDT	Severe Thunderstorm Warning	CTP	Cumberland, Dauphin	67 min
Aug 13, 8:08 PM EDT	Severe Thunderstorm Warning	CTP	Schuylkill	67 min
Aug 13, 10:14 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, Lebanon	61 min
Aug 13, 10:27 PM EDT	Severe Thunderstorm Warning	CTP	Schuylkill	63 min
Aug 13, 11:30 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster	60 min
Aug 14, 2:41 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster	64 min
Aug 14, 2:45 PM EDT	Severe Thunderstorm Warning	CTP	York	30 min
Aug 14, 3:33 PM EDT	Severe Thunderstorm Warning	CTP	Tioga	57 min
Aug 14, 3:50 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster	55 min
Aug 14, 3:56 PM EDT	Severe Thunderstorm Warning	CTP	Perry	64 min
Aug 14, 5:09 PM EDT	Severe Thunderstorm Warning	CTP	Clinton	66 min
Aug 14, 6:25 PM EDT	Severe Thunderstorm Warning	CTP	Columbia, Montour	65 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1999 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.