Alert archive / Pennsylvania / Flash Flood Warnings in 1999
Flash Flood Warning 57, NWS State College, PA
NWS State College, PA issued this flash flood warning at Sep 9, 1999, 5:54 PM EDT for Lancaster County, Pennsylvania. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.
The facts
- Issued
- Sep 9, 1999, 5:54 PM EDT (21:54 UTC)
- Expired
- Sep 9, 1999, 9:00 PM EDT
- In force
- 3 hr
- Issued by
- NWS State College, PA
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Lancaster County, PA
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 9.9 hours before the alert went out and 149 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.
- Mixed-layer CAPE
- 60 J/kg
- Mixed-layer CIN
- -110 J/kg
- Mixed-layer LCL
- 900 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 32 m²/s²
- 0-3 km storm-relative helicity
- 70 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KCTP 092202 FFWCTP PAC071-100100- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE STATE COLLEGE PA 554 PM EDT THU SEP 9 1999 THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A * FLASH FLOOD WARNING FOR... LANCASTER COUNTY. * UNTIL 900 PM EDT. * AT 545 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL 2 MILES NORTH OF COLUMBIA...MOVING EAST AT 5 MPH. SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN THE WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING IN THE MARIETTA...MOUNT JOY...AND COLUMBIA AREAS. MORE SLOW MOVING THUNDERSTORMS WILL MOVE ACROSS THE COUNTY THIS EVENING WHICH COULD PRODUCE MORE FLOODING IN OTHER SECTIONS OF THE COUNTY. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED. MOVE TO HIGHER GROUND. .END/ GRUMM LAT...LON 4013 7669 4001 7651 3995 7624 4024 7630
What forecasters said that day
The local office's own words before this flash flood 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 flash flood warning went out at Sep 9, 2:00 PM EDT, 3 hours 54 minutes earlier.
Area forecast discussion, Sep 9, 2:00 PM EDT, 3 hours 54 minutes before
CENTRAL PENNSYLVANIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 200 PM EDT THU SEP 9 1999 MOST OF THE CWA IS CURRENTLY IN BETWEEN A CDFNT APPROACHING SLOWLY FROM THE WEST...AND TROPICAL DEW PTS POISED JUST TO THE SOUTHEAST. MEANWHILE A SERIES OF MID-LVL SHORT WAVES ARE FORECAST TO MOVE NORTHEAST AROUND A UPPER TROUGH TO THE MID-ATLANTIC COAST. THUNDERSTORMS ARE ALREADY DEVELOPING IN THE TROPICAL AIR FROM MD AND DELAWARE SOUTH THROUGH VIRGINIA. CLOUD ELEMENTS ARE MOVING TO THE NNW IN THIS AREA INDICATING THE POTENTIAL FOR UPSLOPE ENHANCING PRECIPITATION AMOUNTS...AND SAT LOOPS ALSO INDICATE GOOD HEATING GOING ON WITH CLEAR TO PARTLY CLOUDY SKIES ACROSS S CENTRAL AND SE PA. ETA/RUC/NGM AND AVN ALL INDICATE THAT CONVECTION WILL BE ON THE INCREASE LATE THIS AFTERNOON THROUGH THIS EVENING OVER THE SE HALF OF THE CWA AS THE STRONGEST MID-LVL SHORT WAVE ROUNDS THE BEND AND TRACKS NORTHEAST TOWARD THE MID-ATLANTIC COAST. MEANWHILE CONVECTION ALONG THE CDFNT IN WESTERN PA GRADUALLY DIES OUT AS ALL OF THE ACTION SHIFTS TO THE EAST UNDER AN AREA OF INCREASING UPPER DIVERGENCE ASSOCIATED WITH THE RRQUAD OF AN UPPER WIND MAX. MEANWHILE THE MM5 SHOWS MUCH LESS PRECIPITATION FOR THE EASTERN HALF OF PA TONIGHT. WIND FIELDS OVER SE PA ARE NOT VERY IMPRESSIVE FOR SVR WX WITH 850 WINDS PROGGED AT 15 KTS ACROSS SE PA AND 500 MB WINDS PROGGED AT 30 KTS. HOWEVER WITH FORECAST LIS TO AROUND -8 CANT RULE OUT A FEW ISOLATED SVR STORMS. STRONGER STORMS COULD PRODUCE LOCALIZED RAINFALL AMOUNTS OF OVER 2 INCHES WITH PWATS PROGGED TO AROUND 1.5 INCHES THIS EVENING. 3 HR FFG GUIDANCE IS MOSTLY OVER 3 INCHES... EXCEPT 2 TO 3 INCHES ACROSS AREAS THAT WERE FLOODED BY DENNIS. HPC GUIDANCE SHOWS NO FLOODING EXPECTED. FWC POPS ARE VERY LOW WITH JUST HI CHC POPS IN THE FAR EAST AND LOW CHC POPS FOR THE CENTRAL COUNTIES. BASED ON ALL OF THIS WILL HOLD OFF ON A FFG WATCH FOR THE LWR AND MID-SUSQ BUT THAT AREA WILL HAVE TO BE MONITORED FOR TRAINING STORMS TNGT. WILL GO WITH LOW CHC POPS FOR THE NW HALF OF THE CWA...HI CHC CENTRAL AND LIKELY SE. DRY AIR MOVES EAST ACROSS THE CWA ON FRIDAY WHILE ALL OF THE MODELS SHOW A SFC WAVE MOVING FROM THE MID-ATLANTIC COAST NORTH TO NEW ENGLAND. WILL KEEP THE MENTION OF AN AM SHOWER IN THE EAST ON FRIDAY OTHERWISE WILL GO WITH PARTLY SUNNY AND LESS HUMID. SATURDAY WILL BE DRY WITH NEAR SEASONABLE TEMPERATURES. .CTP...NONE. MSE
In the hours before
Special weather statement, Sep 9, 3:55 PM EDT, 1 hour 59 minutes before
PAZ028-036-049>053-056>059-063>066-100157- SEVERE WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE STATE COLLEGE PA 355 PM EDT THU SEP 9 1999 ...ISOLATED SEVERE THUNDERSTORMS WITH VERY HEAVY DOWNPOURS ARE POSSIBLE ACROSS THE LOWER AND MID-SUSQUEHANNA VALLEY TONIGHT... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG AND AHEAD OF A COLD FRONT MOVING SLOWLY EAST ACROSS CENTRAL PENNSYLVANIA THIS TONIGHT. A FEW THUNDERSTORMS COULD CONTAIN STRONG GUSTY WINDS OR HAIL. THESE THUNDERSTORMS COULD ALSO CONTAIN VERY HEAVY RAIN. HEAVY DOWNPOURS COULD CAUSE LOCALIZED FLOODING IN URBANIZED AREAS WHERE STORMS PERSIST FOR OVER AN HOUR. THE BEST CHANCE FOR ANY SEVERE WEATHER WILL BE THIS EVENING...BUT THE CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE NIGHT. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE LOCAL SOURCE OF WEATHER INFORMATION...FOR THE LATEST FORECASTS AND STATEMENTS ON TONIGHTS THUNDERSTORMS. .END/ MSE ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON THE STATE COLLEGE NATIONAL WEATHER SERVICE WEB-SITE AT: HTTP://BOOKEND.MET.PSU.EDU (ALL LOWER CASE)
Special weather statement, Sep 9, 3:55 PM EDT, 1 hour 59 minutes before
PAZ028-036-049>053-056>059-063>066-100157- SEVERE WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE STATE COLLEGE PA 355 PM EDT THU SEP 9 1999 ...ISOLATED SEVERE THUNDERSTORMS WITH VERY HEAVY DOWNPOURS ARE POSSIBLE ACROSS THE LOWER AND MID-SUSQUEHANNA VALLEY TONIGHT... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG AND AHEAD OF A COLD FRONT MOVING SLOWLY EAST ACROSS CENTRAL PENNSYLVANIA THIS TONIGHT. A FEW THUNDERSTORMS COULD CONTAIN STRONG GUSTY WINDS OR HAIL. THESE THUNDERSTORMS COULD ALSO CONTAIN VERY HEAVY RAIN. HEAVY DOWNPOURS COULD CAUSE LOCALIZED FLOODING IN URBANIZED AREAS WHERE STORMS PERSIST FOR OVER AN HOUR. THE BEST CHANCE FOR ANY SEVERE WEATHER WILL BE THIS EVENING...BUT THE CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE NIGHT. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE LOCAL SOURCE OF WEATHER INFORMATION...FOR THE LATEST FORECASTS AND STATEMENTS ON TONIGHTS THUNDERSTORMS. .END/ MSE ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON THE STATE COLLEGE NATIONAL WEATHER SERVICE WEB-SITE AT: HTTP://BOOKEND.MET.PSU.EDU (ALL LOWER CASE)
Special weather statement, Sep 9, 3:57 PM EDT, 1 hour 57 minutes before
PAZ028-036-049>053-056>059-063>066-100158- SEVERE WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE STATE COLLEGE PA 357 PM EDT THU SEP 9 1999 ...ISOLATED SEVERE THUNDERSTORMS WITH VERY HEAVY DOWNPOURS ARE POSSIBLE ACROSS THE LOWER AND MID-SUSQUEHANNA VALLEY TONIGHT... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG AND AHEAD OF A COLD FRONT MOVING SLOWLY EAST ACROSS CENTRAL PENNSYLVANIA TONIGHT. A FEW THUNDERSTORMS COULD CONTAIN STRONG GUSTY WINDS OR HAIL. THESE THUNDERSTORMS COULD ALSO CONTAIN VERY HEAVY RAIN. HEAVY DOWNPOURS COULD CAUSE LOCALIZED FLOODING IN URBANIZED AREAS WHERE STORMS PERSIST FOR OVER AN HOUR. THE BEST CHANCE FOR ANY SEVERE WEATHER WILL BE THIS EVENING...BUT THE CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE NIGHT. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE LOCAL SOURCE OF WEATHER INFORMATION...FOR THE LATEST FORECASTS AND STATEMENTS ON TONIGHTS THUNDERSTORMS. .END/ MSE ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON THE STATE COLLEGE NATIONAL WEATHER SERVICE WEB-SITE AT: HTTP://BOOKEND.MET.PSU.EDU (ALL LOWER CASE)
Special weather statement, Sep 9, 3:57 PM EDT, 1 hour 57 minutes before
PAZ028-036-049>053-056>059-063>066-100158- SEVERE WEATHER OUTLOOK...CORRECTED NATIONAL WEATHER SERVICE STATE COLLEGE PA 357 PM EDT THU SEP 9 1999 ...ISOLATED SEVERE THUNDERSTORMS WITH VERY HEAVY DOWNPOURS ARE POSSIBLE ACROSS THE LOWER AND MID-SUSQUEHANNA VALLEY TONIGHT... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG AND AHEAD OF A COLD FRONT MOVING SLOWLY EAST ACROSS CENTRAL PENNSYLVANIA TONIGHT. A FEW THUNDERSTORMS COULD CONTAIN STRONG GUSTY WINDS OR HAIL. THESE THUNDERSTORMS COULD ALSO CONTAIN VERY HEAVY RAIN. HEAVY DOWNPOURS COULD CAUSE LOCALIZED FLOODING IN URBANIZED AREAS WHERE STORMS PERSIST FOR OVER AN HOUR. THE BEST CHANCE FOR ANY SEVERE WEATHER WILL BE THIS EVENING...BUT THE CHANCE OF THUNDERSTORMS WILL CONTINUE THROUGH THE NIGHT. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE LOCAL SOURCE OF WEATHER INFORMATION...FOR THE LATEST FORECASTS AND STATEMENTS ON TONIGHTS THUNDERSTORMS. .END/ MSE ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON THE STATE COLLEGE NATIONAL WEATHER SERVICE WEB-SITE AT: HTTP://BOOKEND.MET.PSU.EDU (ALL LOWER CASE)
Special weather statement, Sep 9, 4:10 PM EDT, 1 hour 44 minutes before
PAZ004>006-010-011-017-100210- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 410 PM EDT THU SEP 9 1999 ...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THIS EVENING ACROSS PORTIONS OF NORTH CENTRAL PENNSYLVNAIA... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG AND AHEAD OF A COLD FRONT MOVING SLOWLY EAST ACROSS WESTERN AND CENTRAL PENNSYLVANIA THIS EVENING. A FEW ISOLATED THUNDERSTORMS COULD CONTAIN STRONG DAMAGING WINDS OR LARGE HAIL. THE THUNDERSTORMS WILL BE EAST OF THE AREA BY LATE THIS EVENING. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE LOCAL SOURCE OF WEATHER INFORMATION...FOR THE LATEST FORECASTS AND STATEMENTS ON TONIGHTS THUNDERSTORMS. .END/ MSE ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON THE STATE COLLEGE NATIONAL WEATHER SERVICE WEB-SITE AT: HTTP://BOOKEND.MET.PSU.EDU (ALL LOWER CASE)
Special weather statement, Sep 9, 4:10 PM EDT, 1 hour 44 minutes before
PAZ004>006-010-011-017-100210- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 410 PM EDT THU SEP 9 1999 ...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THIS EVENING ACROSS PORTIONS OF NORTH CENTRAL PENNSYLVNAIA... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG AND AHEAD OF A COLD FRONT MOVING SLOWLY EAST ACROSS WESTERN AND CENTRAL PENNSYLVANIA THIS EVENING. A FEW ISOLATED THUNDERSTORMS COULD CONTAIN STRONG DAMAGING WINDS OR LARGE HAIL. THE THUNDERSTORMS WILL BE EAST OF THE AREA BY LATE THIS EVENING. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE LOCAL SOURCE OF WEATHER INFORMATION...FOR THE LATEST FORECASTS AND STATEMENTS ON TONIGHTS THUNDERSTORMS. .END/ MSE ADDITIONAL WEATHER INFORMATION CAN BE FOUND ON THE STATE COLLEGE NATIONAL WEATHER SERVICE WEB-SITE AT: HTTP://BOOKEND.MET.PSU.EDU (ALL LOWER CASE)
The office that day
Everything else NWS State College, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 9, 5:08 PM EDT | Severe Thunderstorm Warning | CTP | McKean, Warren | 67 min |
| Sep 9, 6:01 PM EDT | Tornado Warning | CTP | McKean | 29 min |
| Sep 9, 6:10 PM EDT | Flash Flood Warning | CTP | York | 3 hr |
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.