Alert archive / Pennsylvania / Mesoscale Discussions in 2004
Mesoscale Discussion 615
The Storm Prediction Center issued this mesoscale discussion at May 9, 2004, 1:43 PM EDT for 30 counties in Pennsylvania. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 9, 2004, 1:43 PM EDT (17:43 UTC)
- Expired
- May 9, 2004, 3:45 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 30 counties
Armstrong County, PA, Berks County, PA, Blair County, PA, Cambria County, PA, Cameron County, PA, Carbon County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Elk County, PA, Forest County, PA, Huntingdon County, PA, Indiana County, PA, Jefferson County, PA, Juniata County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Union County, PA
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 12:00Z, 5.7 hours before the alert went out and 212 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
- 9 J/kg
- Mixed-layer CIN
- -135 J/kg
- Mixed-layer LCL
- 1374 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 091744 SWOMCD SPC MCD 091743 PAZ000-091945- MESOSCALE DISCUSSION 0615 NWS STORM PREDICTION CENTER NORMAN OK 1243 PM CDT SUN MAY 09 2004 AREAS AFFECTED...CENTRAL PA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 091743Z - 091945Z THUNDERSTORM DEVELOPMENT IS ANTICIPATED ACROSS CENTRAL PA IN AN E-W ORIENTED BAND. CELLS WILL TRACK GENERALLY ESEWD AT 20-25 KT. THREAT OF DAMAGING WINDS AND ISOLATED HAIL WITH THESE STORMS THROUGH EARLY EVENING MAY NECESSITATE A SEVERE THUNDERSTORM WATCH DURING THE NEXT 1-2 HOURS. AT 1730Z...VISIBLE SATELLITE IMAGERY INDICATES THAT TOWERING CUMULUS HAVE DEVELOPED WITHIN AN E-W ORIENTED LOW-LEVEL CONVERGENCE ZONE STRETCHING FROM 25 SE FKL TO JUST NORTH OF STATE COLLEGE. BOUNDARY LAYER IS MORE DEEPLY MIXED ACROSS THE WRN HALF OF PA...AND AS THIS AIR MASS ADVECTS EWD...DESTABILIZATION SHOULD OCCUR ACROSS THE ERN HALF OF PA THIS AFTERNOON. CONVECTIVE INHIBITION IS MINIMAL IN VICINITY OF SHOWERS DEVELOPING ON RADAR ACROSS JEFFERSON AND CLEARFIELD COUNTIES IN W-CENTRAL PA. MODERATELY STEEP 850-500MB LAPSE RATES /AROUND 7 C/KM/ WILL CONTRIBUTE TO 100MB MLCAPE VALUES AROUND 1000 J/KG THIS AFTERNOON ACROSS CENTRAL PA. WBZ HEIGHTS OF 8-9 KFT SHOULD SUPPORT SEVERE HAIL WITH LONGER LIVED STORMS. ALSO...MODERATE WLY FLOW ON STATE COLLEGE VAD /30-35 KT IN 3-4 KM LAYER/ SHOULD BE SUFFICIENT FOR LOCALIZED DAMAGING WIND GUSTS WITH CONVECTIVE DOWNDRAFTS THIS AFTERNOON. ..BANACOS.. 05/09/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...BGM...CTP...PBZ... 41537942 41497829 41447707 41357612 41307568 40967546 40577537 40227569 40167656 40167786 40257883 40417949 40577980 41097986
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 12:12 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Franklin, Fulton | 3 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2004Every mesoscale discussion in 2004
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.