Alert archive / Pennsylvania / Mesoscale Discussions in 2003
Mesoscale Discussion 2001
The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2003, 4:31 PM EDT for 20 counties in Pennsylvania. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Jul 27, 2003, 4:31 PM EDT (20:31 UTC)
- Expired
- Jul 27, 2003, 6:00 PM EDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
Counties Blair County, PA, Carbon County, PA, Centre County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montour County, PA, Northumberland County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Union County, PA, Wyoming County, PA
The radar
The State College radar (KCCX), 104 km from the middle of the area, began a volume at 20:33 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 8.5 hours before the alert went out and 236 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1565 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 78 m²/s²
- 0-3 km storm-relative helicity
- 102 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
542 ACUS11 KWNS 272031 SWOMCD SPC MCD 272031 PAZ000-272200- MESOSCALE DISCUSSION 2001 NWS STORM PREDICTION CENTER NORMAN OK 0331 PM CDT SUN JUL 27 2003 AREAS AFFECTED...PA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 272031Z - 272200Z EXPECT THREAT FROM STRONG CONVECTIVE WINDS MAY BE INCREASING ACROSS PORTIONS OF NORTH-CNTRL AND NERN PA OVER THE NEXT 1-2 HOURS. THIS AREA WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WATCH. A LINE OF STRONG STORMS CONTINUES DEVELOPING ACROSS NORTH-CNTRL AND NERN PA THIS AFTERNOON. SEGMENTS OF THIS LINE HAVE RECENTLY SHOWN INCREASING REFLECTIVITY AND ACTIVITY WAS MOVING ESEWD AT AROUND 40KT. ADDITIONAL CONVECTIVE DEVELOPMENT/STRENGTHENING IS EXPECTED AS CONVECTIVELY INDUCED COLD POOL SPREADS ESEWD GIVEN MODERATELY STRONG WNWLY MEAN LAYER FLOW. AN AXIS OF STEEPER LOW LEVEL LAPSE RATES PROBABLY EXISTS AHEAD OF THE LINE WHERE SURFACE TEMPERATURES HAVE REACHED THE MID 80S F. THE COMBINATION OF FAVORABLE UNIDIRECTIONAL SHEAR AND STEEP BOUNDARY LAYER LAPSE RATES SHOULD ENHANCE CONVECTIVE DOWNDRAFTS FROM POSSIBLE BOWING SEGMENTS OVER THE NEXT FEW HOURS. ..CARBIN.. 07/27/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...BGM...CTP...PBZ... 41677560 41557510 40777544 40507599 40437676 40397832 40887947 41317868
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 27, 5:40 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Armstrong, Beaver, Bedford, Blair and 29 more | 2 hr |
| Jul 27, 6:05 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Allegheny, Armstrong, Beaver, Bedford, Berks and 31 more | 5 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2003Every mesoscale discussion in 2003
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.