Alert archive / Pennsylvania / Mesoscale Discussions in 2003
Mesoscale Discussion 2221
The Storm Prediction Center issued this mesoscale discussion at Aug 22, 2003, 3:27 PM EDT for 7 counties in Maryland; 45 counties in Pennsylvania; 4 counties in West Virginia. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 22, 2003, 3:27 PM EDT (19:27 UTC)
- Expired
- Aug 22, 2003, 6:00 PM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
All 56 counties
Allegany County, MD, Baltimore County, MD, Carroll County, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Washington County, MD, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bucks County, PA, Cambria County, PA, Carbon County, PA, Centre County, PA, Chester County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Indiana County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Union County, PA, Wayne County, PA, Westmoreland County, PA, Wyoming County, PA, York County, PA, Berkeley County, WV, Mineral County, WV, Morgan County, WV, Preston County, WV
The radar
The State College radar (KCCX), 107 km from the middle of the area, began a volume at 19:27 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 nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 7.5 hours before the alert went out and 143 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
- 1579 J/kg
- Mixed-layer CIN
- -58 J/kg
- Mixed-layer LCL
- 1147 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 56 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
037 ACUS11 KWNS 221927 SWOMCD SPC MCD 221927 PAZ000-NJZ000-DEZ000-MDZ000-WVZ000-VAZ000-222200- MESOSCALE DISCUSSION 2221 NWS STORM PREDICTION CENTER NORMAN OK 0227 PM CDT FRI AUG 22 2003 AREAS AFFECTED...PA...NRN WV...NRN MD CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 221927Z - 222200Z PARTS OF PA AND NRN WV/MD ARE BEING MONITORED FOR A POSSIBLE SEVERE TSTM WATCH LATER THIS AFTERNOON OR EARLY THIS EVENING. COLD FRONT ALONG/NORTH OF A AVP-PIT LINE WAS MOVING SEWD ACROSS PA LATE THIS AFTERNOON AND MAY PROVIDE A FOCUS FOR STRONG TSTM DEVELOPMENT OVER THE NEXT FEW HOURS. AIRMASS AHEAD OF THE BOUNDARY HAS BECOME VERY UNSTABLE WITH LATEST OBJECTIVE ANALYSIS DATA INDICATING MLCAPE VALUES OF 2000-3000 J/KG...WHICH APPEARS REASONABLE BASED ON SURFACE TEMPS IN THE UPPER 80S F AND HIGH SURFACE DEW POINT VALUES IN THE MID 70S F. LARGE SCALE HEIGHT FALLS ASSOCIATED WITH THE UPPER TROUGH CURRENTLY CROSSING THE NORTHEAST SHOULD PROMOTE THE CONTINUED SEWD DEVELOPMENT OF THE LOW LEVEL FRONTAL ZONE ACROSS CNTRL AND INTO SERN PA THROUGH THE EVENING. FORCING ALONG THE FRONT...AND INVOF WEAK THERMAL TROUGH ACROSS ERN PA...SHOULD BE SUFFICIENT FOR STORM IMITATION/SUSTENANCE GIVEN LIMITED CONVECTIVE INHIBITION. A FEW OF THESE STORMS COULD PRODUCE DAMAGING DOWNDRAFTS AND PERHAPS SOME HAIL GIVEN MAGNITUDE OF INSTABILITY. OVERALL SEVERE WEATHER THREAT APPEARS SOMEWHAT LIMITED DUE TO RELATIVELY WEAK MID LEVEL FLOW ON THE ORDER OF 20KT AT 500MB. HOWEVER...THIS FLOW DOES STRENGTHEN ACROSS THE AREA BY EARLY EVENING WHEN FRONTAL FORCING WILL LIKELY MOVE INTO AXIS OF STRONGEST INSTABILITY FROM SCNTRL PA INTO NRN MD. THIS AREA MAY NEED TO BE COVERED BY A WATCH IF STORMS CONTINUE TO INCREASE. ..CARBIN.. 08/22/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...BGM...CTP...LWX...PBZ... 39847539 39367649 39397799 39397965 39848011 40668014 41787601 41777516 40377507
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 1:15 PM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Kent, Queen Anne's | 7 hr |
| Aug 22, 5:42 PM EDT | Mesoscale Discussion | SPC | Charles, Montgomery, Prince George's, Saint Mary's | 2 hr |
| Aug 22, 7:22 PM EDT | Mesoscale Discussion | SPC | Caroline, Cecil, Kent, Queen Anne's | 53 min |
| Aug 22, 12:32 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 3 more | 118 min |
| Aug 22, 4:10 PM EDT | Mesoscale Discussion | SPC | Bucks, Delaware, Montgomery, Philadelphia | 95 min |
| Aug 22, 11:29 AM EDT | Mesoscale Discussion | SPC | Boone, Braxton, Cabell, Calhoun, Clay, Doddridge and 20 more | 2 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2003Mesoscale Discussions in Maryland, 2003Mesoscale Discussions in West Virginia, 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.