Alert archive / Virginia / Mesoscale Discussions in 2012
Mesoscale Discussion 1565
The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2012, 11:48 AM EDT for 5 states. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Jul 24, 2012, 11:48 AM EDT (15:48 UTC)
- Expired
- Jul 24, 2012, 1:15 PM EDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 91 counties
Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Talbot County, MD, Washington County, MD, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Harrison County, OH, Jefferson County, OH, Stark County, OH, Adams County, PA, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Bedford County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Cumberland County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Huntingdon County, PA, Indiana County, PA, Somerset County, PA, Washington County, PA, Westmoreland County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Berkeley County, WV, Brooke County, WV, Grant County, WV, Hampshire County, WV, Hancock County, WV, Hardy County, WV, Jefferson County, WV, Marion County, WV, Marshall County, WV, Mineral County, WV, Monongalia County, WV, Morgan County, WV, Ohio County, WV, Preston County, WV, Taylor County, WV, Tucker County, WV, Wetzel County, WV
The radar
The Sterling radar (KLWX), 119 km from the middle of the area, began a volume at 15:50 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, 3.8 hours before the alert went out and 127 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
- 1981 J/kg
- Mixed-layer CIN
- -91 J/kg
- Mixed-layer LCL
- 1090 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 209 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.8
The text
As transmitted, in the capitals the NWS used until 2016.
368
ACUS11 KWNS 241548
SWOMCD
SPC MCD 241548
DEZ000-MDZ000-PAZ000-VAZ000-DCZ000-WVZ000-OHZ000-241715-
MESOSCALE DISCUSSION 1565
NWS STORM PREDICTION CENTER NORMAN OK
1048 AM CDT TUE JUL 24 2012
AREAS AFFECTED...ERN OH...WRN AND SRN PA...NRN VA...MD...ERN WV
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 241548Z - 241715Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
AND A WATCH MAY BE NEEDED SOON.
DISCUSSION...DESTABILIZATION CONTINUES ACROSS THE REGION WITH
POCKETS OF HEATING AND MIXING. EARLY CELLS CROSSING FROM SWRN PA
INTO MD DID NOT PERSIST...BUT CIN WILL CONTINUE TO DECREASE...AND
DEEP LAYER SHEAR IS FAVORABLE FOR SUPERCELLS TO FORM WHICH COULD
TRACK FOR LONG DISTANCES ONCE DEVELOPED. THE CELL OVER FAR WRN MD
APPEARS TO BE BECOMING BETTER ORGANIZED WITH A HAIL THREAT.
OTHER CU OF INTEREST WERE ACROSS NERN OH NEAR THE COLD FRONT.
ADDITIONAL CELLS MAY FORM HERE AND TRACK SEWD WITH A HAIL AND WIND
THREAT.
..JEWELL/HART.. 07/24/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PHI...AKQ...CTP...LWX...PBZ...RLX...CLE...
LAT...LON 40918153 40978070 40937913 40457758 39497572 38817567
38427582 38087643 38007692 38207797 38377885 38727932
39508052 39568061 40058119 40918153SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 1:08 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 17 more | 6 hr |
| Jul 24, 1:42 PM EDT | Mesoscale Discussion | SPC | Calvert, Dorchester, Saint Mary's, Somerset, Wicomico, Worcester | 2 hr |
| Jul 24, 10:08 AM EDT | Mesoscale Discussion | SPC | Auglaize, Butler, Champaign, Clark, Clinton, Darke and 14 more | 97 min |
| Jul 24, 10:35 AM EDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Butler, Clark, Clermont, Clinton and 12 more | 3 hr |
| Jul 24, 11:59 AM EDT | Mesoscale Discussion | SPC | Adams, Brown, Butler, Clermont, Clinton, Fayette and 8 more | 61 min |
| Jul 24, 12:33 PM EDT | Severe Thunderstorm Watch | SPC | Gallia, Jackson, Lawrence | 6 hr |
| Jul 24, 1:52 PM EDT | Mesoscale Discussion | SPC | Lawrence, Scioto | 53 min |
| Jul 24, 11:43 AM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Wise, City of Norton | 62 min |
| Jul 24, 3:25 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more | 95 min |
| Jul 24, 3:46 PM EDT | Mesoscale Discussion | SPC | Accomack, Brunswick, Charles City, Dinwiddie, Gloucester, Greensville and 28 more | 89 min |
| Jul 24, 4:24 PM EDT | Severe Thunderstorm Watch | SPC | Accomack, Brunswick, Dinwiddie, Gloucester, Greensville, Isle of Wight and 20 more | 4 hr |
Nearby
Mesoscale Discussions in Virginia, 2012Mesoscale Discussions in Maryland, 2012Mesoscale Discussions in Pennsylvania, 2012Every mesoscale discussion in 2012
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.