Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 1003

June 1, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jun 1, 2012, 12:29 PM EDT for 4 states. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
Jun 1, 2012, 12:29 PM EDT (16:29 UTC)
Expired
Jun 1, 2012, 1:30 PM EDT
In force
61 min
Issued by
the Storm Prediction Center
All 43 counties

Anne Arundel County, MD, Calvert County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Washington County, MD, Franklin County, PA, Fulton County, PA, Arlington County, VA, Caroline County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Loudoun County, VA, Orange County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Berkeley County, WV, Jefferson County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 27 km from the middle of the area, began a volume at 16:30 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, 4.5 hours before the alert went out and 22 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2012-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 26 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2012-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
26 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
1061 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
174 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

125 
ACUS11 KWNS 011630
SWOMCD
SPC MCD 011629
MDZ000-VAZ000-DCZ000-PAZ000-WVZ000-011730-

MESOSCALE DISCUSSION 1003
NWS STORM PREDICTION CENTER NORMAN OK
1129 AM CDT FRI JUN 01 2012

AREAS AFFECTED...NERN VA...A LARGE PART OF MD...THE DISTRICT OF
COLUMBIA...A SMALL PART OF THE ERN PANHANDLE OF WV...S-CNTRL PA

CONCERNING...OUTLOOK UPGRADE

VALID 011629Z - 011730Z

SUMMARY...A CATEGORICAL UPGRADE TO MODERATE RISK WILL BE INCLUDED
WITH THE 1630 UTC DAY ONE CONVECTIVE OUTLOOK ACROSS NERN VA...A
LARGE PART OF MD...THE DISTRICT OF COLUMBIA...A SMALL PART OF THE
ERN PANHANDLE OF WV...AND S-CNTRL PA.

DISCUSSION...LATEST OBSERVATIONAL AND MODEL OUTPUT WARRANT AN
UPGRADE TO MODERATE RISK FOR THE UPCOMING 1630 UTC OUTLOOK. PLEASE
SEE FORTHCOMING DAY ONE OUTLOOK FOR ADDITIONAL METEOROLOGICAL
ANALYSIS.

..COHEN/BROYLES/CARBIN.. 06/01/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PHI...AKQ...CTP...LWX...

LAT...LON   38157807 39137827 39687826 40007808 39937734 39207640
            38547612 38157630 37667674 37697733 38157807

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 1, 1:03 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 11 more87 min
Jun 1, 1:28 PM EDTTornado WatchSPCAllegany, Frederick, Garrett, Washington8 hr
Jun 1, 1:50 PM EDTTornado WatchSPCAnne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 13 more7 hr
Jun 1, 3:35 PM EDTMesoscale DiscussionSPCAllegany, Frederick, Garrett, Washington55 min
Jun 1, 3:49 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 11 more56 min
Jun 1, 6:54 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 14 more2 hr
Jun 1, 4:25 PM EDTMesoscale DiscussionSPCBerks, Chester, Delaware, Montgomery, Philadelphia65 min
Jun 1, 5:46 PM EDTMesoscale DiscussionSPCCameron, Centre, Clearfield, Clinton, Elk, Forest and 10 more89 min
Jun 1, 6:04 PM EDTTornado WatchSPCCameron, Centre, Clearfield, Clinton, Columbia, Elk and 10 more5 hr

Nearby

Mesoscale Discussions in Virginia, 2012Mesoscale Discussions in Maryland, 2012Mesoscale Discussions in West Virginia, 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.