Alert archive / Maryland / Mesoscale Discussions in 2016

Mesoscale Discussion 149

February 24, 20165 states

The Storm Prediction Center issued this mesoscale discussion at Feb 24, 2016, 3:06 PM EST for 5 states. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Feb 24, 2016, 3:06 PM EST (20:06 UTC)
Expired
Feb 24, 2016, 4:00 PM EST
In force
54 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 51 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, 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, 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, Wicomico County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Montgomery County, PA, Philadelphia County, PA, Arlington 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, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Prince William County, VA, Stafford County, VA

The radar

The Sterling radar (KLWX), 79 km from the middle of the area, began a volume at 20:09 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, 8.1 hours before the alert went out and 71 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 2016-02-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 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 2016-02-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 526 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
2 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
433 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
526 m²/s²
0-3 km storm-relative helicity
627 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

370 
ACUS11 KWNS 242007
SWOMCD
SPC MCD 242006 
NJZ000-PAZ000-MDZ000-DEZ000-VAZ000-DCZ000-242100-

MESOSCALE DISCUSSION 0149
NWS STORM PREDICTION CENTER NORMAN OK
0206 PM CST WED FEB 24 2016

AREAS AFFECTED...PORTIONS OF NORTHERN VA/DC METRO AND
MD/DE/NJ/SOUTHEAST PA

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 242006Z - 242100Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...UPDATING AN EARLIER MESOSCALE DISCUSSION /145/...A TORNADO
WATCH WILL BE ISSUED SOON ACROSS NORTHERN VA/DC METRO AND PORTIONS
OF MD/DE INTO NJ/SOUTHEAST PA. THE TORNADO RISK WILL CONTINUE WILL
GRADUALLY INCREASE/SPREAD NORTH-NORTHEASTWARD ACROSS THE REGION
THROUGH LATE AFTERNOON/EARLY EVENING.

DISCUSSION...THE NEAR-SURFACE FRONTAL WEDGE CONTINUES TO ABATE/SHIFT
NORTHWARD THIS AFTERNOON...WITH A WARM FRONT EFFECTIVELY EXTENDING
FROM THE DELMARVA PENINSULA SOUTHWESTWARD TO SOUTH-CENTRAL VA. AS
ADDITIONAL DESTABILIZATION OCCURS WITHIN A HIGHLY SHEARED
ENVIRONMENT...THE POTENTIAL FOR TORNADOES WILL INCREASE/SPREAD
NORTH-NORTHEASTWARD THROUGH LATE AFTERNOON/EARLY EVENING. THIS
INCLUDES THE POSSIBILITY OF A STRONG TORNADO OR TWO ESPECIALLY
ACROSS VA AND POSSIBLY INTERIOR MD PORTIONS OF THE WATCH.

..GUYER/GRAMS.. 02/24/2016

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

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

LAT...LON   38157857 39497736 40587563 40027399 38427505 38027622
            38307730 38157857

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 24, 3:20 PM ESTTornado WatchSPCKent, New Castle, Sussex8 hr
Feb 24, 4:46 PM ESTMesoscale DiscussionSPCKent89 min
Feb 24, 1:18 PM ESTMesoscale DiscussionSPCCalvert, Charles, Prince George's, Saint Mary's117 min
Feb 24, 1:46 PM ESTTornado WatchSPCDorchester, Somerset, Wicomico, Worcester9 hr
Feb 24, 6:40 PM ESTMesoscale DiscussionSPCCharles, Saint Mary's2 hr
Feb 24, 6:46 PM ESTMesoscale DiscussionSPCBergen, Essex, Hudson, Hunterdon, Middlesex, Morris and 5 more119 min
Feb 24, 8:14 AM ESTMesoscale DiscussionSPCDickenson, Lee, Russell, Scott, Washington, Wise and 2 more2 hr
Feb 24, 10:46 AM ESTMesoscale DiscussionSPCHalifax, Henry, Patrick, Pittsylvania, City of Danville, City of Martinsville119 min
Feb 24, 11:16 AM ESTMesoscale DiscussionSPCCity of Suffolk89 min
Feb 24, 2:55 PM ESTMesoscale DiscussionSPCMecklenburg, City of Danville95 min

Nearby

Mesoscale Discussions in Maryland, 2016Mesoscale Discussions in Virginia, 2016Mesoscale Discussions in New Jersey, 2016Every mesoscale discussion in 2016

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.