Alert archive / Virginia / Mesoscale Discussions in 2016
Mesoscale Discussion 56
The Storm Prediction Center issued this mesoscale discussion at Jan 22, 2016, 9:56 PM EST for 6 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 22, 2016, 9:56 PM EST (02:56 UTC)
- Expired
- Jan 23, 2016, 3:00 AM EST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 69 counties
Kent County, DE, New Castle 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, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Washington County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA, York County, PA, Albemarle County, VA, Amelia County, VA, Arlington County, VA, Buckingham County, VA, Caroline County, VA, City of Alexandria, VA, City of Charlottesville, 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, Cumberland County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince William County, VA, Rappahannock County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV, Morgan County, WV
The radar
The Sterling radar (KLWX), 36 km from the middle of the area, began a volume at 02:55 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 00:00Z, 2.9 hours before the alert went out and 28 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
- 746 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 225 m²/s²
- 0-3 km storm-relative helicity
- 719 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
192
ACUS11 KWNS 230257
SWOMCD
SPC MCD 230256
NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-230800-
MESOSCALE DISCUSSION 0056
NWS STORM PREDICTION CENTER NORMAN OK
0856 PM CST FRI JAN 22 2016
AREAS AFFECTED...PORTIONS OF THE MID-ATLANTIC
CONCERNING...HEAVY SNOW
VALID 230256Z - 230800Z
SUMMARY...SNOWFALL INTENSITY WILL INCREASE WITHIN A CONSOLIDATING
BAND OVER THE NEXT FEW HOURS. SNOWFALL AROUND 1-2 INCHES PER HOUR
/WITH LOCALLY HIGHER RATES/ IS EXPECTED.
DISCUSSION...IR IMAGERY AND REGIONAL RADAR DEPICT AN EXPANSIVE
SHIELD OF PRECIPITATION ALONG THE MID-ATLANTIC COAST...IN RESPONSE
TO BROAD ISENTROPIC ASCENT ALONG THE EASTERN EDGE OF THE MATURING
CYCLONE. SFC PRESSURE FALLS AROUND 2-3 MB/HR NOTED ALONG THE NC/VA
COASTS AHEAD OF THE DEEPENING SFC LOW SIGNAL A GROWING MASS RESPONSE
FROM THE APPROACHING MID-LEVEL TROUGH. ADDITIONALLY...PRESSURE FALLS
AROUND 2 MB/HR ALONG/NEAR THE CHESAPEAKE/POTOMAC ARE LIKELY
SIGNALING STRENGTHENING WAA/ISENTROPIC ASCENT AHEAD OF THE DEEPENING
850-700 MB LOW. AMPLIFYING FRONTOGENETIC CIRCULATIONS WILL FURTHER
AID ASCENT TO BOLSTER SNOWFALL RATES OVER THE NEXT FEW HOURS.
INDEED...KAKQ/KDOX INDICATE SUBTLE ENHANCEMENTS OF SPECIFIC
DIFFERENTIAL PHASE /KDP/ WITHIN THE -10 TO -20 C LAYER...LIKELY
SIGNALING IMPROVED ASCENT/CRYSTAL GROWTH ALOFT. AS SUCH CONDITIONS
EXPAND N/NWWD IN RESPONSE TO THE AFOREMENTIONED LARGE-SCALE
FORCING...A BAND OF HEAVY SNOW WILL CONSOLIDATE ACROSS THE
DISCUSSION AREA. CONDITIONS SHOULD FURTHER DETERIORATE AS SNOWFALL
RATES OF 1-2 INCHES PER HOUR /WITH LOCALLY HIGHER RATES/
DEVELOP...ESPECIALLY IN ANY SMALL CONVECTIVE ELEMENTS.
ACROSS SOUTHEASTERN PORTIONS OF THE AREA...SOME MIXING WITH SLEET
MAY OCCUR...NOTED IN KDOX/KAKQ CC DATA AND A FEW MPING REPORTS. SUCH
MIXING WOULD TEMPORARILY REDUCE SNOWFALL RATES. HOWEVER...HEAVY
PRECIPITATION AND SUBSEQUENT COOLING DUE TO MELTING HYDROMETEORS
WILL SERVE TO SLOW/STOP THE N/NWWD PROGRESSION OF THIS WARM LAYER.
..PICCA.. 01/23/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...
LAT...LON 39647820 40097599 40127514 40067447 39927421 39167474
38687544 38257694 37547766 37287789 37257843 37697882
38327882 38627869 38927863 39247850 39647820SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 23, 4:20 AM EST | Mesoscale Discussion | SPC | Kent, New Castle | 5 hr |
| Jan 23, 12:44 PM EST | Mesoscale Discussion | SPC | Kent, New Castle | 6 hr |
| Jan 23, 6:40 PM EST | Mesoscale Discussion | SPC | Kent, New Castle | 4 hr |
| Jan 23, 8:51 AM EST | Mesoscale Discussion | SPC | Baltimore, Carroll, Cecil, Frederick, Harford, Howard and 3 more | 4 hr |
| Jan 23, 12:08 AM EST | Mesoscale Discussion | SPC | Bergen, Essex, Hudson, Hunterdon, Mercer, Middlesex and 7 more | 5 hr |
Nearby
Mesoscale Discussions in Virginia, 2016Mesoscale Discussions in Maryland, 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.