Alert archive / West Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 47

January 26, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Jan 26, 2011, 7:30 AM EST for 5 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jan 26, 2011, 7:30 AM EST (12:30 UTC)
Expired: Jan 26, 2011, 12:00 PM EST
In force: 5 hr
Issued by: the Storm Prediction Center

All 40 counties

Allegany County, MD, Garrett County, MD, Washington County, MD, Athens County, OH, Belmont County, OH, Jefferson County, OH, Monroe County, OH, Noble County, OH, Washington County, OH, Allegheny County, PA, Armstrong County, PA, Bedford County, PA, Blair County, PA, Cambria 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, City of Winchester, VA, Clarke County, VA, Frederick County, VA, Loudoun County, VA, Berkeley County, WV, Brooke County, WV, Grant County, WV, Hampshire County, WV, Hancock County, WV, Jefferson County, WV, Marshall County, WV, Mineral County, WV, Morgan County, WV, Ohio County, WV, Pleasants County, WV, Tucker County, WV, Tyler County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 109 km from the middle of the area, began a volume at 12:29 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

Pittsburgh, PA (KPIT), launched 12:00Z, 0.5 hours before the alert went out and 94 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 718 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 143 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.

339 
ACUS11 KWNS 261230
SWOMCD
SPC MCD 261230 
PAZ000-MDZ000-VAZ000-WVZ000-OHZ000-261700-

MESOSCALE DISCUSSION 0047
NWS STORM PREDICTION CENTER NORMAN OK
0630 AM CST WED JAN 26 2011

AREAS AFFECTED...PORTIONS ERN OH...NRN WV...NWRN VA...SWRN/S-CENTRAL
PA...NWRN MD INCLUDING PANHANDLE.

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 261230Z - 261700Z

POTENTIAL SHOULD INCREASE THROUGH 18Z FOR MIXTURE OF MDT/ISOLD HVY
SNOW AND FREEZING RAIN...WITH LIQUID EQUIVALENT RATES .1-.2
INCH/HOUR...INVOF OH RIVER VALLEY FROM PKB AREA NEWD INTO WRN PA.

PRECIP FARTHER SW ACROSS ERN KY...FAR WRN VA AND SWRN WV HAS BEEN
OCCURRING AS RAIN IN CONVEYOR OF ELEVATED LOW-LEVEL WAA JUXTAPOSED
WITH INCREASING LARGE-SCALE DCVA/ASCENT IN MIDLEVELS. THIS TREND
SHOULD CONTINUE...YIELDING MIX OF PRECIP TYPES AS IT CROSSES NEAR-
TO BELOW-FREEZING SFC AIR.  12Z SFC MESOANALYSIS REVEALS THERMAL
AXIS NEAR TRI...CRW...MGW...LBE LINE...BRACKETED BY FREEZING LINE
NEAR LEX...ZZV...30 E HLG...20 N LBE THEN BECOMING ERRATIC DEPENDING
ON ELEVATION SWD AND SEWD ACROSS NWRN WV AND NWRN MD/PANHANDLE
REGION.  WEAK CAA AND DEEP-LAYER COOLING SHOULD HELP TO SHUNT
FREEZING LINE SEWD OVER OH RIVER AREA THROUGH FORENOON HOURS...WITH
LOWER DEW POINTS SUGGESTING SOME WET-BULB COOLING ALSO TO OCCUR OVER
ERN OH/SRN PA/NRN WV PANHANDLE REGION.  ALTHOUGH MUCH OF OH VALLEY
OF WV/SERN OH IS JUST ABOVE FREEZING ATTM...SNOW IS LIKELY DUE TO
COLUMNAR COOLING ASSOCIATED WITH APCHG SWATH OF DEEP-LAYER
ASCENT...AS EVIDENT IN TIME SERIES OF FCST SOUNDINGS.  UNTIL THAT
OCCURS...TEMPS IN SHALLOW LAYER ABOVE SFC MAY REMAIN WARM ENOUGH TO
SUPPORT THREAT FOR FREEZING RAIN INITIALLY.  FARTHER SW INVOF VA/WV
BORDER AND WRN MD...SUPERFREEZING LAYER MAY BE MAINTAINED ABOVE
SFC...WITH FREEZING RAIN BEING MORE DOMINANT THAN
SNOW...TRANSITIONING MORE TOWARD SNOW NWD OVER PA.

..EDWARDS.. 01/26/2011

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

ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...

LAT...LON   39198222 40128131 40738025 40897928 40727827 40247749
            38997753 39027919 37957984 38487984 39047975 40337940
            39548071 39228140 39198222

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 26, 11:19 AM EST	Mesoscale Discussion	SPC	Garrett	4 hr
Jan 26, 2:19 PM EST	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 13 more	6 hr
Jan 26, 11:12 AM EST	Mesoscale Discussion	SPC	Bucks, Montgomery	4 hr

Nearby

Mesoscale Discussions in West Virginia, 2011 Mesoscale Discussions in Pennsylvania, 2011 Mesoscale Discussions in Ohio, 2011 Every mesoscale discussion in 2011

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.