Alert archive / Pennsylvania / Mesoscale Discussions in 2012

Mesoscale Discussion 62

January 23, 201210 counties in Ohio; 15 counties in Pennsylvania; 15 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jan 23, 2012, 3:26 PM EST for 10 counties in Ohio; 15 counties in Pennsylvania; 15 counties in West Virginia. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Jan 23, 2012, 3:26 PM EST (20:26 UTC)
Expired
Jan 23, 2012, 5:00 PM EST
In force
94 min
Issued by
the Storm Prediction Center
All 40 counties

Belmont County, OH, Carroll County, OH, Columbiana County, OH, Harrison County, OH, Jefferson County, OH, Mahoning County, OH, Monroe County, OH, Noble County, OH, Trumbull County, OH, Washington County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Doddridge County, WV, Hancock County, WV, Harrison County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Pleasants County, WV, Preston County, WV, Ritchie County, WV, Taylor County, WV, Tyler County, WV, Wetzel County, WV, Wood County, WV

The radar

The Pittsburgh radar (KPBZ), 11 km from the middle of the area, began a volume at 20:26 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 8.4 hours before the alert went out and 284 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, Buffalo Intl Airport, NY at 12:00Z on 2012-01-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Buffalo Intl Airport, NY at 12:00Z on 2012-01-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 252 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
627 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
214 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.

688 
ACUS11 KWNS 232027
SWOMCD
SPC MCD 232026
PAZ000-MDZ000-WVZ000-OHZ000-232200-

MESOSCALE DISCUSSION 0062
NWS STORM PREDICTION CENTER NORMAN OK
0226 PM CST MON JAN 23 2012

AREAS AFFECTED...FAR ERN OH...NRN WV...SW PA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 232026Z - 232200Z

A LINE OF SHALLOW CONVECTION EXTENDING ACROSS FAR ERN OHIO WILL
CONTINUE TO BE CAPABLE OF PRODUCING GUSTY WINDS AND SMALL HAIL THIS
AFTERNOON. LITTLE LIGHTNING IS EXPECTED WITH THIS ACTIVITY AS IT
MOVES EWD INTO SWRN PA AND NRN WV.

LATEST SFC ANALYSIS SHOWED A COLD FRONT EXTENDING SEWD ACROSS ERN MI
INTO CNTRL OHIO SWWD INTO ERN KY. AHEAD OF THE FRONT AND BENEATH A
MID LEVEL DRYSLOT /PER LATEST WV IMAGERY/...SHALLOW CONVECTION HAS
PERSISTED WITH A FEW CELLS BECOMING DEEP ENOUGH TO PRODUCE
INFREQUENT LIGHTNING STRIKES. WITH BACKGROUND DEEP LAYER SWLY FLOW
ALREADY STRONG /50-80 KT/...THESE SHOWERS AND ISOLATED THUNDERSTORMS
WILL FURTHER ENHANCE CHANCES FOR STRONG/MARGINALLY SEVERE SFC WIND
GUSTS. WITH LITTLE IN THE WAY OF BUOYANCY /MLCAPE VALUES LESS THAN
250 J/KG/ AND WARM TEMPERATURES ALOFT FURTHER INHIBITING UPDRAFT
STRENGTH AND DEPTH...PROLONGED THUNDERSTORM ACTIVITY IS NOT
ANTICIPATED AND THEREFORE A WATCH IS NOT EXPECTED AT THIS TIME.
HOWEVER...CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..LEITMAN.. 01/23/2012

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

ATTN...WFO...CTP...PBZ...RLX...CLE...

LAT...LON   41138103 41508081 41667998 41537912 41307869 40207893
            39347978 39138051 39218164 41138103

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 23, 1:52 AM ESTMesoscale DiscussionSPCAdams, Brown, Butler, Champaign, Clark, Clermont and 14 more113 min
Jan 23, 2:14 AM ESTSevere Thunderstorm WatchSPCAdams, Brown, Butler, Clermont, Clinton, Fayette and 6 more5 hr
Jan 23, 5:11 AM ESTMesoscale DiscussionSPCPike, Ross, Scioto64 min
Jan 23, 11:46 AM ESTMesoscale DiscussionSPCAdams, Athens, Brown, Butler, Champaign, Clark and 34 more89 min

Nearby

Mesoscale Discussions in Pennsylvania, 2012Mesoscale Discussions in West Virginia, 2012Mesoscale Discussions in Ohio, 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.