Alert archive / Pennsylvania / Mesoscale Discussions in 2017
Mesoscale Discussion 162
The Storm Prediction Center issued this mesoscale discussion at Feb 8, 2017, 9:40 PM EST for 10 counties in Ohio; 23 counties in Pennsylvania; 6 counties in West Virginia. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 8, 2017, 9:40 PM EST (02:40 UTC)
- Expired
- Feb 9, 2017, 1:45 AM EST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 39 counties
Belmont County, OH, Carroll County, OH, Columbiana County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Mahoning County, OH, Monroe County, OH, Noble County, OH, Washington County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Blair County, PA, Butler County, PA, Cambria County, PA, Cameron County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Elk County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Somerset County, PA, Venango County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Wetzel County, WV
The radar
The Pittsburgh radar (KPBZ), 92 km from the middle of the area, began a volume at 02:41 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 (KAGC), launched 00:00Z, 2.7 hours before the alert went out and 86 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
- 1 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 458 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 7 m²/s²
- 0-3 km storm-relative helicity
- 248 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
141
ACUS11 KWNS 090241
SWOMCD
SPC MCD 090240
PAZ000-MDZ000-WVZ000-OHZ000-090645-
Mesoscale Discussion 0162
NWS Storm Prediction Center Norman OK
0840 PM CST Wed Feb 08 2017
Areas affected...Southeast OH...western PA...northern WV panhandle
Concerning...Heavy snow
Valid 090240Z - 090645Z
SUMMARY...A band of moderate to occasionally heavy snow is expected
to develop across the region over the next few hours.
DISCUSSION...Current regional radar imagery and surface observations
show an area of moderate snow moving across central and western OH,
while areas farther south (southern OH and western WV) are still
mostly rain. Observational trends and current guidance suggest this
broad area of precipitation will continue eastward/northeastward
into southeast OH, western PA, and the northern WV panhandle.
Precipitation intensity is also expected to increase as low and
mid-level frontogenesis strengthens in response to overall
maturation of the mid-level cyclone. As a result, a band of moderate
to occasionally heavy snowfall is expected to develop across the
region over the next few hours. Snowfall rates over an inch an hour
with brief/localized instances of 2 inch per hour possible.
..Mosier.. 02/09/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CTP...PBZ...RLX...CLE...
LAT...LON 40207823 39677918 39428150 40148180 41308053 41777937
41847835 41517781 40967771 40497796 40207823SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 9, 4:55 AM EST | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Columbia, Delaware and 16 more | 6 hr |
Nearby
Mesoscale Discussions in Pennsylvania, 2017Mesoscale Discussions in Ohio, 2017Mesoscale Discussions in West Virginia, 2017Every mesoscale discussion in 2017
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.