Cold surface temperatures were already in place across the region at least 24 hours leading up to this event. Surface high pressure allowed high temperatures to only reach near freezing while low temperatures bottomed out in the mid-20s.
Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PBZ wrote it up.
Cold surface temperatures were already in place across the region at least 24 hours leading up to this event. Surface high pressure allowed high temperatures to only reach near freezing while low temperatures bottomed out in the mid-20s. A closed upper level low formed just north of Texas on November 14th and tracked northeast. An abundant amount of moisture from the Gulf of Mexico traveled with the system into the northeast United States. Freezing rain eventually transitioned to snow when northwest flow began on the backside of the surface low. Four to seven inches of snow was measured north of I-80 and in the higher elevations, meanwhile 1 to 3 inches of snow happened elsewhere.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Pittsburgh, PA wrote its last area forecast discussion before the first event at Nov 14, 12:41 PM EST, 2 hours 6 minutes earlier.
Area Forecast Discussion
National Weather Service Pittsburgh PA
1241 PM EST Wed Nov 14 2018
.SYNOPSIS...
Dry but cold conditions will occur Wednesday with high
pressure. Low pressure will bring a wintry mix of precipitation
by Thursday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
8am update...made minor tweaks to hourly temperatures and sky
grids. The rest of the forecast package is on track.
Previous discussion...
Light snow showers north of I-80 will dissipate later this
morning as increasing high pressure and subsequent subsidence
dry out the boundary layer. A plume of high cirrus plus residual
stratocu from cool NW flow will limit cooling overnight from
previous forecasts...though morning lows will be below freezing
areawide. The lack of significant cloud clearing plus the cold
start will result in high temperatures struggling to reach the
upper 30s.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
All eyes will be on the storm system moving through the
Tennessee Valley into the Ohio River Valley and Mid-Atlantic
Wednesday night into Thursday. Two areas of sfc low pressure
will develop in response to the upper level low, the weaker one
over central Kentucky and the stronger one off the Atlantic
coast. They will slowly track northeast well ahead of the
upper level low pressure, which will finally reach the area
late Thursday night before swiftly exiting into the northeast
Friday.
Models are in general agreement on the timing and evolution of
precipitation areas. Precip will reach our southern zones mid-
Thursday morning and spread northward through the day. It will
be reinvigorated late Thursday night into Friday morning with
the passage of the upper level low to our south. As the low
exits, dry air and subsidence will begin, though NW flow will
allow for lake enhanced snow showers throughout the day.
The biggest uncertainty is the temperature profile both at the
sfc and aloft, which will greatly dictate precip type. Latest
model guidance and soundings show a slug of above freezing
850mb temps moving northward ahead of the upper level low at the
onset of the event, putting the onus on sfc temps to remain
at/below freezing to create any wintry mix. Sleet/freezing rain
is anticipated at the onset of this event, but these temps plus
daytime heating will change precip to rain for most areas and
limit wintry accumulations during the daytime. Though looking
much less likely...there remains a very small risk for a
prolonged freezing rain and/or sleet event if sfc temps are
slow to warm above freezing due to reinforcing cold air from the
east. Will keep watch in effect and hold off advisory issuance
for daytime crew who will get final look at model changes ahead
of event start time.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Generally dry and cool weather is expected the rest of the
period as we enter a prolonged period of dry NW flow. A cold
frontal passage Sun could create some precipitation chances,
though the GFS/ECMWF disagree on the amount of lift and
available moisture. Used a blend of these two models for PoPs
during this period.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Some occasional MVFR cigs are possible this afternoon under high
overcast skies. Afterwards, all sites will remain VFR until
after sunrise Wednesday when precipitation will move in from
the southwest. By afternoon, all sites should have IFR or low
MVFR cigs. Although a mix of snow, sleet, freezing rain, and
rain is expected, the primary precipitation type at this time
appears to be snow.
Outlook...
Widespread precipitation will come to an end on Friday.
Occasional disturbances will keep a chance of showers in the
forecast through the weekend, primarily north of Pittsburgh.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...Winter Storm Watch from late tonight through Friday morning
for MDZ001.
OH...None.
PA...None.
WV...Winter Storm Watch from late tonight through Friday morning
for WVZ512>514.
&&Hazardous Weather Outlook...UPDATED National Weather Service Pittsburgh PA 1203 PM EST Wed Nov 14 2018 OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029- 031-073>076-WVZ001>004-012-021-509>511-151715- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson-Muskingum- Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest-Lawrence-Butler- Clarion-Beaver-Allegheny-Armstrong-Indiana-Washington-Greene- Westmoreland-Westmoreland Ridges-Fayette-Fayette Ridges-Hancock- Brooke-Ohio-Marshall-Wetzel-Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- 1203 PM EST Wed Nov 14 2018 This Hazardous Weather Outlook is for east central Ohio, northwest Pennsylvania, southwest Pennsylvania, west central Pennsylvania, western Pennsylvania, northern West Virginia and northern panhandle of West Virginia. .DAY ONE...This Afternoon and Tonight. Snow is expected to begin late tonight and will peak in intensity toward rush hour early Thursday morning. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. A wintry mix of snow, sleet and freezing rain is expected Thursday into Friday. A winter weather advisory may be needed. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. MDZ001-WVZ512>514-151715- Garrett-Eastern Preston-Western Tucker-Eastern Tucker- 1203 PM EST Wed Nov 14 2018 ...WINTER STORM WATCH IN EFFECT FROM LATE TONIGHT THROUGH FRIDAY MORNING... This Hazardous Weather Outlook is for western Maryland and northern West Virginia. .DAY ONE...This Afternoon and Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Winter Storm Watch. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Winter Storm Watch. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. Kramar
The national radar mosaic for the moment the first event began.
8 winter weather. Local standard time, as filed.
A combination of snow and ice accumulated in a 24 hour period across the county. Two to four inches of snow accumulated; an average of 0.1 inches of ice was measured.
A combination of ice and snow accumulated in 24 hours. 1 to 3 inches of snow measured; a glazing of freezing rain observed across the county.
One to two inches of snow accumulated in a 24 hour period. A glazing of ice was observed in areas on the morning of November 15th.
One to two inches of snow accumulated in a 24 hour period. A glazing of ice was observed in areas on the morning of November 15th.
One to two inches of snow accumulated in a 24 hour period. A glazing of ice was observed in areas on the morning of November 15th.
The local emergency manager reported patches of ice across the county.
The public estimated a trace to 0.2 inches of ice accumulated across the county.
A glazing of ice was observed across the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2018Every state in 2018This day in weather historyWarnings in Ohio, November 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 794441, 794444, 794447, 794448, 794449, 794450, 794452, 794453.