Area Forecast Discussion
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FXUS61 KPBZ 231936
Area Forecast Discussion
National Weather Service Pittsburgh PA
236 PM EST Thu Feb 23 2017
Record breaking warmth is expected on Friday, followed by a cold
front late Friday night into early Saturday morning which will
eventually drop temperatures near normal by Sunday.
.NEAR TERM /THROUGH FRIDAY/...
The primary focus for any precipitation tonight will come from a
cold front sagging south across Lake Erie into northwestern Ohio
as of early afternoon. While the front is expected to make some
southward progression into northern Ohio and northwestern
Pennsylvania later this afternoon into this evening, the front
should then slide back north through the overnight hours. With
the best upper level support along the front not arriving until
after midnight, have generally stuck with chance pops and expect
more widespread showers to remain north of the local forecast
area. Have also added a slight chance of thunderstorms through
the early evening with modest amounts of instability present.
Yet another night of warm temperatures is expected, with most
locations only dropping into the 50s.
With the front to the north and southerly winds across the
region, the warmest day of the year so far is expected on
Friday, with nearly all locations rising into the 70s and an
isolated 80 degree reading not out of the question. The current
forecast includes record breaking temperatures at all climate
locations and dry conditions.
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
While there is still some minimal model disagreement in timing
of the next cold front, the general consensus shows the front
crossing Pittsburgh around sunrise Saturday. The timing should
help to dampen the threat for severe weather. Although
instability along the cold front will be limited locally, there
will still be a threat for strong winds considering the wind
shear along the front. SPC has maintained a slight risk for
severe weather across most Ohio counties and a marginal risk
elsewhere in the forecast area.
The bulk of rainfall will have moved east by Saturday afternoon,
and a brief lull in showers can be expected before the
combination of west-northwesterly winds and colder air allows
for some lake enhanced showers to develop Saturday night. Some
minimal snow accumulations, less than an inch, will be possible
in the favored locations along Interstate 80 and along the
PA/WV/MD ridges. As high pressure builds in from the southwest,
winds will lose their northerly component and all precipitation
will end Sunday morning. While temperatures will remain in the
50s Friday night, temps will fall all of Saturday and Saturday
night, eventually bottoming out in the 20s. Seasonal highs
around 40 are forecast on Sunday.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Broad southwest flow aloft is in place for the first portion of the
extended period, before a trend towards a troughing pattern towards
the end. While guidance generally agrees with this, details on
shortwaves and surface systems remain murky, with model disagreement
continuing. The flow and increasing moisture with time will support
chances for scattered showers Monday and Tuesday. A more
significant system appears possible for later Tuesday night and
Wednesday, for which likely PoPs were maintained. Once again, this
system will produce nealy all liquid, save for some backside snow
showers later Wednesday night. Northwest flow activity may linger on
Thursday. Made modifications to the SuperBlend guidance to shade
more towards continuity. A trend from normal to above normal
temperatures will be felt from Monday through Wednesday, before
seasonal values return for Thursday.
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
MVFR ceilings will linger into tonight with abundant low level
moisture associated with a frontal boundary. Scattered showers
are possible this afternoon, mainly north of PIT. Ceilings may
fall a bit after sunset, with areas near and north of I-80
possibly sinking to IFR levels. Once the front lifts north and
the region gets into the warm sector, ceilings will begin to
rise back to VFR levels late this evening and overnight, with
FKL/DUJ possibly that level shortly after sunrise. VFR
conditions will then continue through Friday with thinning
clouds by afternoon. Cannot rule out patchy MVFR fog overnight
but elected not to include for now as the boundary layer should
Widespread restrictions are likely with the approach and passage
of a cold front on Friday night and early Saturday.
Record high temperatures for climate sites:
PIT 70 (1922) 70 (1875,1906)
ZZV 64 (2000) 70 (1961)
MGW 68 (1996) 75 (1975)
DUJ 63 (1985) 60 (1985)
HLG 62 (2000) 63 (2016)
PHD 69 (1975) 66 (1985)