Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus61 kpbz 240600 

Area forecast discussion
National Weather Service Pittsburgh PA
100 am EST Fri Feb 24 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 to near normal by Sunday.


Near term /through today/...
dry conditions expected the remainder of the night as the
surface boundary previously draped across the northern fringes
of the forecast area lifts north. Overnight temperatures will
be very mild again with dewpoints in the low to mid 50s and under
extensive cloud coverage.

With the forecast area well within the warm sector, forecast
confidence is high in regards to high temperatures today
and are expected to rise into the 70s with isolated 80 degree
readings...breaking records at all climate locations. Long-term
confidence tools have not deviated from suggesting the
prolonged warm period we have been in this week and with
increased warm advection and mixing ahead of the approaching
cold front along with a break in cloud coverage during the
afternoon...we are going to see the warmest temperatures of the
year thus far and will easily break current records.


Short term /tonight 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. Storm Prediction Center 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 /06z Friday through Tuesday/...
general VFR is expected for much of the period as we remain in
the warm sector through Friday. Frontal passage will be very
late in the 30 hour period, so outside of The Pit and zzv taf,
no shra mention was made. Only concern for the forecast will be
the strengthening SW winds. Wind gusts of 15 to 25 kts are
possible at all ports during the afternoon.

widespread restrictions are likely with the approach and passage
of a cold front Friday night and early Saturday. Restrictions
may continue in cold advection and snow showers through early


record high temperatures for climate sites:

Thu Fri
-------- --------
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)


Pbz watches/warnings/advisories...

National Weather Service Glossary of Abbreviations