Area Forecast Discussion
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FXUS61 KPBZ 181810 AAA
Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
110 PM EST Sat Feb 18 2017
Dry conditions are largely expected until the next frontal
system crosses the region Tuesday afternoon and Wednesday.
Well above normal temperatures are expected through the end of
.NEAR TERM /THROUGH TONIGHT/...
Strong diurnal mixing continues to support rapidly warming
temperatures this afternoon in advance of an approaching upper
level shortwave. Further adjustments were made based on the most
recent observations and trends, with low to mid 60 temperatures
expected everywhere, even in the northernmost zones. We`ve
already surpassed the record highs for several of our sites
before noon...see the climate section for more details.
Cloud cover is slow to increase in advance of the
aforementioned system, as is precip, with dewpoints still in the
30`s. While a slight northern trend is apparent in some
guidance, including hi res models, the amount of precipitation
making it to the ground may be minimal with the dry air in
place. Thus, while slight chance PoPs were pushed just a bit
further north along the northern WV/southern PA border, any
precip should be very light.
Shortwave will continue to pass just south of the region
overnight. Cloud cover should limit the extent of the cooling
but a wnw wind shift even in neutral advection may support some
cooling of the ridge tops. Overall though temperatures are
expected to stay nearly 20 degrees above average.
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
Strong ridging builds in the wake of the departing low through
this period, with 500mb heights approaching 576dam by Monday
night/Tuesday. With nearly clear skies and warm advection,
expect the continuation of very warm temperatures through
Tuesday, before a cold front approaches Tuesday afternoon/night.
Deterministic guidance continues to struggle with the timing of
the front for Tuesday. Have opted to hold the likely PoPs but
adjusted the timing based on a model blend for now, as it
appears the GFS may be just a tad past with the boundary
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Long term continues to highlight an above-average temperature
trend, as has been suggested by long-range guidance. Despite
the passage of the front Tuesday night, mid-level ridging will
quickly build back over the eastern CONUS as the trough
amplifies over the southwestern US and then ejects into the
central Plains by the end of period.
Model guidance appears to be handling the overall trends in the
upper level pattern well, with only minor differences in timing
and evolution of the system for the end of the week. Thus, will
stay close to a blend of solutions with tweaks made to
temperatures as the Superblend tends to dampen anomalous values
in the extended.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR conditions prevailing with southwest winds gusting to 20
Kts diminishing this evening. Clouds will increase this evening
with only a few sprinkles expected at KMGW as a weak mid level
circulation shears out across the Mid-Atlantic states. Weak cool
advection looks to produce a period of MVFR stratus at most
ports late night into early Sunday.
The next chance for widespread restrictions will be with a Tuesday
Record High Temperatures February 18:
Pittsburgh, PA 66 (2011)
Zanesville, OH 64 (2011/1994)
Morgantown, WV 73 (1981)
DuBois, PA 57 (1981) - Surpassed before noon
Wheeling, WV 60 (2008) - Surpassed after noon
New Philadelphia,OH 62 (1961) - Surpassed after noon