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Area forecast discussion
National Weather Service Pittsburgh PA
1007 PM EDT Fri Jun 23 2017

Synopsis...
a cold front sweeping through early Saturday will return
comfortable humidity levels by the weekend. Below normal
temperatures greet US early next week.

&&

Near term /through Saturday/...
tweaked forecast to reflect current radar trends. The heaviest
rain rates appear to be over with. We will be conducing a damage
survey for Greene and Fayette counties Saturday and likely into
West Virginia.

&&

Short term /Saturday night through Monday night/...
dry and less humid air will be welcome news for many this
weekend as dewpoints drop into the 50s. Northwest winds behind
the baroclinic zone will clear out the sky during the morning,
however moisture will be on the increase as a fast moving
shortwave trough crosses during the evening hours. The column is
fairly dry, so no measurable quantitative precipitation forecast is foreseen Saturday. Dry
weather continues for the second half of the weekend despite
less sunshine. Yet another passing short wave will bring clouds
and given its stronger than the one Saturday isolated showers
are possible north of the I-76 corridor in the late afternoon /
early evening hours Sunday.

Mid level heights continue to fall as we kick off a new work
week. Most of the energy will reside along the lakes, so precip
chances are small over northern WV and western Maryland when compared
to northwest PA. Any shower will be brief. The bigger story is
the Spring like feel as daytime high temps do not leave the 60s
Monday! This will be almost 15 degrees below normal.

&&

Long term /Tuesday through Friday/...
highlights:
- cool start - warm end temp wise
- unsettled weather returns Friday
- no heat waves or high water threat

Mid level heights increase with a ridge building into the
eastern United States. This will bring temps back to normal
levels by Thursday and above normal by a week from now.

&&

Aviation /02z Saturday through Wednesday/...
VFR weather will yield to MVFR and IFR cigs this evening in wake
of the cold front. Drier air will work into the area toward 12z
bringing terminals back to VFR where they will stay for the
balance of the forecast. Winds will be gusty from the west-southwest
tomorrow afternoon with peak gusts around 20 kts.

Outlook...
upper trough may bring occasional restrictions sun and Mon in
afternoon showers/storms.

&&

Hydrology...
the Flash Flood Watch remains on track. The axis of highest quantitative precipitation forecast
has shifted a little north to far southern PA where 24 hour
amounts in excess of three inches are possible. Hrrr shows a
several hour period of moderate to heavy rainfall thankfully it
is across a region that was not impacted by the nearly 4-6" of
rain that fell in parts of Indiana County last evening.

Warm rain process and pre setup remain in place. Precipitable waters are
pushing two inches while warm cloud depths are in excess of
13kft. The low level jet continues to pump moisture from Cindy
into our region. All of these point to enhanced convergence
ahead of the Front.

River forecasts have been tweaked upward across Mon and
headwaters of Ohio River. We still do not have any forecast
points going to flood, but Pittsburgh, Elizabeth, and Charleroi
are predicted to reach action stage.

&&

Pbz watches/warnings/advisories...
Maryland...Flash Flood Watch until 2 am EDT Saturday for mdz001.
Ohio...Flash Flood Watch until 2 am EDT Saturday for ohz039>041-
048>050-057>059-068-069.
PA...Flash Flood Watch until 2 am EDT Saturday for paz013-014-
020>023-029-031-073>076.
WV...Flash Flood Watch until 2 am EDT Saturday for wvz001>004-012-
021-509>514.

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