Flood Potential Outlook
Issued by NWS
FGUS71 KPBZ 131724
Winter/Spring Flood Potential Outlook
National Weather Service Pittsburgh PA
124 PM EDT Thu Apr 13 2017
...WINTER SPRING FLOOD OUTLOOK THROUGH APRIL 28...
For early spring...the flood potential is normal for the Upper
A normal risk for flooding means occasional flooding could occur
with water levels having minor impacts.
For the long-range river outlooks and the probability of
exceeding flood stage or the chances of flooding relative to
normal at specific forecast points during the next 90 days...refer
to www.weather.gov/ohrfc and click on the 90-day river outlook on
the left hand side of the page. Click on flood chc vs normal to
view the risk of flooding with respect to normal.
Flood outlooks are issued bi-weekly by the national weather
service during winter and early spring to summarize basin
hydrometeorological conditions and to assess the potential for
winter/spring flooding. The outlooks are based on current and
forecast conditions during the outlook period.
In addition...a 90-day water resource outlook is issued monthly.
Factors considered in assessing flood potential are (1)
antecedent conditions (2) past precipitation (3) recent
streamflows and reservoir levels (4) soil moisture (5) water
content of the snow pack (6) ice conditions on the rivers and (7)
Meteorologically...the winter of 2016/17 was very mild in the
ohio valley leading to much below normal snowfall and no ice
development on rivers in the Ohio River basin.
Precipitation for the winter of 2016/17 was above normal(>125% of
normal) across upper Ohio valley.
Soils are moist to wet...due to frequent rains in the Ohio River
...Spring flood outlook/summary...
Strong onshore flow along the west coast of the United States
precluded intrusions of polar and arctic air masses into the
Eastern U.S. on a frequent basis this past winter. The resulting
lack of a significant snowpack in late winter considerable lowers
the risk for flooding in the Ohio Valley in early spring.
Spring flooding will be dependent on the frequency of rainfall as
well as if tropical plumes of moisture feed into storm systems
moving through the Ohio Valley.
Early spring risk for flooding...normal for the upper Ohio River