Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
616 am EDT Tuesday Sep 2 2014
a cold front will push through the region today...with showers and
thunderstorms and locally heavy rain possible. High pressure will
then briefly build in behind the front...with dry conditions
expected for Wednesday. Southerly flow behind the retreating high
pressure toward the end of the week will increase the threat for
showers and storms.
Near term /until 6 PM this evening/...
despite model uncertainty of extent and spread of heavy rain
potential into area among the cams/rap/NAM...have generally gone
with a blend and timing out convection over Indiana into the forecast
area. Flash Flood Watch mainly for areas which had received from 2
to nearly 5 inches of rain over the extended weekend...and for the
Cincinnati area for morning commute. While ll support and deep
moisture does tend to diminish as the frontal system pushes
east...Flash Flood Watch does extend as far east as Franklin
County/Columbus through the afternoon.
Best moisture transport and deep warm cloud layer...combined with
precipitable waters of over 2" will be in the middle/lower great/Little Miami basin
areas through early/middle afternoon.
Short term /6 PM this evening through Thursday night/...
by 20-22 UTC...frontal system into southern and Easter forecast area
with lingering rain showers/thunderstorms but otherwise drier conditions filtering
into the area as the front pushes through.
Weak high pressure building briefly into the area will briefly
will bring moderating overnight lows and drier conditions. Have
generally gone a little higher than MOS guidance for overnight
lows as strong northwest flow not really realized behind the front with
the fairly shallow nature of the high. The high begins to move
east of the region late Wednesday with a weak warm front lifting
toward area from the middle MS valley and western Great Lakes. Very
little forcing with this boundary and ll moisture not as
established so kept forecast dry through Wednesday/Wednesday night...introducing a
low chance for rain showers/isolated thunderstorms and rain into the day on Thursday.
Long term /Friday through Monday/...
by Friday...a cold front begins to push through the Great Lakes.
Models are showing a range on the frontal passage timing. The GFS is the
quickest...while the European model (ecmwf) is on the slower end of the guidance.
Both models show frontal passage Friday night into Saturday morning with
continued precipitation chances on Saturday. Put the best probability of precipitation Friday night
with 50 pop across the region. Redeveloped the precipitation Saturday
morning with 50 probability of precipitation across the south...but lower probability of precipitation to the northwest.
The GFS dries things out quicker Saturday night as compared to the
European model (ecmwf) which leaves lingering precipitation chances into Saturday night across
the south. Held on to 20 probability of precipitation for the evening hours in the southeast.
High pressure builds across the region Sunday into Monday.
Warm and humid conditions are expected for Thursday and Friday.
Highs will be in the upper 80s to 90 with dewpoints in the upper 60s
to lower 70s. Cooler conditions Saturday with highs ranging from the
middle 70s in the north to the lower 80s in northern Kentucky. By Sunday and
Monday...highs will be in the lower to middle 70s across the region.
Aviation /10z Tuesday through Saturday/...
widespread shower and thunderstorm activity is continuing to
overspread the area this morning. The precipitation is along the nose
of a 30-40 knot 925-850 mb jet. This jet is forecast to shift east
across our area and weaken through 15z. As a result...am
expecting an overall weakening trend in the precipitation coverage and
intensity through late morning. Meanwhile...a cold front dropping
down from the northwest will push through our area this
afternoon. This could allow for some isolated to scattered
shower/thunderstorm redevelopment from late morning into early
afternoon. Instability may be limited though by remnant cloud cover
from this mornings precipitation. As a result...will just allow for a vcsh
ahead of frontal passage. High pressure will build in behind the front for
tonight. With clearing skies and light winds...expect some IFR to
possibly LIFR br development later tonight.
Outlook...thunderstorms possible Friday into Saturday.
Ohio...Flash Flood Watch until 4 PM EDT this afternoon for ohz053>055-
In...Flash Flood Watch until 4 PM EDT this afternoon for inz050-058-