Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
642 am EST sun Dec 21 2014
weak high pressure over the region will move off to the east
today. Southerly flow on the back side of the high will bring a
warming trend. A robust storm system will move through the area in
the middle of the week.
Near term /until 6 PM this evening/...
there has been some erosion of the low cloud deck overnight...
although some of the places that cleared filled back in. Do expect
a decrease in the low deck generally from west to east through the
day. Temperatures will remain cool although with at least some
insolation today went closer to warmer GFS MOS numbers.
Short term /6 PM this evening through Tuesday/...
middle level flow will become southwest ahead of a developing long
wave trough in the middle part of the country. Pieces of energy
moving through the trough will slowly get closer to the forecast
area with time. Meanwhile low level flow will back and become
southerly allowing for an increase in moisture. For the most part
the region will be dry tonight and Monday...although cannot
completely rule out a few light showers Monday morning on the
initial low level moisture surge. Then a chance of showers will
develop Monday night with the probability increasing on Tuesday.
The higher chances will be in the western counties during this
time frame. Several models do suggest that much of the activity
on Tuesday will be in the morning with a lull in the afternoon.
Temperatures will be above normal with a warming trend through the
period. Forecast temperatures are mostly within the MOS envelope.
Long term /Tuesday night through Saturday/...
short wave at the base of a long wave trough will lift across the
Ohio Valley Wednesday and Wednesday night. This will cause low
pressure to track north northeast along a cold front that will
cross the area on Wednesday. Operational 00z GFS looks
overdeveloped with the low. Other 00z guidance has similar looking
solutions that have been followed for the forecast.
Showers will increase in coverage Tuesday night and continue into
Wednesday. There will be a decrease in coverage late Wednesday
into Wednesday night with most if not all activity east of the
area by early Thursday as the entire system lifts out. Cold air is
slower to work in compared to earlier runs. So a transition to snow
showers will not occur until Wednesday night. Light accumulations
still look possible. Winds could be quite gusty in the cold
advection immediately behind the cold front late Wednesday into
Ridging will quickly work in later Thursday into Thursday night.
00z guidance showing timing discrepancies with the next fast
moving system. Have used middle of the Road gefs ensemble mean
which is also similar to previous forecast. This will bring a
chance of showers mainly Friday night with rain changing to snow
before ending early Saturday.
Aviation /12z Sunday through Thursday/...
high pressure will allow for dry conditions across the area today.
A weak disturbance will bring the potential for some light
precipitation to the later kcvg taf however the potential is too
low to include at this time. Winds will be light and less than 10
knots through the taf period. Some MVFR ceilings and visibilities will give
way to VFR conditions later today. Brief IFR visibilities will be
possible at Kiln if there are any additional breaks in the clouds
this morning. Additional MVFR clouds will begin to move into the area at
the end of taf period.
Outlook...MVFR/IFR ceilings and visibilities are possible Tuesday
into Thursday...along with windy conditions.