Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
622 am EST sun Dec 21 2014
a weak ridge of high pressure will dominate the region through
tonight. A warm front will lift north across the area Monday night as
low pressure moves east from the northern plains to Lake Superior
by Tuesday evening. Another low pressure system will move
northeast across Ohio on Wednesday dragging a cold front across
the local area. The low will move well northeast of the region on
Near term /until 6 PM this evening/...
some clearing has occurred over Northwest Ohio but it appears
clouds will spread back over the area shortly. It is supposed to
dry out at low levels later today and this should finally allow
the persistent overcast to begin to break up. Partial clearing
should occur in the south and far west first. Temperatures will be a
couple degrees warmer than Saturday.
Short term /6 PM this evening through Wednesday night/...
I was hoping the models would begin to come into better agreement
but once again I am disappointed. The new GFS appears to be the
outlier today and has been discarded. The European model (ecmwf) and other guidance
have only been marginally more consistent. The best guess for today
is a warm front lifting north across the region late Monday and
Monday night. Will see rain chances increase from west to east Monday
night through Tuesday as this occurs. Northwest PA could realistically remain
dry through sunset on Tuesday. Will ramp precipitation chances up to the
categorical category for Tuesday night all areas as moisture and
warm air advection really get going. Tuesday should see highs
reaching 50 degrees most areas with little drop off Tuesday night.
Surface dewpoints will get well into the 40s and may eventually
need to add some thunder to the forecast. For Wednesday...the
latest best guess is to have a low move northeast across Ohio. A
trailing cold front will move east of the forecast area by late
Wednesday evening. The 00z European model (ecmwf) is showing 8 to 10 degrees of
cold air advection at 850 mb between 12z and 00z with another 5 or
6 degree drop off by 12z Thursday. Critical thicknesses remain
warm enough for rain during the daylight hours but should see a
transition to snow from west to east Wednesday night. The precipitation
Wednesday night will not be as widespread behind the frontal passage
so will just go with snow showers. Some light accumulations could
occur on mainly grassy areas as Road temperatures should be still
warm from two days in the 50s. Will end up going with morning
highs Wednesday and then falling temperatures. The threat for
strong winds does not appear to be as great as it did earlier as
the low is not forecast to be quite as strong.
Long term /Thursday through Saturday/...
no matter which model you use...by 12z Thursday all precipitation
will have transitioned to snow. Both models quickly bring an end to
snow Thursday night as weak ridge moves quickly across the area.
After this models diverge. European model (ecmwf) develops a secondary low which
tracks into the Central Lakes dragging another cold front across the
area on Friday. The GFS on the other hand is much slower pushing a
cold front across the area Friday night into Saturday. Trended
toward the slower GFS bringing in chance probability of precipitation for precipitation late Friday
Aviation /12z Sunday through Thursday/...
stratus deck under dirty ridge extends west to Iowa. That said
clouds are eroding from south...and has reached Northwest Ohio. Do
expect MVFR clouds to gradually rise too VFR today...but probably
not until late afternoon for widespread VFR conditions to return.
Outlook...non VFR possible late Monday into Thursday.
models in good agreement on the lake forecast in the short term but
by middle week models begin to diverge. Models in good agreement with
large area of high pressure over the eastern lakes drifting into the
Canadian Maritimes late Monday. As it does the winds will turn to
the south and remain southerly through Wednesday as a low pressure
system moves across the western lakes. After that things not so
clear. European model (ecmwf) continues to track low NE across the Central Lakes
Wednesday while GFS backs off now until Wednesday night. Low is
weaker in both models today than ydy so only have winds forecast to
30 knots...but potential still remains for gales late Wednesday into