Scientific Forecaster Discussion
fxus61 kcle 291141
Area forecast discussion
National Weather Service Cleveland Ohio
741 am EDT Sat Apr 29 2017
a warm front across the southern half of Ohio will move north
across the local area tonight. Strong low pressure over the
plains early Sunday will move north to Wisconsin by midday
Monday and eventually into Quebec by late Tuesday. A cold front
from this low will move across the local area on Monday.
Near term /until 6 PM this evening/...
tough forecast today with precip timing and coverage a real
challenge. Had hoped to find some windows of dry weather today
but that will be tough to do. Southern areas especially will see
good chances for more showers with embedded thunder as the
surface warm front remains near the I-70 corridor. All of the
guidance shows another wave of precipitation developing along
the front well southwest of here by daybreak. This blob for
lack of a better term should then slide east across the local
area this morning. There could be a sharp cutoff of the precip
on the north side but not confident enough to forecast that.
Will end up with likely or higher pops all areas today. The warm
front will try to edge it's way north into the area by late
today. This will result in a fairly substantial temperature
gradient across the area. Have stayed fairly close to guidance.
Northeast flow off of the lake will result in a chilly day
across the immediate Lakeshore.
Short term /6 PM this evening through Tuesday night/...
the warm front will advance north across the area tonight and by
daybreak Sunday it should be gone. It will take precip chances
with as it GOES. Will need to leave a mention in all areas this
evening but will begin to dry things out from the south late
tonight. Most of the day Sunday should be dry. Have left some 20
pops in much of the area for coordination purposes but would
really be surprised to see any precip except across Northwest Ohio later
in the day. The clouds should also thin some during the day with
partial sunshine likely...especially in the south. 850 mb temps
will get to plus 17 much of the area so highs well into the 80s
seem reasonable. Precip chances will increase from west to east
Sunday as the cold front from the low off to the northwest advances
across the area. Not sure how far east this precip will get by
daybreak Monday but at least the western half of the area will
see precip tomorrow night. Even in the far east chances are
Worth a mention prior to 12z Mon. The surface cold front should
be near I-75 at daybreak and will move into western PA around
21z. Showers are likely till the front crosses the area. By
daybreak Tuesday 850 mb temps will be back below zero celsius
so there is going to be a dramatic airmass change. Instability
showers are likely Monday night all areas and downwind of the
lake Tuesday into Tuesday night. Given the changing airmasses
during the period have stayed close to guidance temps which are
in decent agreement.
Long term /Wednesday through Friday/...
period will be characterized by below to near normal temps as broad
eastern Continental U.S. Trough will hold in place late next week. Deepening
wave will eject and close off from the Southern Plains through the
eastern Continental U.S.. models still vary quite a bit with cutoff upper
low/surface low development and track, as well as temperature
profile. Generally kept pops and temps similar to previous forecast,
however did bump pops up to likely along and south of an Upper
Sandusky to Meadville PA line as converging model solutions yield
Aviation /12z Saturday through Wednesday/...
quasi-stationary boundary lingering across the region will
affect be a focus for low ceilings and showers through the first
half of the taf period. Lower confidence with respect to timing
of precip and ceiling heights. Most of the precip potential will
be from around 14z through 21z or so as a low moves along this
front. Some embedded thunder is possible, especially at kmfd
and kcak, but not enough confidence to include in taf based on
observational trends. Lower ceilings may linger along the
boundary through the day and tonight, with some improvement
possible for a short time this evening north near Lake Erie.
Outlook...non-VFR and scattered showers possible Monday through
cold front will sink south across Lake Erie early this morning.
Winds will pick up out of the north to around 10-15 knots this
afternoon across the western half of the lake. Winds will back
northeasterly tonight into early Sunday as low pressure deepens and
approaches the lake from the southwest. Winds may reach 20-25 kts
but gales are not expected. The low will force a warm front north
across the lake Sunday with winds backing southerly and eventually
southwesterly by Monday afternoon as a cold front through. Gales are
possible across the lake on Tuesday.