Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
122 am EDT sun Jul 31 2016
low pressure will move slowly east across the forecast area through
the remainder of the weekend. High pressure will build over the
region through the middle part of the week.
Near term /until 6 am this morning/...
with the surface low centered over Ohio will keep low chance pops
going through the overnight. Convection has diminished considerably
since sunset to just went isolated thunderstorms and rain. Rest of forecast looks
reasonable for 930 update.
Original discussion... surface low pressure will slowly move
across forecast area overnight. Scattered showers and
thunderstorms have developed over the area due to a combination of
surface heating and an upper level short wave. The showers will
continue to increase in coverage late this afternoon and early
evening, eventually decreasing overnight. Guidance shows the bulk
of the showers should move into northeast Ohio and northwest PA
this evening. I will gradually decrease the probability of
precipitation through the night. Isolated areas of heavy rain are
possible as these storms will move slow and dew points remain
around 70. Guidance temperatures appear to be on track.
Short term /6 am this morning through Tuesday night/...
the surface low pressure system and upper level trough will linger
over the forecast area on Sunday. Precipitation is expected to
develop with the day time heating similar to today. Upper level
support is weaker than today so I expect the coverage of the showers
and thunderstorms to be less. The low will work to the east late
Sunday into Monday. A few showers may linger in the northeast part
of the area late Sunday night and early Monday but the coverage
should be minimal. High pressure will build over the region late
Monday and remain through Tuesday. A warm front will advance
toward the region late Tuesday night. I have elected to hold off
on any mention of precipitation for Tuesday night as any
precipitation chances would be very late in the period.
Long term /Wednesday through Saturday/...
temperatures will be warming again during the period. The upper
pattern will become fairly zonal with numerous weak waves in the
flow. The models...especially the GFS seem to be suffering from
convective feedback today so timing of the precip chances remains a
challenge. There could be a few storms in the west on Wednesday but
better chances will come late Thursday night into Friday night as a
cold front sags south across the area. Both the GFS and European model (ecmwf) show
this scenario so will stick with the high chance pops that were in
the previous forecast. It should dry out on Saturday.
Have kept high temps out of the 90s for the end of next week as 850
mb temps will only get to around plus 18. If the convection fails
to materialize on Friday or it is slower to arrive then
expected...highs will need to be raised some.
Aviation /06z Sunday through Thursday/...
big question is when and where will the showers and thunderstorms
develop? Activity is widely scattered and when it develops it
pretty much collapses where it began or moves very little. Winds
aloft are extremely light. Expecting possibility for low clouds
and some lower visibilities to develop over the next few hours
across the forecast area. Some improvement will take place across
the area during the day but still expecting VFR ceilings to hang
around. Gradual clearing will take place later in the evening as
storm system pulls out to the east. Generally light winds through
Outlook...non-VFR possible Monday morning.
light and variable winds will continue during the period. Lake
breezes are likely in the nearshore waters during the afternoon most
days. Conditions for will be ideal for recreational boaters during
this time period. Scattered thunderstorms could be a threat on the
lake through Sunday morning but dry weather is expected the rest of
the period. We should not need any headlines during the period.