Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
106 am EDT Wednesday Jul 1 2015
a weak trough of low pressure will cross the area overnight and
Wednesday morning. High pressure will move across the Great Lakes
Thursday and Friday. A reinforcing push of high pressure should
build across the eastern Great Lakes this weekend.
Near term /until 6 am this morning/...
the trough was still working its way across the forecast area. By
morning it is prognosticated to be strung along the east Lakeshore and
expect the better chance for showers and thunderstorms to work
into the snowbelt during the early morning hours. There should be
a gradual weakening due to the time of day but with the cool air
aloft some of the showers will survive. There may be very little
thunder left by daybreak. Lows within a few degrees of 60 with 55
to 60 possible mainly where the air was rain cooled and we get
some clearing...mostly likely across Northwest Ohio.
Short term /6 am this morning through Friday night/...
the last piece of jet energy should pass on Wednesday with a cold
front dropping southward across the area during the evening and
overnight hours. Still a threat of showers and thunderstorms ahead
of the front but it does appear the main focus with shift
southward through the day. A little drier so having a hard time
more than a slight chance...maybe chance across northwest PA and extreme
High pressure ridge into the area Wednesday night into Thursday
eventually being centered over the central Great Lakes by Friday
morning. This should mean drier for the region and no new
Middle 70s are expected Wednesday and Thursday. Warmer on Friday
with highs int eh upper 70s to near 80.
Long term /Saturday through Tuesday/...
low pressure will be passing south of the forecast area on Saturday
as high pressure broadens across the lower Great Lakes region. Best
chance of showers Sat will be in the south. A migratory shortwave
ridge aloft will be passing over the area Sat night...so with high
pressure at the surface...kept probability of precipitation low. The GFS is a bit slower than
the ec to break down the shortwave ridge...and keeps things dry
through sun. The ec pushes in the next trough much faster...and
deflects the shortwave ridge downstream in advance of a shortwave
trough. Given the disparity in timing between the models going with
just a slight chance rain/thunder into Sun night. Beyond this point
the models diverge big time. The ec shows a high amplitude trough
extending from a low at 500 mb...with the main axis extending south
across the north central third of the Continental U.S.. in light of the current
pattern...this forecast leans towards the ec instead of the
drier/slower GFS. However...not calling for a wash out. Just
increased probability of precipitation a bit into the low chance category.
Aviation /06z Wednesday through Sunday/...
upper trough across the Great Lakes touching off thunderstorms from
east of kcle. This north/south line will continue east and though
be east of kyng and Keri by 09z. Elsewhere patchy MVFR ceilings are
filling in and will need to carry MVFR and IFR ceilings into the
morning along with fog/mist. After 14-15z or so all MVFR or lower
should burn off with drier air moving in. Could see VFR ceilings
around bkn050 hang on into the early afternoon but the trend will
be towards decreasing clouds as high pressure builds toward the
low pressure will gradually clear the region over the next day with
the wind mostly out of the west across the lake. Wednesday night the wind
picks up from the southeast along the long fetch of the lake behind the low
with wave action increasing to near 4 feet in the nearshore along
NE Ohio/northwest PA beaches. Small craft may be needed. High pressure
will Bud across northern Michigan and gradually spread southeast
through the weekend with waves generally 2 feet or less in the