Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
709 PM EDT sun Mar 29 2015
a cold front will move east across the area tonight then a clipper
low will track across the region Tuesday. High pressure briefly
builds in for Wednesday. Low pressure will track north of the
lakes Thursday and pull a trailing cold front through the region
late Thursday night.
Near term /through Monday/...
the precipitation type in the text portion of the forecast is a
bit of a mess. As I see it... the initial batch of showers will
push east across the area this evening. The northern counties have
a chance of also seeing wet flakes and perhaps some sleet pellets
with the evaporational cooling. The front is still a ways
back...not even to Chicago at 6 PM. We lose most of the deeper
moisture after the initial batch of precipitation. We may be able
to regenerate showers as the front moves east but we may also end
up with a few sprinkles or some drizzle with the actual frontal
passage. The atmosphere will have warmed up enough at that point
for less risk of any frozen precipitation.
Little risk for snow accumulation except for perhaps a slushy
coating on grassy surfaces. Do not see roadways being a problem
after today's sunshine and lows expected to stay above freezing.
Winds gusting 30 to 40 miles per hour should begin to diminish after frontal
passage as the strong low level jet ahead of the front slides off
to the east.
Short term /Monday night through Wednesday night/...
low level moisture hanging on in the snowbelt on Monday will probably
allow for some light rain or snow showers to linger there while the
rest of the County Warning Area should be dry as high pressure moves up the Ohio
Valley. Little or no accumulation is expected.
Temperatures will stay below normal Monday...especially in the NE where clouds
will tend to persist.
A clipper low remains on track to drop east-southeast across the area on Tuesday.
Once again...precipitation type will be in question as the exact track of
the low will likely determine the main precipitation type for the NE third
of the County Warning Area. Where more snow may occur in northwest PA during this
event...guess is that some areas could see up to 2 inches of
accumulation. Highs on Tuesday will likely show a good range from colder
than normal around eri on the north side of the track of the low to
a little warmer than normal in the far SW on the other side of the
A little lingering light precipitation may occur for a while into Tuesday night
in the east but high pressure and dry air move in later in the
night. With the high moving in and calming the wind the lows could
be unseasonably cold Tuesday night where any snow cover exists but won't
get too extreme with lows as there is indication that high clouds
from the next system may begin to move in.
The high should start to shift east of the area by the end of the
day on Wednesday but probably not quick enough to get a lot of temperature
moderation especially if enough high clouds spill into the area.
A low level southerly jet should be developing into the County Warning Area Wednesday
night so moisture will be on the increase along with warm advection.
Probably will be a situation where the lows occur early in the night
then temperatures warm as south winds pick up and clouds increase. Not sure
how far east the threat for precipitation will spread into the County Warning Area but
right now it looks like just the west will have any threat.
Long term /Thursday through Sunday/...
active weather will continue during the long term period. The
period will start with an approaching cold front. Temperatures will likely
make it into the 60s Thursday ahead of this front with dew point
creeping toward 50. Some upper support for convection so will
likely see a line of showers and perhaps the first thunderstorms of
the Spring. The new European model (ecmwf) is much slower with the front than the
GFS so timing issues remain. For now will stick with chance probability of precipitation
both Thursday and Thursday night with best chances probably Thursday
evening. The surface cold front is expected to stall across the
Ohio Valley with another wave of low pressure developing along it.
Because of this will need to keep chance probability of precipitation going into at least
early Saturday. Hopefully later model runs will come into better
agreement allowing further fine tuning of the precipitation forecast. High
pressure will dominate much of the weekend with a return to quiet
and cool weather.
Used a blend of guidance for the temperature forecast.
Aviation /18z Sunday through Friday/...
few showers with the warm front across central Illinois and SW
Indiana. Front will lift NE of the area this evening producing a
few showers. Hourly precipitation amounts barely more than a hundredth an
hour. Should be rain everywhere except possibly extreme NE Ohio/northwest
PA where it could be rasn. Cold front currently near Iowa/Illinois
border...will move across the area after midnight tonight. Not
much behind the front but could see some lake enhanced clouds in
the east behind the front.
Winds will remain from the west with gusts near 30kt until frontal passage
when the winds turn to the west.
Outlook...periods of non VFR Monday morning...Tuesday and then
again on Thursday.
not many changes to the lake forecast today. Got a good look at the
lake on satellite and the ice on the west end continues to break
up. Still expecting increasing S to SW flow on the lake tonight
ahead of an approaching cold front. Some shifting in the ice fields
is likely and could even see water open up along along the south
shoreline. Winds will become westerly behind the front. Will stick
with 30 knots for now which seems reasonable. The westerly flow
will continue into Monday night when a surface ridge crosses the
lake and flips the flow back to the SW. A clipper is still set to
dive southeast across the region on Tuesday with a return to northerly
flow. High pressure will build in for the middle of the week with
light flow. Another strong cold front is expected for Thursday.
Increasing SW flow is expected ahead of this feature. West to
northwest is then expected behind the front for the end of the