Area forecast discussion
National Weather Service Cleveland Ohio
412 am EDT Tuesday may 21 2013
Synopsis...
the air mass will become increasingly moist and unstable through middle
week as an area of low pressure over the upper Midwest slowly
approaches the region. This low pressure system will track through
the eastern Great Lakes late Wednesday and push a cold front south
across the area on Thursday. High pressure will return for the end of the
week.
&&
Near term /until 6 PM this evening/...
the area of showers and thunderstorms was weakening as it was
moving northeast toward the area this am. Some showers and
thunderstorms could occur over Northwest Ohio this morning as the
system lifts off to the northeast. Some middle and high clouds will
continue to overspread the area this morning and then thin. We
should have some thunderstorm activity but the question is how
much...with the moisture between 1000 and 700 mb not that high.
With some morning clouds the convective available potential energy may not get that high. We do
have a trigger... a short wave which will be moving through the
region this afternoon and evening. Some of the thunderstorms could
be severe or approach severe limits. Forecasted likely west and
scattered east. Went with the warmer MOS guidance for
highs...excepting some sun. It will be humid.
&&
Short term /6 PM this evening through Friday night/...
some left over showers and thunderstorms in the evening and then
the area should be in a lull for much of tonight and then waiting
for the next system to affect the region for Wednesday into
Wednesday night. This will be the day with the best chance of
severe weather. The cold front moves through on Thursday. Friday
should be dry and cool with high pressure building in.
The temperature forecast is tough...especially the highs. If the
showers and thunderstorms develop early or if we have a lot of
debris clouds that will affect the highs. Used a blend of guidance.
&&
Long term /Saturday through Monday/...
models in disagreement in the extended. GFS continues with Canadian
high pressure over the entire area through the weekend. The European model (ecmwf)
on the other hand has another front push through the area on
Saturday...and is thus wetter and cooler. Since the GFS has been
consistent with this solution ignored the European model (ecmwf) and went with the
GFS forecast. This will result in dry northerly flow for the area
for the entire weekend and slightly below normal temperatures.
&&
Aviation /08z Tuesday through Saturday/...
little change in previous tafs. Again expect some MVFR br toward
daybreak...could see some IFR or MVFR stratus as well extreme NE
Ohio/northwest PA. Expect scattered thunderstorms and rain this afternoon...confidence is low
exactly when or where. For now left tempo groups for afternoon thunderstorms and rain.
Debris clouds from convection over Illinois and Indiana may
inhibit development over US until this evening. Models hint at
that with convective available potential energy of only 1000-1500 j/kg over area this afternoon.
Much better chance of organized convection Wednesday afternoon.
Outlook...non VFR probable in showers/thunderstorms Wednesday and
Thursday.
&&
Marine...
south to southwest flow will continue on the lake through middle week.
Models have been consistent with the next system moving across the
lake on Thursday. Small Craft Advisory will be needed as north to
northwest winds increase to 15 to 25 knots in colder air. The 850mb
temperatures dip to 2c by the weekend. Strong to severe storms appear
possible both today and Wednesday. Boaters will need to remain
alert.
&&
Cle watches/warnings/advisories...
Ohio...none.
PA...none.
Marine...none.
&&
$$
Synopsis...kieltyka
near term...kieltyka
short term...kieltyka
long term...djb
aviation...djb
marine...djb
