fxus61 kcle 190148
area forecast discussion
national weather service cleveland oh
948 pm edt fri sep 18 2020
a high pressure center moves from the upper great lakes to southern
quebec and strengthens through this weekend. simultaneously, the
associated ridge affects our region.
.near term /through saturday night/...
westerly flow aloft becomes progressively northwesterly over our cwa
through the period. simultaneously, a longwave trough over eastern
canada, the great lakes, and the northeast united states moves
eastward very slowly as a longwave ridge builds from the west. at
the surface, a ridge affects our region as the embedded high
pressure center moves from the upper great lakes to southern quebec.
fair weather is expected through the period.
skies should trend mainly clear through the period. however, as
a cold low-level flow crosses lake erie, lake effect stratocumuli
will stream south-southwestward from the lake through this
early evening and then southwestward overnight tonight into
saturday morning. limited or no lake effect cloud cover is
expected saturday afternoon through saturday night as subsidence
strengthens over our area. no precip is forecast to accompany
the lake effect clouds since limited moisture and sizable
directional shear in the low-levels should allow dry air
entrainment to curb lake-induced instability.
tonight will be chilly, with low temperatures reaching the 30`s in
many locations inland from lake erie. patchy frost may develop where
low temperatures reach the mid 30`s around daybreak. however, more
widespread frost is expected to form in southern erie and crawford
counties in pa, and in southern ashtabula, trumbull, and mahoning
counties in northeast oh. widespread lows in the lower to mid 30`s
are expected in these areas and a frost advisory is in effect from
12 am to 9 am edt saturday morning. relatively-warmer low
temperatures in the 40`s are expected along and very near the lake
below-normal afternoon high temperatures in the upper 50`s to mid
60`s are expected on saturday. saturday night should be colder as
very light or calm surface winds contribute to efficient radiational
cooling. widespread low temperatures in the 30`s are expected inland
from lake erie, which should be accompanied by more extensive frost
formation. additional frost-related headlines will likely be needed.
somewhat warmer low temperatures in the lower to mid 40`s are
expected along and very near the lake erie shore.
.short term /sunday through monday night/...
high pressure will persist over the area through the short term
period. the only concern during this forecast period is for the
possibility of frost headlines overnight sunday and monday.
currently, forecasted overnight lows drop down into the mid to upper
30s, with the lowest temperatures focused in northeastern ohio and
northwestern pennsylvania. with the high pressure in place, mainly
clear skies may lead to temperatures being slightly cooler than
currently forecasted based on guidance. these temperatures will need
to continue to be monitored as they move into the near term forecast
period. currently, the best chance for frost remains across
northeast ohio and inland areas of northwest pennsylvania.
.long term /tuesday through friday/...
the long term forecast will continue to remain quiet as the high
pressure remains over the area through wednesday. temperatures will
remain cool on tuesday with highs in the high 60s to low 70s. as the
high pressure moves off the east coast, warm air advection will
increase over the area as winds become southwesterly on wednesday
and temperatures will again begin to increase. high temperatures on
wednesday will be in low to mid 70s. on thursday, an upper level
trough and surface cold front will move across the area, although it
is uncertain how much moisture will be present over the area. the
amount of moisture will be the deciding factor if the area gets any
appreciable precipitation. for now, opted to keep chance pops for
thursday afternoon and evening, although models are trending with
the trough keeping the front just north of lake erie.
.aviation /00z saturday through wednesday/...
surface high pressure continues building in from the northwest,
currently centered over michigan. the surface high pressure will
be centered over southern ontario by tomorrow afternoon.
scattered lake effect clouds are expected to continue streaming
south-southwestward from lake erie early tonight before
becoming more southwest overnight and through the day saturday.
occasional mvfr ceilings may accompany the lake effect clouds,
which could impact kcle, keri, and ktol. cloud cover dissipates
by saturday evening.
outlook...non-vfr in patchy fog possible around daybreak and
inland from lake erie sunday through tuesday.
current marine headlines will persist through early tomorrow morning
for portions of the central basin as northeasterly winds persist at
20 to 25 knots creating waves 3 to 6 feet. by saturday morning,
winds will shift to more easterly and weaken to 10 to 15 knots and
are expected to persist through sunday. winds will then begin to
veer on monday and become southwesterly by tuesday, remaining at 10
to 15 knots. there are no additional marine headlines anticipated in
oh...beach hazards statement until 4 am edt saturday for ohz009>012.
frost advisory until 9 am edt saturday for ohz014-023-033.
pa...frost advisory until 9 am edt saturday for paz002-003.
marine...small craft advisory until 4 am edt saturday for lez144>147.