000
fxus61 kcle 020526
afdcle
area forecast discussion
national weather service cleveland oh
1226 am est thu feb 2 2023
.synopsis...
high pressure will gradually move into the mid atlantic tonight
and offshore thursday allowing an arctic cold front to dive
south across the lower great lakes region thursday night. arctic
high pressure will build over the region late friday then
gradually shift east over the weekend.
&&
.near term /through today/...
the lake-effect clouds are finally shifting northward as of mid
afternoon as the flow backs in response to broad surface high
pressure building northward into the lower great lakes. this has
left all areas mostly sunny except for extreme ne ohio and nw pa
where mid-level clouds linger. current temperatures range from the
mid to upper 20s, so don`t let the sun fool you, it is still quite
cold!
warm air advection will start up tonight ahead of a broad northern
stream mid/upper longwave trough pressing southward from the
northern plains and upper great lakes and a southern stream
mid/upper shortwave trough progressing into the southern plains. sw
flow ahead of these features will be enhanced by the surface high
beginning to slide into the mid atlantic, so only expect
temperatures to fall to the 15-20 range tonight despite skies
remaining clear. the sw flow and resultant warm air advection will
further strengthen thursday as the broad northern stream mid/upper
trough axis digs into the central great lakes, eventually absorbing
the southern stream mid/upper trough by thursday night as full
latitude troughing carves out over the eastern conus. the associated
arctic frontal boundary dropping southward will reach southern lower
michigan and southern ontario by thursday evening, but strong warm
air advection ahead of this boundary will boost highs into the
mid/upper 30s. most areas will stay dry through the day, but
increasing frontogenetic forcing and height falls as the front
approaches from the nw could bring a few rain/snow showers into far
ne ohio and nw pa by evening.
thursday night looks to be the main show as the arctic frontal
boundary crosses the region and the big trough carves out across the
eastern conus, bringing a short duration nw flow and blast of deep
arctic air to the eastern great lakes region. moisture advection
ahead of the front will be mostly cut off by the southern stream
energy traversing the deep south, but the sharp height falls and
strong frontogenetic forcing aided by a 170-180 knot h3 jet will
lead to a band of snow showers pushing nw to se. the front looks to
cross in the 02 to 05z timeframe, so the convergent band of snow
showers will coincide with this frontal passage. there will be some
instability along the boundary aided by 850 mb temps quickly
dropping below -15 c over the relatively warm lake, but the best
moisture convergence along the boundary will be over western and
central new york, with ne ohio and nw pa only catching the trailing
portion of the boundary lessening the convergence. this along with
very dry air above 5000 feet should reduce the depth of convection
and limit any potential for thunder snow, and the snow squall
parameter from the wrf-arw is in agreement with this. kept thunder
out of the forecast, but still expect a burst of snow showers with
the front which could put down a quick inch or two. the greatest
coverage will be over the primary snowbelt of ne ohio and nw pa. by
the pre-dawn hours of friday, a well-aligned nw flow, strong cold
air advection, and 850 mb temps falling to -23 c will set up
multiple bands of lake-effect snow showers. the organization will
again be limited by a lot of mid-level dry air, which when combined
with a short nw fetch, often reduces the coverage of snow showers,
but equilibrium levels rising to near 9000 feet by friday morning as
the cold air deepens and moderate lake induced cape values
approaching 600 j/kg combined with the well-aligned boundary layer
flow will get at least light lake-effect going. both the primary and
secondary snowbelts should see an additional 1-2 inches through
friday morning in the typical upslope areas well inland (little to
none at the lakeshore). the wild card continues to be the lake huron
connection. this will likely waver between ashtabula and
erie/crawford counties, so locally 3-6 inches is possible there. the
snow will be very fluffy with 20:1 to 25:1 snow ratios, so feel
confident on these amounts despite the above mentioned
negatives.
&&
.short term /tonight through saturday night/...
deep upper level troughing will exit to the east friday allowing an
upper level ridge to build slowly east out of the plains states.
this should allow surface high pressure just west of the area to
produce strong cold air advection over the local area friday into
saturday morning. eventually, as the surface high moves east over
the region, strong cold air advection will come to an end. ahead of
the high, there should be some residual lake effect snow expected
over the northeast snowbelt counties friday into friday evening.
eventually, flow shifts up toward buffalo and this should bring an
end to the lake effect precipitation. otherwise, fair weather
should be the rule across the rest of the area friday into saturday
night under the influence of the high. some of the guidance suggest
highs may not even get out of the single digits friday across the
area in the strong cold air advection but consensus suggests highs
in the teens so will stay close to this trend. otherwise, overnight
lows should drop into the single digits friday night. high pressure
will return warmer air back to the area saturday and should push
temperatures back into the 30s for highs as 850 mb temperatures
recover from -20c to 0c west and -6c east. rapid warm up will take
place.
&&
.long term /sunday through wednesday/...
weak ridge of high pressure builds east across the area resulting in
surface high pressure that is expected to move east from the local
area to the east coast. another rather fast moving shortwave trough
is expected to slide east into the region during this forecast
period and then exit east by early next week. this trough will be
quickly followed by an upper level ridge and subsequent upper level
shortwave by mid week in the fast moving flow. as a result, a weak
wave of low pressure should move through the great lakes by sunday
night with associated moisture and a threat for rain. a surface
ridge and drier air should then affect the local area by monday
ahead of a cold front monday night with another shot for some
precipitation extending possibly into wednesday. after this next
cold shot exits the area, a considerable warm-up is in store for
this forecast period in the mild nearly zonal flow.
&&
.aviation /06z thursday through monday/...
vfr conditions across the taf sites early this morning with vfr
to persist through today. deterioration to mvfr ceilings
areawide will occur by later this evening and overnight. brief
ifr vsby drops from bursts of snow associated with an arctic
cold front are possible across the eastern taf sites, including
cle/cak/yng/eri after 0z.
south to southwest winds are generally 10 knots or less early
this morning. winds will become more southwest later this
afternoon, increasing to near 15 knots with gusts of 20 to 25
knots possible. winds will abruptly shift towards the northwest
behind the cold front later this evening and overnight, with
wind gusts of 25 to 30 knots possible.
outlook...periods of snow with non-vfr possible on friday,
mainly across ne oh and nw pa. non-vfr may return on sunday in
scattered rain and/or snow showers.
&&
.marine...
winds will be gradually increasing through the night into tomorrow
from the southwest and expect to see peak winds sustained to 30
knots on the lake by thursday afternoon. cold front slips southeast
across the area thursday night and winds shift to a northwest
direction through friday. a shift to a westerly direction is then
expected as high pressure builds east across the area friday night
and winds diminish. weak low pressure will track southeast to the
great lakes and setup a southwest flow saturday night and continue
through sunday. a cold front slips southeast and shifts flow to a
more westerly direction for monday. small craft advisory will remain
in effect where currently issued but will extend small craft further
west to the central basin thursday morning through friday night.
&&
.cle watches/warnings/advisories...
oh...none.
pa...none.
marine...small craft advisory from 10 am this morning to 4 pm est
friday for lez144-145.
small craft advisory from 10 am this morning to 1 am est
saturday for lez146-147.
small craft advisory until 1 am est saturday for lez148-149.
&&
$$
synopsis...garuckas
near term...garuckas
short term...lombardy
long term...lombardy
aviation...kahn
marine...lombardy