608 
fxus61 kcle 220437 
afdcle 


Area forecast discussion 
National Weather Service Cleveland Ohio 
1137 PM EST Friday Nov 21 2008 


Synopsis... 
high pressure over the plains states will move to the Tennessee 
Valley on Saturday and the East Coast Sunday. A cold front from the 
northern plains will sweep across the area on Monday. 


&& 


Near term /until 6 am Saturday morning/... 
flow has become well aligned producing some intense lake effect 
snow bands with embedded lightning in the bands. The heaviest 
bands are located over Cuyahoga County and appears to be morphing 
into one large band over the entire County. Another band extends 
inland over Eastern Lake County into Ashtabula County. An intense 
band also extends inland across eastern Erie County Pennsylvania 
that appears to be shifting southwest and increasing in 
intensity. The Erie band and the one over Cuyahoga County appear 
they are dropping snowfall rates of up to 2 inches an hour. 


The snow bands will continue as moisture from Lake Michigan and 
Lake Huron continue to feed the area with deeper moisture. As high 
pressure tries to build in across the Ohio Valley...the mean flow 
should try to shift to a more westerly component. This will place 
the bands more along the Lake Shore by morning. 


Will continue with lake snow warnings and advisories where they 
are currently in effect. 


Temperatures are already in the lower 20s over most areas and 
current forecast of teens away from the lake look good. So will 
not be making any temperature adjustments at this time. 


&& 


Short term /6 am Saturday morning through Monday/... 
not sure exactly how the short wave prognosticated to cross the Midwest on 
Saturday will affect the local weather...particularly the lake 
effect. Ridge axis will not cross the area until Sunday morning 
but there will likely be subsidence developing and increasing low 
level wind shear and continued backing of the wind. Inversion 
prognosticated to lower from west to East. Lake Huron contribution should 
account for the heaviest snow and should shift mainly to northwest PA 
Saturday and into West New York Saturday night. Current forecast takes 
this into account. Should see the lake effect taper off across the 
NE Ohio snowbelt and shift mainly to northwest PA by Sat night. Elsewhere on 
Saturday...will likely see an increase in high clouds. With the low 
sun angle...will call it "becoming mostly cloudy". Maximum temperature 
guidance is too warm Saturday as current temperatures to our west are 
mainly in the 20s. 


Sunday should be nice...especially relative to recent weather. High 
pressure will be sliding by and SW flow will develop. Some high 
clouds will spread into the area but hoping they will be mostly 
thin. Forecast maximum temperatures will be close to the GFS/mav maximum temperature 
guidance which is the cooler of the maximum temperature guidance. 


GFS is faster with the showers ahead of the next cold front on 
Monday. It makes a difference in whether precipitation may start as snow or 
rain/snow mixed or perhaps even a little freezing rain across Northwest 
Ohio early Monday morning. Precipitation should hold off long enough across 
NE Ohio/northwest PA that things will likely warm up except perhaps inland 
northwest PA where some mixed rain and snow possible. 


&& 


Long term /Monday night through Friday/... 
models in good agreement developing another deep trough over Lake 
Erie by Tuesday with 850 temperatures dropping to -6 to -8 range. Series of 
troughs will rotate across the area Tuesday and Wednesday too far 
out to pin down timing of precipitation. Majority of the the snowfall will 
again be in the snow belt...with another lake effect event possible 
into Wednesday night. Models do try to move ridge of high pressure 
over the area Thursday into Friday...but the timing varies 
somewhat. Leaned toward the slightly faster European model (ecmwf) and ensemble 
instead of the slower GFS run. Expect temperatures to rebound into 
the 40s by day 7. 


&& 


Aviation /06z Saturday through Wednesday/... 
lake effect snow showers continuing from cle east. The snow 
showers over northwest and north central Ohio have decreased. 
The tough area is northeast Ohio and northwest PA...trying to 
figure out exactly where the bands will be. No real short 
wave...the airmass will slowly try to dry out. The flow off of 
Lake Huron will continue into northwest PA through Saturday. In 
Ohio the bands are trying to decrease especially near cle. However 
according to the models a band of lake effect may develop from 
Lake Michigan to near cle and then into northeast Ohio. On the 
edge if the band will develop and if it does where it will be 
located will it be over cle or south of cle. VFR condition west of 
cle with VFR to LIFR conditions elsewhere...lowest conditions in snow 
showers. Snow showers will begin to decrease Saturday afternoon 
and evening as high pressure builds in. 


A break going on at cle at this time but if the winds becomes more 
290 degrees aloft that may shift the snow showers band back over 
cle. For the overnight occasional snow showers with the visibility 
briefly down to 1 or 2 sm. From 05z through 13z 1 to 2 inches of 
additional possible at cle. Confidence is low. 


Outlook...high pressure moves over the area into Sunday with VFR 
conditions. Another cold front is anticipated for Monday as 
deepening low pressure moves east across the region. Conditions 
may begin to improve over western Ohio Tuesday with lake effect 
snow showers continuing over the eastern portion of the forecast 
area through Wednesday. 


&& 


Marine... 
things have begun to quiet down on the lake but it will take another 
24 hours before we can get rid of the small craft. A ridge is 
expected to move across the lake on Saturday afternoon which will 
cause the winds to become SW from west to east. This will allow the 
waves to finally subside. The SW flow will gradually increase on 
Sunday and Sunday night ahead of the next system. A clipper type 
low still on track to dive southeast across the eastern lakes on 
Monday. Winds will become northwest and increase during the day Monday 
behind an Arctic cold front trailing the low. Northwest winds could get 
close to gale on Tuesday as a strong push of cold air arrives 
aloft. High pressure will try to build over the lake from the SW on 
Wednesday which allow wind speeds to diminish considerably. Lake 
effect snow bands will remain over the lake through Sat afternoon 
with more snow expected with the system on Monday. 


&& 


Cle watches/warnings/advisories... 
Ohio...Lake effect snow warning until 4 am EST Saturday for 
ohz011>013-022-023. 
Lake effect snow warning until 4 PM EST Saturday for ohz014- 
089. 
Lake effect Snow Advisory until 4 am EST Saturday for ohz021- 
033. 
PA...lake effect snow warning until 4 PM EST Saturday for 
paz001>003. 
Marine...Small Craft Advisory until 3 PM EST Saturday for lez142>149. 


&& 


$$ 
Synopsis...kosarik 
near term...Lombardy 
short term...kosarik 
long term...djb 
aviation...kieltyka 
marine...kubina 

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