450 
fxus61 kcle 220841 
afdcle 


Area forecast discussion 
National Weather Service Cleveland Ohio 
341 am EST Sat Nov 22 2008 


Synopsis... 
high pressure centered over the lower Ohio Valley with a ridge 
extending north through the western Great Lakes will move through 
the Tennessee Valley today and to the East Coast on Sunday. A cold 
front from the northern plains will sweep across the area on Monday. 


&& 


Near term /until 6 PM Saturday morning/... 
lake effect snow showers continued overnight though decreased in 
intensity over much of the area as high pressure is beginning to 
strengthen its hold on the areas weather. However northwest flow 
will continue across Lake Erie for much of the day. Also over 
extreme northeast Ohio and northwest Pennsylvania the flow should 
maintain and Lake Huron connection. Moisture will be on the decrease 
and the inversion will be slowly lowering during the day helping to 
diminish the snow showers. One of the heavier bands across SW 
Geauga and northwest Portage County has shown signs of decreasing 
significantly past hour. Will keep the lake effect snow warning 
going for Ashtabula County and our northwest Pennsylvania area where 
the Lake Huron connection will provide some heavier snow showers 
but nothing like the previous few days. With the radar showing 
some of the other bands in NE Ohio decreasing in intensity will 
let the warnings or advisories expire elsewhere. Locally up to 4 
or 5 inches possible in the warning area and generally 1 to 2 inches 
elsewhere in the snowbelt of NE Ohio. 


&& 


Short term /6 PM Saturday through Monday night/... 
few snow showers or flurries could still linger over northwest Pennsylvania 
early tonight with little if any accumulation. Otherwise flow backs 
as high pressure moves from Tennessee Valley to the East Coast. 
Sunday should be relatively pleasant with high pressure ridge moving 
east and SW flow developing. Should be a fair amount of sunshine 
with mainly high clouds expected. Mav guidance temperatures look OK...close to 
previous forecast...only the middle and upper 30s far east and lower 
40s far west. Next low and cold front approach western areas late 
Sunday night. Fairly good agreement with the operation runs of 
GFS/NAM and European model (ecmwf) holding precipitation off until Monday. Some question on 
precipitation type during the daytime Monday. NAM a little further north 
with the track of the low compared to GFS and would probably have 
most of the precipitation as rain. Though European model (ecmwf) has similar track as NAM 
doesn't appear to have quite the push of the warm air into the area 
either. For snow went with just rain showers south and rain or snow 
showers north. Track and speed of timing of precipitation with this system 
will have to be watched closely...if it arrives to soon freezing 
rain would be possible. 


&& 


Long term /Tuesday through Friday/... 
models generally agree with fairly deep low moving east of Lake Erie 
Tuesday with moderate west-northwest cold advective flow and wrap snow and snow 
showers with lake enhancement. Series of troughs expected to rotate 
across the area Wednesday into Friday per GFS but other models differ 
somewhat by Thursday. Majority of the the snowfall will again be in the 
snow belt. Models do try to move ridge of high pressure near or 
over the area Friday. With decent possibility of mean flow 
continuing off of Lake Erie Friday will add mention of shsn which 
will better coordinate with eastern bordering forecasts. Expect 
temperatures to remain below normal. 




&& 


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... 
Ridge of high pressure moving east into Lake Erie this afternoon 
should bring the winds down from west to east so that small craft 
can be dropped but may need to extend on the east end into early 
tonight. Will split difference somewhat and extend current Small Craft Advisory until 
9 PM. SW flow will increase late tonight through Sunday ahead of 
next cold front...but offshore angle of flow should keep small craft 
conditions away from nearshore waters until passage of low Monday 
night. By then it becomes a question of whether gales will develop. 
For coordination purposes will stay with 30 knots for Tuesday into Tuesday 
night forecast for now. Gradual diminishing of the northwest flow expected 
Wednesday and Wednesday night as low moves further away from Lake Erie and 
pressure gradient weakens. 


&& 




Cle watches/warnings/advisories... 
Ohio...Lake effect snow warning until 4 PM EST this afternoon for 
ohz014-089. 
PA...lake effect snow warning until 4 PM EST this afternoon for 
paz001>003. 
Marine...Small Craft Advisory until 9 PM EST this evening for 
lez142>149. 


&& 


$$ 
Synopsis...randel 
near term...randel 
short term...randel 
long term...Adams 
aviation...Adams 
marine...Adams 

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