446 
fxus63 kdlh 062010 
afddlh 


Area forecast discussion 
National Weather Service Duluth Minnesota 
310 PM CDT Monday Oct 6 2008 


Discussion...forecast focus is on precipitation chances tonight through 
Tuesday night. Band of showers moving over the Minnesota 
arrowhead...Western Lake Superior and northern WI at this time are 
associated with nose of 850 mb low level jet ahead of the upper level trough 
moving through the Dakotas. These showers will continue to move NE 
and out of the forecast area by 00z tonight. Showers occurring along and 
ahead of surface boundary in eastern Dakotas will slow move into the 
far western portion of the forecast area this evening. With the front 
parallel to the upper level flow...the precipitation will be slow to spread 
from west to east...but should cover half of the forecast area by 12z Tuesday. 
Instability is limited so only mention an isolated thunderstorm with 
the showers. 


Frontal boundary should bisect the forecast area on Tuesday from north to S with 
majority of the precipitation falling in the vicinity of the front and upper 
trough. Isolated thunderstorms will be found ahead of the front where 
instability axis is maximized. Precipitation will end very slowly from west to east 
Tuesday night with progression of system. Surface wind will be light 
Tuesday night and with moist layer locked in under 
inversion...patchy fog will develop. 


A very weak frontal boundary attempts to cross the forecast area on Wednesday. 
Moisture is limited and with a fairly dry column...not expecting any 
precipitation. Maximum temperatures should reach into the 60s f in most locations in warm air advection 
ahead of the approaching boundary. Thursday should be a quiet day 
with dry air in place over the forecast area. 


Showers and a few thunderstorms return to the forecast area Thursday night and 
are forecast to persist through Sunday night. This is in response to 
an inverted surface trough setting up over the forecast area and moving very little 
as it will be parallel to the upper flow. Upstream kicker not 
anticipated until Monday. 


&& 


Aviation...a cold front will slowly make its way across the upper 
Midwest tonight and Tuesday. Scattered showers and isolated storms 
with low clouds and fog will affect all of the Northland tonight. 
Ceilings and visibilities will generally range from MVFR to VFR...although 
there will be areas of IFR ceilings and visibilities...especially near Lake 
Superior. Showers and storms will become more numerous across the 
County Warning Area on Tuesday as the front moves over the Northland. Heavy rain 
with low visibilities and ceilings is expected for most locations Tuesday. 
However conditions will improve across our western zones in the 
afternoon as high pressure builds in from the plains. 


&& 


Point temps/pops... 
dlh 49 57 44 62 / 10 80 10 10 
inl 51 59 40 62 / 40 80 10 10 
brd 52 60 39 66 / 80 70 10 10 
hyr 54 62 45 66 / 10 80 80 10 
asx 54 61 46 66 / 10 80 80 10 


&& 


Dlh watches/warnings/advisories... 


Minnesota...none. 
WI...none. 
Ls...Small Craft Advisory until 10 PM CDT this evening for lsz144- 
lsz145-lsz146-lsz147. 


Small Craft Advisory until 4 am CDT Tuesday for lsz140-lsz141- 
lsz142-lsz143. 




$$ 


Gsf/berdes