113 
fxus63 kdlh 052040 
afddlh 


Area forecast discussion 
National Weather Service Duluth Minnesota 
340 PM CDT Sat Jul 5 2008 


Discussion...the main focus for tonight is precipitation chance 
in mainly the western zones. 


Fairly quiet across the County Warning Area this afternoon. There has been a fair 
amount of cumulus development across the County Warning Area this afternoon...but still 
partly cloudy most areas. There were a few middle level returns just 
west of our County Warning Area...but no surface reflection at this point. 


The models are generally in decent agreement with no major 
initialization errors on the 12z run. Will continue to follow the 
GFS in the short term...but trend toward the European model (ecmwf) Sunday night 
into Monday. 


For tonight...strong warm air advection will continue across the County Warning Area. Forecast 
soundings show a fairly strong cap in place across the 
area...which weakens especially west of the area. Elevated 
instability increases from west to east later tonight. The day one 
severe still places the main threat area west of the County Warning Area 
tonight...with some storms possibly spilling eastward into our 
area and weakening overnight. Will increase to chance probability of precipitation in the 
western third of the County Warning Area. GFS paints a large bullseye of more than 
an inch of quantitative precipitation forecast in our northwest County Warning Area overnight...but European model (ecmwf) has less. Have 
basically followed HPC quantitative precipitation forecast. Most GFS ensemble members paint much 
less quantitative precipitation forecast across that area...but still have a bullseye of quantitative precipitation forecast. 


The front will move eastward across the area on Sunday...eventually 
orienting from the SW to NE and even more of a west to east. This 
will place the best chance for severe from the North Shore...into 
east central Minnesota...and northwest WI on Sunday afternoon. MUCAPE 
values are impressive at more than 2000 j/kg and agree with Storm Prediction Center 
regarding the multicell line type of storm development with 
isolated supercells due to the shear environment. 


European model (ecmwf) pushes the front mainly south of the County Warning Area by Sunday night and 
Monday...but the GFS hangs it back across northwest WI. Will lend some 
credence to this solution...as the sref also hints at this...but 
mainly kept low probability of precipitation at this point. High pressure will build in 
from central Canada...settling over the northern Great Lakes. This 
will in turn dry out much of the area with dry NE winds coming off 
Lake Superior. 


Another system will move in from Monday into Wednesday...and then 
again later in the week. Could be a fairly active week. 


&& 


Aviation...low pressure will advance into the upper Midwest from 
the Dakotas overnight and into Saturday. Middle and high clouds will 
increase from west to east tonight...while at the same time the 
low level jet increases after sunset. This will create low level 
wind shear after 02z. Increasing moisture and instability will set 
the stage for scattered thunderstorms to develop in northwest Minnesota by 00z... 
spreading east and southward overnight into early Sat morning. The 
best forcing and lift will be found in northern Minnesota...where ts will be 
most widespread. Conds will remain VFR through the taf period except 
MVFR in thunderstorms. 


&& 


Point temps/pops... 
dlh 62 86 55 70 / 30 40 20 30 
inl 63 81 55 75 / 40 20 10 20 
brd 67 87 60 80 / 40 30 20 40 
hyr 63 85 60 79 / 20 40 30 30 
asx 62 83 57 73 / 20 40 30 30 


&& 


Dlh watches/warnings/advisories... 


Minnesota...none. 
WI...none. 
Ls...none. 


$$ 


Dap/tl