Discussion scientifique du spécialiste des prévisions météorologiques

NWS Discussion
			
				

Area forecast discussion 
National Weather Service Duluth Minnesota 
326 PM CDT Sat may 25 2013 


Short term...building ridge aloft continues to allow thinning of 
middle level cloud mass across the region this afternoon. Some cumulus have 
also developed as a result of diurnal warming of boundary layer. Temperatures 
linger in the 40s near Lake Superior with middle to upper 50s common 
inland. 


Tonight/Sunday...fairly benign pattern this period as surface/middle level 
ridging continues to prevail across the Northland. Main change to 
previous forecast was to slow the arrival time of the next area of 
clouds and precipitation until Sunday evening. Raised maximum temperatures a 
little Sunday with more sunshine expected. 


Long term...Sunday night through Saturday. 


The extended period is shaping up to be a quite unstable and 
potentially very wet period...as the upper level pattern evolves 
from a dry surface high dominated pattern to a mean trough/SW flow 
pattern. The surface high and upper level ridge will still be 
battling the advancing moisture Sunday night and into Monday...with 
dry air to the east with easterly winds...and a moist S/SW flow 
developing in the plains. This is shaping up to be a notoriously 
tricky set up...with the potential for mesoscale convective system development. The 
complexity of frontal boundaries...tracking various upper level 
impulses that will eject out of the main trough in the western 
states...and outflow boundary development means that we will need to 
go with fairly high probability of precipitation for a majority of the remainder of the 
extended time period...with the precipitation tending to favor the 
south and eastern portions of the County Warning Area. This wet pattern will hold 
for the entire extended time frame once it develops as an upper 
level low moves into the plains along with increasing Gulf moisture. 
Temperatures will largely be in the 60s and 70s...but it will be cooler 
near Lake Superior for much of the time. 






Aviation.../18z taf issuance/ 
widespread VFR conditions will persist throughout the taf cycle as 
high pressure to the east battles low pressure to the west. There 
could be some scattered lower clouds but all in all it looks like 
like VFR conditions with mainly high to middle clouds. 










Point temps/pops... 
dlh 40 62 44 61 / 10 0 10 30 
inl 42 69 44 68 / 10 0 20 40 
brd 44 63 50 68 / 10 10 30 50 
hyr 38 69 46 68 / 10 10 10 40 
asx 37 63 43 64 / 0 0 0 30 


&& 


Dlh watches/warnings/advisories... 
Minnesota...none. 
WI...none. 
Ls...none. 
&& 


$$ 


Short term...Cannon 
long term....dap