Area forecast discussion
National Weather Service Duluth Minnesota
640 PM CDT Sat may 25 2013
Aviation...00z tafs
VFR conditions covered the Northland. A few light showers were
occurring...with radar picking up on some returns just west of
kdlh. These showers were quickly diminishing and should be gone in
an hour.
We kept the tafs VFR through the period with the main baroclinic
zone south and west of the Northland. The NAM does suggest some
MVFR ceilings may move into kbrd around 12z continuing into early
Sunday afternoon. However...the rap kept the low level moisture
west and south of there...and we followed that trend as well.
&&
Previous discussion... /issued 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.
&&
Point temps/pops...
dlh 40 62 44 61 / 20 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 / 10 0 0 30
&&
Dlh watches/warnings/advisories...
Minnesota...none.
WI...none.
Ls...none.
&&
$$
Short term...Cannon
long term....dap
aviation...melde
