Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Duluth Minnesota
720 am CDT Monday may 4 2015
Short term...(today through tuesday)
issued at 340 am CDT Monday may 4 2015
Dry and mild today into tomorrow as an area of high pressure builds
across the northern plains into the upper Midwest...moving east
across the Great Lakes on Tuesday.
Today...mostly sunny and dry. Soundings depict very dry air in the
low levels with diurnal heating leading to mixing beyond
800mb...leading to afternoon minimum relative humidity values in the
15 to 20 percent range across northeast Minnesota into the 20 to 25
percent range in northwest Wisconsin. Light northerly winds this
morning weaken to become nearly calm late in the afternoon as the
area of high pressure becomes centered over northern Minnesota.
Expect a few high clouds across the southern third of the
County Warning Area...generally south of Highway 2...but otherwise clear skies.
Highs not as warm as yesterday but still above normal...in the middle
to upper 60s.
Tonight...high pressure over northeast Minnesota will lead to clear
skies and calm conditions. Overnight lows flirting with freezing in
a few spots across far northern Minnesota...otherwise in the middle 30s
to around 40.
Tuesday...increasing high to middle level clouds as a warm front
approaches from the south. Cloud cover forecast may be a bit too
optimistic...but expect most locations to be under mostly sunny
skies through at least the early afternoon. Temperatures will be
warmer due to southeast flow developing at low levels as the area of
high pressure moves to the east over the Great Lakes. Winds will
also pick up...especially out towards the Brainerd lakes region
where gusts as high as 30kts will be possible. Afternoon relative
humidity values will fall to 15 to 25 percent...driest where skies
remain sunny for most of the day...but as warmer and more moist air
moves in from the south relative humidity values will rise. Generally the driest
air will not coincide with the strongest winds...thus do not expect
widespread critical fire weather conditions...see the latest fire
weather forecast for more details. Highs will climb to the upper 60s
to low 70s....which is 10 to 15 degrees above normal.
Long term...(tuesday night through sunday)
issued at 340 am CDT Monday may 4 2015
Confidence increasing for a wet and unsettled extended period.
Focus on a closed low/long wave trough in the Pacific northwest that
ejects a short wave into the western Dakotas Tuesday
night/Wednesday....lifting a warm front across Minnesota/Wisconsin.
The wave will deepen into a closed 850 mb low with surface reflection over
the Dakotas Wednesday night...tracking over northern minn Thursday...and
finally lifting into Ontario Friday. The strengthening pressure
gradient from the approaching low/warm front will result in gusty
southerly winds for inland areas. Locations near Lake Superior can
expect gusty east winds with much cooler temperatures through the
end of the week.
The prolonged period of return flow and increased
moisture/instability will bring periods of rain showers with
embedded thunderstorms across the Northland through the Tuesday
night through Friday period. Latest guidance and wpc quantitative precipitation forecast outlooks
suggest widespread rainfall totals of a half to around an inch are
expected during this time.
Latest ecm/Gem/GFS are in good agreement that upper level ridging
returns briefly during the Friday night/Saturday periods...before
another short wave lifts into the region and brings a return for
rain and thunder chances late in the weekend and into next week.
Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 703 am CDT Monday may 4 2015
VFR conditions through the forecast period. High pressure will
build into the region today and tonight allowing for clear skies.
Winds will increase out of the north to northwest this afternoon
around 10 knots...becoming light after sunset.
Preliminary point temps/pops...
dlh 66 42 67 44 / 0 0 0 50
inl 64 38 73 44 / 0 0 0 10
brd 67 41 67 48 / 0 0 10 60
hyr 67 42 70 47 / 0 0 10 50
asx 64 37 65 44 / 0 0 0 50