Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

000
FXUS63 KDLH 241949
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
249 PM CDT WED AUG 24 2016

.SHORT TERM...(This evening through Thursday)
Issued at 249 PM CDT Wed Aug 24 2016

A cold front is nearly through the Northland as of this afternoon
ushering in lower dew points and sunny skies. The upper low
associated with this cooler air is still off to the northwest and
will move northeast across southern Manitoba into northwest Ontario
tonight into Thursday, resulting in increasing clouds and a chance
for rain showers across northern Minnesota. With 850mb temps falling
to around +5C, this could be the coolest airmass since about July 1
looking at sounding records at International Falls, resulting in
highs in the 60s in northeast Minnesota, low 70s in northwest
Wisconsin.

Tonight the line of clouds and a few showers along the cold front
will have moved off to the east and the fair-weather cu across north-
central Minnesota will dissipate, resulting in clear skies except
for some high-level clouds moving in from central Minnesota
spreading across parts of northwest Wisconsin this evening. With dew
points currently in the low to mid 50s behind the front, low
temperatures are expected to fall just as cool, except warmer near
Lake Superior and larger inland lakes.

Early Thursday morning and through the day Thursday clouds will be
on the increase from west to east across the Northland as the upper
low approaches. At this point it looks like the track of the low
will keep the best chances for precip and most clouds over north-
central to northeast Minnesota, while northwest Wisconsin will see
partly sunny skies. Isolated to scattered rain showers and perhaps a
few thunderstorms are expected through the day as the upper low
lifts into northwest Ontario. Cooler air aloft will result in a bit
of instability - up to 500 j/kg along the international border -
which will be enough to produce a few thunderstorms. Besides the
clouds and chance for precip, west-northwest winds will be breezy at
10-15 mph with peak gusts approaching 30mph. Highs in the low to mid
60s in north-central Minnesota, warmer in the upper 60s to low 70s
in northwest Wisconsin.

.LONG TERM...(Thursday night through Wednesday)
Issued at 249 PM CDT Wed Aug 24 2016

Initially in the extended, aloft a trough will move across Ontario
into Quebec. At the surface a trailing surface trough will move
northeastward from northern MN into Ontario. This will bring a few
scattered showers to the MN Arrowhead. Behind the trough, high
pressure will build into the region. This will bring decreasing
cloud cover and a cool night with lows ranging from the mid to upper
40s inland, to the low to mid 50s along the Lake Superior shoreline.

High pressure will remain in place over the Northland for Friday.
This will result in dry and quiet weather. Will see 850 hPa warm air
advection with temperatures around 10-12 degrees Celsius. This will
result in high temperatures in the 70s throughout the Northland.

A positively tilted trough axis will dig and deepen into the
Northern Plains on Friday and become neutrally tilted as it moves
into northern MN on Saturday. There still are some differences with
the progression of the trough moving in and through, with the
GFS/GEM being a bit more progressive and the NAM/ECMWF a bit slower.
Decided to compromise between the two solutions as suggested by the
latest GEFS output. So, have chance POPs from Saturday into early
Sunday before precipitation chances decrease as the system exits.
Highs on Saturday will be around 70, while readings on Sunday will
be a bit warmer with highs in the low to mid 70s. Mild temperatures
are in store for Monday with WAA bringing 850 hPa temperatures
around 18 degrees Celsius. Still kept the forecast dry, but the
GFS/ECMWF hints at a cold front moving into MN from a mature
cyclone moving across northern Manitoba. The ECMWF is a bit slower
with this front, but has better upper level support for the
system.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1234 PM CDT Wed Aug 24 2016

The main concern in the current TAF set is the lingering stratus
with ceilings ranging from 1-3 kft ahead of the cold front moving
through. This will initially impact KDLH/KHYR, but the front is
nearly through KDLH and will move through KHYR around 20Z per
satellite observations and the latest RAP/NAM. Behind the front
VFR conditions will prevail with gusty winds.

Winds will decouple around 00Z-01Z tonight. VFR conditions will
continue at all terminals until 11Z-14Z. Around this time will see
MVFR ceilings develop at all terminals except KDLH/KHYR as a
trough axis nudges into northern MN per the latest forecast
guidance. There is a possibility of IFR ceilings developing at
KINL as rain showers move in. Feel this will only occur for an
hour or two before ceilings rise back into the MVFR range as the
mixed layer develops.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  55  67  49  72 /   0  10   0   0
INL  55  62  45  74 /  20  60  10   0
BRD  55  67  48  74 /  10  10   0   0
HYR  54  71  49  71 /   0  10   0   0
ASX  58  73  53  71 /   0  10   0   0

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...JJM
LONG TERM...WL
AVIATION...WL



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.