Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Text Only | 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

FXUS63 KDLH 210800

Area Forecast Discussion
National Weather Service Duluth MN
300 AM CDT TUE JUN 21 2016

.SHORT TERM...(Today through Wednesday)
Issued at 300 AM CDT Tue Jun 21 2016

The Northland will have another mostly sunny and breezy day with
northwest flow. The winds will not be as strong as yesterday
though. The RAP, NAM, and GFS soundings are in fairly good
agreement with about 20 to 25 knots in the mixing layer, so
forecasted widespread gusts to a little over 20 mph. Scattered
cumulus should develop over the northern forecast area, primarily
the Arrowhead and near and north of the Iron Range, as well as
downwind of Lake Superior over inland northwest Wisconsin. Highs
should primarily range from the lower to middle 70s. The Twin
Ports shoreline could approach 80 degrees because of downslope
flow heating.

Surface high pressure will move through the Northland this
evening, resulting in a period of very light wind speeds and clear
skies. Leaned on the cooler GFS/NAM MOS blend for lows. Lows
should dip to the middle to upper 40s for most areas, and the low
50s across the far south and southwest forecast area.

A nearly stacked low will move from southern Saskatchewan early
Wednesday to northern/central Minnesota by Wednesday evening. It
will bring an increasing chance of showers for the Northland, from
the west, late tonight into Wednesday evening. The NAM, GFS, and
SREF indicate there could be up to several hundred J/kg of most
unstable cape across the southwestern and southern forecast area,
so have some lower chances of thunder for those areas, and the
thunder threat looks very low across the north and near Lake
Superior. The cloud cover and easterly flow will result in cooler
temperatures ranging from the middle to upper 60s near Lake
Superior to the lower 70s inland.

.LONG TERM...(Wednesday night through Monday)
Issued at 300 AM CDT Tue Jun 21 2016

Showers and a few thunderstorms exit the region Wednesday night
with mild and mostly sunny conditions through the rest of the work
week. Warmer and more humid through the weekend with a chance for
thunderstorms, then cooler late in the weekend into next week.

On the synoptic scale a fast-moving upper jet across the northern
tier of the CONUS and southern Canada will lead to a progressive
pattern. A weak mid-level shortwave trough will be exiting to the
east-southeast by Wednesday night with a broad longwave ridge
building in behind it across the northern Plains and upper
Midwest. As the low-level ridge axis (i.e. 850mb) and surface high
drift east of the Northland Friday, warmer and moister air will be
advected into the region with highs near 80 Friday and especially
Saturday. Higher dew point values in the low 60s Friday to upper
60s/near 70 Saturday will make it feel very humid. The low level
humidity combined with steeper mid-level lapse rates come late
Friday into Saturday will result in instability with MUCAPE values
2000+ j/kg by Saturday afternoon. These will all be ahead of
strong mid-level shortwave trough approaching from the west for
the weekend. GFS continues to indicate scattered convection may be
possible along the warm front lifting northeast into the upper
Mississippi valley late Friday, but the model consensus seems to
point towards Saturday having the best chance for widespread
thunderstorms across the Northland along and ahead of what at that
point may be an occluded front moving east towards the upper Great
Lakes. While there remains considerable model differences, it
seems there is a slight trend for a slightly slower progression of
the surface low as it deepens across southern Manitoba towards
Sunday morning.

As the low weakens and moves eastward towards northeast Ontario
Sunday, cooler air will be advected in from the northwest with
highs as cool as the upper 60s by Monday. Gusty west winds
expected Sunday in the wake of the low, with a low chance for
showers along a cold front moving in from the north Monday.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1230 AM CDT Tue Jun 21 2016

VFR conditions will continue to prevail through the TAF period.
Clear skies overnight with a few mid to high level clouds on
Tuesday. Light to near calm winds tonight with gusty northwest
winds returning Tuesday.


DLH  78  51  67  49 /   0   0  60  60
INL  72  45  69  48 /   0   0  40  20
BRD  79  55  74  53 /   0  10  60  30
HYR  77  49  75  51 /   0   0  60  70
ASX  76  48  68  49 /   0   0  50  70


.DLH Watches/Warnings/Advisories...


SHORT TERM...Grochocinski
AVIATION...Graning/JJM is the U.S. government's official web portal to all federal, state and local government web resources and services.