Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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
FXUS63 KDLH 271138

Area Forecast Discussion
National Weather Service Duluth MN
638 AM CDT WED JUL 27 2016

.SHORT TERM...(Today through Thursday)
Issued at 305 AM CDT Wed Jul 27 2016

A diffuse inverted surface trough, associated with a low in
eastern South Dakota, will move east through the Northland today,
while multiple shortwaves could traverse the region in the near-
zonal flow aloft. The weak surface convergence from the inverted
trough, combined with the atmospheric lift generated by any little
shortwave ripple in this warm and humid airmass could trigger
showers and thunderstorms. The best chances will be across the
southern forecast area. The threat of strong storms looks very low
due to the lack of MUCAPE and deep layer wind shear. Heavy rain
will be the main threat considering the precipitable water values
of 1.5 to 1.75 inches and somewhat slow movement of rains.

Meanwhile, high pressure will be over Saskatchewan/Manitoba today,
and the northerly flow to its east will attempt to filter drier
air into the Northland. A Lake Superior breeze will kick in today,
and keep areas near and downwind of the Lake cooler. The
temperature differences between the lakeshore and inland areas
probably will not be particularly pronounced today, though,
because the extensive cloud cover will limit solar heating. Highs
should range from the upper 60s and low 70s near Lake Superior, to
the middle to upper 70s well inland (and not downwind) from the

The Canadian high pressure will continue to slowly approach the
Northern Plains tonight and Thursday, leading to clearer skies.
There could be lingering showers and weak storms over the far
southeast forecast area. Overnight lows will primarily be in the
lower to middle 50s. Thursday`s highs should be in the middle to
upper 70s, highs will be near 70 degrees near Lake Superior
because of the east-northeast flow.

.LONG TERM...(Thursday night through Tuesday)
Issued at 305 AM CDT Wed Jul 27 2016

Northwest flow aloft and an area of high pressure at the surface
will start the extended period. The northwest flow aloft will
continue into Sunday night but the high will drift east Saturday
allowing for a southerly flow to develop. A shortwave is forecast
to move through the region late Friday night into Saturday, but
there is little else to support precipitation. We went dry
Thursday night through Saturday night. The moisture transport and
warm air advection looks to be rather weak and there is little
upper support for organized convection. It`s not out of the
question some showers and storms could develop at times,
especially during the afternoon and evening hours, but there is no
clear signal as to where they may develop. Temperatures Friday
into Sunday will be seasonable. There will be off lake winds
during this period which will keep lakeside temperatures cooler.

Warm air advection and moisture increase over the latter half of
the weekend into early next week and we increase POPs during this
time. Surface dewpoints will rise from the the lower to mid
sixties Sunday to the mid sixties to lower seventies on Tuesday.
We have mainly low POPs Sunday into Monday as an area of low
pressure and frontal boundary are still well west of the
Northland. However, these features move east Monday night into
Tuesday with chances for storms increasing then. Plenty of
moisture will be present so any storms that do occur Monday night
into Tuesday night will produce heavy rain.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 638 AM CDT Wed Jul 27 2016

Scattered to numerous showers and thunderstorms were occurring
across the Northland this morning due to a slow moving cold front
and shortwave aloft acting on a moist airmass. Coverage of the
showers and storms is expected to be greatest for most areas this
morning over much of northeast Minnesota but continue into the
afternoon over northwest Wisconsin into at least Pine county in
Minnesota. A period of MVFR conditions will occur with the
stronger showers/storms. The RAP, as well as some of the other
guidance, suggests MVFR ceilings will expand from KBRD to KDLH
and points south and east through the morning into at least mid
afternoon. We do have more of those ceilings in the TAFs and may
have to expand some.

The showers/storms will be on the decrease tonight as weak high
pressure noses south into the area. Winds are expected to become
light tonight, especially over northern Minnesota. Fog will be
possible and we dropped the visibility to IFR at most TAF sites.


DLH  72  55  74  52 /  60   0   0   0
INL  77  52  78  52 /   0   0   0   0
BRD  75  58  79  56 /  60  10  10  10
HYR  75  56  78  52 /  60  20  10  10
ASX  71  56  74  53 /  60   0   0  10


.DLH Watches/Warnings/Advisories...
LS...Small Craft Advisory from 10 AM this morning to 10 PM CDT this
     evening for LSZ144>146.

     Small Craft Advisory from 10 AM this morning to 4 PM CDT this
     afternoon for LSZ143.



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