Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 230936

Area Forecast Discussion
National Weather Service Duluth MN
436 AM CDT Fri Jun 23 2017

.SHORT TERM...(Today through Saturday)
Issued at 435 AM CDT Fri Jun 23 2017

The next 24 hours are going to be dominated by the large upper low
over the James Bay area, producing cyclonic flow over the region.
Shortwaves rotating through this northwest cyclonic flow is going
to bring periodic chances for showers and thunderstorms today
through Saturday. Today, the first and weakest of these waves is
going to move through the area with diurnal effects to help
generate scattered showers mainly for areas along and north of the
Iron Range, with lower chances farther south. Thunder is possible,
but we just do not develop much CAPE today and have kept the
chances for that relatively low. Clouds to also follow this trend,
with mostly cloudy conditions north and a bit more sunshine to the
south. This extra cloud cover is going to keep conditions cooler
today than yesterday, with highs mainly in the 60s for northern
Minnesota, with lower 70s mainly for northwest Wisconsin. Tonight
chances for showers continue with a weak surface trough in the
vicinity, also mainly for areas to the north. Lows to be warmer
than this morning as well, staying in the 40s for most locations.
Saturday a stronger shortwave moves through the upper level flow,
but mainly to our southwest, which is going to increase pops
overall compared to today, but will increase the most across the
southern CWA. We will also have more instability around, and
expect a number of garden variety thunderstorms Saturday afternoon
and early evening. Highs Saturday to remain cool in the northwest
flow, with highs only in the upper 50s far north to mid 60s south.

.LONG TERM...(Saturday night through Thursday)
Issued at 435 AM CDT Fri Jun 23 2017

Summary: A broad and slow-moving longwave trough will keep the
Northland in a northwest flow pattern through Monday. The main upper
trough will push eastward Tuesday and Wednesday as a ridge to our
west flattens into a quasi-zonal flow for mid-week. A number of
shortwave troughs will rotate through the region during the period
with several chances of showers and thunderstorms.

A broad longwave trough will remain over the area Saturday evening
with a departing shortwave over central and southern Wisconsin.
Showers and thunderstorms should be ongoing over the Northland and
will gradually diminish in coverage and intensity overnight. Far
northern Minnesota has the best chance of keeping scattered showers
overnight thanks to falling heights ahead of another shortwave
trough. The next trough will continue to rotate southeastward across
the Northland during the day Sunday. Continued cool air advection
aloft and a few breaks in the cloud cover should yield weak
instability with MUCAPE values between 250 and 500 J/kg by mid-
afternoon. Thunderstorms will be possible once again, but severe
weather is not anticipated.

A surface ridge will slide southeastward across the Dakotas and much
of Minnesota on Monday. Increasing sunshine is expected along with a
break in rain chances. Temperatures will trend warmer but are
expected to remain below seasonal averages. The warming trend
continues into Tuesday as southerly flow develops behind the
departing surface ridge. The increasing northward moisture transport
will set the stage for showers and thunderstorms Tuesday night and
Wednesday. A progressive shortwave trough will move across the
Dakotas Tuesday night and into Minnesota and Wisconsin on Wednesday.
A surface low and cool front will accompany the passing trough.
Deterministic models point to a potential for strong to severe
storms, but confidence is low given the myriad of mesoscale details
which will contribute to any severe weather threat. A few more
thunderstorms will be possible on Thursday as another fast-moving
shortwave races through the region.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1241 AM CDT Fri Jun 23 2017

The Northland will be impacted by a couple upper level low
pressure systems over the TAF period. We should see largely VFR
conditions overnight, but a weak trough/front moving through early
Friday will bring some MVFR CIG`s to portions of northern and
western TAF sites. These conditions will linger into Friday
evening as well. Some scattered showers will be possible at times.


DLH  67  49  62  48 /  30  10  30  30
INL  64  48  58  47 /  30  30  50  50
BRD  66  48  62  48 /  20  10  30  30
HYR  70  50  64  48 /  20  10  40  20
ASX  71  51  64  49 /  10  20  40  20




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