Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 250829
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
329 AM CDT SUN SEP 25 2016

.SHORT TERM...(Today through Monday)
Issued at 325 AM CDT Sun Sep 25 2016

At 325 AM, numerous showers and thunderstorms were moving across
the Northland. We have even had a report of pea size hail in West
Duluth this morning. Further south, additional showers and
thunderstorms were spreading into Minnesota from the south.
Temperatures were generally in the 60s.

The focus for today through Monday will be resolving precipitation
timing and amounts. Water vapor imagery shows a stream of moisture
from Mexico northward into south central Canada, while an upper
level low rotates through the Dakotas. The upper level low is
expected to rotate northward today, while an elongated trough
develops overnight and into Monday and moves through MN and WI.

Showers and thunderstorms will continue to stream northward across
the area this morning, while pushing eastward. The main area of
showers and storms should be exiting the eastern portion of the
CWA by midday, while the dry slot moves in behind it. We could
even see a bit of sunshine for most areas for a few hours today.
The sunshine should help to boost temperatures into the upper 60s
to around 70. Behind the dry slot, the elongated upper level
trough will result in an increase of showers this afternoon and
into Monday. The showers will start to move into the western CWA
by mid to late afternoon, and they will spread eastward and become
more widespread overnight.

Monday is shaping up to be a blustery day across the Northland, as
the elongated upper level trough transitions to an upper level
low over Lake Superior. Strong west to northwest winds will
develop overnight and on Monday, with numerous showers across the
western Lake Superior region through Monday.

.LONG TERM...(Monday night through Saturday)
Issued at 325 AM CDT Sun Sep 25 2016

An upper low will linger over the upper Great Lakes early in the
work week resulting in clouds and rain showers for parts of
northeast Minnesota and northwest Wisconsin as late as Wednesday
morning. However, a strong mid-level ridge and surface high building
in from the west will result in mild and sunny skies through the
rest of the work week into the weekend.

On the synoptic scale a stacked low will be North of Superior Monday
night, with fairly good model agreement for the low to be centered
around Geraldton, ON (CYGQ). On Tuesday this low drifts south-
southeast across the upper Great Lakes, with parts of the Northland
under the cloud shield associated with the stacked low. Increased
the chances for precipitation a bit as guidance has trended a bit
slower than previous runs, and depending on how fast the drier
airmass builds in from the west, rain could last into Wednesday
morning across parts of the MN Arrowhead into NW Wisconsin.
Temperatures will be cooler in the wake of the low, though the
window for a chilly night seems limited given a warm air advection
regime will return by Thursday. Ridge axis moves across the Plains
and upper Midwest through the weekend. Some minor model disagreement -
specifically the ECMWF which depicts an upper low over the Ohio valley
this weekend when the GFS/GEFS/GEM have a broad ridge - but ignoring
the outlier this looks like a fairly reliable forecast. Highs in the
low 50s to low 60s Tuesday, but warmer mid week through the weekend
with highs in the 60s to near 70. Lows coolest Tuesday night as
skies clear out across much of the Northland with lows in the mid
30s across inland areas, but these too rise through the weekend in
the 40s to as warm as the mid 50s this weekend. While these
temperatures are far from record-breaking, they do continue the
trend of a mild fall thus far.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1253 AM CDT Sun Sep 25 2016

As with previous forecast, MVFR/IFR flight categories expected
overnight into Sunday morning before conditions improve. Strong
southerly low-level winds are developing over the area and will
shift east-northeast through mid-morning Sunday. Have continued
and expanded the LLWS mentions to account for this feature. The
southerly flow aloft is bringing a bit more lift and instability
into the region, which is reflected by the increasing shower
coverage and intensity over the past 3 hours. Think a few
thunderstorms are likely within the widespread showers. Visibility
may decrease into IFR category with the heavier showers/storms.
Subsidence and associated drying will move into the region Sunday
morning leading to clearing skies and improving flight categories.
Winds will remain breezy through the day, but the LLWS threat will
diminish. Another round of showers, and possibly thunderstorms, is
expected to follow the clearing by late afternoon/early evening.
Bring VCSH, at least, back into all terminals in the 25.22Z to
26.03Z timeframe with prevailing -SHRA in some spots. There could
be a few thunderstorms, as well, but confidence in timing and
location is low at this time so opted to leave out the mention of
thunder. Overall confidence in this forecast is average through
25.15Z and then above average for the rest of the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  68  48  57  44 /  70  70  50  20
INL  68  48  55  42 /  60  70  50  30
BRD  64  47  59  43 /  30  50  20   0
HYR  69  48  56  43 /  70  60  60  30
ASX  73  51  58  46 /  80  70  70  60

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...Gale Watch from Monday morning through Monday evening for LSZ121-
     146>148.

     Small Craft Advisory from 10 PM this evening to 10 AM CDT Monday
     for LSZ121-146>148.

     Small Craft Advisory from 10 PM this evening to 10 PM CDT Monday
     for LSZ144-145.

     Small Craft Advisory from 4 AM Monday to 4 AM CDT Tuesday for
     LSZ140>143.

&&

$$

SHORT TERM...DAP
LONG TERM...JJM
AVIATION...Huyck


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