Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 221120
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
620 AM CDT MON AUG 22 2016

.SHORT TERM...(Today through Tuesday)
Issued at 320 AM CDT Mon Aug 22 2016

Strong warm air advection continued tonight across the Northland
with rain falling over parts of far northern Minnesota as of this
morning. We extended POPs a bit further south this morning due to
latest radar trends. This rain will continue to move southeast
this morning clearing the tip of the Arrowhead by late morning. A
southerly low level flow will increase through the day, especially
this afternoon as mixing deepens. The flow at 850MB will be from
40 to 45 knots out of the southwest. Some of the models show a few
showers developing over portions of our southern CWA, mainly
across northwest Wisconsin, this afternoon. We held off on adding
a chance for now but did increase cloud cover mid to late
afternoon. Temperatures will be warmer today with highs from the
upper seventies to lower eighties.

Continued warm air advection and moisture transport tonight may
lead to some showers and storms over portions of the Northland and
we left a mention of those in the forecast. The GFS is the main
model developing precipitation tonight.

An area of low pressure will be centered in southeast Manitoba at
00Z Wednesday with a cold front trailing through the Red River
Valley. We expect much of the day will be dry and it will be
warm. 850MB temperatures will warm to around 23C in our western
zones and to near 20C in our southeast during the day. This should
allow temperatures to climb in the upper eighties west and lower
to mid eighties east. Areas along the North Shore will be cooler
as a southerly wind persists.

.LONG TERM...(Tuesday night through Sunday)
Issued at 320 AM CDT Mon Aug 22 2016

Initially in the extended the concern will be the passage of a cold
front late on Tuesday through Wednesday. Aloft a slightly
positively tilted trough will dig and deepen into the Northern
Plains. Ahead of the trough, an area of low pressure will deepen
and lift northeastward from eastern ND into Ontario. The cold front
associated with the system will slide eastward through MN Tuesday
night into early Wednesday. Ahead of the cold front there will be
around 1000 to 2000 J/kg of CAPE, but the best 0-6 km bulk shear is
behind the cold front per the latest GFS/NAM. Still think there is a
potential for strong thunderstorms especially along the cold
front, but expect that the severe risk to be limited as the best
shear remains behind the front. Will see PWAT values around 1.5 to
1.7 inches. This is higher than normal for this time of year, so
expect heavy rain with some of the showers/storms that move through.

Left some low trailing POP chances as the latest ECMWF/GEM suggest
there may be some lingering activity behind the front. Think this
trailing precipitation may be a bit over done as drier mid level air
works its way in behind the front as suggested by the GFS/NAM.

Late on Wednesday and into Thursday the trough axis will lift from
the Northern Plains into Ontario. With the trough axis nearby and
cool northwest flow, expect there to be some lingering rain showers
across northern MN on Thursday with more clouds than sunshine. It
will be cooler behind the front with readings in the 60s.

Will see a return to southwesterly flow later on Friday as the Upper
Midwest returns to the western side of an 850 hPa ridge. This will
bring temperatures back into the 70s for Friday and through the
weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 620 AM CDT Mon Aug 22 2016

VFR conditions expected through the upcoming TAF period. Main
concern will be the gusty southerly winds developing this morning
and continuing through the afternoon. This is a result of the
tightening pressure gradient from the high building off to the
southeast and a low developing across the Northern Plains per the
latest guidance. Will see some fair weather cumulus develop late
this morning/afternoon with ceilings around 6-8 kft.

Kept winds at or above 10 kts during the evening/overnight at all
terminals as the latest NAM/GFS/DLHWRF suggest that winds will
not decouple and it will stay breezy overnight. Think this is most
likely with the strong pressure gradient remaining in place
overnight. However, if winds do decouple then low level wind
shear will need to be added in future TAF sets due to the
strengthening low level jet.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  80  64  85  65 /  10  20  10  40
INL  83  62  86  63 /  10  20  10  40
BRD  82  63  87  63 /   0  10  10  40
HYR  78  63  85  65 /  10  20   0  40
ASX  81  64  85  67 /  10  20  10  30

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...Small Craft Advisory from 10 AM this morning to 4 PM CDT this
     afternoon for LSZ140-141.

&&

$$

SHORT TERM...Melde
LONG TERM...WL
AVIATION...WL



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