Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Text Only | 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 46 47 48 49 50
000
FXUS63 KDLH 190541
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1241 AM CDT Mon Aug 19 2019

.UPDATE...
Issued at 1239 AM CDT Mon Aug 19 2019

Updated for the 06Z Aviation discussion.

&&

.SHORT TERM...(This evening through Monday)
Issued at 307 PM CDT Sun Aug 18 2019

An area of high pressure building across the Midwest will lead to
clear skies tonight and seasonable to mild temperatures on Monday.
Breezy both today and on Monday - today northwest winds gusting to
around 25-30 mph will gradually diminish this evening, then
southwest winds increase Monday with gusts again around 25-30 mph.
Lows tonight in the mid 40s to near 50, then highs on Monday ranging
from the mid to upper 70s in northwest Wisconsin to the mid 70s to
low 80s in northern Minnesota. Dew points will be on the increase
Monday in the southwesterly flow, but still not too bad with values
only reaching the mid 50s to near 60 on Monday afternoon. Some
afternoon cu possible Monday but otherwise mainly sunny skies.

.LONG TERM...(Monday night through Sunday)
Issued at 307 PM CDT Sun Aug 18 2019

Quiet conditions will be in place at the start of the extended, but
that is expected to quickly change as a shortwave moves through the
Dakotas Monday night. This will lead to surface cyclogenesis in
eastern North Dakota into northern Minnesota. The best energy from
this system looks to split the Northland, but showers and storms are
expected to develop late Monday evening in the Red River Valley and
push east overnight. Additionally, the tail end of a front
associated with a low over Hudson Bay will move through ahead of
this system and may lead to a few isolated showers and storms, but
the main threat for any rainfall will occur during the early morning
hours on Tuesday. CAPE ahead of the stronger system will approach
1000 J/kg, so storms that do develop will have energy to maintain as
they push east. However, these will most likely be elevated which
will reduce the threat for damaging wind gusts, but hail will still
remain a concern. Latest NAMNEST run is hinting at a line of storms
straddling the International Border overnight and that doesn`t seem
too far fetched. SPC does have a marginal risk in place for
Koochiching and western Itasca Counties and this seems reasonable.
Heavy rainfall will also be possible with these storms as PWATs rise
into the 1-1.5" range.

The cold front will push across the Northland from northwest to
southeast on Tuesday and may lead to additional showers and
thunderstorms, some of which may be strong, but shear looks fairly
unidirectional through the column. The timing of the front will play
into this threat as well. In any case, conditions quickly improve
Tuesday night in the wake of the front with high pressure in place
through much of Thursday. As the high shifts to the east Thursday
night, a shortwave will move into the Northern Plains and set up
decent southwesterly flow across the region. This will lead to an
increase in moisture and temperatures heading into the weekend.
Models then handle this next system for the weekend differently, but
it is safe to say given the instability that will be in place, there
will be chances for showers and storms, but whether any strong or
severe storms will be possible remains unknown.

Highs will be in the middle to lower 70s for Tuesday through
Thursday before warming into the middle 70s to around 80 heading
into the weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1239 AM CDT Mon Aug 19 2019

Mainly VFR conditions expected through the TAF period with high
pressure in place tonight and Monday. There is a concern that
patchy fog may develop tonight due to clear skies and calm winds,
primarily at HIB, BRD, and HYR. Relative humidity is already
between 80 to 90 percent at these sites, and while most model
guidance does not suggest any robust fog development, current
conditions and climatology suggest that some light fog may form.
Therefore, included MVFR visibilities during the early morning
hours at these sites. Otherwise, aside from a few clouds skirting
along the International Border overnight, expecting quiet
conditions.

On Monday, southwesterly winds will increase during the midday and
afternoon hours. Most sites will see sustained wind speeds around 10
kt with some gusts around 20 to perhaps 25 kt. A few clouds may
develop through the day, but expecting conditions to remain VFR.
Winds will become light after sunset on Monday.

&&

.MARINE...
Issued at 946 PM CDT Sun Aug 18 2019

No hazardous conditions are expected over the next 48 hours.
Northwest winds will diminish tonight and shift to the southwest
before increasing tomorrow morning to 10 to 15 knots with gusts to
20 knots during the afternoon hours. This will lead to waves of
1-2 feet over most of the nearshore zones, although waves of 2-4
feet will be possible from Silver Bay northward along the North
Shore. This is expected to remain below small craft criteria.
Southwest winds at 5 to 10 knots will then be seen for Tuesday
with waves around a foot or less.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  50  78  58  77 /   0   0   0  30
INL  52  80  57  73 /   0   0  40  40
BRD  50  81  61  80 /   0   0  10  30
HYR  49  78  57  81 /   0   0   0  40
ASX  51  80  59  82 /   0   0   0  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

UPDATE...KC
SHORT TERM...JJM
LONG TERM...BJH
AVIATION...JS
MARINE...BJH/GSF


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.