Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 202110
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
410 PM CDT WED JUL 20 2016

.SHORT TERM...(This evening through Thursday)
Issued at 410 PM CDT Wed Jul 20 2016

Elevated convection continues to bubble across west central
Wisconsin within the broad synoptic scale warm frontal zone this
afternoon. Ongoing warm/moist advective processes could initiate
additional isolated/scattered TStorms just about anywhere from
NCent/NE Minnesota south-southeastward along this frontal zone
tonight, so we have maintained low chances for precip in these
areas. The next item of concern related to precip will be the
potential for an MCS propagating eastward along the International
Border region overnight and Thursday morning, and we have raised
chances for precip in this area in anticipation of some complex of
TStorms moving across northern Minnesota after midnight. There
likely will be at least some attendant severe weather threat,
primarily wind damage and heavy rainfall.

The other major item of concern is the heat and humidity. The
persistent stratus deck across the western parts of our area still
continues to hang on as of 4 PM, and has basically rendered the
excessive heat warning for Cass/Crow Wing Counties as dead. We
have replaced that warning with an advisory, and also replaced the
watch for NW Wisconsin with an advisory. In an attempt to simplify
things a bit, we also have all heat advisory headlines starting
immediately, and lasting until 9 pm Thursday evening. If things
set up correctly (i.e. clouds or convection, or both) just ahead
of the boundary Thursday, we could skirt with warning thresholds
across NW Wisconsin with dewpoints pooling into the mid/upper 70s,
and this leaves the door open for a local upgrade if it were to
become necessary.

.LONG TERM...(Thursday night through Wednesday)
Issued at 409 PM CDT Wed Jul 20 2016

Main concerns this afternoon are focused on the potential for
strong/severe thunderstorms Saturday and Saturday night.

Cooler conditions will arrive Thursday night across the Northland
behind a departing cool front. Temperatures will return to more
seasonal levels for the remainder of the work week as a quasi-zonal
flow pattern develops. A potent, but compact, shortwave trough will
push east across the Northern Plains and into the Upper Midwest
Friday night and Saturday. Showers and thunderstorms will redevelop
and may become strong. Another shortwave trough will push eastward
into the Northland Saturday afternoon. Strong to severe
thunderstorms are expected with the passage of this feature Saturday
afternoon and evening. Damaging wind gusts and torrential rainfall
will be the main threat. However, the most rambunctious
thunderstorms will be capable of producing very large hail.

Quieter weather settles in for the second half of the weekend
through Monday as upper ridging follows on the heels of the
departing trough. An unsettled pattern returns once again by Monday
night and Tuesday continuing through the end of the period. Several
rounds of showers and thunderstorms are expected, but there is no
clear signal regarding timing or an especially favorable setup for
severe weather. Will need to keep an eye on these trends through the
weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 0116 PM CDT Wed Jul 20 2016

Low stratus deck over north-central Minnesota early this afternoon
will continue advancing northward through early evening. Still
think clouds will mix out and dissipate by late afternoon. Added a
TEMPO group at INL with MVFR CIGS in case clouds do not erode
before arriving. Attention then shifts to precip/thunder chances
overnight and associated lower ceilings and visibilities. Think
previous forecast had the right trend introducing VCTS with a
period of MVFR visibilities and -SHRA. Added some lower visibility
immediately following the most likely time for precip at INL and
HIB. Think conditions will improve once again Thursday morning
after showers/storms move out.

&&

.CLIMATE...
Issued 409 PM CDT Wed Jul 20 2016

Provided below are the record high temperatures for various
locations across northeast Minnesota and northwest Wisconsin.
Please note that other than our two official climate sites (Duluth
and International Falls) the records are considered "unofficial."

Record Highs for Wednesday July 20...

Duluth................98 in 1901
International Falls...97 in 1923

=>Please note stations below are not official climate sites
Brainerd..............97 in 1977
Hibbing...............91 in 2011
Grand Portage.........90 in 1977
Superior..............94 in 2011
Hayward...............102 in 1901
Spooner...............95 in 1940
Hurley................88 in 2011
Grantsburg............94 in 1977
Madeline Island.......88 in 2004

Record Highs for Thursday July 21...

Duluth................93 in 1960
International Falls...96 in 1923

=>Please note stations below are not official climate sites
Brainerd..............99 in 1901
Hibbing...............90 in 2014
Grand Portage.........83 in 1977
Superior..............95 in 1963
Hayward...............95 in 1901
Spooner...............96 in 1934
Hurley................95 in 2011
Grantsburg............96 in 2011
Madeline Island.......92 in 2011

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  70  91  65  87 /  50  50  10   0
INL  71  87  63  86 /  60  30   0   0
BRD  74  93  65  90 /  20  20  10   0
HYR  73  93  64  90 /  30  40  10   0
ASX  72  92  66  87 /  40  40  10   0

&&

.DLH Watches/Warnings/Advisories...
WI...Heat Advisory until 9 PM CDT Thursday for WIZ001>004-006>009.

MN...Heat Advisory until 9 PM CDT Thursday for MNZ025-033>038.

     Heat Advisory until 9 PM CDT this evening for MNZ010-018-026.

LS...None.
&&

$$


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