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Area forecast discussion...updated 
National Weather Service Duluth Minnesota
1240 PM CDT sun may 3 2015

Update...
issued at 952 am CDT sun may 3 2015

A cold front was making progress through the forecast area at 14z
and was located along a brd/ait/gpz/inl line. Thunderstorms were
beginning to fire up south of the Brainerd lakes region at 14z and
should see some impinging on this area soon. Based on these radar
trends and latest hrrr/rap...have made some adjustments for the
rest of today.

Update issued at 653 am CDT sun may 3 2015

Minor update to temperature/dew points this morning as temperatures were
a bit warmer than originally anticipated. Also adjusted winds per
latest short-range guidance on timing of wind shift due to
approaching cold front. Afternoon storms appear well on
track...especially with the showers/storms that traveled farther
east than even our most optimistic thinking. The result of this will
probably lead to enhanced middle-level moisture for storms to take
advantage of this afternoon.

&&

Short term...(today through monday)
issued at 355 am CDT sun may 3 2015

Another mild day today with showers and thunderstorms as a cold
front moves through the region. Slightly cooler and very dry under
sunny skies on Monday.

On the synoptic scale...a longwave trough moves across the
international border region from the northern plains into the upper
Great Lakes today with an associated surface cold front leading to the
possibility of unsettled weather today. An area of high pressure
will move in behind the front on Monday...centered over North Dakota
by Monday morning...which will lead to slightly cooler temperatures and
clearing skies. Incoming airmass will be very dry...but with the
high pressure nearby winds will be light tomorrow.

Today...isolated to scattered showers/T-storms will weaken this
morning before the second and more potent round of showers and
thunderstorms kicks off this afternoon. Have some concerns with
regards to storm initiation...but generally expect storms to fire
19z-22z somewhere between the twin ports the St Croix River
Valley...or perhaps somewhere further east into northwest Wisconsin.
Initiation will be dependent on the near-surface environment...and
it is possible that storms may fire further east if temperatures do not
warm as fast as anticipated this afternoon. Some of the
convection-allowing guidance is depicting such a delay...but the
general operational model consensus is that showers and
thunderstorms will trigger early this afternoon.

A few storms may be strong to severe this afternoon...with the best
chances east of an Ashland to Hayward line. This will be due to a
better low level moisture environment as well as better shear with
effective shear of 40 to 45 knots. Most of the shear will be in the
way of speed shear...and expect convection to congeal into a broken
line of storms by the late afternoon as they race eastward out of
the County Warning Area. Cape will be great in this better environment /due to the
improve low level moisture quality/...with MUCAPE values well over
2000 j/kg. Steep middle-level lapse rates will support the likelihood
for vigorous storm development when storms initiate...and expect the
initial few discrete storms to be capable of large hail and gusty
winds. Once storms begin to merge the primary threat will transition
to locally heavy rainfall...but with the front moving fairly quickly
do not expect any flooding concerns. Rainfall amounts of a tenth to
a half inch today...with the best chances in northwest Wisconsin and
especially on the northwest Wisconsin/Michigan border.

Tonight...dry and cooler air moving in will lead to clearing skies.
Some fog may be possible in the early evening across the South Shore
of Lake Superior...but any fog that develops will dissipate towards
midnight with the drier air moving in. Lows in the middle 30s up by the
international border region to the middle 40s from Interstate 35 east
across northwest Wisconsin.

Monday...dry and sunny. Winds go light and variable in north central
Minnesota due to the high pressure just to the west. Afternoon
relative humidity falling to around 20 percent...with light winds
precluding fire spread risk. Highs not as warm but still above
normal...in the middle to upper 60s inland...cooler by the Lake.

Long term...(monday night through saturday)
issued at 355 am CDT sun may 3 2015

Potential for a wet and unsettled week ahead.

Middle level riding with surface high pressure will remain anchored over
the Northland Monday night...gradually pushing east across the Great
Lakes Tuesday. The high pressure and dry air will allow for strong
radiational cooling Monday night...with overnight lows in the low
30s. Some locations across the Minnesota Iron Range have the potential to
fall into the 20s.

Focus turns to a closed low/long wave trough in the Pacific
northwest that ejects a short wave into the upper plains middle
week...tracking across the Northland through the end of the week.
The prolonged period of return flow and increased moisture will
bring the potential for widespread, long duration, rainfall and
thunderstorms across much of the forecast area Tuesday night through
Friday.

The short wave will lift a warm front into southern minn/wis during
the Tuesday/Tuesday night time frame. The wave deepens into an elongated
surface low in the Dakotas Wednesday/Wednesday night...while continuing to lift the
warm front further north into northern minn and northern wis.

The approaching low/warm front will bring a transition to gusty
southerly winds /except east near Lake Superior/ and increasing
moisture through middle week. Long range models are coming into better
agreement that the short wave/surface reflection low...slowly migrates
east across Minnesota through Friday.

The prolonged period of return flow and increased moisture will
bring the potential for widespread, long duration, rainfall across
much of the forecast area.

&&

Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1237 PM CDT sun may 3 2015

VFR conditinos will prevail through the forecast period. There
will be scattered thunderstorms from kdlh to kbrd and khyr this
afternoon. The storms will develop ahead of a cold front. The cold
front will move through early this afternoon in the kbrd and kdlh
areas...and early this evening at khyr. While winds will gust to
up to 25 kts this afternoon...they will quickly diminish after
sunset. It will again be breezy from the north on Monday.

&&

Preliminary point temps/pops...
dlh 77 43 68 37 / 30 0 0 0
inl 71 37 67 34 / 0 0 0 0
brd 78 43 68 41 / 30 0 0 0
hyr 79 43 68 37 / 60 20 0 0
asx 79 44 66 37 / 70 10 0 0

&&

Dlh watches/warnings/advisories...
Minnesota...none.
WI...none.
Ls...none.
&&

$$

Update...gsf
short term...jjm
long term...graning
aviation...clc

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