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Area forecast discussion 
National Weather Service Duluth Minnesota
1246 am CDT Thursday may 7 2015

Update...
issued at 1245 am CDT Thursday may 7 2015

Updated aviation section below.

Update issued at 912 PM CDT Wednesday may 6 2015

A quick update to freshen up the latest trends. Updated aviation
section below.

&&

Short term...(this evening through Thursday night)
issued at 319 PM CDT Wednesday may 6 2015

A broad area of low pressure extended from the southeast
sk/southwest mb area into northwest Kansas this afternoon. Low
pressure will move into the eastern Dakotas tonight...then into
Minnesota on Thursday and drag a cold front through the region
into Friday. Few echoes were occurring as of 20z over our
County Warning Area...with a line of showers and storms from western Minnesota
into southeast Iowa with more showers over northwest Minnesota.

Moisture will continue to increase tonight and precipitable water values are
expected to rise 1 to 1.3 inches by 12z...and remain that high
through Thursday. Precipitable water values are expected to be around 1.2
inches at inl around 12z...that puts them near the highs for this
time of year. A southerly low level jet...with 850mb winds from 40 to 50 kts
will develop across the region tonight. The axis of strongest
moisture transport will nose into southern parts of Northland
around 12z...then continue north through the day gradually
shifting into our eastern County Warning Area in the afternoon then moving east
late Thursday night. Showers will becoming increasingly more
likely late tonight into Thursday from west to east. We kept a
mention of thunderstorms tonight into Thursday morning...but
coverage may be limited until Thursday afternoon when better
instability develops. Showers and storms will gradually diminish from
west to east Thursday night as the better forcing and the low
level jet shift east.

In addition to the shower threat...fog may develop late tonight
and last into at least Thursday morning. Areas around Lake
Superior will have the best chance at seeing some fog.

Long term...(friday through wednesday)
issued at 319 PM CDT Wednesday may 6 2015

There could be lingering light rain showers over the Northland
Friday morning in the wake of the cold front that will have passed
through the region Thursday night and early Friday. High pressure in
Canada will build into the region...providing cooler and drier
weather for Friday afternoon through Saturday.

An upper level low will cross through the American southwest Friday
and Saturday and lift into the plains Saturday night and Sunday. It
will become a stacked low pressure system by Sunday once it meets
its surface reflection in the Central Plains. This stacked low will
lift NE into the Iowa/MN/WI region Sunday night and Monday. The
GFS/ECMWF/Gem models have some noticeable differences in the track
of the low...but are still indicating the potential for the
Northland to get rainfall Sunday night through Monday night as the
low moves through the region. The GFS and Gem have similar low
tracks...from northwest Iowa to just north of Green Bay. The European model (ecmwf) is a
little farther south. Leaned on a blend of the three models. The
northern forecast area will likely have the lowest chances of
getting rainfall because of the dry NE flow from Ontario which may
shunt the showers farther to the south. Temperatures will be cool
Sunday and Monday.

The European model (ecmwf) and GFS indicate surface high pressure will move back into
the Northland during the Tuesday and Wednesday timeframe.
Temperatures will should trend back to near normal by Wednesday.
There could also be an upper level low over Ontario at this time.
The cooler air aloft means late morning and afternoon scattered
cumulus clouds are likely Tuesday and Wednesday...so avoided
forecasting sunny skies.

&&

Aviation...(for the 06z tafs through 06z Thursday night)
issued at 1245 am CDT Thursday may 7 2015

Mainly VFR-MVFR ceilings and visibilities across northern
Minnesota and northwest Wisconsin as of 05z. Some isolated showers
expected the next few hours...bringing MVFR ceilings and
visibilities. With the moisture continuing to pump up into the
area...expect some lowering of cloud bases...and terminals should
see development of MVFR ceilings the next few hours. A strong low
level jet of 35-45kts has produced low level wind shear over the terminals which
should continue through approximately 12z when surface winds
increase. The next wave of showers to push through the terminals
beginning around 09z...bringing IFR-MVFR ceilings and visibilities
for a few hours...before once again returning to VFR. Another wave
of showers with some thunderstorms will push through the terminals
beginning around 15z...and may bring a period of thunder with MVFR
ceilings and IFR visibilities with stronger cells.

&&

Preliminary point temps/pops...
dlh 47 58 39 55 / 80 20 10 0
inl 41 53 35 57 / 60 20 0 0
brd 45 57 39 61 / 70 10 0 0
hyr 55 63 40 60 / 80 30 10 0
asx 54 62 40 53 / 70 30 10 0

&&

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

$$

Update...le
short term...melde
long term...grochocinski
aviation...le

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