Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 211630
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1130 AM CDT SUN AUG 21 2016

.UPDATED for 18z aviation discussion...
Issued at 1127 AM CDT Sun Aug 21 2016

&&

.SHORT TERM...(Today and tonight)
Issued at 400 AM CDT Sun Aug 21 2016

Today and tonight...Surface analysis this morning puts a low
pressure center in the middle of the Great Lakes region with its
associated cold front extending nearly due south along the IN/OH
border then through the MO bootheel. There is a secondary weak
cold front sweeping through NE MN and much of WI, and this feature
looks to swing through the Great Lakes during the day today.
Behind these features, surface high pressure oriented over the
central Plains and extending northward will slide across the
region today through tonight. Meanwhile, aloft, a longwave trough
axis associated with the Great Lakes low will slowly move east
while a longwave ridge builds over the Rockies, keeping the area
within northwest flow today. Upper level heights will increase
slightly today which, when combined with the surface high, will
keep the area mainly clear throughout the next 24 hours. This will
result in not only plenty of sunshine today followed by clear
skies tonight but also an increase in temperatures. Highs will
climb to the upper 60s in western WI along with highs in the lower
to middle 70s in central- southern MN. Tonight, lows will range
from the lower 50s in western WI to the upper 50s in western MN
and in the Twin Cities metro.

.LONG TERM...(Monday through Saturday)
Issued at 400 AM CDT Sun Aug 21 2016

Tomorrow will bring a strong warming trend in strong southerly
flow as we remain in between a high pressure area over the Ohio
river valley and a low in southern Alberta. In terms of wind
speed, 20-25MPH winds with gusts in the 30-35MPH range still look
likely.

Surface cyclogenesis out ahead of a deeply amplified upper trough
is expected Tuesday to our west with a cold front set to push into
the Dakotas during the day. Ahead of the front, we`ll see
continued warm air and moisture advection as surface dew points
rise into the upper 60s. This will set the stage for likely
thunderstorm development ahead of the cold front Tuesday night
that will push through our area overnight. Generally we do not
expect severe weather with this system but can`t completely rule
it out. Very heavy rainfall in some of the stronger storms is
the more prominent threat as a lack of shear combined with PWAT
values rising to around 1.75" would indicate the potential for
heavy rainfall rates.

The cold front will push through Wednesday morning and will be
followed by another cool down to highs falling back into the
middle 70s across the region. Broad high pressure will work in
behind this system for late in the week, but a shortwave trough
may produce more thunderstorm activity in MN and WI friday night
through Saturday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1127 AM CDT Sun Aug 21 2016

VFR conditions throughout. Northwest winds will become westerly,
and then southwesterly tonight. Winds will be southerly on Monday,
with gusts over 20kts by late morning.

KMSP...
VFR conditions throughout. West northwest winds will become
westerly, and then southwesterly tonight. Winds will be southerly
on Monday, with gusts over 20kts by late morning.

/OUTLOOK FOR KMSP/
Tue...VFR. -TSRA possible late. Wind SSW 15-20G25 kts.
Wed...VFR with -TSRA/MVFR possible. Wind SW 5-10 kts becoming W.
Thu...VFR. Wind NW 5-10 kts.

&&

.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&

$$

SHORT TERM...JPC
LONG TERM...SPD
AVIATION...JRB



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