Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 280343
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1043 PM CDT MON JUN 27 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 358 PM CDT Mon Jun 27 2016

The main forecast concern overnight is the formation of fog,
especially in central/east central Minnesota and into west central
Wisconsin. Although temperatures will fall into the 50s overnight,
crossover temperatures, and little mixing in the boundary layer are
more in line of just patchy fog. However, the typical areas of west
central Wisconsin once skies clear, will have a good setup of ground
fog to form. This is a good night to use the vis/fog satellite
imagery and see how things develop. Otherwise, no other concerns as
high pressure dominates the Upper Midwest. Tuesday will have less
cloud cover with temperatures slightly warmer due to almost full
sunshine.

.LONG TERM...(Tuesday night through Monday)
Issued at 358 PM CDT Mon Jun 27 2016

For the extended, only seeing a couple of chances for precip Wed/Thu
and again Mon/Tue of next week. Temperatures this week will
generally run on the cool side of normal, but we will start to see
both temperature and humidity creep up toward the Fourth of July.

Large scale pattern evolution. Wednesday through Saturday, we will
be in NW flow as a closed h5 low slowly tracks across the Hudson Bay
region. A positively tilted shortwave dropping through NE MN
Thursday will bring us our first chance for Precip. On Sunday, a
powerful wave will start digging down the west coast of North
America, with upper ridging beginning to drift out across the
Plains. Pieces of this western trough will begin impacting our
region as early as Monday.

Tuesday night through Thursday. Still a good deal of spread with
this weakly forced front coming through, especially in the timing
department.  The GFS/Canadian swing this boundary through Wednesday
night, while the ECMWF/NAM hold it back for a Thursday afternoon
passage. There is little LLJ support for this wave and the shortwave
driving the front will be going across the Arrowhead. Surface
convergence is limited on the front as well thanks to a baggy
pressure gradient. All of this adds up to the primary driver for
precip chances along the front coming from diurnal destabilization.
If we end up with a GFS/Canadian timing, we will see very little if
any precip with an overnight fropa, with the ECMWF/NAM offering us
our best hope for seeing some scattered activity as they develop 1k-
1.5k j/kg of MLCAPE along the boundary Thursday afternoon. This
instability along with about 30 kts of 0-6km shear and freezing
levels down around 10k feet will give us at least a marginal threat
for seeing some marginally severe hail. Behind this front, dry high
pressure from Canada will lead to dry and mild conditions Friday and
Saturday.

Bigger changes in the models were noted for the system toward the
beginning of next week.  Though timing differences still exist, with
the ECMWF bringing a cold front across the upper MS Valley Monday,
with the GFS going for Tuesday, both saw a significant increase in
speed with which energy ejects out of the PAC NW wave. At this
point, we just have some slight chances PoPs over MN on the 4th
given the spread. At the very least, the holiday weekend will
feature increasing temperatures and humidity with any thunderstorm
chances holding off until the 4th if we are to see anything.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1043 PM CDT Mon Jun 27 2016

The main concern overnight is the low cloudiness stretching from
central and northeast MN on eastward across much of WI. The clouds
are associated with troughing and cold air aloft. Movement of the
back edge in northern MN is SSE near 18 knots. Some acceleration is
expected overnight as the trough upstairs is moving much faster.
Therefore, had to hold on to more bkn-ovc through much of the
night from KSTC and the Twin Cities on eastward. There is a pretty
good chance that a brief period of MVFR ceilings will be
encountered at KRNH after 06z and a temp group was inserted.
Otherwise, light winds overnight and Tuesday as surface high
pressure passes by.

KMSP...bkn-ovc045 will occur at the start of the taf period with
clearing expected just before daybreak. There is a small threat
that the ceiling could dip to 030 for a short time after 08z.

/OUTLOOK FOR KMSP/

Wed...VFR. Isolated SHRA/TSRA late. Southwest wind 5 kts.
Thu...VFR. Scattered SHRA/TSRA early. Northwest wind 5 to 10 kts.
Fri...VFR. Northeast wind 5 kts.

&&

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

$$

SHORT TERM...JLT
LONG TERM...MPG
AVIATION...RAH



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