Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
FXUS63 KMPX 100916

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
416 AM CDT Thu Aug 10 2017

.SHORT TERM...(Today and tonight)
Issued at 411 AM CDT Thu Aug 10 2017

A cool and cloudy day is expected today, with cyclonic flow
fostering scattered showers, along with a potential for isolated
thunderstorms given relatively steep lapse rates during the
afternoon. In the meantime, patches of dense fog will be possible
prior to and shortly after daybreak in locations that cleared out
temporarily near the front. Highs will top out 10 to 15 degrees
below normal, which translates to upper 60s to mid 70s.

Clearing ensues across the Minnesota portion of the area tonight,
which will bring the potential for fog development as lows dip into
the mid to upper 50s.

.LONG TERM...(Friday through Wednesday)
Issued at 411 AM CDT Thu Aug 10 2017

Again no huge concerns in the extended with some rain possible in
west central/southwest MN Saturday night/Sunday with no other
systems of significance that may bring more widespread rains until
the middle of next week. Temperatures will run on the cool side
through the weekend with highs only in the 70s, but we will start to
warm next week, with 80s becoming more common by the middle of the

Concerns in the long term don`t really start until the
second half of the weekend, with a surface high keeping us mild and
dry Friday and Saturday. This weekend, we`ll see another shortwave
work around the upper low centered near Hudson Bay. This wave will
be rather diffuse with a positive tilt, working south across the
Canadian Prairies Friday, east across the Dakotas on Saturday, then
across southern MN for Sunday. Forcing with the upper wave looks
weak, with no surface reflection of the wave expected. In addition,
mid level lapse rates around 6 C/km and surface dewpoints in the 50s
will limit instability build up. It all adds up to it looking dry
this weekend, with a cloudy Sunday as mid/upper level clouds work
across the area with the shortwave.

Next week, upper level shortwave energy will begin pouring into
western Canada, which will work to flatten and push the western
ridge east. That ridge will be working across the upper MS valley
during the first half of next week, keeping us dry. As we make the
transition to the west side of the ridge and more zonal flow, models
continue to indicate a boundary working across the region
Wednesday/Thursday. Although all of the guidance shows a boundary
working through this period, there is still a good deal of spread in
terms of timing, strength of forcing, and the degree of moisture
return ahead of it, but with dewpoints looking to return to the 60s
and temperatures into the 80s, we`ll have the potential to have a
bit more instability to work with for this go around.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1115 PM CDT Wed Aug 9 2017

A complex of TSRA/SHRA in a band 30-50 miles wide west of the Twin
Cities, will continue to move eastward across far eastern
Minnesota, and into west central Wisconsin before 9z. Otherwise,
MVFR/IFR cigs will develop in west central/central Minnesota and
expand south/southwest in the pre dawn hours, and likely continue
through the morning before lifting to VFR Thursday afternoon. A
few SHRA are possible by mid/late morning as the main storm system
rotates across central Minnesota. An isolated TSRA is also
possible, but not likely.


The complex of SHRA/TSRA west of the airport as of 415z, will move
across the airport between 5-7z with a period of 2-3SM in +SHRA.
This area of precipitation will move out by 7z, with MVFR,
possibly IFR cigs during during the pre dawn hours. Confidence
remains low on these cigs, but enough to continue the trend in the
TAF. These cigs will begin to lift and become VFR by the
afternoon. A few SHRA are also possible during the
morning/afternoon time frame. Winds will become west/northwest
Thursday morning, and more north Thursday afternoon.


Fri...VFR. Wind N 5-10 kts.
Sat...VFR. Wind NE 5 kts.
Sun...VFR. Slight Chc SHRA/TSRA afternoon. Wind ESE 5 kts.




AVIATION...JLT is the U.S. government's official web portal to all federal, state and local government web resources and services.