Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 42 43 44 45 46 47 48 49 50

196
FXUS63 KMPX 251108
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
508 AM CST Sat Nov 25 2017

.UPDATE...
Issued at 502 AM CST Sat Nov 25 2017

Updated to include 12z aviation discussion below.

&&

.SHORT TERM...(Today and tonight)
Issued at 230 AM CST Sat Nov 25 2017

Surface analysis early this morning shows a cold front draped
nearly E-W over northern Minnesota with extensive surface high
pressure occupying much of the central and south- central CONUS.
The cold front originates from a surface low just north of Lake
Superior and after dropping into northern Minnesota extends WNW
into North Dakota and southwestern Canada. Aloft, the north-
central CONUS is caught in solid northwest flow aloft due to a
large longwave eastern NOAM trough and a deep western NOAM ridge.
Over the next 24-30 hours, aside from a slight eastward shift in
these large-scale features, the pattern of northwest flow aloft
over the Upper Mississippi River valley region will not change.
What this flow will allow is for the cold front, which per early
morning surface observations amounts to nothing more than a
dewpoint drop and wind shift aside from the noticeably colder
temperatures, to drop south southeast through both Minnesota and
Wisconsin during the day today. By definition, cold air advection
will occur with this cold front but barely any change in cloud
cover can be expected. Thus, even with mostly clear skies through
the day today, highs will only hit the mid 30s to mid 40s;
obviously quite the change from the 50s and 60s the WFO MPX
coverage area experienced yesterday. Clear skies will be
maintained overnight but winds will drop off to light and variable
as the aforementioned cold front lifts back north as a warm front
associated with another southern Canadian low pressure center.
Even with the passage of the warm front overnight, which will then
shift winds to a more southerly direction close to daybreak, no
sensible effects will be felt. In fact, the cold air already in
place will allow for a return to slightly below normal
temperatures for lows early Sunday morning. Lows will range from
the lower 20s in western WI to the upper 20s and lower 30s in
western MN.

.LONG TERM...(Sunday through Friday)
Issued at 230 AM CST Sat Nov 25 2017

The longer term concerns are minimal significant weatherwise.
Temperature trends remain the main concern as mild westerly flow
continues.

Sunday should be continued mild with plenty of sunshine as heights
aloft build over the cwa. Southerly winds develop later Sunday
night and should help keep temperatures falling off too much to
the southwest as the Pacific warm front begins to move into the
area.

Monday looks very warm again for the cwa. We should see at least
similar temperatures to Fridays highs. The front is slower and is
dry with perhaps some highs clouds in the morning. This brings the
favorable thermal ridge into the southwest during the afternoon.
We were able to mix to about 890 mb Friday afternoon and the GFS
has at least 900 mb. Straight mix down yielded upper 60s to the
southwest, which doesnt look too bad. If these trends continue we
will have to bump Monday highs a little more, especially to the
southwest. This could bring readings close to record highs.

Record Highs for November 27
MSP - 64 1998
STC - 58 1998
EAU - 67 1998

The front moves through Monday night cooling readings somewhat.
It still looks like overall pattern remains with the potential of
at least 5 to 10 degree above normal trend will continue.

The next threat of precipitation arrive later Wednesday possibly
into early Thursday as the deterministic models now bring a
northern stream trough through the cwa. The blended guidance
decreased PoPs further as far as coverage, leaving just the
northeast cwa. This looks good for the moment as the models have
diverged on handling the flow pattern after midweek.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 502 AM CST Sat Nov 25 2017

VFR conditions throughout this TAF set with possibly some high
cirrus drifting across the region from time to time. NW winds
5-10kt today will become light and variable this evening through
the overnight hours then pick up from the south to southwest at
around 5 knots after daybreak Sunday.

KMSP...No significant weather impacts expected.

/OUTLOOK FOR KMSP/
Mon...VFR. Winds SE 10-15G25 kts.
Tue...VFR. Winds NW 10-15 kts.
Wed...VFR. Winds S 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&

$$

UPDATE...JPC
SHORT TERM...JPC
LONG TERM...DWE
AVIATION...JPC



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