Area Forecast Discussion
Issued by NWS Twin Cities, MN
FXUS63 KMPX 260013
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
713 PM CDT THU AUG 25 2016
.SHORT TERM...(This evening through Friday)
Issued at 315 PM CDT Thu Aug 25 2016
A "Fall" type air mass has swept across Minnesota and western
Wisconsin today with cold air stratocumulus diving south-southeast
across the northern half of the state. Mid afternoon temperatures in
central Minnesota were held in the low to mid 60s which is more
typical of mid September, than late August.
The main forecast concern tonight is the formation of fog,
especially near the river/stream valleys as temperatures fall into
the 50s. Although the ingredient are set up for fog to develop with
clearing skies and light winds, I have a problem with another short
wave moving northeast across the Plains later tonight. This short
wave will likely have some cloud cover with it, so it may limit
totally clear skies. In addition, these clouds may help keep
temperatures from falling too low. Anyway, not much change on Friday
with a few clouds (No rainfall), and a light and variable wind.
Temperatures will be similar to today as highs rise back into the
60s and 70s.
.LONG TERM...(Friday night through Thursday)
Issued at 315 CDT Thu Aug 25 2016
The longer term starts out on the cooler side with timing of the
initial trough/front the main concern into Saturday night. Then
the overall warming trend into midweek.
The deterministic models all lift higher PW air into southern
Minnesota later Friday night in advance of the incoming Dakotas
trough. The GFS is farthest north with its weak surface low and
heavier rain band associated with the trough. The NAM and
Canadian continue their more southern track across southern MN
into Wisconsin...with the 12z ECMWF more split with the
trough...with a southern stream system lifting northeast over the
region and the main upper trough lagging further west. This splits
the precipitation pattern over the area with the other models
handling a more phased trough. It still should provide a good shot
of rain and thunder across the region late Friday night into much
of Saturday. We continued to trail off pops from west to east into
Saturday night...and will continue a dry day for Sunday as the
Whatever front moved through into Sunday will begin to lift north
again as a warm front into midweek. The GFS continues its overall
trend of increasing heights over the area with the surface
boundary lifting into northern MN. This should leave the overall
focus for rain and thunderstorms across northern MN...with perhaps
small threats of some "ring of fire" type activity along the
northern bribery of the area. The ECMWF is a bit slower and
flatter with the flow pattern early in the week...but brings a
significant trough onto the west coast by Thursday...lifting the
surface front into northern MN. This may leave the area close to
the nearly stationary boundary early...but we should see
temperatures warm back into the lower and mid 80s with increasing
dewpoints/humidity by Wednesday regardless. This pattern should
hold through then through at least the work week.
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 708 PM CDT Thu Aug 25 2016
The clouds cover is on the decrease across WI and the southern
half of MN. VFR is expected at most airports tonight and tomorrow.
A few sites could get fog late tonight (KEAU-KRNH-KSTC), although
that`s not a sure thing. Fairly dry out there, but it will also
get quite cool tonight, which cold favor fog or dew.
VFR with no aviation weather concerns until Friday night.
/OUTLOOK FOR KMSP/
Sat...MVFR/IFR psbl. TSRA likely. Wind E-SE 5-10 kts.
Sun...VFR. Wind S-SW 5-10 kts.
Mon...VFR. Wind S 5-10 kts.