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FXUS63 KMPX 261153

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
653 AM CDT Sun Mar 26 2017

.SHORT TERM...(Today and tonight)
Issued at 330 AM CDT Sun Mar 26 2017

A vertically stacked low pressure system was located along the IA/MO 
border early this morning. This feature will move slowly northeast 
to the central Great Lakes by Monday morning. A mid level 
deformation zone extends northward from the low, stretching from 
southwest MN through the west metro to northern WI. The deformation 
zone will move a little bit farther west early this morning before 
becoming stationary for the balance of the day. This zone is where 
likely pops were indicated. Farther east, there will be minor short 
waves rotating northwestward around the upper low aiding in bands of 
light rain across the eastern FA. Chance pops were indicated for 
these areas. Rain amounts today will be light and only a few 
hundredths of an inch. The clouds and precipitation will keep a lid 
on high temperatures today. After seeing highs on Saturday only 
reaching the lower to middle 40s with little to no rain, it's hard 
to imagine we would be warmer today. Therefore, went more 40 to 45 
degrees for highs. The cooler readings are to the west of the metro 
under/near the deformation zone. 

For tonight, the flow aloft will become more westerly as the night 
progresses due to the low moving off to our east. This will shift 
the deformation zone and precipitation off to the east as well. 
There will be considerable low/mid level cloudiness through the 
night which should keep dense fog chances at bay considering the 
light rain today/this evening. This will also help keep temperatures 
up overnight with lower to middle 30s forecast.

.LONG TERM...(Monday through Saturday)
Issued at 330 AM CDT Sun Mar 26 2017

Longer term concerns remain model inconsistencies in handling
movement of troughs over the CONUS with split type flow regime. 
Overall lower confidence in trend of the extended...especially in
the Wednesday/Thursday time frame. 

Initially...the remnants of the upper low is forecast to move 
east early Monday. Models are already having issues with how much 
of an influence the secondary upper circulation now over 
Colorado/New Mexico region will affect the eastern portion. We
will hold onto a small chance of light rain lingering at least
during Monday morning. 

After this we should see morning sunshine and warmer temperatures
Tuesday and Wednesday ahead of the next western CONUS trough.
Temperatures win the 50s should be common. Clouds will already be
on the increase Wednesday with a chance of light rain.  

The real inconsistencies arrive for the Wednesday night through 
Thursday night as the GFS and ECMWF diverge on handling the
trough. The GFS still cuts it off from the northerly flow 
resulting in a flatter, further south solution and keeping our 
region mainly dry. The ECMWF continues to show a merging of the
northern stream trough and southern stream upper low. Moisture is
lifted north ahead of the trough and does affect the area. It is 
ejected more easterly an even stronger trough moves 
ashore over the west coast. What I was able to discern from the 
Canadian too brings more of the southern stream 
influence into the region with a better shot of at least some 
rain. We will continue the middle of the row scenario...and hold 
onto the chance PoP scenario for now. With more clouds 
expected... temperatures will be held at bay as well...with upper 
40s to lower 50s a good bet. 

The upper flow pattern remains fairly active. We should see dry 
conditions Saturday into between systems. Timing of 
the next trough brings another chance of rain later Sunday into 
early next week. 


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 653 AM CDT Sun Mar 26 2017

Low MVFR/IFR ceilings will occur today and tonight as a low
pressure system over SE IA moves slowly NE. One band of rain will
exist through much of the day from near KRWF on NE through KSTC.
This represents the mid level deformation zone. There will be
bands of -ra/-dz that will rotate NW across western WI and SE MN,
keeping the eastern TAF sites in periodic precipitation today. N
to NE winds today less than 10 knots becoming light NNW tonight.

KMSP...Confidence high on IFR ceilings through the day with low 
MVFR ceilings tonight. Although the main band of rain will be just
to the west and north of the airfield today, there will be minor
bands that will rotate NW across the airfield causing periods of
rain and drizzle, especially into early this afternoon. 


Mon...MVFR early, then VFR. Wind N 5 kts. 
Tue...VFR. Wind NE 5 kts.
Wed...VFR. Wind SE at 10kts.




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