365 
FXUS63 KMPX 232355 AAA
AFDMPX

Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
655 PM CDT Fri Apr 23 2021

.SHORT TERM...(This evening through Saturday night)
Issued at 322 PM CDT Fri Apr 23 2021

Surface analysis this afternoon depicts a weak low pressure center  
over southwest MN along a cold front extending NE into the Arrowhead 
and then WSW over northern Nebraska, southern Wyoming and southern 
Idaho. High pressure is nudging southward from western Canada into 
Montana and the Dakotas. Aloft, the north-central CONUS remains under
the influence of a broad longwave trough associated with an upper 
level low in northern Canada. One notable axis is to the west of the 
aforementioned Upper Midwest surface low.

Scattered rain showers are north of I-94 and east of I-35 this  
afternoon and will continue shifting off to the north and east 
through the rest of this afternoon and evening as the upper trough 
axis nudges the cold front east. Some modest lift with the sharpening
of the trough axis may allow additional rain/snow shower development
over the northern half of the WFO MPX coverage area overnight, 
resulting in some snowflakes falling close to sunrise Saturday 
morning. If any snow accumulation occurs, it'd be a tenth or two on 
grassy areas. Otherwise, any and all precipitation will shift off to 
the east and diminish overnight through the first half of Saturday. 
Surface high pressure and drier northwest flow aloft will then take 
hold across the Upper Midwest Saturday afternoon and be the 
prevailing influence through Saturday evening, allowing for clearing 
skies and tranquil conditions. 

However, a stronger area of low pressure, currently over the  
Intermountain West and along the aforementioned western front, will 
shift across the Rockies Saturday night into Sunday morning. The 
coldest air of this system will remain in place over the Dakotas and 
Minnesota while isentropic lift increases in advance of this system. 
This will allow precipitation to return to the area early Sunday 
morning over western MN, mainly in the form of light snow. It is with
this stronger system that some snow accumulations are possible but 
there is still plenty of uncertainty on where the focus area of the 
accumulation will be. The proverbial bullseye could be anywhere from 
west-central MN to far southwest MN to along the MN River, so while 
there is fairly good confidence that snow will occur, trying to 
pinpoint the highest amounts is still a bit problematic. Through 
early Sunday morning, highest amounts would be up to about an inch.

Temperatures will remain below climatological normals through  
Saturday night. After highs generally in the 50s area-wide today, 
highs behind the cold front for Sunday will generally run in the 40s,
with some 50s possible near the Iowa border. Lows tonight will range
from the upper 20s to upper 30s, but with cold air advection more 
solid Saturday night, lows will drop to the 20s to lower 30s.

.LONG TERM...(Sunday through Friday)
Issued at 322 PM CDT Fri Apr 23 2021

The typical roller coaster of Spring-time weather continues this   
coming week. Winter will make a brief return Sunday, as snowfall 
appears likely. However, temperatures quickly warm heading into 
Monday, with summer-like temperatures possibly across southern MN 
Monday afternoon. More normal weather returns Tuesday onward along 
with multiple chances for rain.

On Sunday morning, most models show a warm front draped across SD,  
extreme southwest MN, and into northern IA. A band of strong, 850 mb 
WAA will be present over eastern SD and into southwest MN along the 
nose of a southerly LLJ. This WAA band should shift northeast across 
MN during Sunday as the LLJ pushes east. Surface temperatures will be
in the upper 20s to lower 30s at 7am Sunday morning and warming into
the mid 30s as the morning progresses. However, low to mid- level 
temperatures north of the warm front will be cold enough to support 
snow crystal growth. Thus, as precipitation pushes east with the band
of WAA, snow will be the most likely precip type during the morning 
hours until a changeover to rain occurs when temperatures rise to 
well above freezing. In fact, with guidance hinting at the 
possibility of over a half inch of QPF in western MN, there is 
potential for larger snowfall accumulations. The GFS gives further 
support showing very strong lift occurring within the dendritic 
growth zone over Redwood Falls for a 2-3 hour period. Future model 
trends will need to be monitored regarding the snowfall potential. 
Farther east, snowfall accumulations should be minimal. Rain will 
last into Sunday evening before exiting to the east. Forecast highs 
Sunday will be near 40 across western MN increasing to mid 40s east 
and south.

A break in the rain is likely Sunday night before another round of  
light, widespread rain develops Monday morning across the Northern 
Plains. This precip will be generated by strong, southerly WAA as a 
strong 850 mb thermal ridge shifts eastward into the Upper Midwest. 
Precipitation should stay focused across the northern halves of MN 
and WI, meaning only 0.1-0.2" of QPF is possible for our northern 
counties. Monday's high temperatures for the central and northern CWA
will be very dependent on the southern extent of a WAA stratus deck.
If skies fail to clear, highs will be cooler in the low to mid 60s. 
However, any clearing could quickly boost temperatures. Farther 
south, breaks in the clouds are more likely and highs should easily 
reach the mid 70s. Have also boosted winds Monday across southern MN 
to account for strong southerly winds and greater mixing.

Temperatures will return to near normal Tuesday onward as the 
thermal ridge axis shifts east. Another chance of rain is progged 
Tuesday into Tuesday night as an eastward moving cold front follows 
the thermal ridge. One or two thunderstorms may also be possible.

The long-range deterministic and ensemble guidance continues to  
trend drier mid to late next week. The southern stream upper-level 
wave that was supposed to travel northward from the Southern Plains 
has remained farther south in latest model runs keeping our region 
mostly dry Thursday, aside from possibly our extreme southeast. After
Thursday, large model differences build. The GFS shows the Northern 
Plains remaining warmer next weekend while the ECMWF and GEM hint the
possibility of another cool down.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 655 PM CDT Fri Apr 23 2021

Scattered light showers and areas of drizzle continue early this
evening, especially across WI. Stratus will remain in place tonight,
then clear from west to east Saturday with few-scattered CU 
remaining into the afternoon. Cigs should drop to IFR levels across
eastern MN and WI later tonight, with generally MVFR elsewhere.

KMSP...Cigs are VFR for now, but as low pressure pulls away, lower
cigs from the northwest will move in and then likely become IFR
overnight. A small band of rain or snow could rotate through late
tonight as well, but it's expected to be brief. 

/OUTLOOK FOR KMSP/
Sun...-RASN likely early, -RA likely late. MVFR ceilings likely. 
Wind SE 10-15 kts. 
Mon...Chc -RA early. MVFR ceilings likely. Wind SE 10-20 kts. 
Tue...Chc -RA. MVFR ceilings likely. Wind NW 10 kts.

&&

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

$$

SHORT TERM...JPC
LONG TERM...CTG
AVIATION...Borghoff