842 
FXUS63 KMPX 141930
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
230 PM CDT Sun Jul 14 2019

.SHORT TERM...(This evening through Monday night)
Issued at 230 PM CDT Sun Jul 14 2019

Main issue in the short term is for severe weather and heavy 
rainfall potential this afternoon through tonight.

As of early afternoon, a distinct MCV was evident on satellite 
imagery near Aberdeen, SD and is the key feature of interest for 
thunderstorm potential through the remainder of the day. The MCV 
will continue eastward across northeast South Dakota through the 
afternoon, moving across west central MN toward St. Cloud by around 
sunset or just after. Destabilization has been occurring through the 
afternoon east of the MCV with the latest analysis indicating 2,500-
3,500 J/kg MLCAPE. Across western MN, temperatures have warmed to 
around 90 degrees with ample moisture given surface dew points in 
the low 70s. Effective layer shear of 30-40 knots along with the 
strong instabiity will certainly be capable of producing severe 
thunderstorms including supercells. There is however, a cap in place 
across portions of southern MN. Overall, we expect the MCV to be the 
impetus for new thunderstorm development over the next several hours 
and as the MCV moves into a more deeply unstable airmass, expect the 
I-94 corridor in western and central MN to be most at risk for 
severe weather. The main risk with storms this afternoon and evening 
will be severe wind gusts and large hail. SR helicity is somewhat 
limited given fairly limited speed sheer, despite a veering profile 
in the low levels. An isolated tornado or two can't be ruled out, 
however.

Later this eveing, expect ongoing storms to turn ESE feeding into 
the better instabilit to the south as the cap weakens/begins to 
erode. This could lead to strong thunderstorms turning toward the 
Twin Cities metro this evening, and eventually western WI. PWAT 
values will increase to around 2" as moisture pools across the area, 
and the low level jet will increase to 30-40 knots overnight. Hence, 
additional thudnerstorm development will remain possible overnight, 
and heavy rainfall will be the primary threat by then.

Monday will be another hot and humid day, with highs in the low 90s 
and dew points in the mid 70s most likely. There could be morning 
cloud cover left behind from overnight convection, but generally 
expect partly cloudy skies to develop through the day. Continued the 
heat advisory for the metro, and expansion could be possible but due 
to uncertainty with overnight storms and cloud cover, decided to 
keep the advisory as is for now.

.LONG TERM...(Tuesday through Sunday)
Issued at 230 PM CDT Sun Jul 14 2019

Warm and humid weather looks to prevail during the long term 
period, but given model trends toward a weaker ridge and more 
zonal flow over the north central CONUS, it looks less likely to 
be oppressively hot. This change will, however, make for active 
weather in terms of shower and thunderstorm chances. 

Have kept 20-30% precip chances on Tuesday with the baroclinic
zone situated over the area. Higher pops look to be warranted on
Wednesday into Thursday with a cold front passing across the area
and additional support supplied by jet streak upper level 
divergence. After that, confidence decreases given the difficulty
with timing weak shortwaves in the fast westerly flow, so periodic
15-20% POPS can't be ruled out.

Temperatures will mostly range from the mid to upper 80s for highs
and the mid 60s to lower 70s for lows. 

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1256 PM CDT Sun Jul 14 2019

Main issue this period is thunderstorms. Thunderstorms are
expected to develop across eastern South Dakota and expand into
western MN this afternoon. From there, expansion and a turn ESE
will likely lead to storms along the I-94 corridor late this 
afternoon through tonight. Additional thunderstorms development
will be possible overnight, especially across far southern MN.

KMSP...Thinking at this time is thunderstorms after 00Z, timing
confidence is not high, and could foresee an earlier arrival time.
Will need to monitor latest trends and convective initiation this
afternoon.

/OUTLOOK FOR KMSP/
Tue...Mainly VFR. Possible TSRA. Winds light and variable. 
Wed...Mainly VFR. Possible TSRA. Winds S 5 kts. 
Thu...Mainly VFR. Possible TSRA. Winds light and variable.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...Heat Advisory until 10 PM CDT Monday for MNZ060>063-068>070.

&&

$$

SHORT TERM...SPD
LONG TERM...LS
AVIATION...SPD