← Previous May 30, 2023 4:06 AM

FXUS63 KMPX 300906

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
406 AM CDT Tue May 30 2023

.DISCUSSION...(Today through Monday)
Issued at 406 AM CDT Tue May 30 2023


- Showers likely with a few thunderstorms this morning, then
  thunderstorms redevelop this afternoon. A few storms could contain
  large hail and heavy rain later today.

- On and off thunderstorm chances will continue into early next week.
  Widespread precipitation is not expected beyond today, but storms
  could drop heavy rainfall totals in localized areas. 

- Heat and humidity build through the rest of the week with highs 
  likely reaching the lower 90s by Thursday or Friday area wide.

A weak MCV has become more progressive early this morning across
southwest MN and is spreading showers and a few thunderstorms into
south central and east central MN. SPC mesoanalysis highlights
weakening instability in these areas, but modest 925-850 mb moisture
transport vectors seem to be compensating some to keep these storms
going a bit longer. Eventually they'll outrun any elevated
instability and dissipate a little later this morning. Showers will
likely continue for the next several hours though and will need to
touch up PoPs in a bit to reflect that better. 

This morning's MCV will shift to the northeast and skies will clear
some by this afternoon. Daytime heating and increased low level
moisture will result in surface-based instability development while a
stronger shortwave tracks northeast across NE SD and NW MN. Depressed
mid level heights with the trough and weak convergence along a
diffuse boundary bisecting the area will provide focus for additional
thunderstorm development this afternoon. Coverage is still a bit
uncertain due to the lack of more focused forcing, but an uncapped
atmosphere and possibly some residual localized boundaries may help
kick off initiation. Any storms would be slow moving with a fairly
uniform wind flow throughout the column, resulting in MBE velocities
less than 10 kts. Additional boundaries created from outflows could
then spark subsequent development into the evening. Wind shear is 
quite weak, but some of the more vigorous updrafts could contain some
hail. The main threat is probably heavy rain though given the slow 
storm motions. Today's activity will slowly diminish tonight with 
loss of daytime heating, but a low level jet across the Plains will 
keep thunderstorm chances going well into the overnight across 
southern MN. 

Rising heights adds a level of complication to redevelopment 
Wednesday despite plentiful surface instability. However, another 
shortwave tracking northeast from the central Plains to western MN 
could be a sufficient focus for development Wednesday afternoon and 
evening across central and western MN. 

Convection chances begin waning late week as the ridge builds over
the Great Lakes and shortwaves or disturbances are shunted westward 
to the High Plains. The heat dome will center itself over the Upper 
Midwest Friday with 925 mb temps maximizing around +26C. This should
get us into the low 90s area wide, with mid 90s not out of the
question. Deterministic NBM highs of 88-91 were only near the 10th 
percentile, so blended in some 50th percentile to bring them up a 
couple degrees into the 90-93 deg range. Dew points will be low
enough to avoid excessive heat, barring of course any further 
adjustments with air temps upward. Nonetheless, it looks like the
hottest day of the year so far is on the near horizon.

Temperatures will remain above normal into early next week with the 
ridge remaining centered over central North America. The amplitude of
the ridge may weaken some allowing us to return to the 80s. Later
next week, a trough could dive south into the eastern U.S. and
southeast flow may tap into some cooler air but consistency with this
feature has been poor. 


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1207 AM CDT Tue May 30 2023

Scattered thunderstorms continue across western Minnesota, slowly
progressing eastward. The precipitation will slowly weaken 
overnight, with a chance for scattered -shra around daybreak at 
AXN/STC/MSP/RNH. Most of the morning & afternoon will remain dry, but
scattered showers and thunderstorms are expected to develop again
late Tuesday afternoon, especially across eastern MN & western WI. 
SCT/BKN high clouds will persist through the period with winds 
generally southeasterly to southerly around 10 kts.

KMSP...Precip is not expected overnight, but scattered showers are 
expected to pass through Tuesday morning around daybreak. Lightning 
can't totally be ruled out but is not expected. A better chance for 
thunderstorms comes late Tuesday afternoon into the evening.

WED...VFR. Chc aftn/eve TSRA. Winds S 10-15 kts. 
THU...VFR. Chc aftn/eve TSRA. Winds S 10-15 kts.
FRI...VFR. Chc aftn/eve TSRA. Winds SE 10-15 kts.