Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 11/02/22

Area Forecast Discussion

National Weather Service Twin Cities/Chanhassen MN

 615 PM CDT Tue Nov 1 2022

.UPDATE...
Issued at 559 PM CDT Tue Nov 1 2022

Updated to include the 00z aviation discussion below.

&&

.DISCUSSION...(This evening through Tuesday)
Issued at 241 PM CDT Tue Nov 1 2022

KEY MESSAGES:

- Much above normal temperatures through Thursday with records
  expected Wednesday.

- Rain finally returns late week, but the heaviest rain appears
  likely to bypass the extreme drought areas.

Early Tuesday afternoon, aircraft soundings suggest that a strong
inversion remains across the Upper Midwest with little mixing in the
boundary layer. However, it has managed to rise into the mid 60s
prior to 2 pm. At the surface, winds were generally light from the
south/southeast with a bit stronger wind speeds along the South
Dakota border.

Upstream surface observations and soundings suggest that
temperatures will surpass low 70s across a large area of
central/southern Mn, and into west-central Wi on Wednesday. This is
record territory and it will likely break these record highs on the
2nd. Differences from today vs. tomorrow is the amount of mixing in
the boundary layer as winds increase significant by Wednesday
afternoon, and will likely continue into Wednesday evening based on
lapse rates near the surface. Currently, wind speeds will start in
the 15-25 mph range by late morning, and increase to around 20-40
mph by late afternoon, and early evening. I wouldn`t be surprised to
see a few gusts in the 45 mph range in the typical areas across
southern and western Mn. A wind advisory is possible based on the
amount of mixing this time of year and the expected boundary layer
winds. Temperatures Wednesday night will also be very mild with
readings likely holding in the 50s, or possibly low 60s. High
temperatures this time of year are averaging around 50 degrees. As
temperatures only fall into the 50s, this would be at least 20 to 25
degrees above normal for morning lows on Thursday.

In addition to the winds, humidity levels will slowly increase
Wednesday, and into Wednesday night as moisture from the Gulf of
Mexico begins to increase across the plains.

Thursday through Monday night...The slower frontal passage solution
is favored across most model guidance. The cold front will move
through Thursday night into Friday morning. Thursday`s temperatures
are trending warmer, but cloud cover over parts of the area should
limit how warm the high temperatures get Thursday afternoon. Highs in
the upper 60s/low 70s seems like likely. Rain will develop along the
frontal boundary Thursday evening across MN and spread east into WI
overnight. The front will stall over WI Friday and Friday night with
rain expected to continue through most of that time from central IA
to central WI. However, a piece of energy is held back across the
southern Plains and is slower to eject. 12z ECMWF ejects the piece of
energy Friday night with resulting cyclogenesis occurring across the
southern Plains. The Euro solution tracks a deepening low pressure
through SE MN into NW WI. This would result in another round of
widespread precipitation for Saturday/Saturday night. It`s important
to highlight other solutions where the low tracks 100+ miles to the
east with a glancing blow across our west-central WI counties (east
of the most significant drought areas). NBM has increased PoPs into
the 50-60 range as the likelihood of precipitation has increased
across most guidance. Best chances for the second round are still
east of I-35 but if an 12z ECMWF-type solution gains traction, a more
widespread precipitation event would deliver much-needed
precipitation across our forecast area.

The southwest upper flow will be maintained into next week. Another
trough will enter onto the northern Plains Monday/Tuesday which
could bring widespread rain and/or snow to the northern Rockies, ND,
and northern MN. Warm sector precipitation chances will increase the
closer you are to the cold sector, but widespread rain chances
appear lower across much of our forecast area at this time. Model
spread is significant with this system so confidence is low in any
solution.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 559 PM CDT Tue Nov 1 2022

VFR conditions at all terminals through the period. The only concern
is low level wind shear overnight into tomorrow morning as the low
level jet ramps up. LLWS will diminish tomorrow as mixing brings
gusty winds to the surface.

KMSP...Added LLWS to the 6 hour extended portion of the TAF for
Wednesday evening. Otherwise, no addition concerns.

/OUTLOOK FOR KMSP/
Thu...VFR. Chc -SHRA/MVFR late. Wind SSW 10-20G25kts.
Fri...MVFR Chc IFR. -SHRA early. Wind NW 10kts.
Sat...MVFR Chc IFR. -RA or -SN poss. Wind N 10-20kts.

&&

.FIRE WEATHER...
Issued at 241 PM CDT Tue Nov 1 2022

Although wind speeds are expected to increase on Wednesday, humidity
levels Wednesday afternoon are only expected to fall to around 30%
at the lowest and this is based on the 10 percentile of the NBM.
This will need to be monitored if humidity levels are lagging a few
hours tomorrow leading to much lower humidity levels.

&&

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

$$

UPDATE...CEO
DISCUSSION...BPH/JLT
AVIATION...CEO
FIRE WEATHER...JLT