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fxus63 kdmx 230809 
afddmx

Area forecast discussion
National Weather Service Des Moines Iowa
309 am CDT Wed Oct 23 2019

Discussion.../today through Tuesday/
issued at 309 am CDT Wed Oct 23 2019

Biggest concerns through the forecast period are on precip
chances and type today into early evening. Currently have an area
of weak high pressure that has been in place across the area
overnight with the main upper trough that impacted the state the
past few days having lifted into Ontario toward Hudson Bay.
Another upper level shortwave trough is digging into the northern
rockies/northern plains currently with the trough breaking apart
into different pieces as it drop southward through the central US.
One lobe will transition more eastward swinging through Iowa
today before lifting toward the Great Lakes region tonight. A weak
surface reflection is evident across central/western South Dakota into
northern NE with the sfc low expected to track eastward across
central and southern Iowa by late today before pushing into
northern Illinois this evening. This system is producing some
light precipitation across western South Dakota and into northern NE
currently, with a band of precipitation expected to pivot across
northern Iowa and into portions of central Iowa as the wave digs
through the region today. Initial precipitation expected to be
rain with warm air advection through the morning hours, however into the
afternoon cooling aloft will likely allow for a transition to a
rain/snow mix to develop across far northern Iowa. With northerly
flow at the surface and aloft, and cold air advection by mid/late afternoon,
expect surface temperatures to cool across the far north with the
potential to transition to all snow possible. Current model
temperatures trends seem to be too warm given current readings, so
have trended temperatures cooler toward some of the high-res
blends which should only warm temps to around 40 or into the low
40s north. If temperatures trend cooler than currently projected
toward the hrrr/rap solutions some light accumulations of snow may
be possible toward Estherville on grass and elevated surfaces.
For now ran the grids with mainly a rain/snow mix and little or no
accumulations across the far north.

Precipitation should quickly diminish into early evening as the wave
lifts off to the northeast with mainly low clouds remaining across
the area as another weak lobe of energy rotates southward around the
main upper low off to the northeast. A large area of high pressure
then builds into the region for Thursday with cool and dry
conditions expected. One of the pieces of energy from the initial
system dropping into the central US today will shove southward and
intensify over the Southern Plains by late week, before lifting off
to the north and east Friday into Saturday. This system will just
skirt that area bringing some small chances for precipitation to
mainly the southeastern forecast area by Saturday with moderating
temperatures for the weekend.

Another large upper trough will come slamming into The Rockies and
central US to end the weekend with a strong cold front sweeping
through the state Monday. This will send a much colder airmass into
the state for much of next week with some potential precipitation
chances toward Tuesday into Wednesday. The ec is much more bullish
than the GFS toward early next week, so confidence in precipitation
is lower during that time frame. However both solutions show the
cold into the state, so expect lows and high well below the seasonal
averages for much of next week as h85 temperatures fall to around -5
to -10c. This could yield Max temps in the 30s to low 40s with lows
into the 20s by midweek.

&&

Aviation.../for the 06z tafs through 06z Wednesday night/
issued at 1228 am CDT Wed Oct 23 2019

Increasing clouds through the period with ceilings becoming MVFR
through the day and remain tonight. Could even see some IFR
conditions across the north, and have highlighted with a sct deck
mention. Some light precipitation possible up north today.
Westerly to southwesterly winds to become more southerly then
shift around to the north to northwest through the period.



&&

Dmx watches/warnings/advisories...none.

&&

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