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FXUS63 KDMX 231058

Area Forecast Discussion
National Weather Service Des Moines IA
558 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 SD 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 SD 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 WAA 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 CAA 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 12Z TAFS through 12Z Thursday morning/
Issued at 558 AM CDT Wed Oct 23 2019

Clouds increasing and expected to lower to MVFR and then IFR by
later today into tonight. Some light rain around this morning, to
become more widespread impacting the northern TAF sites through
the day. Some SN may mix in at times at KMCW late this afternoon.
Have not included in the TAF currently due to high uncertainty.
Winds to shift around to the north to northwest by tonight with
some gustiness. 




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