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fxus63 kdmx 141729 

Area forecast discussion
National Weather Service Des Moines Iowa
1129 am CST Thu Nov 14 2019

Discussion.../today through Wednesday/
issued at 328 am CST Thu Nov 14 2019

Overview...temperatures will be on the rise from today into early
next week with temperatures nearing typical values for the middle
of November by late this weekend and early next week. There are
several passing chances for light precipitation Saturday night and
Monday with perhaps a stronger cold front middle of next week.

Details...early morning GOES-east nighttime microphysics rgb
shows stratus clouds exiting our eastern and southern forecast
area. However, upstream over southern Minnesota there are plenty
of additional low clouds and these will move into much of our
forecast area this morning. Model guidance is not picking up on
this the best, but climatology would have the clouds persisting
into Iowa. These should break up and move out late this morning
into this afternoon. There have also been some flurries over
southwest Minnesota along the Buffalo Ridge. Rap and hrrr
soundings at EST have dry mid-levels and the moisture that is in
the low levels is less than 1km with top down drying also expected
over time. So, will keep mention of flurries out at this time.
Cooler air will filter into the state today on light breezes from
the northwest that will become from the west this afternoon as
high pressure moves across the region.

Milder air will arrive tomorrow with temperatures steadily moving
upward into this weekend as mid-level heights rise. The next trough
that will bring light precipitation chances Saturday night is
currently over the Gulf of Alaska/North Pacific. This trough will
remain positively tilted and traverse the southern Canadian
provinces and northern states Friday night through Saturday. While
the surface low will be well north of Iowa, there will be plenty of
qg convergence along with a surface cold front that will pass
through the state Saturday night. Overall, there is not a lot of
moisture with this system, but global models and wpc all paint low
quantitative precipitation forecast over at least part of our area. This will quickly exit Sunday
morning with northwest flow allowing the next shortwave trough to
come down Monday. This will bring another chance for generally light
precipitation over the area. Depending on surface temperatures and
warmer temperatures in the low levels, there is a non-zero chance of
a wintry mix. For now, will keep just rain and snow mentions. This
shortwave will continue to move southeastward away from Iowa and
help to carve out a longwave trough over the eastern US with ridging
building into the center part of the country. There is disagreement
between the GFS and European model (ecmwf) with a possible longwave trough moving
ashore the West Coast during this timeframe with the European model (ecmwf) having a
cutoff low moving down the West Coast. The GFS takes the longwave
trough and brings it into the center part of the country with
possible phasing with a northern stream wave. With the European model (ecmwf) mid-
level cutoff low still lagging behind, this phasing with a northern
stream wave does not occur. Both have precipitation and with warm
air advection likely, this may favor more rain than snow toward


Aviation.../for the 18z tafs through 18z Friday afternoon/
issued at 1129 am CST Thu Nov 14 2019

Patchy MVFR ceilings will gradually exit to the south and east
early this afternoon leading to VFR conditions and mostly clear
skies for the remainder of the period. Winds will gradually back
to southwest then south tonight, even going light southeast in
spots Friday morning.


Dmx watches/warnings/advisories...none.


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