Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 292052

Area Forecast Discussion
National Weather Service Sioux Falls SD
352 PM CDT Wed Mar 29 2017

.SHORT TERM...(This evening through Thursday)
Issued at 352 PM CDT Wed Mar 29 2017

The upper level low presently located over Kansas will move only
slowly eastward overnight, becoming situated over eastern Missouri
by Thursday afternoon. In relation to this, rain chances will remain
likely over the southeastern portions of our CWA tonight, before
waning by late Thursday morning. Additional rainfall amounts will
range from around a tenth of an inch from Vermillion to Worthington,
to as high as three tenths just east of Sioux City to Spencer.  Low
temperatures tonight will be in the mid to upper 30s, and with
temperatures aloft running just under 0 C over parts of the area,
cannot completely rule out that some snow will mix in with any rain
over parts of southwestern MN late tonight. Soundings suggest that
saturation in the dendritic layer over that area will be iffy at
that point, so confidence is not that high, and any impacts would be
minimal anyway with surface temps remaining above freezing.

Otherwise, Clouds will linger in the east on Thursday, where highs
will only be in the lower 40s. Back to the west where more sun is
possible, looking at highs in the lower to mid 50s.

.LONG TERM...(Thursday night through Wednesday)
Issued at 352 PM CDT Wed Mar 29 2017

The low affecting our southeast zones in the near term will be
shifting off further to the east by Thursday night. Behind it
through this area, a surface ridge of high pressure will nudge in
from the northeast continuing a northeasterly fetch of stable air
through Friday night. With at least partial sunshine expected on
Friday, it will be a seasonably pleasant day with highs
in the 50s which is a little above normal.

The next upper and surface low will track across the central and
southern plains this weekend. This far north, we are nearly cutoff
with a zonal northern stream jet extending across the northern tier
of the country. However there is some hookup with the southern
stream jet around the upper low primarily late Saturday afternoon
and evening. These periods will provide the best chances for light
rainfall primarily along and south of I 90, extending northeastward
into southwest MN. But again, rainfall amounts this far north will
not be very substantial. Highs this weekend will continue to be
seasonably pleasant, with a lot of readings in the mid 50s to around
60. Depending on the amount of light rain coverage late Saturday
afternoon, the error for the high may be a little too warm for our
southeast half of our forecast area.

We still are monitoring the next strong system for the Tuesday and
Wednesday time frame. The deterministic ECMWF and GFS solutions
continue to be fairly close with the development and track of this
system. At this time, the atmosphere looks rather stable per the
elevated CAPE and lifted index values off of the GFS. Therefore left
the mention of thunder out of the grids. But it could be more of a
widespread rain maker for the entire forecast area. Highs next week
continue to be mainly in the 50s to around 60 degrees. Continued
above normal but nothing real outstanding in terms of abnormally
warm temperatures for this time of year. With no big wind events
forecast coinciding with low humidity, fire weather conditions look
muted for the next several days.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1207 PM CDT Wed Mar 29 2017

Rain with MVFR ceilings will continue through tonight for
northwestern IA and portions of southeast SD, with MVFR
visibilities possible in heavier showers. KFSD will remain at the
edge of the better rain chances, so expecting little visibility
impacts there. East/northeasterly winds will gust to around 20 kts
at KFSD and KSUX through the afternoon.




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