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fxus63 kfsd 140811 

Area forecast discussion
National Weather Service Sioux Falls South Dakota
211 am CST Thu Nov 14 2019

Short term...(today and tonight)
issued at 152 am CST Thu Nov 14 2019

Stratus will continue to pivot southeast across the eastern third of
the forecast area into Thursday morning. A few reports of flurries
within this stratus as the relative humidity layer remains situated right at the -
12c layer.

Today: rather quiet conditions are expected today, as surface winds
begin to turn more westerly in direction. Temperatures will climb
into the 30s in many areas, with 40s possible west of the James
River Valley.

Tonight: models indicate that another subtle shortwave will cross
into the western Great Lakes, dragging a backdoor cold front
towards the area eastern zones overnight. Further southwest,
fairly strong warm advection will develop overnight and will keep
temperature in the 20s in most locations. Condensation pressure
deficit plots indicate that an area of stratus is likely to drop
southward towards the area after midnight, and given the alignment
of the 925:850 mb ridge axis this stratus may dip as far south as
Huron, Sioux Falls, and Storm Lake. The NAM/arw/nmm all seem far
too aggressive in developing widespread fog and stratus, likely
due to the cold/moist bias in the boundary layer.

Long term...(friday through wednesday)
issued at 152 am CST Thu Nov 14 2019

Friday: there is decent potential that this stratus gets trapped
under the warm layer above it on Friday, and have increased cloud
cover over a fairly large area. Have generally followed the
rap/gfs1hr guidance for stratus placement. The cooler southeasterly
surface fetch won't help our cause either, and have lowered
temperatures where this stratus is likely to remain.

Friday night: agree with previous forecaster that overnight lows
Friday night should remain on the warmer side of the guidance
cluster, especially given the broad increase in mid-lvl cloud cover.

Saturday-Saturday night: models continue to show a progressive
shortwave moving through the northern plains Saturday into Saturday
night. Ahead of this boundary, temperatures should rise near to
above normal in some locations. Moisture remains limited with this
system, so pops will remain low, with minimal impact from any light
precipitation that falls.

Sunday: weak cold advection moves through by Sunday morning, but the
Pacific nature of the wave really doesn't bring any significant
cold air behind it. Temperatures are likely to climb back into the

Monday-thursday: we'll transition to a rather progressive pattern
for much of next week. No significant systems on the horizon next
week, but a few nuisance systems moving through Monday and again
towards Wednesday. Right now, no strong signal in guidance for
concentrated higher pops, so will maintain broad 20 pops. High
temperatures remain near to slightly below normal with low
temperatures a few degrees either side of normal.


Aviation...(for the 06z tafs through 06z Thursday night)
issued at 1027 PM CST Wed Nov 13 2019

VFR conditions are expected through the taf period. MVFR stratus
presently over northeastern South Dakota may stream southward through
southwestern Minnesota during the night, though is not expected to
affect taf sites.


Fsd watches/warnings/advisories...
South Dakota...none.

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