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Area forecast discussion
National Weather Service Quad Cities Iowa Illinois
543 PM CST Sat Nov 16 2019

..00z aviation update...

issued at 204 PM CST Sat Nov 16 2019

The upper mid Mississippi River valley Sat between high pressure
departing into the Canadian Maritimes and a fast moving storm
moving moving across the southern Canadian prairie with a cold
front that extended southward into the Panhandle of Nebraska.
Some virga was falling from mid level clouds along the Highway 20
corridor. Temperatures at 2 PM ranged from 37 degrees at Freeport
and Dubuque to 46 degrees in far southeast Iowa. Centerville and
Kirksville were the warm spots at 50 degrees.


Short term...(this evening through sunday)
issued at 204 PM CST Sat Nov 16 2019

Models are in good overall agreement through the period. The main
forecast concerns revolve around type of precipitation Sunday.

A 500 mb shortwave trough will dig into the upper Midwest tonight and
move across the region during the day on Sunday. Ahead of this
wave clouds will slowly increase overnight and thicken. Models
suggest that best lift and moisture are offset from one another.
Model soundings and moisture profiles show precipitation holding
off until after 12 UTC on Sunday and lingering through most of the
day. Precipitation should start as all snow north of Interstate
80 with rain to the south. North of I-80 rain will quickly mix
with snow before changing over to all rain by late morning.
Precipitation may remain as a rain and snow mix through the day on
Sunday. Snowfall accumulations will be light with only a couple
of tenth across the northeastern third of the area. Precipitation
will come to an end from west to east late Sunday afternoon and
early evening.

This storm system will drive a cold front across eastern Iowa,
northeast Missouri, and northwest Illinois during the late
afternoon and early evening on Sunday. There is not much of a
change associated with this front with not much of a gradient
associated with the front.

Long term...(sunday night through saturday)
issued at 204 PM CST Sat Nov 16 2019

Monday night through Wednesday, northwest flow aloft and surface
high pressure will produce dry weather with moderating temperatures.
Daytime highs will be in the 30s and 40s on Monday and Tuesday but
climb into the 50s by Wednesday. During this time period, a very
active, quickly changing, uppel level flow will be occurring. An
upper level longwave ridge will build along the West Coast of U.S.
And Canada, as a strong shortwave moves onshore near Washington and
Oregon. This wave will split its energy with some moving east toward
the mid-west and another part diving south to intensify a Deep Cut
off low over the Baja Peninsula.

Wednesday night and Thursday, model solutions differ making for a
low confidence forecast. The closed low over the baja will eject a
piece of energy northeast toward the region. This energy is expected
to phase over the Midwest with the shortwave that moved onshore over
the Pacific northwest. A surface boundary associated with this
system will move over the Mississippi River valley. Depending where
the flow aloft phases, and where the surface boundary crosses the
region, will determine the amount rain that falls, and whether or
not mixed precipitation occurs. 12z Saturday blended model runs
suggest an all rain solution is more likely with 850 mb
temperatures progged to be around +9 degrees. However, these
temperatures will be considerably colder if the low tracks south
of the region. Surface high temperatures will also depend on where
the low tracks, ranging anywhere from the 30s and 40s, or to near
60 degrees.

Friday and Saturday, the upper level flow will once again switch to
the northwest. Surface high pressure will build over the area making
for dry condtions. High temperature will be in the 30s with lows in
the 20s. ..Kuhl..


Aviation...(for the 00z tafs through 00z Sunday evening)
issued at 535 PM CST Sat Nov 16 2019

Through 15z predominantly VFR conditions are expected, with some
patchy MVFR in fog. Winds will be from the south to southeast
around 10 kts, and may occasionally gust under 20 kts at Cid this

After 15z a cold front will begin to make inroads and bring a
period of light rain, possibly mixed with snow at dbq, with
conditions lowering into MVFR and IFR. Winds will shift to the
west and northwest with the passage of the front into early
evening with lower ceilings, predominantly MVFR, lingering in the


Dvn watches/warnings/advisories...


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