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fxus63 kdvn 120446 

Area forecast discussion
National Weather Service Quad Cities Iowa Illinois
1046 PM CST Mon Nov 11 2019

..aviation update...

issued at 206 PM CST Mon Nov 11 2019

Widespread snow from the system that blanketed the area overnight
into this morning had shifted southeast of the forecast area as of
2 PM. Scattered flurries and snow showers continued in the cold
air advection in its wake, mainly along and east of the
Mississippi River. Satellite images showed clearing skies and
scattered, diurnal stratocu over much of Iowa, southern Minnesota and WI.
North to northwest winds from 20 to 30 mph continued to cause
some drifting snow. Early afternoon temperatures were in the lower
to mid 20s with wind chill readings mostly in the single digits
above zero. Surface maps showed a strong surface high, around 1045
mb. Centered over the northern plains, which will build southeast
into the mid Mississippi Valley through Tuesday under a northwest
flow aloft. The associated clear sky and light winds will lead to
a stretch of bitter cold weather tonight that may end up setting
some new records.


Short term...(this evening through tuesday)
issued at 206 PM CST Mon Nov 11 2019

Bitter cold temperatures are the primary concern tonight and
Tuesday. The fresh snow cover, high pressure and clearing skies
will be nearly ideal for record setting temperatures tonight. Will
continue to undercut most guidance lows with mins near zero to 5
above over the deepest snow over east central Iowa into northwest
Illinois and around 5 to 10 across the south. These will be near or
below record lows for the 12th, as referenced in the climate
segment. If the timing of the high pressure center passing to the
south was a bit faster, allowing lighter winds and more complete
decoupling tonight, much of the area could plunge below zero based
on the strength of the 850 mb thermal trough.

Tuesday, light winds under the passing ridge and snow cover will
again limit warming, despite the November sunshine. Going highs
in the teens north to low 20s south may lead to record cool high
temperatures, as listed in the climate section.

Long term...(tuesday night through monday)
issued at 206 PM CST Mon Nov 11 2019

The extreme cold regime should break on Wednesday, after a Tuesday
evening to early overnight low in the single digits again east, to
teens west. Warm advection should hold temperatures steady to slowly
rising as winds increase and clouds roll in advance of a clipper
system due to impact the region on Wednesday. For now, it appears
that saturation for that clipper will all be on the cold side of the
low path, and for that reason I have a gradient from likely pops
north for an inch of snow, to dry south of I-80. The GFS is the
farthest south on that low's path, and the most saturated, but a
look at the Gem, NAM, and ec suggest the event may only graze our
northern counties, thus this should mainly be a light snow event,
Wednesday afternoon, north of Highway 30. Amounts appear rather
light, and should the spread south, it will be later Wednesday night
on the back side of the system. Thus, amounts under 1 inch may slide
down near I-80 as it exits. In any case, this minor system will be
moving out before midnight, and a multi day warm up is going to
spread in for the remainder of the extended.

While this warm up will gradually melt all of the snow cover, we
likely will remain below normal, with highs in the mid 30s to mid
40s, and lows in the 20s through the upcoming weekend. Some slight
chance pops are in the later periods of the forecast, for rain or
snow, but that does not appear to be any significant threat of a



Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1045 PM CST Mon Nov 11 2019

VFR conditions expected through the period. No sig impacts for
aviation expected at this time.


issued at 206 PM CST Mon Nov 11 2019

Record lows for November 12...

Moline.........8 in 1986
Cedar Rapids...5 in 1986
Dubuque........6 in 1986
Burlington.....9 in 1986

Record cold highs for November 12...

Moline.........20 in 1911
Cedar Rapids...19 in 1940
Dubuque........18 in 1940
Burlington.....25 in 1940


Dvn watches/warnings/advisories...


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