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Office: DMX

FXUS63 KDMX 160505

Area Forecast Discussion
National Weather Service Des Moines IA
1105 PM CST Sat Dec 15 2018

...Updated for 06z Aviation Discussion...

.DISCUSSION.../Tonight through Saturday/
Issued at 252 PM CST Sat Dec 15 2018

The general weather theme through the period will remain above
normal temperatures and little in the way of precipitation with
our primary window seeming to be around Wednesday or Thursday.
The pattern will remain similar to the recent past with
progressive flow and systems of Pacific origin keeping any arctic
cooling or significant moisture return at bay.

The short wave and deep PV anomaly moving through the Dakotas
this afternoon looks ominous via water vapor imagery and does
have deep QG forcing ahead of its path but very little moisture
will result in nothing more than high level cloudiness. A weaker
system following close behind, now moving through the Bitterroots,
will drop into the MO Valley tomorrow but with similar results.
This will be followed by brief long wave ridging into the start of
the coming work week keeping our forecast relatively warm and

The current Baja short wave will eventually be aided by
additional Pacific energy into the middle of next week introducing
some chances for light precipitation. Deterministic and ensemble
solutions are in fair agreement for this time range developing a
long wave through through the central CONUS. There are some
uncertainties with how or if north and south stream short waves
will eventually phase, but the general consensus is for a period
of weak, mainly kinematic forcing Wed into Thu. This will result
in only spotty deeper moisture keeping any precip on the light
side. The precip type mainly looks to be rain, but some light snow
is possible at night and on the back side as the system exits.

This will be followed by higher amplitude flow and relatively
cooler temps, but staying no worse than normal. There looks to be
some token precip chances into Day 7/Sat and beyond as waves drop
through the northwest flow but confidence is low at this point,
even for this time range.


.AVIATION.../For the 06Z TAFS through 06Z Sunday night/
Issued at 1104 PM CST Sat Dec 15 2018

Few changes to previous forecast. High level bkn to overcast
moving through region now with light or light south winds. Expect
first system with thicker high clouds to exit region by 12 to 15z
but another patch of mid to high level clouds to follow by 23-05z.
Winds generally light shifting to north northwest and remaining
under 12kts for period. VFR conditions expected as well. /rev





Office: DVN FXUS63 KDVN 160459 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1059 PM CST Sat Dec 15 2018 ...AVIATION UPDATE... .SYNOPSIS... Issued at 121 PM CST Sat Dec 15 2018 This afternoon an area of high pressure stretched from north of the Great Lakes, through Iowa and southwest into Oklahoma. As a result, clear skies and light winds were reported across the area. Temperatures across this region have climbed well into the 40s and are close to breaking 50 in some areas. This is well above average for this time of year. A weak trof was located across the Dakotas and will move towards the area for Sunday. && .SHORT TERM...(This Evening through Sunday) ISSUED AT 121 PM CST Sat Dec 15 2018 Quiet weather with above average temperatures are expected through the short term as zonal flow and high pressure are expected into the area. A weak wave and cold front is expected tomorrow morning, however the passage of this system will likely only result in some cirrus clouds. Tonight, lows will drop into the 20s and we could see some drainage fog in the river valleys. Have maintained the patchy fog the overnight shift had. Today's high temps have shot into the 50s as the solar insolation has won out. As for highs, expect the same thing to happen tomorrow. Temps could be higher than currently forecast but at this time still expect highs in the 40s. Overall a nice sensible weather day for the middle of December. .LONG TERM...(Sunday Night through Saturday) ISSUED AT 121 PM CST Sat Dec 15 2018 Very quiet early winter weather will continue through much of the extended, with high pressure moving through the region through Tuesday, noted by mainly clear skies and a gradual shift toward south winds as the center passes to the east. This high will continue to be represented by well above normal temperatures. A deep progressive trof, though not entirely phases with southern and northern stream energy is expected to move through the Midwest Tuesday night through Thursday. Moisture should be drawn up ahead of this trof, and depending on how far north the system can cut off aloft, we may see some wrap around moisture into Thursday. For now, rain amounts Wednesday appear quiet light, as the main system moves along the gulf coast states. However, despite the light nature, the likelihood of stratiform coverage suggests potentially high pops. As the system, moves off, cold air will be advected in, and depending on the upper air evolution of the cut off low, we may see a transition to snow before precipitation ends. At this point, any accumulation beyond a dusting appear unlikely. After north winds pull seasonally cold air back over the region, we will see a near normal end to the week with highs in the lower to mid 30s and lows in the lower to mid 20s.&& && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) ISSUED AT 1053 PM CST Sat Dec 15 2018 MVFR visibilities are being observed across a portion of central and northern Illinois and as far west as areas just across the Mississippi River in Iowa. Very light to calm winds along a surface boundary will keep these lower visibilities of 4 to 6 miles into Sunday morning, mainly for KMLI, but potentially for KBRL as well. Winds will shift to the west or west-northwest during the day Sunday, yet stay light below 10kts. There will be some cloud cover, but with just a cirrus shield with cloud heights of greater than 20K ft. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Gibbs SHORT TERM...Gibbs LONG TERM...Ervin AVIATION...Brooks