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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

                            
000
FXUS63 KTOP 172333
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
533 PM CST Sun Feb 17 2019

...Update to aviation forecast discussion...

.SHORT TERM...(This evening through Monday)
Issued at 321 PM CST Sun Feb 17 2019

Temperatures warmed to near freezing today with pockets of sunshine 
appearing at times across northeast KS. Quiet weather is expected to 
continue in the short-term before another system approaches the 
region.

The upper level flow currently shows an amplified pattern across the 
country with one upper low moving into the Great Lakes region and 
another digging into the Great Basin. Dry weather is expected to 
continue overnight with surface ridging building into the area. With 
the ridge in place, lows are expected to dip into the teens by early 
tomorrow morning. Northwest winds will be fairly light but wind 
chills could be in the single digits to start the workweek. For 
tomorrow afternoon, a weak piece of energy looks to advect into the 
Plains ahead of the main upper level system in the west, which could 
produce some light snow over portions of central KS. At this time, 
the TOP CWA looks to stay dry throughout the day with clouds filling 
back in ahead of that main wave. 

Attention will then turn to the chance for another round of wintry 
precipitation and accumulating snowfall as the main wave approaches 
on Tuesday.

.LONG TERM...(Monday night through Sunday)
Issued at 321 PM CST Sun Feb 17 2019

The H5 low currently located over northern CA/NV will continue 
digging into the southwest and begin pivoting out toward the High 
Plains Tuesday, advecting energy and moisture into the region. 
Fairly uniform large-scale ascent will occur over the CWA in 
response to upper level divergence and lifting associated with the 
left exit region of the upper jet. As a result, a wide swath of 
precipitation is likely to develop over portions of central OK and 
KS midday Tuesday and move toward northern and eastern KS. The low 
level temperature and moisture profile, per BUFKIT forecast sounding 
guidance, should support a mainly snow event Tuesday evening through 
Tuesday night for the area with temperatures below freezing and 
saturation occurring through the ice growth region of the profile. 
As mid-level drier air moves in late the event, freezing rain or 
freezing drizzle could mix in briefly early Wednesday morning before 
precipitation comes to an end. Current thinking for total 
accumulations is a widespread 2 to 4 inches of snow with a glaze 
of ice possible on top.

There will be a brief break in precipitation chances midweek as a 
surface ridge takes control of our conditions. Slight warming is 
expected to occur through midweek with highs finally reaching above 
freezing (but still below climatological normals) on both Thursday 
and Friday. Meanwhile, yet another deep upper level trough will 
begin building across the western CONUS, which would indicate the 
possibility of a return to unsettled weather by next weekend. 
Being a good 5 to 7 days out, there is currently a considerable 
amount of model variability and disagreement from run to run and 
model to model with that next system. Will have to monitor through
the week to hone in on precip type and timing details for the 
Friday through Sunday timeframe.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 528 PM CST Sun Feb 17 2019

For the 00z TAFs, borderline MVFR/VFR cigs will persist into early
this evening before lifting to VFR. Main uncertainty with the
forecast is that several models suggest a shallow MVFR stratus 
deck could develop through the day on Monday, but models vary on 
the best timing for that potential. As a result, have kept just a
mention of scattered MVFR cigs and will continue to monitor this
potential in future TAF updates.  

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Teefey
LONG TERM...Teefey
AVIATION...Hennecke