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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

FXUS63 KTOP 221143

Area Forecast Discussion
National Weather Service Topeka KS
643 AM CDT Mon Apr 22 2019

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 336 AM CDT Mon Apr 22 2019

Early this morning an upper level trough was lifting northeast 
across eastern NE and northeast KS. Thunderstorms that developed 
across west central and north central KS last evening have 
diminished. There is one cluster of thunderstorms southwest and 
south of TOP that have maintained themselves northwest of a surface 
outflow boundary, due to isentropic lift from a southerly low-level 
jet about 1500 feet above the surface crossing perpendicular to the 
outflow boundary. The stronger updrafts in this cluster of storms 
may produce small hail and wind gusts of 30 MPH as they move along 
and south of I-70 and along and north of I-35. A few elevated 
thunderstorms will be possible farther north across portions of 
northeast KS through the early morning hours. A surface cold front 
was moving southeast into the northwest counties of the CWA early 
this morning. 

Today, the low amplitude H5 trough located across eastern NE and 
northeast KS this morning will move east into the mid MS river 
Valley Tonight. An amplified upper level trough across southern NV 
and southern CA will dig southeast into southern AZ and northwest 
Mexico late Tonight. The surface cold front will push southeast 
across the CWA through the morning hours and should move southeast 
of the CWA around 18Z. Low-level CAA behind the front will keep 
highs cooler Today with mid 60s across north central KS and lower to 
mid 70s across east central KS. Skies will gradually become partly 
cloudy from west to east during the afternoon hours.

Tonight, the cold front will become stationary across northern OK 
and may begin to work back northward as a warm front, towards the KS 
border by sunrise. Weak isentropic lift north of the boundary will 
cause scattered showers to develop across southeast KS late Tonight. 
These showers will remain south of the CWA through the night. 
Cloud cover will increase through the night across the southern 
and eastern half of the CWA. Overnight lows will range from the 
mid 40s across the northern counties to around 50 degrees across 
the southeast counties.

.LONG TERM...(Tuesday through Sunday)
Issued at 336 AM CDT Mon Apr 22 2019

Rain chances on Tuesday are looking less likely across northeastern 
Kansas. Models are in good agreement with the placement of an upper 
level closed low located over southern AZ/northern Mexico by early 
Tuesday. Moisture and broad scale ascent look to stream out 
ahead of the system and are likely to interact with the surface 
cold front that should be located near the I-44 corridor in southern 
MO/central OK by midday Tuesday. Based on the placement of that 
front, am currently thinking that the better chances for rain will
remain south of the area, with a slight chance as far north as 
east- central KS. The upper low will take a southern track across 
the CONUS and keep rain and storms chances south, while our 
conditions will be largely controlled by surface high pressure 
through the rest of the workweek.

Return flow will set up over the area early in the weekend as a 
surface cyclone and associated trough move into the central Plains. 
A cold front associated with that low could move through northeast 
KS during the day Saturday which will bring rain chances back into 
our forecast. Will have to see how quickly moisture can return to
the area given the ridging pattern we will have in place most of 
the week.

Otherwise, with the exception of Tuesday being more on the cool side 
given cloud cover and rain south, temperatures through the week look 
to stay pretty mild with highs mainly in the 70s and lows generally 
in the upper 40s and low 50s.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 641 AM CDT Mon Apr 22 2019

There may be a period of MVFR ceilings along and just northwest 
of a cold front that will pass through the terminals between 15Z 
and 16Z. Most numerical models show deep enough mixing behind the
front for VFR stratus ceilings. The 6Z NAM model keeps MVFR 
ceilings through 00Z TUE. 




LONG TERM...Teefey