National Weather Service Raw Text Product

024 
FXUS63 KTOP 180820
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
320 AM CDT Sat Mar 18 2017

.SHORT TERM...(Today and tonight)
Issued at 254 AM CDT Sat Mar 18 2017

Northwest flow aloft is supporting a surface high pressure across
the northern plains. This ridge axis will push through the area 
during the day today therefore winds stay relatively light and 
gradually veer. Temperatures should start out in the 30s this 
morning and warm into the 60s this afternoon with mostly sunny 
skies. Tonight a ridge aloft progresses over the plains causing 
the lee side trough to deepen. The deepening pressure will support
a low level jet that will advect warm moist air northward. This 
moist warm nose will be accompanied by modest mid level lapse 
rates, which will yield some elevated cape. The model consensus is
for cape to be about 1500 j/kg with the NAM suggesting as high as
2400 j/kg. This is likely due to the high moisture bias this time
of year. With the elevated instability in place the nose of the 
low level jet should provide some forcing for isolated to 
scattered storms. If the cape can be realized perhaps some small 
hail will be possible. There is a chance parcels could be unstable
over central KS in the early morning hours although the forcing 
from the low level jet may not be enough for storm development. 
Also, the GFS soundings shows that over central KS the moisture is
not as deep, lower in the profile, and a weak mid level cap. The 
models do agree that this is more likely over portions of eastern 
KS around the predawn hours therefore have kept the chances for 
storms there after midnight.

.LONG TERM...(Sunday through Friday)
Issued at 254 AM CDT Sat Mar 18 2017

Have some lingering slight chances for thunder in the eastern
counties as the overnight convection that may form on the nose of
the LLJ moves eastward, and should end by mid morning. Mid level
temperatures in the teens to low 20s bring high temperatures up
into the 80s across the area Sunday afternoon. 

Next boundary moves southward into the area through the day 
Monday but still only cools highs into the 60s north to mid 70s 
south. Overnight lows fall from 50s the previous night to 40s 
Monday night. As this boundary lies across the Central Plains 
Tuesday and Wednesday, and small impulses move through the upper 
flow over the boundary, we start seeing some periodic chances for 
rain, possibly mixed with some snow into early Wednesday. Highs 
Tuesday and Wednesday forecast in the 50s.

By Thursday morning, area is forecast to undergo transition from
zonal flow aloft back to southwesterly flow aloft, bringing 
return flow back over the state, along with some instability and 
chances for thunder. EC and GFS keep adjusting track and speed of 
the western trof, but for now will carry higher chances Thursday 
morning as the front lifts back northward, and then after a 
break, as the main trof approaches will keep increased PoPs on 
Friday into Friday evening as current runs have the upper low on 
our western doorstep by that hour. Both tracks would linger some 
wrap around precip into early Saturday. For now, worth noting that
could see a chance for strong to severe storms Thursday and 
Friday, but there is considerable uncertainty in timing, strength 
and track overall. 

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1139 PM CDT Fri Mar 17 2017

VFR conditions are likely through the TAF period with light winds
generally less than 9 kts out of the north, remaining light but
turning out of the southeast by tomorrow afternoon/evening.

&&

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

$$

SHORT TERM...Sanders
LONG TERM...67
AVIATION...Barjenbruch