Area Forecast Discussion
Issued by NWS Topeka, KS

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000
FXUS63 KTOP 211653
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1153 AM CDT Tue Oct 21 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 312 AM CDT TUE OCT 21 2014

An upper level ridge will move east across the plains Today, then
east into the MS river valley by 12Z WED.

A lee surface rough will deepen Today and Tonight across the high
plains. light surface winds this morning will gradually strengthen
to 10 to 15 MPH during the afternoon hours from the southeast. WAA
at 850mb will help to warm afternoon highs into the mid to upper 70s
Today.

Tonight, high clouds will gradually increase ahead of the next H5
trough approaching the high plains. Southerly low-level winds will
transport deeper moisture north through the night. Late Tonight
there will be enough isentropic lift ahead of the deeper moisture
return for stratus clouds to develop and perhaps an isolated shower
across the eastern counties of the CWA. I placed in 14 percent pops
at this time, since only the ARW and NMM versions of the WRF
solutions, along with the 00Z NAM forecast light QPF across the
extreme eastern counties of the the CWA between 9Z and 12Z WED.
Overnight lows will only drop into the upper 40s to lower 50s.

.LONG TERM...(Wednesday through Monday)
Issued at 312 AM CDT TUE OCT 21 2014

Tomorrow morning the mid/upper level trough continues to track
eastward over the northern plains and upper Midwest. Models also
show pieces of energy lifting out of the southwest and over the area
tomorrow night. There is some indication of isentropic lift ahead of
the approaching trough that could produce an isolated rain shower
across far eastern KS around the 12Z time frame before quickly
moving eastward into MO. Confidence in this scenario is a low at
this point and amounts should be minimal therefore left it out of the
forecast. NAM soundings show a decrease in the 850mb moisture and saturation
during the late morning hours. A cold front then slides through
the region as the system advances towards the Great Lakes. The mid
level lift increases as the trough passes overhead and the sfc
front swings through. Precipitation looks to move into north
central KS first during the early evening hours, and then the
remaining areas overnight. The instability during this period
still appears to be rather limited without any steep lapse rates,
which should keep thunder isolated. Behind the front mid level dry
air begins to filter in Thursday morning putting an end to
precipitation from west to east. Most of the rain should exit the
forecast area around noon or late morning hours.

A mid/upper level ridge then builds and moves over the southern
plains causing a rise in temps. Highs this weekend look to reach the
upper 70s and low 80s, which is a good 10 degrees above normal. The
next weather system moves over the Pacific Northwest early next week
although the models disagree on how to handle this energy. The ECMWF
is still breaking off a shortwave to cut off in the southwest US,
while the GFS keeps everything in tact as is progresses across the
northern US. This will have implications of the timing of the next
front.

&&

.AVIATION...(For the 18Z TAFs through 18Z Wednesday Afternoon)
Issued at 1129 AM CDT TUE OCT 21 2014

VFR expected at KTOP/KFOE/KMHK as southeast winds blo 10 kts
prevail through Wednesday morning. Outside chance of an isolated
shower impacting KFOE/KTOP otherwise forecast soundings show
increasing moisture and broken stratus developing near 4 kft from
09Z to 13Z. If showers develop near sites, scattered MVFR cigs are
possible.

&&

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

$$

SHORT TERM...Gargan
LONG TERM...Sanders
AVIATION...Bowen







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