Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KTOP 301137

National Weather Service Topeka KS
637 AM CDT SAT JUL 30 2016

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 310 AM CDT SAT JUL 30 2016

Early this morning a mid-level trough remained anchored just east of
the forecast area, resulting in northwest flow aloft. An embedded
shortwave was noted on water vapor imagery near the Colorado/Kansas
border, with cirrus extending eastward into central and portions of
eastern Kansas. This cloud cover should allow for a large enough
dewpoint depression to limit fog development across much of the
forecast area.  The only exception is across far northeast Kansas
where the potential for cloud cover may be limited with low
temperatures dropping into the low/mid 60s, so have added the
mention of patchy fog for a couple of hours around sunrise.

The shortwave near the Colorado/Kansas border will progress
southeastward along the western edge of the trough into central
Kansas this morning.  While the better moisture and lift should
remain west of the area, some short range models show the potential
for a few isolated showers and storms to skim across north central
Kansas this morning, so have some slight chance PoPs. With a surface
high located just north of the area, light easterly winds will keep
high temperatures in the mid/upper 80s this afternoon.

Precipitation chances will increase by late afternoon into this
evening across north central and central Kansas as another embedded
shortwave approaches the area. This shortwave will be accompanied by
increased moisture convergence and isentropic lift as the low-level
jet increases across central Kansas. There is still some uncertainty
with regards to the coverage of these scattered storms this evening
through the overnight hours, but storms that do develop should track
east-northeast overnight. Cannot rule out the potential for a few
strong to possibly marginally severe storms late tonight across
north central Kansas as the low-level jet begins to gradually veer.
The primary hazard with these storms would be hail. Also, with PWAT
values reaching upwards of 1.8-2.0 inches, some locally heavy
rainfall will be possible overnight, primarily across central
Kansas. With overcast skies in place, expect low temperatures to be
a few degrees warmer in the upper 60s to low 70s.

.LONG TERM...(Sunday through Friday)
Issued at 310 AM CDT SAT JUL 30 2016

Thunderstorms seem likely to be ongoing across some portion of the
forecast area after sunrise on Sunday. The activity as a whole
should gradually shift east as the focused convergence along the
LLJ also shifts east. While moisture transport will weaken
through the morning, do expect some continued moisture influx
along with upslope flow and convergence into northeast KS for a
good part of the day, so while precip chances will decrease with
time, especially northeast KS will see chances persist even into
the afternoon. The question then for the late afternoon and
evening will be if additional storms can develop along the warm
front as it moves north across the area. Upper flow looks likely
to weaken through the day with no notable incoming forcing for the
evening. This will mitigate precip chances, but will maintain at
least a slight pop near the front owing to persistent low level
convergence and likelihood of a rather moist near-front boundary
layer. Later Sunday night, expect another round of elevated
thunderstorms to develop but the focus for this development will
probably be just north of the area. Even still, there is a period
during which the storms could impact mainly far northeast KS.
Through the entire Sunday to Sunday night time frame, severe
weather potential is quite low, while at least some low-end
potential will exist for heavy rain mainly early Sunday with
localized flooding not out of the question.

The forecast for Monday through the rest of the week continues to
look warmer than normal, with every day at least having the
potential for max heat indices in the 103-107 range. However,
every day is not exactly clear cut for heat as the flow pattern
around the ridge building overhead will allow a surface front to
hang just barely northwest of the forecast area (or even extending
into north central KS), and weak upper disturbances may pass close
enough to the forecast area to support occasional thunderstorm
chances and cloud cover. That said, continued with several low
end chances for precip through the period mainly in northern parts
of the forecast area, and am hesitant to go much warmer with
forecast temps than the previous forecast. Dewpoints have a good
chance to hold on the high side through the period so even if
temperatures should be slightly lower the potential to reach heat
advisory criteria still exists.


.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 634 AM CDT SAT JUL 30 2016

For the 12z TAFs, VFR conditions are expected through the period.
A few isolated to scattered storms will be possible across north
central Kansas this morning, however short-range models show this
activity remaining west of KMHK. Increasing showers and storms are
expected later tonight, however there is still some uncertainty
with regards to the exact timing of this precipitation near the
TAF sites. At this time, have added a VCTS group by around 07z-
09z. Winds will be light through the period, veering from
northeast to southeast.


.TOP Watches/Warnings/Advisories...


SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Hennecke is the U.S. government's official web portal to all federal, state and local government web resources and services.