286
FXUS63 KTOP 281131
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
631 AM CDT Sun Apr 28 2024

.KEY MESSAGES...

-Scattered storms could develop (30-50% chance) along a front
 moving across northeast KS today. A few severe storms will be
 possible in far eastern KS.

-After a brief break in precipitation chances on Monday, a very
 active pattern brings more rounds of rain and possibly severe
 weather during the workweek.

&&

.DISCUSSION...
Issued at 355 AM CDT Sun Apr 28 2024

At 09Z this morning, mid-level low pressure was spinning over
southwest Nebraska. A large complex of thunderstorms was ongoing
from around Chicago back through northern Missouri, southward
through central Texas, along and ahead of where a surface
boundary was positioned. Surface low pressure and the associated
front will slowly advance eastward across the forecast area
today. Ahead of the boundary, sfc heating will contribute to an
increase in instability once again today. HREF shows between
1000 and 1500 J/kg of SBCAPE developing by early afternoon.
Shear is not as impressive as previous rounds of storms, with
various models only showing between about 20-30 kts of bulk
shear. Thinking is that there will be enough forcing along the
boundary and ahead of the trough axis aloft to generate
scattered storms this afternoon, mainly in far eastern sections
of the forecast area. A few storms could be capable of small
hail and strong winds. However, widespread severe weather is not
expected today.

The cold front should pass to the east of the area late this evening
as high pressure begins to build in. Skies will clear and winds will
become light. Given recent rain and wet grounds, could see some
fog developing tonight, especially in low lying areas and in
river valleys. High pressure will move southeast Monday as the
next in a series of mid-level systems digs across the Pacific
Northwest. Conditions should stay dry Monday as temps warm into
the low 70s. Return flow strengthens on Tuesday as low pressure
deepens across KS and brings another cold front toward the area.
Moisture advection and ascent as a shortwave approaches will
likely lead to more thunderstorms by Tuesday afternoon and
evening. A few deterministic models (GFS/NAM) have upwards of
2000 J/kg of MLCAPE and around 40-45 kts deep layer shear by
21Z Tuesday. Thus, more severe weather could occur.

An active and progressive pattern will bring additional
opportunities for storms through the workweek. On Wednesday,
another shortwave trough and a low level WAA pattern could generate
another round of wet weather. Once again, some models show
sufficient instability and deep layer shear for severe weather.
Chances for thunderstorms will linger into Thursday as low
pressure and an attendant cold front move across northeast KS. A
drier air mass is then expected by the end of the week, providing
another possibly brief break in precipitation.

Given this active pattern, there are numerous details to sort
out with each consecutive round of thunderstorms through the
week, so be sure to check back with the forecast for
updates/changes.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 622 AM CDT Sun Apr 28 2024

The main forecast challenges are ceilings and whether scattered
storms develop and impact airports today. Have kept VCSH in
TAFs early this morning with a few lingering showers on radar.
Then went with VCTS toward midday when chances for storm
development increase along a cold front. The expected scattered
coverage of storms leads to lower confidence on whether
airports will be impacted, so will amend if needed. Ceilings
may fluctuate this morning, but am thinking a period of MVFR is
likely for a few hours. South winds shift to the west-northwest
this afternoon/evening as the aforementioned from moves through
TAF sites.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 AM CDT this morning for KSZ040-KSZ054-
KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

DISCUSSION...Teefey
AVIATION...Teefey