943
FXUS63 KTOP 060548
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1248 AM CDT Mon May 6 2024

.KEY MESSAGES...

-Dense fog tonight, generally south of I-70.

-A dynamic system is still on track to bring severe weather back
 to the area tomorrow afternoon and evening. Very large hail,
 strong winds and tornadoes will all be possible.

-Drier weather is then expected mid and late week.

&&

.UPDATE...
Issued at 1242 AM CDT Mon May 6 2024

A Dense Fog Advisory has been issued for areas along I-35 and
south for tonight into early Monday morning. Visibility is
already falling to around one mile across portions of east
central Kansas. Some short-term models suggest this fog will
spread further north by the early morning, so further expansion
of the Dense Fog Advisory may be needed.

&&

.DISCUSSION...
Issued at 254 PM CDT Sun May 5 2024

This afternoon, there are two systems of importance to note - a
shortwave trough over Arkansas, slowly moving northeast within the
mid-level flow, and a stronger system over the western CONUS,
evident on water vapor imagery by a tight cyclonic circulation
centered near the OR/ID stateline. Light rain associated with the
first system has slowly moved northward with time today. Light QPF
is forecast across east-central KS into mid-afternoon before rain
tapers off and moves east of the area. Cloud cover and rain today
are keeping temperatures in the upper 50s and low 60s. Stratus will
remain in place tonight with models also showing some signal for fog
development, mainly were rain fell today. If winds are able to go
light (less than 5 mph), fog will become more likely. For now,
however, the extent of fog is expected to be limited.

The western CONUS system still looks concerning regarding the severe
weather potential in central and eastern KS tomorrow. Surface low
pressure will deepen and move out over the northern high plains late
morning as the mid-level negative tilt trough axis approaches that
region. Instability may be slow to increase in eastern KS through
the midday hours, given lingering low cloud cover. However, strong
low level moisture transport into the area will increase buoyancy
while mid level lapse rates steepen, resulting in between 1500-2500
J/kg of MLCAPE ahead of the dryline tomorrow afternoon. Expected
shear parameters remain impressive, with forecast sounding analysis
showing near 250 m2/s2 of effective inflow layer SRH and around 50
kts of effective bulk shear. CAMs are in good agreement with
development occurring along the cold front/dryline in central KS
early to mid afternoon with storms forming into a line or broken
line segment and quickly advancing eastward into the evening hours.
If this exact scenario plays out, very large hail and tornadoes will
be the main concerns initially, with an increasing wind and QLCS
tornado threat as the evening progresses. Evolution of storm mode
remains somewhat in question, but the bottom line is that all modes
of severe weather could again occur as our active spring season
continues tomorrow.

Storms moves east of the area Monday night, leaving dry weather in
the forecast for Tuesday. However, another shortwave looks to
develop and move around the main system that will then be sitting
north of the area Tuesday night and early Wednesday. That could
generate a few showers or storms early Wednesday. A severe weather
threat could develop ahead of that secondary boundary, but will
likely be southeast of the area, mainly in the Ozarks. A stretch of
dry and seasonable weather is then expected through the remainder of
the workweek.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1242 AM CDT Mon May 6 2024

IFR conditions tonight, becoming MVFR by late morning. Low
stratus, fog and drizzle are all likely tonight as warm, moist
advection from the south overspreads the area. There is some
uncertainty as to how low and thick cloud cover will remain
through the day tomorrow, but MVFR conditions are currently
favored. A line of thunderstorms is still favored to move
through after 00z Tuesday.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from 4 AM to 9 AM CDT this morning for
KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

UPDATE...Jones
DISCUSSION...Teefey
AVIATION...Jones