414
FXUS63 KMKX 152115
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
415 PM CDT Wed May 15 2024

.KEY MESSAGES...

- Scattered showers and thunderstorms are expected Thursday
  afternoon and evening. Some could be strong to severe with
  small hail and gusty winds as the main threats. A marginal
  risk (1 out of 5) has been issued for most of southern WI on
  Thursday.

- Warming trend into the weekend with chances of rain and a few
  rumbles of thunder interspersed with calm, dry conditions.

&&

.SHORT TERM...
Issued 408 PM CDT Wed May 15 2024

Tonight through Thursday night:

High pressure will persist through tonight promoting dry
conditions. High clouds will move in overnight as a warm front
approaches from the east. Low temperatures will drop into the
low 50s west to upper 40s east.

Attention then turns to tomorrow as we have a Marginal Risk for
severe storms (1 out of 5) over our area . Models depict a
surface low approaching western Lake Superior by Friday
afternoon and dragging a sfc warm and cold front over our area
from the early afternoon into the evening hours. A wedge of a
warm sector should move over our area, promoting sfc dew points
in the upper 50s to low 60s, amid air temperatures in the low
70s. SBCAPE ~1500 J/kg will result and the sfc frontal
boundaries and PVA from a 500mb shortwave aloft should provide
lift for storms. These storms should be hit or miss and fairly
scattered but nevertheless look to provide a wind/hail threat,
as models depict effective bulk shear around 30 knots, Tdd`s
around 10 degrees, and DCAPE around 700 J/kg, with modest low to
mid level lapses rates just short of 7 C/km. Transient
supercellular structures can`t be ruled out, especially along
the warm from where 0-3km SRH will be higher. Models also depict
sufficient enough 0-3km CAPE for low level stretching and some
low level turning in hodographs along the warm front lending a
bit of credence to the supercell threat. A very conditional
tornado threat exists if a storm effectively uses helicity along
the warm front as well, but this threat is low relative to the
wind and hail threats.

A potential limiting factor for the strong to severe storm
threat tomorrow will be the skinny CAPE profiles which may allow
for dry air entrainment. This may stifle some of the updrafts
that try to develop.

Activity will generally move from west to east over the area
between 2PM to 10PM and then exit east over Lake Michigan.

CMiller

&&

.LONG TERM...
Issued 342 PM CDT Wed May 15 2024

Friday through Wednesday:

Friday is projected to be relatively dry over the region as
surface pressure rises, height rises aloft, and the lack of a
surface lifting mechanism promotes clear skies. With some broad,
nebulous WAA over the region, temperatures will get toasty in
the afternoon, highs ranging from 75 to 80 degrees inland.

Dry weather will remain until Saturday evening, when a weak
front is expected to drag a line of broke showers and storms
over the region. The timing of the front has the best CAPE axis
west of our CWA, meaning activity may be on a downward trend in
intensity as it moves through Saturday evening into early
Sunday.

High pressure will then take root again on Sunday with
continuing warmth. Beyond Sunday, the pattern looks active, as
models depict deeper moisture reaching further north into the
Upper Midwest amid continuing warmth and a low amplitude western
US trough. This should give us multiple chances at showers and
storms into the middle of next week.

CMiller

&&

.AVIATION...
Issued 328 PM CDT Wed May 15 2024

VFR conditions will persist into tonight amid light to moderate
northeasterly winds that will come around to southeasterly by
daybreak on Thursday. High clouds increase overnight, and
tomorrow, low VFR to MVFR clouds should form as warm moist
advection increases on southeast to south winds and showers and
storms develop in the afternoon. Shower and storm activity will
linger through the afternoon into the evening moving from west
to east before generally dissipating.

CMiller

&&

.MARINE...
Issued 324 PM CDT Wed May 15 2024

High pressure will retreat northward with time ahead of
approaching low pressure that will move toward western Lake
Superior from southeastern North Dakota through the overnight
hours. Breezy north winds will ease tonight and become light and
southeasterly by daybreak on Thursday. Winds will then remain
light and southeasterly to southerly as the low pressure slowly
moves northeast of Lake Superior through Thursday into Friday
night. Some strong thunderstorms may occur Thursday afternoon
and evening over the southern two thirds of Lake Michigan as the
low pressure drags a weak front over the lake.

CMiller

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

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