967
FXUS63 KDTX 040413
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1213 AM EDT Tue Jun 4 2024

.KEY MESSAGES...

- Temperatures warm up today with highs returning to the 80s.

- Showers and some thunderstorms likely Wednesday as a cold front
sweeps across the area.

- Pattern shift for the latter half of the week brings below normal
temperatures through at least the end of the week along with
periodic chances of rain.

&&

.AVIATION...

Rain has held north of MBS early tonight with VFR conditions
expected through the bulk of tonight. There will be a period from
about 09Z to around sunrise for fog to develop, mainly across PTK
and metro terminals. The high surface moisture remains in place
supporting the fog potential. However, gradient flow looks to stay
at about 5 knots and good degree of high clouds is filtering into
southeast Michigan downstream of the showers to the north. This will
greatly limit fog development, but MVFR visibility restrictions will
be possible. Any fog will lift shortly after sunrise with VFR
prevailing through remainder of the day. Winds today will be up to
around 10 knots or less and out of the south- southeast. Chances for
rain and possible thunderstorms arrive return late tonight, but will
be more likely beyond this TAF period on Wednesday

For DTW/D21 Convection...Low chance for thunderstorms arrive after
06Z. Greatest chance for thunder will be after 12Z Wednesday.

DTW THRESHOLD PROBABILITIES...

* Low for cigs/vsby falling below 200 ft and/or 1/2 SM near sunrise
  this morning.

&&

.PREV DISCUSSION...
Issued at 345 PM EDT Mon Jun 3 2024

DISCUSSION...

Looking aloft, we currently find ourselves positioned in between an
approaching longwave trough moving into the Plains and the exiting
ridge stalling over the east coast. The surface is similar with high
pressure now centered over eastern Canada and the NE conus but still
resulting in anticyclonic flow over the eastern Great Lakes with
southwesterly flow ahead of the next cold front still primarily
held over the Upper MS Valley and into the Midwest off to our west.

The trend in the forecast over the next 36 hours is to dry it out.
There will be an opportunity for an isolated shower to pop up,
mainly around the Saginaw Valley, but overall there just isn`t
enough forcing to use the little diurnal instability we can build,
even as PWATs reside over an inch+ through this stretch. For today,
upper level ridge with anticyclonic flow down low, and with the low
level jet over WI, we will remain dry. Tonight there will be a mid
level shortwave rippling along a developing warm front draped across
Mid MI. It will be weakening while approaching and the nocturnal jet
driving it will be lifting north into the UP so there won`t be much
to help it survive into the Saginaw Valley. Tuesday should be mostly
dry yet again as a shortwave ridge lifts back into lower MI drying
out the mid levels with the cold front still too far west to allow
any jet forcing to ease into SE MI. Winds will turn a bit more out
of the south which will encourage warm air advection and help high
temps rise into the mid-upper 80s. Can`t rule out a couple showers
trying to go up on lake breezes or in the higher terrain to the
north or west, but overall will favor a dry forecast.

Late Tuesday night into Wednesday brings better chances for
precipitation as a southern stream wave lifts up into the approaching
northern stream trough. Enhanced plume of theta e start entering
southern MI around 09Z and spreads northward from there through
Wednesday morning. This while the developing surface reflection on
the approaching cold front pulls a warm front up through the region
that morning followed by a cold front that afternoon/evening. Model
soundings show tall skinny MUCAPE and SBCAPE around 500-1000 J/kg
with around 20-30 knots of shear. The longwave trough becoming
negatively tilted will help sling the southern wave northward along
with its moisture while the nose of the 130+ knot jet begins working
into the area. Moral of the story, much more synoptically to help
generate widespread showers and embedded thunderstorms Wednesday.
SPC continues to offer a large area of General Thunderstorms across
the region for this activity.

The low amplitude longwave pattern will become more amplified mid to
late week owning to a strong upper level jet around 140 knots
entering the NW conus tonight into Tuesday morning, then passing
through the Great Lakes Wednesday. Several reinforcing jet maxes
then feed into the trough over the region heading through the
weekend. The closed upper low sitting and spinning over the Great
Lakes through the weekend will result in a cooler forecast (highs in
the 60s on Friday, Low/mid 70s the rest of the week and weekend) and
periodic chances for precipitation as several shortwaves are
directed around the low over the area.

MARINE...

Upper level shortwave ridge sustains high pressure to the east
today. Southeasterly winds remain gentle ahead of the approaching
warm front on Tuesday. Chances for light showers are possible ahead
of this front, mainly over northern Lake Huron. Winds behind the
front stay southerly before Wednesday brings the arrival of the cold
front, and with it chances for stronger showers and storms. Winds at
the surface remain moderate to fresh, but strong flow aloft may
provide the chances for a strong gust to occasionally mix down.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....AA
DISCUSSION...DRK
MARINE.......BC


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