Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
FXUS63 KDTX 241948
Area Forecast Discussion...CORRECTION
National Weather Service Detroit/Pontiac MI
311 PM EDT SUN JUL 24 2016
MCs that has been slowly passing across southeast Michigan will
continue to weaken this afternoon as it exits. Temperatures remained
quite steady during the day a bit far from forecasted highs but as
clouds thin, several hours of decent amount of sunshine the rest of
this afternoon and evening will push most location into the 80s.
Two boundaries remain across the area that will be the main focus for
convection the rest of the day. One outflow boundary is laid out
across central lower from about Saginaw bay/Thumb westward and the
other is from about Toledo back to southern Lake Michigan. Broken
line of showers and thunderstorms have developed along the northern
boundary but have been weakening somewhat as it pushes southward away
from main cold pool aloft. Expect this boundary to make it near i69
corridor before stalling this evening. The better chance for shower
and thunderstorm development will be more westward were the better
instability lies. The southern boundary is a bit stronger as
a result from the cooler air from todays MCs and substantial heating
across northern Indiana as this area has had a good amount of
sunshine all day. Expecting regeneration of storms along this
boundary from nw Ohio back into sw lower Michigan. Most activity
should remain south and west of the cwa but some showers could spill
over into Lenawee and Monroe counties as main flow aloft is from the
Main cold front is moving through eastern Wisconsin and that will
push slowly through the area overnight. Not much dynamical forcing
with the front, just mainly surface convergence. Southeast
Michigan will not likely get into the good deep instability as that
will remain to our south, shunt off by todays MCs and boundary to
the south. Only expecting scattered showers and thunderstorms to
accompany fropa. The front should be close to exiting the area
around sunrise. Will still carry a chc for precip far southeast
corner Monday morning as this area will still be close to the front.
Drier air will slowly work in behind the front with dewpoints
starting off the day still in the upper 60s in the north to lower
70s south but dropping a 10 or so degrees by end of day. With
plenty of moisture in the boundary layer, expect a rapid
development of cu shortly after sunrise with clouds slowly
thinning and diminishing throughout the day from nw to se. It will
still be quite warm Monday as airmass behind front more drier then
Zonal upper flow Wednesday over the Great Lakes will transition to
cyclonic by the end of next week/weekend as a series of shortwaves
act to carve out a trough. Midrange deterministic models time the
lead disturbance for Thursday, so Wednesday will likely be another
dry and warm day. Then, indications are that a low-level circulation
attendant to the upper height falls will slowly track across the
lower Great Lakes. This could focus a more well-defined period of
precipitation, but still significant model spread with respect to
the timing and placement, so have kept general chance PoPs Thursday
through Saturday. Temperatures are expected to trend back toward
normal late next week.
A cold front will move across the region tonight turning the winds
from south/southwest to west/northwest. Speeds are expected to
remain below 15 knots. High pressure will set the stage for light
and variable winds on Tuesday.
Additional showers and thunderstorms are possible in advance of a
cold front tonight. Widespread rainfall is not expected - however
localized downpours are still possible, capable of totals up to an
Issued at 1257 PM EDT Sun Jul 24 2016
Showers from this morning continue to rapidly decay across the
Southeast Michigan terminals. Additional thunderstorms are
attempting to make progress east across Central Lower Michigan and
will affect the airspace around MBS - but may not have enough to
reach FNT. Additional lingering activity over Southwest Lower will
continue to weaken and only present the opportunity for light
showers early this afternoon across the Detroit vicinity terminals.
The possibility still remains for additional thunderstorm
development in advance of an approaching cold front later this
evening and overnight. Ceilings will remain rather variable with
locally lower clouds within showers. Southwest winds should become
established through the afternoon...with a few gusts in excess of
20kts. The flow will become more northwesterly in the wake of the
front on Monday.
For DTW...limited chances for convection directly affecting the
terminal as best forcing will remain west of the immediate airspace.
The greatest chance for thunderstorms will be in the hours preceding
the cold front. Clouds will flirt with BKN at or below 5kft - but
will maintain a SCT condition for the most part.
//DTW Threshold Probabilities...
* Low for thunderstorms between 04-09Z.
* Low for ceilings at or below 5kft.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
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