Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
FXUS63 KDTX 201901
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
301 PM EDT FRI MAY 20 2016
Mid level circulation evident on water vapor imagery now lifting
into west-central Illinois will continue a general eastward
downstream trajectory over the next 24 hours. Extensive mid cloud
canopy along the broadening cyclonic northern periphery will
continue to make steady inroads into SE Michigan heading into
tonight. A greater push of low level moisture advection will be
lacking, low level flow locked into an easterly component
immediately south of prevalent surface ridging centered over
northern lake Huron. However, a consolidating corridor of modest
mid level forcing/deformation will pivot into the vicinity of the
Ohio border overnight, with the potential to briefly glance across
SE Michigan between early Saturday morning and roughly midday.
Recent model guidance holding firm on this positioning, while
increasing the depth of moisture across this layer /775-600 mb/.
This will leave an underlying environment conducive for some light
shower and/or sprinkle development during this time. Greatest
potential remains along and southeast of roughly a Howell to Pontiac
to Port Huron line. Placement and duration of thicker cloud cover
toward the south will likely translate into a slightly greater north
to south gradient in high temperatures Saturday. Potential for the
Tri-Cities to push toward the mid 70s under a higher degree of
insolation, where points toward the south peak near 70.
Stronger height falls within the western periphery of an amplifying
northern stream trough digging into the eastern Great Lakes will
ease a weak backdoor front into SE Michigan Saturday Night and
Sunday. This may introduce a period of low cloud as the thermal
gradient enters Sunday morning, but appears shallow enough to either
mix out or lift into a broader diurnal cu field by afternoon.
Moisture depth seemingly lacking to warrant any precipitation
mention at this stage. The uptick in northeast/onshore flow off
Lake Huron will dampen the diurnal temperature response,
particularly across the thumb. High temperature distribution
ranging from mid 60s in the thumb to lower 70s well inland.
Sunny and warm Monday and most of Tuesday...however several waves of
low pressure are expected to move through the Great Lakes region
beginning midweek. Expect increasing clouds late Tuesday
afternoon/evening ahead of the first wave...a developing low moving
out of the central plains. The second wave is progged to push into
the area Friday afternoon/evening. Chances for showers and
thunderstorms enter the forecast on Wednesday and remain in the
forecast through the remainder of the week.
High pressure and a weak pressure gradient will sustain light winds
and tranquil weather across the marine waters through the weekend.
Light southerly winds and warmer temperatures arrive early next
week...leading to a chance of showers and thunderstorms by mid week.
Issued at 100 PM EDT Fri May 20 2016
High VFR clouds will continue to work in from the south this
afternoon before mid VFR clouds start working into the area this
evening and tonight. There is a chance for some high based showers
(6-10 kft) along the I-94 corridor and south by early tomorrow
morning. Light easterly winds expected today...becoming
variable/shifting to the northeast tonight.
//DTW Threshold Probabilities...
* Medium confidence in ceilings above 5k tomorrow morning
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
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