Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 221722

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
122 PM EDT SUN MAY 22 2016


The onset of diurnal heating and growth of boundary layer this
morning has allowed fresh mixing to access residual higher momentum
that existed in the midlevels. As the pbl mixing now matures during
the afternoon...the magnitude of the windgusts should lessen with
time. Otherwise...the combination of modified polar air with
increasing midlevel heights will support stable and cloud free
conditions throughout the forecast period. The exception is the few-
sct 050 cumulus that is now advecting south of the DTW terminal.


FEW-SCT 050 cumulus will push south of the DTW airfield during the
first hour or two of the period. No aviation weather is then
expected through the remainder of the period.

//DTW Threshold Probabilities...



Issued at 340 AM EDT Sun May 22 2016


A pattern of mid clouds and virga will finish moving through SE
Michigan prior to sunrise associated with an upper wave and backdoor
cold front. The incoming air behind this front will be a few degrees
cooler compared to yesterday, especially in the Thumb region where
onshore flow from Lake Huron will provide extra cooling. The lake
will also add some boundary layer moisture that will likely produce
patches of stratocu in moderate low level cold advection given a
boost by daytime surface heating. Boundary layer growth/mixing will
then dissipate these clouds by afternoon and allow late May sun to
carry max temps into the upper 60s and lower 70s away from
shoreline. The mild afternoon will be followed by a clear and cool
night. Guidance projections for lows well down into the 40s look
reasonable given ideal radiational cooling conditions in place with
surface high pressure overhead by Monday morning.

The coast to coast omega block in the upper air pattern will
continue to mature today and begin to break down over the west
during Monday. In the meantime, the sharp upper level ridge aligned
over the central U.S. will produce a due north flow over lower
Michigan that will be strongly subsident on the downstream side of
the ridge axis. This will bolster a broad area of surface high
pressure that will produce a couple of outstanding mid to late
spring days in our area to start the week. Max temps steadily
warming through the 70s Monday have a chance to break 80 Tuesday
depending on cloud cover late in the day. These clouds will be the
result of deepening and strengthening southwest flow as the upper
ridge moves eastward and is flattened by fragments of the upper low
out west as it opens and slides toward central Canada. The forecast
plays this to favor slower model solutions on this upper air process
considering we are starting from such a highly amplified pattern.

A transition toward a less amplification in the upper levels will
gain some traction during the second half of the week. Southwest low
level flow ahead of low pressure developing over the plains will
bring a warm and increasingly humid air mass into SE Michigan. At
this point, it appears in medium range models that gulf moisture
transport will peak Wednesday night with the development of a warm
front and low level jet in the Great Lakes. This will usher in a
taste of summer with warm and somewhat stormy conditions lasting
into next weekend.


Northerly winds are expected to top out in the 15 to 20 knot range
today, which will lead to an increase in waves over the southern
basin of lake huron. Winds will become light and variable tonight
however...with light southerly winds and warmer temperatures
arriving early next week...leading to a good chance of showers and
thunderstorms during the mid week period.


Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.



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