Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 111942

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
342 PM EDT Sun Mar 11 2018


Relenting confluent mid level northwest flow still largely governing
conditions locally late this afternoon, with a higher degree of deep
layer stability and dryness simply yielding a low coverage diurnally
supported stratocu. A generally suppressed upper height field and
weakly anti-cyclonic low level flow leaving little opportunity for
thermal advection, sustaining a resident airmass characterized as
just a shade below average for mid March. The local area will
maintain position through tonight immediately downstream of an
inbound strengthening mid level wave now diving across central
Canada. Therefore, given a nearly carbon copy thermal/moisture
profile and limited cloud coverage aside from patches of thicker
cirrus, looking at a low temperature forecast defined by general
persistence. This will again brings readings down into the upper
teens and lower 20s most locales Monday morning.

Steady amplification of the aforementioned wave over the next 18
hours will leave a closed mid level circulation centered just north
of lake Superior by Monday morning. A lead piece of energy shearing
off the southern flank of this system will rapidly rotate across SE
MI early Monday. Pronounced period of cva locked onto the tight
height fall gradient will support an uptick in snow shower coverage
during this time. The infusion of colder mid level cyclonic flow
with an accompanying diurnally driven increase in low-mid level
lapse rates will then subsequently sustain the potential for
scattered to numerous snow showers throughout the latter half of the
day. This development likely characterized by transient quick bursts
of heavier snow showers, given magnitude of convective depth /6-7k
ft/. Accumulation potential limited by the short duration window of
each occurrence, modest moisture quality and the less favorable
daylight timing where temperatures of mid-upper 30s contribute to a
quick melting of the snow outside of elevated surfaces and the
existing snowpack.

Western expanse of the mid level circulation remains projected to
then pivot across the region on Tuesday. Favorable diurnal timing
will again present a tremendous opportunity to witness a high
coverage of brief but potentially intense snow showers. Impressive
mid level cold pool tied to this system /-40C at 500 mb/, suggesting
even greater convective depth potential assuming some improvement in
moisture quality relative to Monday. A few lightning strikes
certainly not out of the question given the thermodynamics. As with
Monday, accumulation will be governed by time of day and brevity of
each occurrence, so still looking at a general total accumulation of
less than an inch, but with the possibility for very localized
higher amounts. Period of moderate cold air advection will bring 850
mb temperatures down into the mid negative teens by afternoon. This
will keep readings in the vicinity of the freezing mark thru the

Mid level shortwave ridging will traverse the region on Wednesday
bringing drier conditions before yet another wave dives SSE across
the region early Thursday. After the passage of this wave, gradually
rising heights will push into the region as a dampening upper level
ridge across the Central US slowly pushes eastward through late next
week. This pattern will bring a gradual warming trend while dry
conditions continue. Some disagreement exists among model solutions
regarding the speed and evolution of the upper ridge as it
translates eastward. The GFS favors a more progressive ridge and
more aggressive warming trend while the ECMWF and CMC favor a slower
ridge and more gradual warming trend. Regardless, expect highs to
rise from the mid 30s midweek to near 50 by next weekend.



High pressure building into the region will result in light
northwesterly winds through most of tonight. A low pressure system
will then drop through Ontario toward eastern Lake Erie which will
pull a cold front through the region by Monday afternoon. Winds will
switch to southwesterly for a short period Monday morning ahead of
this cold front, but will quickly flip back to northwesterly behind
the front. Surge of colder air Monday night will cause winds to
increase, with gusts between 25 and 30 knots expected Tuesday and
Tuesday night.


Issued at 129 PM EDT Sun Mar 11 2018


High pressure will keep VFR conditions going across the region
through tonight. Outside of a few hours of diurnal cu this
afternoon, mainly just some cirrus debris overhead. Winds will be
light and variable as the center of the surface high passes tonight.
Conditions will start to deteriorate Monday morning as the next
system approaches from the north. Mid level clouds will move into
MBS/FNT around 09Z, spreading southward through the morning. This
next system will bring the possibility for snow showers which will
bring reduced VSBYs and CIGs for several hours.

For DTW...VFR conditions today and tonight though light
northeasterly winds will result in a low chance of flipping to NE
flow operations this evening. Lower CIGS and VSBYS with bursts of
snow showers Monday afternoon may result in a period of MVFR or IFR


* High for CIGS aob 5kft Monday afternoon.

* High for ptype as snowfall Monday.


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



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