Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
FXUS63 KDTX 181959
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
359 PM EDT WED MAY 18 2016
High resolution NWP underestimated available boundary layer moisture
this afternoon despite initializing reasonably well this morning, a
good indicator that green-up is beginning to have a more substantial
impact on boundary layer moisture content during the day. As such,
bumped up cloud cover for Thursday given that environmental
variables will be largely unchanged. Lake reinforced high pressure
will remain firmly in place through Friday and ambient humidity
should be better than today on each day. Reduced sky cover a bit on
Friday compared to Thurs as model soundings indicate strengthening
subsidence in advance of upstream longwave ridge amplification.
General columnar warming as height rebound occurs will allow h85
temps to rise into the mid single digits Thurs and upper single
digits by Fri...supporting high temps approaching then exceeding 70
degrees by Thurs & and friday respectively.
Regarding frost potential tonight...clear skies and full decoupling
is highly likely. Sided forecast strongly toward to the colder
guidance which yields widespread mid 30s in outlying and rural
areas. Certainly plausible that a few favorable stations such as
lapeer/bad axe/port huron see temperatures in the low 30s but
confidence & expected coverage precludes issuance of frost advisory
attm. Instead hinted at potential with mention of patchy frost
within this corridor.
Little change in the extended period as high pressure holds over the
Great Lakes region through the weekend. Temperatures will gradually
warm through the period with inland locations reaching the mid to
upper 70`s by early next week. There will likely be some cloudiness
Saturday off the north flank of a low pressure system to our
south...this will keep temperatures in check assuming the
Ohio/Tennessee valley track holds. A northern stream short wave is
also shown to pull a weak backdoor cold front into lower Michigan by
Sunday which washes out over our area Sunday. This should also keep
temperatures in check...but will still allow readings to reach the
lower 70s inland from the shorelines. High pressure is then expected
to lock in dry and mild conditions to start next week as a blocking
closed low develops over the mid Atlantic states.
High pressure will remain anchored across the region through the end
of the week. This dry and stable environement will ensure a longer
stretch favorable marine conditions. Generally light and variable
winds through this time.
Issued at 202 PM EDT Wed May 18 2016
Extended stretch of dry and stable conditions as high pressure
maintains control through the TAF period. Brief increase in late
afternoon CU, with CIGS expected to exceed 5k ft. Progressive
clearing this evening with the loss of heating. Prevailing
northeast winds this afternoon become light/variable overnight.
Prevailing modest northeast wind may still ease just enough to allow
the Lake Erie lake breeze to advance inland and across metro. Window
for this occurrance between 21z and 23Z, which would lead to a brief
wind shift to southeasterly before winds drop with sunset.
//DTW Threshold Probabilities...
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
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