Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

000
FXUS63 KDTX 200750
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
350 AM EDT Fri Apr 20 2018

.DISCUSSION...

After a chilly start, a long overdue period of spring weather is
shaping up for today through the weekend. Expect dry conditions to
be ensured by high pressure building over the region and
temperatures moderating toward normal values in the upper 50s to
lower 60s Saturday and Sunday. North wind will linger today but will
be much lighter compared to yesterday, and then trend light and
variable over the weekend. The exception will be the usual lake
breeze development and resulting colder afternoon temperatures along
the Great Lakes shorelines each day.

Moderating temperatures will gain traction today as the low level
thermal through is already east of Lower Michigan. This, and
considering temperature performance yesterday, expect highs in the
upper 50s across inland areas. The typically warmer interior
locations could touch 60 down through Detroit metro, as long as the
wind is not SE from downriver. These afternoon highs will be capped
off by a shallow mixed layer building to only about 900 mb in model
soundings despite just thin cirrus for cloud cover during mid to
late afternoon.

Tonight will be another chilly one, although cirrus coverage is
projected to become meaningful for inhibiting radiational cooling
resulting in no less than partly cloudy sky after midnight. However,
light and variable wind will be in place and low temps will make it
back down to around 30 most locations. This will lead to a repeat
performance Saturday, although the Detroit area through downriver
will experience a little more lake breeze cooling both Saturday
and Sunday while interior sections make a run at lower 60s.

The upper air pattern is setting up favorably for the Great Lakes
with a nearly full latitude ridge extending from central Canada to
near the western Gulf. This is downstream from a closed low over the
Four Corners region that is helping establish a slowly progressive
northern stream large scale flow that will allow high pressure to
remain over the Great Lakes through the weekend. Upper jet energy
will gradually migrate into split flow north of the closed low
allowing long range models to project a short wave trough reaching
northern Ontario Tuesday night. This feature is shown to siphon some
moisture from the remains of the southern stream closed low and
bring our next chance of rain Tuesday night into Wednesday of next
week.

&&

.MARINE...

Small Craft Advisories for the nearshore waters of Lake Huron from
Port Austin to Harbor Beach will remain in effect through this
morning as northwest winds maintain elevated wave action. A weak
pressure gradient will result in light winds. Conditions will remain
dry as a high pressure drifts across the Great Lakes through the
weekend. Winds will be southerly to start next week as the high
pressure moves east of the Great Lakes. The next shot at unsettled
weather conditions will be toward the middle of next week.

&&

.PREV DISCUSSION...
Issued at 1146 PM EDT Thu Apr 19 2018

AVIATION...

VFR conditions will prevail as high pressure builds across the area
and only wisps of cirrus traverse the area. A general northwest flow
will persist into Friday, mixing to 8-10 knots by midday. Light and
variable winds after 00z as decoupling occurs with the high overhead.

DTW THRESHOLD PROBABILITIES...

* None.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

Lake Huron...Small Craft Advisory until 10 AM EDT this morning for LHZ441.

Lake St Clair...NONE.

Michigan waters of Lake Erie...NONE.

&&

$$

DISCUSSION...BT
MARINE.......AA
AVIATION.....DG


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.