Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 151800
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
200 PM EDT Fri Mar 15 2024

.KEY MESSAGES...

- Breezy and mild Saturday as southwest wind gusts around 35 mph help
  lift temperatures into the 50s, 10-15 degrees above normal for mid
  March.

- There is also a chance of showers as a front moves through the region;
  earlier in the day toward the Tri Cities, mid to late afternoon
  toward metro Detroit.

- A surge of cold air follows Saturday night and Sunday which is
  then reinforced Monday through Wednesday next week.

- Daytime temperatures drop into the 40s Sunday and then below
  normal into the 30s Monday and Tuesday. The cold air also brings a
  chance of snow showers for the early week period.

&&

.AVIATION...

Northerly flow off of Lake Huron has maintained healthy coverage of
IFR to MVFR stratus across the northern terminals for most of the
day. Gradual erosion of this cloud deck continues from the south and
west, with all sites becoming VFR by this evening. Brief surface
ridge builds in tonight to support relaxed winds with a backing
trend to the west-southwest by early Saturday morning. This precedes
a broad longwave trough that brings intervals of cloud cover (based
around 3.0-5.0 kft agl) to the airspace Saturday morning. Thickening
mid cloud develops by early afternoon in closer proximity to the
troughing feature though broader low cloud scours out. It is
possible by 18z that this wave can squeeze out light showers toward
MBS/FNT but confidence is low attm.

For DTW... scattered shower coverage is possible between 18-00z
Saturday owing to steep low level lapse rates and moisture aloft.
Shower intensity is expected to be light although ceiling heights
may drop below 5 kft agl at times.

.DTW THRESHOLD PROBABILITIES...

* Low for ceilings at or below 5000 feet Saturday morning through
  Saturday evening.

&&

.PREV DISCUSSION...
Issued at 300 AM EDT Fri Mar 15 2024

DISCUSSION...

Cold front has cleared southeast Michigan and drier air is slowly
working in which should allow for developing sunshine today,
especially as the pronounced mid level dry slow (30+ C 700 MB dew pt
depression) moves in. With the mid March insolation and based off
current temperatures, expecting highs reaching into the 50-55 degree
range across most locations as the cold advection through the day is
not terribly strong. The thumb region will be significantly cooler
(40s) with the cold northerly flow off Lake Huron.

Breezy southwest winds on Saturday ahead of the dry cold front
passage, with up to 40 knots of flow at 850 MB conducive for gusts
aoa 30 mph during the day. 850 MB temps of 0.5-1.5 C supports highs
in the mid 50s to around 60 degrees.

Big pattern shift to occur this weekend as the strong upper level
wave over Western Canada early this morning dives into the Great
Lakes region on Saturday, with additional upper level PV streaming
in from Hudson Bay. The end result is a amplified longwave trough
extending all the way to the Gulf Coast States by Monday.
Temperatures over southeast Michigan will reach and likely dip below
normal as 850 MB temps in the negative lower teens takes hold. A re-
enforcing cold pool/upper level wave looks to arrive on Tuesday,
with 850 MB temps even potentially lowering into the negative mid
teens Tuesday night-Wednesday, per 00z Canadian/Euro. The cold
cyclonic flow will be conducive for periods of lake enhanced light
snow shower activity, with more broad upper level support and better
low level instability in the Tuesday-Wednesday time frame.
Confidence in timing and location of any light accumulating snow
remains very low at this time.

MARINE...

The low has pass to our east and pushed the cold front east of the
area as well allowing high pressure to start building into the
region. As a result, the tightened gradient and onshore flow has
produced elevated wave heights along the southern Lake Huron
shoreline. The strongest of the winds have ended which will allow
waves to continue to subside through the early morning. Small Craft
Advisories will come to an end during this time with the high
pressure system then providing a brief period of favorable marine
conditions. A larger low pressure system then approaches from
central Canada Saturday that quickly ramps up SW wind and waves to
near Small Craft thresholds. The low tracks north of Lake Huron
Saturday night while pulling multiple cold fronts across the Great
Lakes Sunday. A turn toward below normal temperatures maintains a
higher wind and wave regime into early next week.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....MV
DISCUSSION...SF
MARINE.......DK


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