NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

LCZ423 851 Pm Edt Wed Sep 6 2023
.strong Thunderstorms approaching the waters...
the areas affected include...
detroit river... Michigan waters of lake erie...
at 848 pm edt, doppler radar indicated strong Thunderstorms, capable of producing winds to up 30 knots. These Thunderstorms were located along a line extending from 16 nm west of lake erie metropark harbor to 8 nm northwest of Monroe harbor to near luna pier, moving northeast at 20 knots.
strong Thunderstorms will be near, Monroe harbor, bolles harbor of refuge, north cape, luna pier, woodland beach, and detroit beach around 855 pm edt. Stony point around 900 pm edt. Lake erie metropark harbor, estral beach, and gibraltar around 910 pm edt. Detroit river light around 915 pm edt. Elizabeth park marina and wyandotte around 920 pm edt. Grosse ile around 925 pm edt.
other locations impacted by strong Thunderstorms include woodland beach, stony point, gibraltar, estral beach, and detroit beach.
precautionary/preparedness actions...
mariners can expect gusty winds up to 30 knots, locally higher waves, and lightning strikes. Boaters should seek safe harbor immediately until these storms pass.
these strong Thunderstorms will likely produce winds up to 30 knots, and could pose a serious hazard for boaters. A special marine warning may eventually be required when these storms reach the nearshore waters. Boaters should consider heading for shore before these storms arrive.
&&
lat...lon 4173 8350 4180 8350 4195 8337 4197 8328 4226 8317 4233 8311 4238 8294 4235 8293 4232 8307 4224 8313 4212 8312 4203 8315 4196 8311 4180 8333 4172 8341

LCZ400
No data

FXUS63 KDTX 300442 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1142 PM EST Wed Nov 29 2023


AVIATION

Low level southwest flow will increase during the course of the morning hours. A shallow near surface stable layer will generally keep surface winds around 10 knots or less. The onset of daytime mixing will support an increase in the SW winds after 15Z. Model soundings and probabilistic guidance suggests frequent gusts over 20 knots from 15Z through roughly 20-22Z. Low level warm and dry air will keep skies clear (aside from some high based clouds) into early Thursday afternoon. Moisture will then increase along a frontal boundary forecast to drop into Se Mi Thursday evening, leading to increased chances for low end VFR and MVFR ceilings.

DTW THRESHOLD PROBABILITIES

* Moderate in ceilings aob 5000 feet Thursday evening.

PREV DISCUSSION
Issued at 330 PM EST Wed Nov 29 2023

DISCUSSION...

Upper troughing that has been entrenched over the Great Lakes thus far this week finally has begun shifting east today reestablishing zonal flow over the central CONUS. Modest WAA follows with 850mb temps climbing from -2C to +2-4C by Thursday afternoon supporting highs back into the mid to upper 40s, potentially around 50 towards the Ohio border. While a 45-50kt LLJ develops over southern lower MI Thursday, milder airmass looks to support an inversion around 1.5kft limiting the magnitude of mixing down of these stronger winds. That said, forecast soundings are still supportive of a fairly breezy day with peak afternoon gusts in the 25-30mph range, approaching 35mph over the Thumb/Tri-Cities where the core of the LLJ crosses.

Attention then turns to a southern stream mid/upper level wave that will be ejecting out of the Desert southwest Thursday morning.
Partial phasing between the northern and southern streams over the eastern CONUS results in this shortwave tracking northeasterly across the southern Midwest and eventually into the Ohio Valley/southern Great Lakes by early Friday morning. In advance of this system, a weak northern stream cold front tied to a shearing shortwave over northern Ontario is progged to drop into the central Great Lakes overnight Thursday. Little to no precip, at least initially, is expected along this frontal boundary given the geographic detachment from parent vorticity. This changes Friday morning with the arrival of the southern wave and subsequent better moisture quality (PW increasing to 0.5-0.75in) as well as strengthening synoptic ascent. This boundary, which looks to being residing south of I-69 if not south if M-59 by this time, provides an early focal point for enhanced forced lift offering a period of light showers in advance of the main system isentropic ascent. Said ascent then overspreads the region through the remainder of Friday morning/afternoon. General trends amongst both deterministic and ensembles has been for a more northerly track providing precip across the vast majority if not all of SE MI. Only the far northern Thumb/Saginaw Valley currently look to have any shot at missing precipitation however though chances are trending lower.

Primary area of uncertainty wrt to this system remains on the thermodynamic side of things given the numerous moving parts in play. First is how far north warm air advection reaches into SE MI which is highly dependent on the track of the mid-level wave. The second factor is unfavorable diurnal timing (for snow) as the bulk of QPF is expected during the daylight hours Friday. That said with dewpoints in the lower 30s for areas north of M-59, there is the potential for evaporative cooling during the peak precip rates Friday afternoon to offset diurnal heating and support a shallow enough warm layer or a complete aob freezing column to transition to all snow. Lower ratio (solidly sub 10:1) snow would be favored in this scenario cutting down of max potential snowfall amounts.
Additionally with the milder day Thursday and marginal freezing temps Friday, accumulation potentials on pavement would be further reduced likely having to rely on enhanced snowfall rates to overcome melting. Based on 12Z trends/consistency amongst the ECMWF emsemble family and deterministic as well as the NAM, areas north of M-59 looking to have the best shot at seeing accumulating snowfall Friday with areas to the south having a better chance to stay all rain or a rain-snow/melting snow mix.

A secondary weaker shortwave quickly trails this lead wave Friday night-Saturday taking a similar track and offering another window for rain and/or snow. Again thermodynamic uncertainty wrt to p-type is likewise high with this wave. Amplified upper troughing pattern dominates the central CONUS through at least the first half of the week allowing for additional shortwaves to impact southern MI maintaining an active pattern. Temperatures however currently looking to hold around normal through this period with the core of the arctic airmass remaining confined in northern/eastern Canada.

MARINE...

Southwest winds decrease slightly through this evening as a more mild airmass arrives into tomorrow. The southwest winds do remain elevated enough across southern Lake Huron to maintain Small Craft Advisory conditions across Saginaw bay to Harbor Beach. Winds hold generally less than 25 knots through most of tomorrow morning before another quick passing low pressure system moving across Ontario into Quebec increases the west to southwest gradient again with some colder air starting to filter in as well. This will result in wind gusts to around 30 knots mostly across central and southern Lake Huron and continued and likely expansion of Small Craft Advisories to the south into tomorrow evening. Winds will shift from the southwest Thursday afternoon to east-northeast by Friday morning as a low pressure system moves into the Ohio River Valley and then into the southern Great Lakes bringing rain and snow Friday and Friday night. These winds will again bring building waves to the nearshore zones of the Thumb. The active weather pattern will continue into the weekend.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Small Craft Advisory until 9 PM EST Thursday for LHZ421-422-441.

Small Craft Advisory from noon to 7 PM EST Thursday for LHZ442-443.

Lake St Clair...None.
Michigan waters of Lake Erie...None.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Detroit, MI,