Sunrise 5:48 AM   Sunset 9:13 PM Moonrise 5:11 PM   Moonset 2:05 AM

  Print   HELP   Reset   Save   Recall  New

LHZ463 Expires:202406181545;;219371 Fzus63 Kdtx 180736 Glflh
open lake forecast for lake huron national weather service detroit/pontiac mi 336 am edt Tue jun 18 2024
for waters beyond five nautical miles off shore on lake huron
waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum.
Synopsis - Southwest winds, related to a bermuda high, 30.30 inches, will continue to pump hot and humid air into the central great lakes through mid week. Winds likely shift to light north/northeast over lake huron Thursday and Friday as surface front boundary sinks south in response to high pressure tracking through ontario.
lhz462>464-181545- lake huron from port austin to harbor beach beyond 5nm off shore- lake huron from harbor beach to port sanilac beyond 5nm off shore- lake huron from port sanilac to port huron beyond 5nm off shore- 336 am edt Tue jun 18 2024
Today - Southeast winds 5 to 10 knots increasing to 10 to 15 knots in the afternoon. A chance of showers and Thunderstorms. Waves 1 to 3 feet. Tonight - Southwest winds 5 to 10 knots becoming south 10 to 15 knots in the late evening and overnight. A chance of showers and Thunderstorms. Waves 1 to 3 feet. Wednesday - South winds 5 to 10 knots increasing to 10 to 15 knots in the late morning and early afternoon - .then decreasing to 5 to 10 knots early in the afternoon. A chance of showers and Thunderstorms. Waves 1 to 3 feet. Wednesday night - Southwest winds 5 to 10 knots. A chance of showers and Thunderstorms. Waves 2 feet or less. Thursday - North winds 5 to 10 knots. A chance of showers and Thunderstorms late in the afternoon. Waves 2 feet or less. Friday - North winds 5 to 10 knots. Waves 2 feet or less. Saturday - Southwest winds 5 to 10 knots backing to the southeast until early evening - .then increasing to 10 to 15 knots in the late evening and early morning. A chance of showers and Thunderstorms. Waves 2 feet or less.

LHZ400
No data

FXUS63 KDTX 181301 AFDDTX

Area Forecast Discussion National Weather Service Detroit/Pontiac MI 901 AM EDT Tue Jun 18 2024

KEY MESSAGES

- Hot and humid conditions will persist across most of the area through the week.

- Chances of thunderstorms will continue each day of the week. Some of these storms may be strong to severe with locally heavy downpours.

UPDATE

One of the first tasks of the day was to update the grids to offer some definition to precipitation chances.

This afternoon, absolute vorticity center/associated leafing now centered over far northeastern sections of Illinois will lift northward arriving west of the Saginaw Valley by 18Z. A modest but organized kinematic field will push west to east in response of the shortwave with an area of speed convergence pushing into eastern sections of the cwa. Concurrently, a low-mid dry slot feature will also impinge into Southeast Michigan from the west, setting the stages for a coherent plume of low to midlevel thetae/moisture to coalesce in place locally. There may also be a differential heating component also at play, but overall the convergence axis and boundary look to be synoptically forced from southern Lake Huron southward to the Ohio River.

The MPAS runs and the HRW-ARW are all bullish on thunderstorm activity across the far eastern 1/3rd of the cwa including Metro Detroit between 18-22Z timeframe. This thunderstorm activity does match up very well to the expected thetae plume. So did give some thought about increasing PoPs to likely between 18-00Z. Thunderstorm activity may lift northward into the eastern Thumb region then between 22-01Z. Forecast soundings support around 1750 MLCAPE and SBCAPE of around 2000 J/kg with all exhibiting weak to nil cap this afternoon (700mb at only 7C). 0-6km bulk shear gets a little interesting as the eastern edge of the kinematics arrive pushing 30 knots for a portion of the forecast area. Given the shear combined with CAPE densities, the potential for strong to severe storms is higher than yesterday. Much of the area is designated as a Marginal risk for Severe Weather. The main threat will be strong to severe windgusts from wet microbursts and water loading. Orientation of the convergence forcing and resolved omega (parallel to mean flow) also gives some real concern for heavy rainfall and isolated Flash Flooding today over Metro Detroit. PWATS may exceed 2.0 inches this afternoon.

PREV DISCUSSION
Issued at 607 AM EDT Tue Jun 18 2024

AVIATION...

Airmass recovery gets underway this morning after a stormy evening.
Where marginally MVFR fog develops, visibilities should improve before or shortly after the 12Z TAF issuance. Diurnal cumulus response expected with high based VFR clouds AOA 5 kft AGL this afternoon before convection initiates within an unstable/uncapped airmass. Coverage of storms carries uncertainty with the better CVA along the edge of the ridge forces storm development further north (FNT/MBS), but the denser instability reservoir and lake breeze interactions will have greater influence over the Metro Detroit terminals. Given those considerations, kept the inherited TEMPO groups for TSRA with MVFR visibility reductions. Winds generally remain AOB 10 knots with southerly flow, but strong gusty winds and microburst potential exists with the deepest convective storms.
Storms are expected to diminish quickly around 00Z this evening.

For DTW/D21 Convection...Another round of storms expected this afternoon with potential for wet microbursts should stronger storms develop over/near D21 airspace. Coverage will be scattered in nature.

DTW THRESHOLD PROBABILITIES...

* Moderate for thunderstorms from 19 to 23Z.

* Moderate for ceiling at or below 5000 ft, conditional with thunderstorms.

PREV DISCUSSION...
Issued at 329 AM EDT Tue Jun 18 2024

DISCUSSION...

Amplification of the East Coast mid level ridge will be ongoing today into Wednesday, with the ridge becoming more elongated as it stretches across the Ohio Valley during the end of the week. Short wave energy rotating along the western periphery of this ridge will advance across western Lower Mi today. Hi res model solutions generally suggest this will set up a thermal/instability gradient across the western portions of the forecast area this afternoon.
This and potential lake breeze convergence zones across the eastern portions of the area will provide enhanced boundary layer convergence to support additional rounds of convection, mainly this afternoon and evening. ML Cape values projected near 2k J/kg with model soundings showing respectable CAPE density within an uncapped environment will again be supportive of localized strong/severe convection despite relatively week deep layer shear profiles. The depth of the warm layer, with PWATs around 1.8 inches will support some locally high rain totals as well.

Expectations are for temps to be a little cooler today compared to yesterday given high clouds and the chances for an earlier convective release. Forecast highs in the low 90s with dewpoints near 70 will still push heat indices well into the 90s. The humidity will sustain another warm night tonight as lows will likely hold in the 70s. Some building/expansion of the mid level ridge across the eastern lakes will sustain heat and humidity across Se Mi Wednesday.
Timing and coverage of convective development within a moderately unstable and uncapped atmosphere will play heavily into forecast highs. Thermal profiles suggest low to mid 90s for highs Wed with heat indices well into the 90s to around 100. The potential for ML CAPE values to exceed 2k J/kg with little to no capping inversion will again support locally strong/severe convection.

A little more elongation in the mid level ridge noted in the 00Z model suite increases the chances for a southward push of slightly cooler air from the north on Thursday as high pressure expands across the northern lakes. Short wave impulses embedded within the westerly flow with a lingering instability gradient over southern Lower Mi also looks favorable for additional convection. Therefore, the heat headlines will extend only through Wednesday evening. A longer wavelength trough forecast in the northern stream over the weekend will attempt to drive the front back northward as a warm front. The potential for convection will however support a low confidence forecast on temps during the first half of the weekend.
The passage of the mid level trough and associated cold front will then support cooler and less humid conditions by the end of the forecast.

MARINE...

Southwest winds will continue to advect hot and humid air into the Central Great Lakes through the mid week period. High degree of surface stability with the cooler waters should keep wind speeds under 25 knots through the rest of the work week. The exception will be in and near and strong thunderstorms which develop. Timing and location will be highly uncertain, but the typical peak heating of the day into early evening hours will be favored. Indications are the surface frontal boundary will be sinking south Thursday and Friday as seasonably strong high pressure tracks through Ontario.
This will allow for light northeast/northerly flow (~15 knots) over Lake Huron. Airmass will remain warm, thus any wave build up with the longer fetch remains below 4 feet.

HYDROLOGY...

A moist and unstable airmass will be in place across the region through the end of the week. Scattered thunderstorms are expected each day this week. The most intense thunderstorms have the potential to produce rainfall amounts in excess of 2 inches over a short period of time, resulting in urban and low lying area flooding. Uncertainty in specifics for both timing and potential for flooding precludes issuance of a flood watch.

DTX WATCHES/WARNINGS/ADVISORIES
MI...Heat Advisory until 8 PM EDT Friday for MIZ047-053-060-068-075-082- 083.

Heat Advisory until 8 PM EDT Thursday for MIZ048-049-054-055-062- 063.

Excessive Heat Warning until 8 PM EDT Friday for MIZ061-069-070-076.

Lake Huron...None.
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,