Sunrise 5:19 AM   Sunset 8:17 PM Moonrise 2:23 PM   Moonset 2:52 AM

  Print   HELP   Reset   Save   Recall  New

LMZ521 Green Bay South Of Line From Cedar River To Rock Island Passage And North Of A Line From Oconto Wi To Little Sturgeon Bay Wi- Green Bay South Of Line From Oconto Wi To Little Sturgeon Bay Wi- 1236 Pm Cdt Fri May 17 2024
This afternoon - SE wind 5 to 10 kts. Areas of dense fog. Waves 2 ft or less. Tonight - SE wind 5 to 10 kts. Mostly clear. Waves 2 ft or less.Saturday - S wind 5 to 10 kts increasing to 10 to 20 kts in the afternoon. Sunny. Waves 2 ft or less. Saturday night - S wind 10 to 15 kts veering W 5 to 10 kts after midnight. Mostly clear. Waves 2 ft or less.

LMZ500
No data

FXUS63 KGRB 171729 AFDGRB

Area Forecast Discussion National Weather Service Green Bay WI 1229 PM CDT Fri May 17 2024

Updated aviation portion for 18Z TAF issuance

KEY MESSAGES

- Dense fog is likely in the Fox Valley, the lakeshore counties, and the area west of the bay early this morning.

- Dense fog is likely over the bay through mid morning, and over the nearshore waters of Lake Michigan through mid afternoon.

- There is a chance of thunderstorms in northcentral Wisconsin this afternoon.

- Isolated thunderstorms are possible Saturday afternoon and evening, although most of the area is expected to remain dry throughout the day.

DISCUSSION
Issued at 400 AM CDT Fri May 17 2024

Short Term
Today
Tonight...and Saturday

AIr with low 50s dewpoints flowing over the 45 degree waters of Lake Michigan was producing areas of dense fog over the lake, bay and adjacent land areas early this morning. The fog over the land should dissipate a couple hours after sunrise, while the fog over the bay should dissipate by mid morning. The fog over the nearshore waters of Lake Michigan could last through late afternoon, or perhaps even later, as there will be a lake breeze.

Skies should become sunny once the fog has dissipated. 925mb temperatures support high temperatures in the middle 70s to lower 80s this afternoon, but of course much cooler near the lake. An upper trough moving across Upper Michigan could produce scattered thunderstorms this afternoon and early evening in northcentral Wisconsin.

Tonight will mild, with some clouds and a steady wind. Lows will range from the middle 40s over northern Door county to the middle 50s in the Fox Valley. Summer like weather is expected Saturday, as south winds increase. Highs will be mostly in the 80s, though dewpoints in the 50s will keep it from being too humid. There is a chance of thunderstorms in central and northcentral WIsconsin in the afternoon ahead of a weak cold front.

Long Term...Saturday Night Through Thursday

As the weekend trends drier, main focus for the extended will turn to another active pattern to set up early next week. A train of shortwaves are expected to bring multiple rounds of rain/storms to the forecast area beginning Sunday evening and lasting through mid-week. This type of spring pattern can be volatile, so changes to the forecast are possible over the next few days as models come in to better agreement about the timing and track of two driving systems.

Saturday evening... Models continue to be unimpressed with rain/storm chances Saturday evening due to moisture inhibition. As widespread subsidence behind the cold front places weak high pressure across the western Great Lakes, dry air will make it difficult for any rain or storms to get going. Thus, dewpoints will need to be on the rise to saturate the profile enough to warrant any precip. This being said, potential for isolated pulse storms and light rain remains due to temperatures in the upper 70s and low 80s resulting in sufficient surface-based instability (approaching 1000 J/kg CAPE). Dry conditions will then persist through Sunday as a dry airmass situates over Wisconsin.

Next week... On and off rain/storm chances will continue through at least mid-week as large-scale ridging across the eastern CONUS puts most of the Midwest under a southwest flow regime. Meanwhile, a robust trough settled over the western US will eject several shortwaves and accompanying precip chances up into the region. The first round of precip is expected to move through the forecast area Sunday night through Monday. In its wake, a more dynamic system is expected to trek from the central Plains to the upper Mississippi Valley by Tuesday evening. A first glance shows that this system has the potential to bring heavy rain and thunderstorms to the area, although it is too soon to make out any details. Will continue to monitor convective potential and precip amounts as we get closer to the event.

AVIATION
for 18Z TAF Issuance Issued at 1229 PM CDT Fri May 17 2024

VFR conditions and partly to mostly sunny skies were noted across the TAF sites early this afternoon. VFR conditions are expected through Saturday morning as a low pressure system approaches from the west late Saturday morning. Some high based showers are possible across far north-central Wisconsin late this afternoon, but is expected to mainly stay away from KRHI. Late tonight into early Saturday morning some low clouds and fog could move inland from Lake Michigan, possibly to the MTW/2P2 and 3D2 airports.

GRB WATCHES/WARNINGS/ADVISORIES
None.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


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

Green Bay, WI,