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7 Day Forecast for Marine Location Near Sturgeon Bay, WI

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Area Discussion for - Green Bay, WI

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FXUS63 KGRB 090848 AFDGRB

Area Forecast Discussion National Weather Service Green Bay WI 348 AM CDT Sun Aug 9 2020

Forecast discussion for routine morning forecast issuance

SHORT TERM. Today . Tonight . and Monday Issued at 348 AM CDT Sun Aug 9 2020

Main issues to settle out in the short-term will be convection trends and intensity of any storms that develop. Still low to medium confidence with the convective scenarios this afternoon into this evening. Storms will be capable of producing torrential rainfall this afternoon and tonight.

MSAS surface analysis and surface observations show a remnant outflow boundary draped across the area from west to east this morning. Generally stretching from near or just south of Minneapolis to near Milwaukee. Radar shows a few showers have developed along and just north of this boundary. Satellite imagery shows some mid clouds across central/east-central WI this morning with quite a bit of clearing across much of the rest of the WI along with some fog development. IR imagery shows an MCS sliding across eastern SD and far southwest MN. Several severe wind reports have been associated with this system early this morning.

Today: Models continue to keep a temperature inversion in place across the area through much of the morning hours as the boundary lifts to near the U.P. border. This should keep fairly quiet conditions in place across the area under partly cloudy skies. It is possible that an elevated shower/storm could develop along the boundary this morning; however, the best chance looks to be in the afternoon. This will be as the aforementioned potent shortwave/MCS pushes into central Wisconsin between 17Z and 21Z. It is possible that the outflow boundary could arrive a little earlier as the system is surging eastward quickly this morning. As the outflow boundary and MCS/MCV pushes into the area, the cap will likely be overcome, especially as moisture transport increases across the area, allowing scattered showers and thunderstorms to develop over central/north-central WI and then spread eastward through the rest of the CWA into the late afternoon/early evening hours.

Where convection does initiate, models are painting out around 3000- 4000 J/kg of MUCAPE during this time period with direction shear ahead of and under the shortwave around 25-35 kts. The shear vectors are orthogonal to the expected outflow boundary, which would likely lead to more organization of any storms that develop along the boundary. Fairly steep mid-level lapse rates (around 8C/km) along with fairly strong winds in the lower levels of the atmosphere will likely lead to a damaging wind threat along with hail potential. SPC has continued the Slight Risk of severe storms for this afternoon into this evening. PWATs are expected to remain in the 1.5-2 inch range across the area, which will lead to very heavy rainfall potential under any of the storms. Portions of central and north- central WI are under a marginal risk of excessive rainfall. High temperatures are expected to be in the mid to upper 80s. Temperatures could be impacted by cloud cover/precipitation, but it does look there will be enough of a window for temperatures to warm well into the 80s. Dewpoints running in the upper 60s to low 70 will make it feel very muggy!

Tonight: Attention then turns to an approaching cold front, from the northwest. Forcing along the front will allow showers and thunderstorms to develop, with a continued unstable airmass ahead of it. The amount of instability will largely be determined by afternoon convection. This front would approach central WI between 06Z and 12Z. This would be the next round of potentially more widespread showers and thunderstorms. Models generally paint out around 1500 to 2500 J/kg of MUCAPE through the late evening hours; however, if the atmosphere gets worked over enough this afternoon and can't recover, then instability may be closer to the lower end of that range. If the afternoon thunderstorms have trouble developing, then the stronger storm threat may last later into the night. Shear values ahead of the front are progged to be in the 20 to 25 kt range, which will help to limit the overall organization. Any storm that develops will have the potential to produce gusty winds and very heavy rainfall as PWAT values are still expected to range from 1 to 2 inches. Dewpoints will remain high ahead of the front with readings in the upper 60s to low 70s, similar to the expected overnight lows.

Monday: The cold front will continue to shift southeastward through the Fox Valley and the Door Peninsula between 18Z and 00Z. This will force most of the shower and thunderstorm potential to the east- central and far northeast portions of the area. By the early afternoon hours, a nose of MUCAPE is expected to build up ahead of the front, which will likely be enough to keep the chance of thunder in the forecast. Shear values continue to be fairly marginal ahead of the front, with most of the models showing around 20 to 25 kts. If the 1500-2500 J/kg of MUCAPE is realized, then a couple of the thunderstorms could pulse up ahead of the front and produce gusty winds and marginally severe hail. Areas to the west and northwest of the front will see a bit cooler and drier day, with more comfortable humidity levels. High temperatures are forecast to be in the mid 80s ahead of the front and mid to upper 70s behind the front.

LONG TERM. Monday Night Through Saturday Issued at 348 AM CDT Sun Aug 9 2020

Fairly zonal pattern at 500mb expected through much of the week with disturbances moving along the mean flow along the Canadian border. This pattern should allow for daytime temperatures to be at or a few degree above normal each day.

For Monday night, there is some concern precipitation may linger into the early evening hours across east-central Wisconsin. Per coordination with Milwaukee, will leave Monday evening dry for now and pass on concerns to the next shift.

For Tuesday, high pressure will move across the region. It will be considerably less humid than Monday as dewpoints drop into the 50s. Some of the sandy soil regions across the north could see dewpoints drop into the upper 40s in a few spots. Dry conditions will continue through Wednesday evening as the high shifts east. From Thursday into Saturday, confidence is low with the arrival of precipitation chances. The ECMWF would keep us dry into Saturday while the GFS/Canadian models have convection spilling over into our areas at times Thursday and Friday. Due to the low confidence in the precipitation chances, did not deviate from the forecast initialization grids. High temperatures through much of the period will be in the upper 70s to middle 80s. After a few days of lower dewpoints, dewpoint readings should gradually increase late in the week.

AVIATION. for 06Z TAF Issuance Issued at 1247 AM CDT Sun Aug 9 2020

An isolated shower or thunderstorm could pop up on any lingering boundaries across the area; however, the chances look to be fairly low across much of northeast WI through Sunday morning. Have left this out of the TAF sites with this issuance. Some fog may develop where rain fell Saturday, which may result in MVFR conditions or possibly as low as IFR conditions if skies clear for any length of time. Otherwise, more impactful weather will likely arrive at the central TAF sites late this afternoon, spreading to the eastern TAF sites by late evening as a thunderstorm complex treks eastward into the area. Some of those storms could become strong to severe with very heavy rain, gusty winds and hail. Additionally, a cold front is expected to approach the area late Sunday night into Monday morning, which will keep a chance of showers and lower ceilings at each of the TAF sites.

GRB WATCHES/WARNINGS/ADVISORIES. Beach Hazards Statement until 4 AM CDT early this morning for WIZ022-040-050.

SHORT TERM . Cooley LONG TERM . Eckberg AVIATION . Cooley

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Weather Reporting Stations

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Stations	Dist	Age	Wind	Air Temp	Water Temp	Waves	Pressure	DewPt
MN4 - 9087088 - Menominee, MI	19 mi	49 min	SW 4.1 G 5.1	71°F	71°F		1015 hPa	69°F
45014	20 mi	49 min	SSW 7.8 G 9.7	74°F			1014.2 hPa
CBRW3 - Chambers Island, WI	23 mi	39 min	SSE 2.9 G 6	70°F
KWNW3 - 9087069- Kewaunee, WI	28 mi	49 min	WSW 1.9 G 6	74°F			1015.4 hPa

Wind History for Menominee, MI

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Airport Reports

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Airport	Dist	Age	Wind kt	Visibility	Sky/Weather	Temp	DewPt	Humidity	Pressure
Door County Cherryland Airport, WI	3 mi	23 min	SW 3	10.00 mi	Partly Cloudy	72°F	70°F	94%	1015.6 hPa
Menominee - Marinette Twin County Airport, MI	21 mi	23 min	N 0	10.00 mi	Fair	70°F	68°F	93%	1015 hPa

Link to 5 minute data for KSUE

Wind History from SUE (wind in knots)

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Tide / Current Tables for

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Tide / Current Tables for

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Weather Map

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GEOS Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for Green Bay, WI (7,2,3,4)

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Ground Weather Radar Station Green Bay, WI

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