Marine Weather and Tide Forecast for Whiting, IN

UPDATE
Issued at 913 PM CST Mon Jan 20 2025

Forecast low temps, winds, wind chills, and flurries/light snow all right on track for tonight. Still anticipate flurries and patchy light snow south of I-80 to end late tonight. Can't rule out some ice crystal/pixie dust like flurries in the air tomorrow morning with such bitter cold temps, but nothing that seems worthy of adding flurries to the forecast.

Did make some adjustments to hourly temp trends Tuesday morning into the early afternoon. The heart of the Arctic air mass with 850mb temps around -30C will be centered over our CWA 15-18z tomorrow. Suspect that the recovery from overnight lows will be slow to occur with many areas north of I-80 likely near or a hair below zero still by noon. Winds will ease ever so slightly late tonight, but by mid morning winds should begin picking up again, so even with temps rising slowly, the increasing winds will result in a very slow improvement in wind chills. Expect many areas to still have wind chills between -17F and -23F at noon tomorrow, so extended the Cold Weather Advisory out 2 more hours into the early afternoon.

Otherwise, forecast appears right on track with no changes planned.

- Izzi

DISCUSSION
Issued at 300 PM CST Mon Jan 20 2025

Through Tuesday Night:

Cloud cover has been increasing across much of the Midwest (including northern IL) this afternoon as an upper-level disturbance pivots through the region. Given the cold air mass in place, cloud top temperatures are sitting below -20C which has yielded some flurries and even a few bonafide snow showers where low-level instability has maximized. These flurries and snow showers are expected to drift into northern IL and northwest IN over the next 1 to 3 hours and persist through at least midnight before tapering. While accumulations with any flurries are not expected, the fine snow grains and blustery winds may produce local visibility reductions in the 3 to 5 mile range with lower values possible with any true showers.
However, some snow accumulations (generally under a quarter inch) may occur with the snow showers; especially for areas south of the Kankakee River where better shower coverage is forecast. That said, those planning to be out and about tonight should use caution in case of slippery roads and visibility changes.

The bigger weather story of the night will be the return of bitterly cold temperatures and wind chills as the snow departs.
While some guidance is showing cloud cover persisting overnight, the thin nature of any clouds shouldn't inhibit radiational cooling much. Therefore, expect overnight lows to dip below zero with wind chills expected to bottom out in the -20F to -30F range by daybreak. Since the -30F wind chills will be more isolated, have decided to maintain the Cold Weather Advisory for now but if more widespread coverage of these wind chills occur an upgrade to a Extreme Cold Warning may be considered.

Temperatures will rebound a bit on Tuesday, but despite the sunshine, highs will only top out in the low single digits.
Couple this with the 15 to 20 mph winds, wind chills will remain in the negative teens through the day on Tuesday. However, as winds turn more south-southwesterly Tuesday night temperatures should gradually increase heading into Wednesday morning. Though, lows Tuesday night will still be around zero to negative single digits before this occurs.

Yack

Wednesday through Monday:

Southwesterly warm advection will be well underway at the beginning of the extended forecast period with the region situated between a 1030+mb high over the Mid-Atlantic and low pressure developing across northern Minnesota/southwest Ontario.
While temperatures will accordingly be increasing steadily throughout the day, sub-zero wind chills are expected to persist through Wednesday morning due to strong winds.

In addition to the warming temperatures and gusty winds to 25-30 mph, there remains the potential for accumulating snow Wednesday morning through the evening. A pair of shortwaves are forecast to move through the broader region during this time, one paired with the aforementioned surface low across the northwest Great Lakes and a separate sheared out wave pivoting out of the central Plains. While these features don't appear to phase fully (at least at this range), ascent associated with them should be sufficient for snow.

Modeled vertical profiles show a stout but dry layer in the lowest levels, at least initially Wednesday morning. However, the mid-levels are expected to saturate, with the saturation becoming quite deep through the DGZ (2-3+ km at times) which would support large enough dendrites to punch through this dry layer. While it will be notably warmer than the first part of the week, air temperatures still in the teens and lower 20s would allow snow to readily accumulate on untreated surfaces. Models continue to support a mostly lighter QPF scenario with this system, with snowfall amounts generally in the 1" or less range, just enough to make untreated roads slippery. For now have maintained mainly 30-40 percent chances for snow with this system. Would like to see how some of the hi-res guidance handles things before introducing "likely" or higher PoPs (55%+), but suspect that is where things are headed.

The cold front eventually moves through late Wednesday night into Thursday morning, temporarily stalling our warming trend with highs in mid-upper 20s. Lake effect snow may linger in northeast Porter County on Thursday, otherwise dry conditions are forecast through the end of the week with temperatures gradually moderating each day back above freezing on Saturday. While a quick hit of light snow can't be ruled out at times, ensemble trends favor generally drier conditions continuing.

Petr

AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/
Issued at 1120 PM CST Mon Jan 20 2025

There are no major aviation weather concerns for the 06Z TAF period.

The light snow which managed to coat roads and drag vsbys down to MVFR in spots will move to the east of the TAF sites by 06Z, except for GYY where snow may continue until closer to 07Z.
Some additional, non-impactful flurries can't be ruled out into the night.

Expect WNW winds near 10 kt occasionally gusting into the teens kts through Tuesday morning. Gusts will pick up to near 20 kt for the afternoon before subsiding and backing to SSW for the evening. Gusts will build again during the latter part of the overnight and we should begin Wednesday with gusts into the 20 to 25 kt range out of the SSW.

Doom

LOT WATCHES/WARNINGS/ADVISORIES
IL...Cold Weather Advisory until 2 PM CST Tuesday for ILZ003-ILZ004- ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-ILZ019- ILZ020-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-ILZ103-ILZ104- ILZ105-ILZ106-ILZ107-ILZ108.

IN...Cold Weather Advisory until 2 PM CST /3 PM EST/ Tuesday for INZ001-INZ002-INZ010-INZ011-INZ019.

LM...Small Craft Advisory until 3 AM CST Tuesday for the IL and IN nearshore waters.