Marine Weather and Tide Forecast for Hamilton, OH

NEAR TERM /THROUGH TONIGHT/
While low pressure pivots northeast across the western Great Lakes tonight, a trailing cold front from the low will make inroads into our forecast area. Low levels are expected to be quite saturated. However, this moisture is not overly deep.
Also, forcing appears weak as well along and ahead of the boundary. As a result, will continue with only a slight chance of pcpn. However, due to the depth of the moist layer having temperatures generally warmer than -10 C (a general rule of thumb of having the atmosphere cold enough to support enough ice nucleation in the cloud), the pcpn, albeit light, may fall as light snow or flurries and/or light drizzle/light freezing drizzle dependent on surface air temperature and atmospheric column conditions. With such low confidence in measurable pcpn, will keep the HWO wording as a low probability for widespread hazardous weather. Temperatures will remain relatively mild ahead of the cold front, but they should begin to drop some as CAA begins to take place.

SHORT TERM /MONDAY THROUGH MONDAY NIGHT/
Aforementioned cold front should be exiting our eastern zones during the first part of the morning on Monday. The threat for light pcpn will come to an end once it exits. Thereafter, our region will be under a quasi-zonal flow from the surface through the middle troposphere. CAA will continue such that some locations will see readings slowly drop during the day. Skies will vary between partly and mostly cloudy as CAA stratocumulus is expected.

For Monday night, colder air will continue to funnel into our region under partly cloudy skies. With surface winds staying up some, these winds, combing with lows forecast in the 5 to 10 degree range, will result in wind chill values between 0 and -10. Will continue to mention this hazard in the HWO.

LONG TERM /TUESDAY THROUGH SUNDAY/
On Tuesday morning, mid-level troughing over the Great Lakes will be gradually moving to the east-southeast. At the surface, high pressure will be in place across the southeastern states, with another high moving out of Canada into the upper Mississippi Valley region. A boundary between these two surface highs will be moving east into the Ohio Valley, at around the same time that the Great Lakes wave -- and some jet energy -- will be moving east through the region as well.

With some weak and transient forcing aloft also coinciding with these features, there will probably be some snow on Tuesday.
While models continue to produce very little QPF with this feature, this is a scenario where even very weak forcing could produce light measurable snowfall (generally under an inch)
thanks to the cold air mass and favorable thermodynamic juxtaposition with the dendritic growth zone. Will continue to gradually increase PoPs from forecast to forecast with this feature.

The already-cold conditions will only get colder as the aforementioned surface boundary moves through the area Tuesday afternoon. This will shift winds to the WNW and bring a frigid air mass into the Ohio Valley by Wednesday morning. Min temps are expected to be within a few degrees on either side of zero.
NBM probabilities for <0F seem underdone for this kind of air mass, snow cover, and expected combination of fairly light winds and mostly clear skies -- not quite perfect radiational cooling conditions, but close to it. It seems likely that much of the CWA will get below zero, with some readings of -5F or even lower in outlying or sheltered locations.

Regarding specific hazards, wind chill / apparent temperature values will be cold enough to continue to mention in the Hazardous Weather Outlook on the mornings of Tuesday, Wednesday, and Thursday. This may require Cold Weather Advisories as these days get closer.

A weak trough could bring some light snow to the northern and eastern sections of the forecast area on Thursday, as the surface high begins to move away to the east and weaken. Once the surface high has moved east of the area, the pattern will switch to warm advection -- which will bring temperatures above freezing on Friday. There are indications that another storm system will bring precipitation to the area by the weekend, with timing, intensity, and precipitation type all still very unclear this far out.

AVIATION /20Z SUNDAY THROUGH FRIDAY/
Into tonight, as low pressure pivots northeast across the western Great Lakes, a trailing cold front will make inroads east into our region. There will be sufficient low level moisture associated with the front to bring ceilings down into the MVFR/IFR categories with pockets of MVFR visibilities possible. Moisture overall is not deep, and forcing is weak, so will continue with a slight chance of precipitation along and ahead of front. The spotty precipitation could fall in the form of light snow/flurries or light drizzle/light freezing drizzle depending on air temperature and atmospheric conditions. Winds will initially be from the south between 8 and 14 knots with local gusts in the 18 to 22 knot range. These winds will veer overnight to the southwest, and then eventually will shift west with the passage of the front.

On Monday, our area will be in the wake of the front. Winds will remain westerly in the 8 to 14 knot range with local gusts to 20 knots. CAA will keep some post frontal stratocumulus clouds around. Ceilings should eventually lift toward or above 2000 feet.

OUTLOOK.. MVFR/IFR conditions possible Tuesday. MVFR ceilings possible on Thursday.

ILN WATCHES/WARNINGS/ADVISORIES
OH...None.
KY...None.
IN...None.