Area Forecast Discussion
Issued by NWS Wilmington, OH
Issued by NWS Wilmington, OH
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700 FXUS61 KILN 220229 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 929 PM EST Thu Nov 21 2024 .SYNOPSIS... Cool temperatures and chances for precipitation remain in place through the end of the working week. Dry conditions and near normal temperatures return to the region for Saturday and Sunday. Precipitation chances increase again on Monday with the next disturbance. && .NEAR TERM /THROUGH FRIDAY/... As of 920PM, the final area of moderate snow is moving southeast through the eastern half of the Cincinnati metro area. TCVG radar also shows some slightly heavier echoes across the rest of the ILN northern Kentucky counties as well. This snow has been passing through the area for the past couple hours, with accumulations increasing on grassy areas, but area DOT cameras showing only wet roadways. This will likely be the case through the overnight, as pavement temperatures are likely to remain warm enough for any travel issues to be isolated. Behind this batch of snow that is exiting the area, patchy light radar echoes are still being observed well to the north. A mix of light snow and possibly drizzle will continue through the region overnight, and PoPs have been increased somewhat through 12Z to account for this. Even where light snow occurs, any additional accumulations will be limited to a tenth or two. The surface low is currently in the northern ILN CWA, with winds going very light to even calm in its vicinity. The low will track southeast through central and then southern Ohio, and winds will shift from the SSW to the NNW to the west of its track. A few gusts in the 15-20 knot range will be possible at times where this occurs. Previous discussion > A second vort lobe rotating around the parent low will be pivoting through the region at the start of the near term. This will provide the forcing needed for widespread snowfall. Guidance suggests that the more negative values of omega (ascent) will pivot primarily through central Indiana and past the Tri-State before midnight. This echoes what was seen on the mid-night shift with regards to a westward shift in highest PoP potential. Have continued to trend higher PoPs over the Tri- State and OH/IN border this evening into overnight. Pavement temperatures still look to remain above freezing and recent pavement models suggest that it will be well past midnight before pavements fall into the 30s. With that being said, as we saw this afternoon, any area experiencing efficient snow rates may have some accumulation on overpasses, sidewalks/ parking lots/ elevated surfaces and grassy areas. Thinking continues to be that an additional 1-2 inches will fall around the Tri-State with snow tapering off after 2AM. Due to these factors, the timing falling during a weekday rush hour commute, and this being the first somewhat impactful snow of the season... have continued the Winter Weather Advisory for those southwest counties. While daytime highs have trended a bit cooler than most guidance suggested, the coldest 850 temps and strongest CAA have now departed the region. Even so, have trended nighttime lows slightly below guidance and dropped the area into the upper 20s. && .SHORT TERM /FRIDAY NIGHT/... Upper level system continues to slowly move off to the east, though continues to be the dominant influencer for our sensible weather for at least another day. Cyclonic flow moving through the region supports persistent low cloud cover and additional moisture being pulled off of the Great Lakes. Overall, expecting this to be a dreary day. Low ceilings, northwesterly winds around 15 MPH with gusts to 25, and on and off rain showers/ drizzle. There will be a slight warm up as weak warm air advection is wrapped around the low and Friday high temperatures reach the 40s. However, since the day will still be rather breezy, feels-like temps will be in the 30s. By Friday night, the parent low finally moves off toward the Atlantic Coast and is slowly replaced by ridging in the Midwest. The area will begin to dry out and precipitation chances decrease from west to east. Wind gusts subside slightly and overnight low temperatures into Saturday fall to the upper 30s/ low 40s. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Broad, low-amplitude mid-level ridging will build into the area over the weekend. This will translate east as a short wave moves out of the northern Plains and tracks across the Great Lakes early next week. So surface high will pass south of the area allowing for a warming trend with temperatures getting back to or slightly above normal by Sunday. Then showers will develop and pass across the region ahead of a cold front on Monday into Monday night. Still some spread in guidance, so exact window when the front passes is a bit uncertain. Mid-level flow will become more zonal mid week. A short wave will move out of the central Rockies and push eastwards into the Ohio Valley by Thursday. There is a fair amount of spread on how that evolves, and even if it comes out in multiple pieces. This pattern favors low pressure passing across Tennessee and Kentucky with a shield of precipitation north of that spreading across the forecast area. Timing is uncertain, but greatest chance of rain at this point is Wednesday night into Thanksgiving. Highs will be below normal during this period with lows near normal. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Snow will be the main impact through about 05Z, with IFR conditions at KCVG/KLUK/KDAY/KILN, and generally MVFR conditions at KCMH. Once the snow comes to an end, visibilities will improve, but ceilings will likely remain IFR to MVFR. There will also be a notable wind shift overnight, as winds shift from SW to NNW over the course of a few hours between 01Z and 06Z, and then back slightly to the WNW by 12Z. Through the overnight hours, winds will generally be around 10 knots, but they will begin to increase again tomorrow. Some gusts of around 25 knots are expected tomorrow afternoon. There may be a brief period where ceilings break to VFR tomorrow morning, before MVFR ceilings fill back in for the rest of the day. Although not in the TAF, some IFR ceilings are possible tomorrow afternoon as well. Finally, there will be a chance of rain tomorrow, indicated in the TAFs with a -SHRA or VCSH. This rain could reduce visibilities, but aforementioned ceilings will be the more significant issue for aviation. OUTLOOK... MVFR ceilings will continue through Saturday. MVFR conditions are possible again Monday night into Tuesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...Winter Weather Advisory until 4 AM EST Friday for OHZ042- 060>062-070>072-077>081. KY...Winter Weather Advisory until 4 AM EST Friday for KYZ089>100. IN...Winter Weather Advisory until 4 AM EST Friday for INZ050-058- 059-066-073>075-080. && $$ SYNOPSIS...CA NEAR TERM...CA/Hatzos SHORT TERM...CA LONG TERM... AVIATION...Hatzos