Marine Weather and Tide Forecast for Alexandria, OH

KEY MESSAGES
1) Some wintry precipitation expected early Sunday morning and early Monday morning.

2) Warmer and wetter conditions expected from Tuesday through the rest of the week.

DISCUSSION
KEY MESSAGE 1) Some wintry precipitation expected early Sunday morning and early Monday morning.

There will be two chances for precipitation over the next couple of days, with some wintry impacts possible, but far from certain.

After a dry and mild day on Saturday, northeasterly surface flow will help temperatures to drop considerably Saturday night into early Sunday morning. As this occurs, a weak wave will move east into the region, with a low-amplitude surge of theta-e on southeasterly flow just above the surface. The forcing and moisture return are both rather marginal, so not all models are particularly robust with precipitation development. Some are nearly dry. However, the depiction of precipitation, which may be a bit showery, is a little more robust on some of the high-resolution models. Nonetheless, precipitation amounts should be very light. Precipitation type should be rain for the southern half of the area, with a mix with snow for the northern half of the forecast area. Accumulations are not expected as of now. There is also a low probability that the theta-e overrunning could lead to a brief period of freezing rain over the colder surface conditions in central Ohio. Even if this occurs, road temperatures are likely to be starting out fairly warm, so impacts appear unlikely.

The second system will occur late Sunday night into Monday. Models continue to trend a toward a solution that keeps the bulk of the precipitation south of the ILN forecast area, and some models are even coming in with very little snow at all. Based on these trends, the snow forecast has been shifted slightly southward, and slightly lower, compared to the previous forecast. Current model blends suggest there could still be some light accumulations, perhaps up to an inch on grassy areas, for a swath in the southern half of the ILN forecast area. Confidence in this forecast, however, remains low.
Warming temperatures on Monday should change any precipitation to rain by mid to late morning, though precipitation will also be exiting at around the same time.

KEY MESSAGE 2) Warmer and wetter conditions expected from Tuesday through the rest of the week.

A pronounced shift in the large-scale weather pattern is expected to begin on Tuesday. On the western periphery of the Bermuda high, deep-layer southerly / southwesterly flow will become established over the southeastern CONUS. A significant feed of warmth and moisture is expected to develop from the Gulf through the deep south, the lower and middle Mississippi Valley, and into the Tennessee and Ohio valley regions. For the ILN CWA, boundary layer flow is expected to switch to southerly early in the daytime hours on Tuesday, bringing theta-e advection and the start of both a warming and moistening trend. Max temps in the 50s are expected Tuesday, warming each day and getting into the upper 60s to lower 70s by Friday.

On the periphery of the zone of higher theta-e, repeated rounds of precipitation are expected to develop. Some embedded areas of heavy rain, and certainly some convection, will occur at times. This is still too far out in the forecast to get into specifics, but from a synoptic pattern standpoint, this is a setup that will favor heavy rain and possible flooding -- focused to the west and southwest of the ILN CWA, but extending into the ILN CWA to some degree as well.
While forecast confidence is a little higher for Tuesday and Wednesday, as they are closer in time, the concern could extend through the end of the week. Not out of the question that some strong storms could occur at some point next week, but still too early to look at when or where that may occur.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
VFR conditions are expected today. Winds will generally remain under 10 knots, and will shift from the southwest to the north this morning. Lighter winds are expected this evening.

Early Sunday morning, some light precipitation will move into the area, but confidence remains low on any impacts to the TAF sites. A PROB30 has been added for light precipitation and MVFR visibilities for CMH/LCK. There will also be some MVFR ceilings moving into the area early Sunday morning as well.

OUTLOOK.. MVFR conditions will continue into Sunday morning. Periods of MVFR/IFR conditions are possible at times from Sunday night through Wednesday.

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