Marine Weather and Tide Forecast for Byesville, OH

KEY MESSAGES
1) Strong wind gusts possible Sunday into early next week

2) Large-scale disturbance returns thunderstorm chances followed by snow

3) Cold temperatures Tuesday

DISCUSSION
KEY MESSAGE 1...
A strong low pressure system lifting across the Great Lakes will bring another round of gusty winds to the region Sunday into early next week. Winds will begin to strengthen after sunrise on Sunday as the local pressure gradient tightens between the low to our west and surface high pressure to our east. Initially out of the south, winds should remain below advisory levels through early afternoon as even the 90th percentile wind gusts in ensembles remain in the 30 to 40 mph range (locally up to 45 mph in the ridges). However, later in the day the 850mb jet should begin to strengthen, first over eastern OH up into NW PA and then spreading across the rest of western PA and northern WV. As a result, probabilities for gusts exceeding 45 mph increase to around 50% for most of the lowlands as we head into Sunday night. At the same time, low- level flow is forecast to shift to southeasterly, which would foster downslope enhancement near the ridges. Unsurprisingly, probabilities for gusts exceeding 45 mph jump to 70% in those areas once that wind shift occurs. At this time there is still a bit too much uncertainty to warrant wind headline issuances, especially for the lowlands as it is unclear how much mixing will occur during nighttime hours when the low-level jet is at its strongest.

For areas near the ridges, the decision right now is to hold off on wind headlines to allow more hi-res ensemble members to capture the Sunday night timeframe in future runs. Wind headlines may need to be hoisted in the next forecast package if probabilities remain unchanged or increase.

Heading into Monday, the low-level jet is actually forecast to weaken as a cold front makes its way through the area during morning and afternoon hours, leading to a decrease in probabilities for advisory-level gradient winds. However, following the frontal passage winds shift to westerly and strengthen again in a tightening post-frontal pressure gradient and cold air advection. There is some signal in ensembles that a few post-frontal maximum wind gusts could reach advisory criteria Monday evening/night. This appears most likely in the ridges of eastern Tucker County, WV.

KEY MESSAGE 2...
A large-scale disturbance that will bring significant snowfall to the Midwest over the next 24 hours is expected to move east into the Ohio River Valley early Monday morning. Ahead of an advancing cold front, periods of gusty showers are possible between 3am to 6am across eastern Ohio. By late morning, the front is expected to reach the vicinity of Pittsburgh and the Laurel Highlands. Strong wind shear will accompany this system; however, atmospheric instability may be limited, with dew points only in the low to mid-50s. This could result in a more disorganized or loosely clustered storm environment. The Storm Prediction Center (SPC) currently holds portions of our area (mostly east of Pittsburgh) in a Marginal Risk (1 out of 5) for severe weather. The extend of this threat will depend heavily on the exact timing of the cold front. If severe storms do occur, it would most likely result in wind damage and for a small time period (1-3 hours).

Behind the cold front, temperatures will quickly fall into the 30s and snow chances will return. Impacts in the lower elevations are expected to be minimal due to the unseasonably warm temperatures (in the 60s/70s) from Monday afternoon. The best opportunity for accumulating snow of more than an inch would be in the ridges due to upslope enhancement. A Winter Weather Advisory may be needed for eastern Tucker for the potential of 3+ inches Monday night into Tuesday. However, confidence is still considered low.

Key Message 3...
Record or near-record low maximum temperatures are expected Tuesday, with daytime highs likely likely to remain near to below freezing as 850mb temps fall to around -15C to -17C.

Westerly wind gusts of 25 to 35 mph will accompany the cold air, causing wind chill values to fall into the single digits before dawn and remain in the teens through much of the day. In the higher ridges, wind chills may briefly drop below zero in the hours before daybreak. However, conditions are not expected to be cold enough to warrant a Cold Weather Advisory.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
VFR will prevail over the TAF period. Light and variable winds are expected overnight tonight before increasing out of the east- southeast early Sunday morning. Winds will then strengthen and veer to south- southeasterly by midday Sunday, with sustained speeds returning to around 10-15 knots and gusts reaching 25-30 knots.

Outlook...
VFR is expected until restrictions and rain chances increase Sunday night and Monday with a strong crossing cold front. A strengthening low-level jet will continue to promote gusty conditions during that time and another around of wind headlines may be needed, especially near the ridges where some downslope enhancement will be possible. Following the cold front passage on Monday, winds shift to westerly and remain breezy through Tuesday as temperatures drop and rain transitions to snow. At this time, only minor snowfall accumulations of a dusting to perhaps an inch appear possible everywhere except the ridges, where locally heavier snow may result in higher totals.

PBZ WATCHES/WARNINGS/ADVISORIES
PA...None.
OH...None.
WV...None.