NWS Wilmington, OH Office (ILN)


Area Forecast Discussion/SKEW-T

          FXUS61 KILN 220608
          AFDILN
          
          AREA FORECAST DISCUSSION
          National Weather Service Wilmington OH
          208 AM EDT Thu Oct 22 2020
          
          .SYNOPSIS...
          A warm front will lift through the region tonight bringing warm
          conditions for Thursday and Friday. The next chance for rain will
          arrive later in the day on Friday with the next cold front. Cool
          conditions return for the weekend behind the cold front.
          
          &&
          
          .NEAR TERM /UNTIL 6 AM THIS MORNING/...
          Showers have been skirting the far northwest part of the
          forecast area. While these are moving away from the area, cannot
          completely rule out some brief light rain in west central Ohio
          for the next few hours.
          
          Fog and stratus have developed across the central part of the
          forecast area where there is shallow moisture under an
          inversion. Short range guidance suggests that this near surface
          layer will dry a bit before daybreak, so there is the potential
          for some improvement. And across the southern counties, river
          valley fog has become established and will most likely persist
          into the morning.
          
          &&
          
          .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
          The Ohio Valley will be sandwiched between high pressure to the
          east and a low pressure system to the west on Thursday and Thursday
          night. The resulting pressure gradient will result in increasing
          southerly flow and well above average temperatures.
          
          On Thursday, forecast highs are near 80 areawide under mostly sunny
          skies. Lows only drop to near 60 on Thursday night with southerly
          flow in place.
          
          &&
          
          .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
          There is high confidence that a surface low pressure is expected to
          be moving through the Great Lakes region during the day on Friday. A
          cold front associated with the low pressure moves into western
          locations by late Friday afternoon, moving through the area from
          west to east during the evening and overnight hours. Ahead of the
          front, brisk southerly winds provide warm air and moisture advection
          over all of the forecast area. Increasing cloud cover may help keep
          temperatures a couple degrees cooler than Thursday, however, still
          felt upper 70s and few lower 80s were appropriate. Throughout the
          overnight, widespread rain showers and embedded thunderstorms help
          to provide another modest chance for rainfall across abnormally dry
          ground. Majority of the rain exits to the east by Saturday morning
          with perhaps some light drizzle/showers hanging around through the
          morning hours.
          
          For the rest of Saturday, surface high pressure builds in from the
          north, promoting cooler, northeasterly flow over the forecast area.
          Temperatures struggle to climb out of the 50s as cloud cover limits
          heating. Best chance for some clearing is across the north where
          drier air attempts to erode away lower level overcast skies.
          Temperatures cool fairly efficiently with upper 30s not out of the
          realm of possibility across the north Saturday night. On Sunday,
          attention switches to another low pressure developing in the Central
          US. Warm air advection of the low allows for some moderation in
          temperatures on Sunday, but cloud cover still keeps temps limited
          across the north.  Limited rain chances across the far north for
          Sunday as a warm front moves northward during the day.
          
          For the work week, the Ohio Valley is situated within stubborn
          southwesterly flow as a deepening trough attempts to advance through
          the Central US. This focuses southwesterly upper level flow over the
          Ohio Valley. As a result, the region will be located within the
          storm track as southwesterly flow advects moisture northeastward.
          Rain chances are highest on Monday as confidence remains moderate
          that a the low pressure and it`s associated cold from move through.
          Uncertainty increases for Tuesday and Wednesday as there is low
          confidence on the timing of the next shortwave embedded within the
          flow. Model guidance now suggests a cut-off low forming over the
          Southwest US, potentially providing a break in strong forcing within
          the mean flow. Rain chances remain for Tuesday and Wednesday but are
          low at this time. Temperature forecasts are made with low confidence
          as frontal boundary positioning, precipitation, and cloud cover
          differences lead to a wide range in temperature possibilities.
          
          While rain chances are low, it`s hard to avoid the potential for
          heavy rain associated with the positively tilted trough conceptual
          model. At this time, guidance only holds on to this pattern for a
          couple of days before cutting off a low over the Southwest US. If
          this trough remains in the flow, much of next week could feature
          chances for rain.
          
          &&
          
          .AVIATION /05Z THURSDAY THROUGH MONDAY/...
          Low level moisture has resulted in the development of fog and
          stratus across most of the terminals. Not a straight forward
          forecast as there are indications in guidance that this moisture
          will decrease before 12Z. This is counter to what would be
          expected in normal conditions and there are not signals as of
          initial issuance that this will pan out. So have cautiously
          allowed for some improvement in visibilities and ceilings.
          during the early part of the TAF period with conditions becoming
          VFR after 12Z. Thereafter just expect some cumulus with
          southerly winds up to 10 kt during the day. Clouds and winds
          will diminish around 00Z. Some fog is likely again at KLUK
          before the end of the period.
          
          OUTLOOK... Thunderstorms are possible on Friday afternoon and
          evening. MVFR ceilings possible Friday night into Saturday
          morning. Thunderstorms are possible again on Monday.
          
          &&
          
          .ILN WATCHES/WARNINGS/ADVISORIES...
          OH...None.
          KY...None.
          IN...None.
          
          &&
          
          $$
          SYNOPSIS...Campbell
          NEAR TERM...
          SHORT TERM...Campbell
          LONG TERM...McGinnis
          AVIATION...
          
          
          
Skew-T

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