Area Forecast Discussion
Issued by NWS Wilmington, OH

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KILN 161346 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 946 AM EDT Wed Aug 16 2017 .SYNOPSIS... A weak frontal boundary will stall across the area this morning, offering a threat for isolated showers. After some morning fog, a disturbance approaching from the southwest will combine with the stalled boundary to produce a threat of showers and storms this afternoon and night. A stronger frontal system will swing through the Ohio Valley on Thursday afternoon and evening bringing a higher chance of more widespread shower and thunderstorm activity. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
With showers generally dissipating across the area earlier this morning, mostly clear skies have been left in place, outside of the southern sections of the CWA. Though there is not a significant gradient in surface dewpoints, a gradual advection of moisture a little further aloft is expected as the day progresses, which should add clouds (from current stratocumulus to additional cumulus development) to the region over the next few hours. Though MLCAPE values may increase into the 500-1000 J/kg range today, absent any notable low-level forcing, there should not be significant coverage of precipitation -- with the best chances near the greater moisture in the southern and southwestern sections of the CWA. One change for this forecast is a 20-percent chance of showers added to the entire CWA by mid-afternoon, with the atmosphere appearing favorable for a few very light showers to develop just about anywhere. Nonetheless, most locations should still remain dry. Made some near-term decreases in sky grids, but temperatures appear to be on track with the previous numbers. Previous discussion > A few showers continue to linger across central Ohio in the vicinity of weak frontal boundary. Due to lack of upper level support with mid level ridge over the region, expect this activity to continue to weaken early this morning. Mostly clear skies, light winds and moist low level has lead to patchy fog across ILN/s area. This shallow fog will quickly improve with sunrise. Shortwave ridging to move across the Ohio Valley downstream from wave moving across the plains today. The morning and first part of the afternoon expected to be dry. Moisture increases with boundary layer cape values of 1000-1500 j/kg into the southwest this afternoon. Have thunderstorm chances developing into the southwest with increasing chances from southwest to northeast through the later afternoon hours. Temperatures will continue above normal with todays highs similar to yesterday in the mid and upper 80s.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... Mid level ridge to shift east with flow backing as s/w tracking into the MS VLY tonight. Thunderstorm chances will increase, especially over the nw counties as low level convergence/warm front develops. Have continued high chance pops late tonight. With increasing moisture and clouds temperatures will be mild tonight with lows generally in the lower 70s. Ongoing storms to start Thursday especially invof of the warm front. Moisture increases as 30-35 kt southwesterly low level jet comes into play with precipitable water values increasing to near 2 inches. Boundary layer cape values of 2000-2500 j/kg expected to develop across the area Thursday in the warm sector. Bulk shear of 35-40 kts across the southern Great Lakes along with this instby will support convective development with some organized clusters. Isolated damaging wind gusts will be possible along with the potential for heavy rain and local flooding. will mention this threat in the HWO product. Warm temperatures to continue with Thursdays highs from the lower 80s northwest to the upper 80s southeast. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Cold front will be moving east Thursday night. Showers and thunderstorms are likely to be ongoing Thursday evening, diminishing during the overnight hours as daytime heating dwindles and frontal forcing departs. Some thunderstorms may contain strong wind gusts early Thursday night, and localized flooding will be possible in an atmosphere containing about 2 inches precipitable water. A few thunderstorms may even linger on Friday, mainly over eastern locations where greater residual instability and moisture will be evident. After a weak ridge brings a brief dry period Friday night, a disturbance traveling across the Great Lakes may trigger a few thunderstorms during peak heating on Saturday. Dry weather is indicated for Sunday when a large area of high pressure is forecast to be centered to the east. Isolated thunderstorms cannot be ruled out for Monday in the increasingly humid return flow around the high. A better chance for thunderstorms will exist on Tuesday due to a strong short wave and cold front. High temperatures starting near normal in the low to mid 80s will boosted by warm advection to the mid and upper 80s by the end of the long term. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... A weak frontal boundary which has stalled out across central Ohio, continues to offer a few isolated showers east of Columbus. Coverage is too limited to mention in the TAF forecast. Skies continue mostly clear this morning. These clear skies and light winds has led to the development of areas of fog. The fog is shallow and will improve quickly after sunrise. Increasing moisture through the day will combine with an approaching mid level short wave to produce an increasing chance of showers and thunderstorms from the southwest. Have kept the TAFs dry through the daytime period with an enhanced chance tonight as a warm front lifts north across the area. Have kept VFR conditions, but have a mention of VCTS overnight to account for this chance of thunderstorms. Southeast winds at less than 10 kts will veer to the south late tonight into Thursday. OUTLOOK...Thunderstorms possible Thursday and Thursday night. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Binau/AR NEAR TERM...Hatzos/AR SHORT TERM...AR LONG TERM...Coniglio AVIATION...AR is the U.S. government's official web portal to all federal, state and local government web resources and services.