Area Forecast Discussion
Issued by NWS Wilmington, OH

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000 FXUS61 KILN 032043 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 343 PM EST Sat Dec 3 2016 .SYNOPSIS... High pressure that was over the area this afternoon will pull east Sunday as an upper level disturbance quickly moves towards the Great Lakes. High pressure will then briefly build back into the Ohio Valley on Monday. Another upper level disturbance will move over the area Tuesday afternoon bringing the chance of rain back across the region. Much colder air will then work into the region for the second half of the work week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Surface high pressure was centered directly overhead this afternoon with overcast skies across the region. An upper level low was noted on the water vapor over the Baja of California with pieces of PVA ejecting off towards the northeast. There is also a shortwave located over the Mountain West that is headed east. The PVA from the upper level low looks to remain just south of the area with the shortwave still west of the region. Therefore have kept the region dry through the 6 AM Sunday morning. Given the persistent cloud cover across the region have gone above guidance for Sunday morning lows. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Sunday morning a shortwave trough will approach the area from the west with weak isentropic upglide commencing across the Ohio valley. The shortwave will across the midwest will push east and then take on a negative tilt and clip the area. Looking at the 300 K and 295 K surfaces shows that condensation pressure deficits don`t really approach zero until Sunday afternoon into evening. Precipitation will be fighting dry air in the low levels with forecast soundings being slow to fully saturate. Looking at high res models precipitation doesn`t really arrive until Sunday afternoon. Looking at the thermal profiles across the area they mostly support rain. With that being said, snow could mix with rain across the north. Precipitation amounts will likely be a tenth of an inch or less. Monday afternoon, surface high pressure will build back into the region with forecast soundings showing some breaks in the clouds. 850 mb temperatures Monday are around 3 degrees C which would support highs in the mid to upper 40s. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Mid level short wave energy will eject northeast across the Tennessee Valley through the day on Tuesday as an associated surface low moves up across the upper Ohio valley. There are some model timing differences with this as the 12Z NAM is about 6 hours faster than the 12Z ECMWF while the 12Z GFS is somewhat in between, but closer to the slower ECMWF. Will trend toward the slower solutions and have a decent pop gradient north to south across our area at the start of the long term period. Higher pops will then overspread the rest of the area through the morning hours and then continuing into Tuesday afternoon. Low level thermal profiles appear warm enough to keep precipitation all rain through the day on Tuesday with highs ranging from the lower 40s northwest to the lower 50s in the southeast. Precipitation will taper off quickly from west to east Tuesday evening as the short wave weakens and moves off to the east. Some cooler air will filter in behind the system but the pcpn should be over before it is cold enough to change any of it over to snow. A broad trough will develop over the central United States by mid week and then shift quickly east through through the end of the work week. Short wave energy rounding the base of the trough will lead to an increasing chance of precipitation Wednesday night as an associated strong cold front pushes east across the area. This will usher in a much colder airmass through the end of the week. The 12Z GFS has trended faster with the cold push than the ECMWF and this will ultimately affect temperature trends Wednesday afternoon into Thursday and how fast any pcpn chances over to snow. Highs on Wednesday will range from the upper 30s northwest to the mid 40s southeast. Precipitation Wednesday night may start as a rain/snow mix but as the cooler air begins to move in, it will transition over to all snow. However, the models have trended drier with this feature so would expect any accumulations to be fairly minimal. Much colder air will then settle into the region through the end of the work week as 850 mb temperatures drop down into the -14 to -16 degree celsius range. In somewhat cyclonic low level flow and with possible fetches off of the warm water of the Great Lakes, will hang on to some lower end pops for snow showers Thursday into Friday. Depending on the exact timing of the strong cold push, we may likely have non diurnal type temperatures on Thursday with highs then on Friday only in the 20s. We will quickly transition into a more zonal flow pattern by Saturday, allowing for bit of a moderation in temperatures. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... A few sites will have MVFR this afternoon with moisture trapped under an inversion in weak high pressure. Models indicate improvement to VFR tonight. For Sunday, a trough of low pressure will bring showers to the vicinity of TAF sites, with prevailing showers and MVFR ceilings expected at CVG starting at 18z. Winds will be near calm today, with speeds increasing but staying under 10 knots out of the southeast on Sunday. OUTLOOK...MVFR conditions are possible Tuesday morning through Wednesday morning, along with rain. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Haines NEAR TERM...Haines SHORT TERM...Haines LONG TERM...JGL AVIATION...Coniglio is the U.S. government's official web portal to all federal, state and local government web resources and services.