Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000 FXUS63 KIND 171109 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 610 AM EST Sun Dec 17 2017 .UPDATE... Aviation Section has been updated below. && .SYNOPSIS... Issued at 310 AM EST Sun Dec 17 2017 Mid/Upper level trough over the ARKLATEX region on recent satellite imagery is moving slowly northeast this morning toward the lower OH Valley region. Surface analysis shows a quasistationary frontal boundary lying E-W across northern IN. && .NEAR TERM /Today/... Issued at 310 AM EST Sun Dec 17 2017 Mid/upper level shortwave trough will gradually dampen out as it becomes part of the strong northern branch of the mid level jet stream that extends over the Ohio Valley region. Infrared satellite imagery shows large baroclinic leaf signature associated with the ARKLATEX signature and will result in rain spreading over the area mainly during this afternoon into the evening. Clouds and associated rain will keep temperatures in the 40s for today. && .SHORT TERM /Tonight through Tuesday/... Issued at 310 AM EST Sun Dec 17 2017 As weakening low pressure moves across southern IN then off to the east, low clouds and some light rain/drizzle should remain from cooler air circulating around the backside of the low. Given the rain producing wet ground and low clouds with light winds, have collaborated with keeping low clouds, drizzle and fog across the region for tonight into early Monday morning. Would expect the possibility of some dense fog especially across urban areas where the wet comparatively warmer ground is covered by the cooler air on the backside of the surface system/trough in low levels. This may impact morning commute on Monday morning before skies gradually clear by afternoon. Area will be between systems going into Tuesday as a strong frontal boundary will be across the Great Lakes westward over southern WI/northern IL, and a shortwave trough moving in the southern branch over south central TX. Southwest surface flow over the southern Plains is forecast over are area providing some clouds but temperatures in the low-mid 50s for Tuesday providing the best day in the week before the cooler air to the north drops into the area. && .LONG TERM /Wednesday through Saturday/... Issued at 307 AM EST Sun Dec 17 2017 Extended models indicate a somewhat zonal upper flow Wednesday and Thursday will become more amplified towards the weekend as a strong upper trough digs first into the upper midwest and then the great lakes. Quiet and mild weather will occur Wednesday and Thursday as an area of low pressure track`s east across the deep south. It now appears that any precipitation from this will will remain to our south. Models indicate an area of low pressure over the central plains Thursday will track across the upper midwest Friday and into the great lakes and a trailing cold front will move east across Indiana Friday night. Models indicate rain will be possible by Friday changing to light snow Friday night and then ending. This seems reasonable given the above pattern. Superblend temperatures are least 5 degrees too cool Thursday night and will raise them to better match MOS and HPC values. This change will keep precipitation all liquid Friday morning. Otherwise...only minor tweaks made to superblend temperatures in other periods. && .AVIATION /Discussion for the 17/12Z TAF Issuance/... Issued at 610 Am EST Sun Dec 17 2017 VFR through 22Z-24Z...then MVFR or IFR after that. Area of low pressure over the central Mississippi valley will move east across Indiana later today and light rain will spread our way. Expect ceilings to gradually lower today...but remaining VFR until late afternoon. The light rain will end tonight...but ceilings will lower as a low level inversion develops. Expect areas of stratus and fog later tonight into Monday with some improvement by midday Monday. Winds will be 8 knots or less through the period. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DM NEAR TERM...DM SHORT TERM...DM LONG TERM....JH AVIATION...JH is the U.S. government's official web portal to all federal, state and local government web resources and services.