Area forecast discussion National Weather Service Indianapolis in 711 PM EDT Tuesday Jun 18 2013 Update... the aviation section has been updated below && Synopsis... issued at 330 PM EDT Tuesday Jun 18 2013 A cold front will move through the area early tonight bringing scattered thunderstorms. Overnight high pressure will build in and then persist across the area through the end of the work week. Another system could bring some more rain early next week. After a brief cool down Wednesday...above normal temperatures will return for the weekend into early next week. && Near term /late this afternoon and tonight/... Issued at 330 PM EDT Tuesday Jun 18 2013 Scattered thunderstorms have formed across central Illinois along the cold front...and these will spread east-southeast across the southern half of central Indiana this evening. Meanwhile isolated storms have formed across northern Illinois. An upper trough and an upper jet will move across the area late this afternoon and early this evening. These should aid in scattered thunderstorm development...especially near the cold front. Plenty of instability around as well. Will go high chance probability of precipitation south before 00z with chance or slight chance north. After 00z...will keep slight chance probability of precipitation north /as storms are across northern Illinois at the moment/ and chance probability of precipitation south. Will quickly diminish probability of precipitation though as instability wanes after sunset. Will be dry all areas before 06z. There could be some strong to severe storms across southern sections of the area ahead of the front...and Storm Prediction Center has this area in a Severe Thunderstorm Watch until 02z. For temperatures went closer to the warmer met MOS numbers since drier air is taking is time coming south behind the front. && Short term /Wednesday through Friday/... Issued at 330 PM EDT Tuesday Jun 18 2013 Focus is on any chances for rain...then on sky and temperatures. Models are close enough with most features that a blend can be used. High pressure will move in during the short term...with an upper ridge just to the south and west. The NAM keeps a dewpoint gradient across the forecast area...and then generates isolated convection along it at times during the short term. However the NAM looks too high with its dewpoints...especially compared to the other models. Thus believe NAM/S convection is also overdone...so will keep forecast dry through the short term. Skies will be clear to partly cloudy during the period with the high in control. For temperatures generally stuck with a blend which looks good given expected sky cover and dewpoints. && Long term /Friday night through Tuesday/... Issued at 147 PM EDT Tuesday Jun 18 2013 An upper ridge will maintain control over the region through most of the extended period...however there will be periods where it will weaken or break down slightly as a few short waves cross through the region and bring small chances for showers and thunderstorms to the region starting Sunday and continuing through early next week. Allblend handled the pattern well so did not deviate except for quality control. && Aviation /discussion for the 19/0000z taf issuance/... Issued at 702 PM EDT Tuesday Jun 18 2013 The severe threat has diminished across taf sites...but there is still potential for isolated pop-up storms through sunset. This activity would be too isolated to mention in tafs though at this time. High pressure/subsidence will build into central Indiana tonight...resulting in clear skies and VFR conditions for duration of taf period. Winds have already shifted to the northeast at kind and klaf...and they will do so at khuf and kbmg as well within the next few hours. Sustained speeds will range from 5 to 10 kts. && Ind watches/warnings/advisories...none. && $$ Synopsis...50 near term...50 short term...50 long term....smf aviation...tdud Visit US at http://www.Weather.Gov/ind Follow US on twitter and youtube at: www.Twitter.Com/nwsindianapolis www.Youtube.Com/nwsindianapolis