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fxus63 kind 221104 
afdind 


Area forecast discussion 
National Weather Service Indianapolis in 
700 am EDT Monday Mar 22 2010 


Aviation...discussion for 12z tafs. 
Conditions will deteriorate a little more this morning as low 
pressure tracks east northeast across the Ohio Valley. Weather 
depiction shows an area area of IFR ceilings near the surface low 
center and this could spread into kbmg. Most other sites should 
remain with low MVFR ceilings. But klaf may even remain VFR at times 
as low level moisture a little less there. 


As surface low moves up the Ohio Valley gradient will slowly 
decrease next 24 hours and winds may become quite light especially 
over western Indiana. Will mention some fog there tonight as some 
clearing is possible late tonight. Elsewhere stratus should be the 
rule until after sunrise Tuesday. 


&& 


Discussion... 


Forecast focus is on rain chances through middle week. 


At 06z an upper low was across Alabama. One surface low was across 
far southern Indiana while another was across far western 
Virginia. Rain extended from Ohio southwest through southern 
Indiana and into Illinois. 


Models are in decent agreement today...so will use a blend. 


As the upper low moves northeast today...expect dry slot to move 
into far southern Indiana. Isentropic lift will continue on the 
backside of the low across central Indiana during the day. The 
best lift looks to occur in a relatively narrow band on the 
backside of the low...and exactly where this sets up across the 
forecast area is a tough call at the moment. At any 
rate...believe that all of the forecast area should at least get 
measurable rain today...so will go at least likely probability of precipitation all areas. 
Went categorical probability of precipitation across parts of the eastern forecast area 
based upon what is currently upstream as well as after 
collaborating with surrounding offices. Depending on where the dry 
slot sets up today across the area...some locations will see some 
dry hours. Thus in areas with categorical probability of precipitation have worded the 
weather as periods of rain to indicate possible dry hours. For 
highs today the mav/met MOS are similar and look reasonable with 
cooler temperatures east where the higher probability of precipitation are and a little 
warmer west where less overall rain is expected. 


Tonight forcing will diminish from west to east as the system 
pulls off to the east. Will have some probability of precipitation all areas during the 
evening...then end them across the western third overnight and 
reduce them to low chance elsewhere as forcing really drops off 
during the overnight. For low temperatures...ended up with a 
compromise between MOS and sref temperatures with thicker 
clouds/slower rain exit across the east keeping temperatures 
warmer there. 


Skies will become partly cloudy on Tuesday allowing temperatures 
to rebound back to around 60 degrees. A cold front will swing 
through dry on Wednesday then stall to our south. As a wave moves 
along it...models are showing rain possible across our area 
Thursday and Thursday night. Upped probability of precipitation a little on Thursday with 
both GFS and 12z Euro showing rain across the area. 


&& 


Ind watches/warnings/advisories...none. 


&& 


$$ 


Aviation...jh 
public...50