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Area forecast discussion...updated 
National Weather Service Nashville Tennessee 
916 PM CDT sun Mar 21 2010 


Update... 
updated forecast to mention categorical showers only across 
northern portions of Cumberland Plateau remainder of this evening. 
Other locations across the middle state will experience only a slight 
chance of showers...as main moisture associated with upper level low 
has moved to our north. Still expecting upper level low to be centered 
across NE Alabama by 12z Monday. Still believe there will be a chance of 
rain/snow mix after midnight...especially between 09z and 15z. 
Still all indications point to no significant snow accumulations. 
Also updated sky conditions to cloudy across the entire middle state 
for the remainder of the night as moisture across areas previously 
experiencing mostly cloudy skies have increased and will stay that way. 
Otherwise...temperatures and winds still in line with current values and 
previously forecasted projections. 
&& 


Previous discussion... /issued 650 PM CDT sun Mar 21 2010/ 


Update... 
in keeping with current radar...satelitte...and surface observation trends... 
have updated forecast from a transition of categorical showers 
across northern Cumberland Plateau region...southwestward to a 
slight chance of showers near the Tennessee/Alabama border. Have also gone with 
a transition of cloud coverage from cloudy northern Cumberland 
Plateau to mostly cloudy near the Tennessee/Alabama border. Can not rule out a few 
locations near the Tennessee/Alabama border temporarily having partly cloudy skies... 
but mostly cloudy conditions will be the prevailing trend. Model 
consensus solution showing a decrease in probability of a rain/snow 
mix after midnight...and have lowered probability of precipitation from the likely to 
chance across the entire middle state. Additional model data will be 
coming in over the next few hours...and at least an additional 
update is expected per majority of rainfall moving out of the 
area and will also have more detailed information to take a closer 
look at the rain/snow mix and see if any further changes need to 
be made. Still...due not expect any significant accumulations. 
&& 


Previous discussion... /issued 635 PM CDT sun Mar 21 2010/ 


Update...for aviation discussion. 


Aviation...00z tafs 


MVFR conditions will occur most of the coming 24 hour period at bna 
and csv. 


For bna in the first few hours...VFR will be dominant as dry slot 
moves northward. Winds will be variable along the frontal zone... 
but should become definitively southwest shortly. Later in the night 
MVFR ceilings will develop with scattered light rain/snow showers 
associated with upper level low. Coverage and intensity will be on 
the low side...so kept visibilities 6+. Scattered very light rain showers 
will persist through Monday along with MVFR ceilings. 


For csv...band of heavy showers early will give way to dry slot 
around 02z. Light rain/snow mix late night with light showers and 
persistent MVFR ceilings through Monday. Ceilings may go briefly IFR at times 
csv. 
13 
&& 


Previous discussion... /issued 254 PM CDT sun Mar 21 2010/ 


Discussion...surface map at 19z shows 1003 mb low pressure 
centered near Pulaski, with the cold/occluded front showing up 
very nicely on radar reflectivity. Light to moderate rainfall 
still covers most of middle Tennessee, although no lightning 
showing up, even in the more intense echoes right along the front. 


Look for temperatures to begin cooling from southwest to northeast 
as the front pushes across middle Tennessee. Deepest moisture will 
exit the middle state with the front, although we'll still see some 
precipitation overnight and tomorrow as occluded front moisture 
gets pulled around the low. 


Believe we will still see some snow mix in with the rain roughly 
between 09z and 15z, as temperatures settle into the 30's. Am 
not forecasting any freezing temperatures, and with ground and 
Road temperatures still relatively warm, do not expect any 
accumulation, even along the plateau. 


We may still see a light shower or two tomorrow night before 
moisture pulls completely out, and am looking for a quick warm-up, 
with much of middle Tennessee getting up to 60+ degrees on 
Tuesday. 


High pressure will dominate our weather pattern during the middle 
part of the week, with the next surface system bringing scattered 
showers Thursday and Thursday night, and possibly some 
thunderstorms on Friday. 


Rose 
&& 


Ohx watches/warnings/advisories... 
none. 
&& 


$$ 
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