241 
fxus64 klch 041722 
afdlch 


Area forecast discussion 
National Weather Service Lake Charles la 
1221 PM CDT Sat Jul 4 2009 


Aviation... 
southerly winds have brought a very moist atmosphere across the 
region. With daytime heating scattered to broken cumulus has developed 
roughly between 4k and 5k feet. Mainly VFR conditions will 
continue through the remainder of the afternoon as bases of cumulus 
field remain around 5k feet. Isolated showers are also possible. 
However probability too low to place in tafs. Clouds will 
dissipate after sunset with light and variable winds. 


Rua 


&& 


Previous discussion... /issued 1011 am CDT Sat Jul 4 2009/ 


Update...have issued heat advisory for the entire area. Over the 
last few days have seen apparent temperatures flirting with our 
heat index advisory criteria of 108 degrees...briefly going above 
in just a few locations. Initially thought a similar situation 
setting up for today but have noted dewpoints thus far running 
several degrees above that of the previous days and also higher 
than previously ingested MOS guidance suggested....particularly 
over central Louisiana. Tweaked up dewpoints a few degrees in 
grids and is now yielding a large portion of the area moving above 
the 108 heat index magic number. 


Npw for advisory as well as updated zones already out. Have a safe 
and fun Independence day!!! 


Marcotte 


Previous discussion... /issued 757 am CDT Sat Jul 4 2009/ 


Discussion... 
12z taf package. 


Aviation... 
VFR expected to prevail today. 


Previous discussion... /issued 353 am CDT Sat Jul 4 2009/ 


Discussion... 
a big transition is on the way next week. 


In the short term...expecting another hot day...with temperatures 
reaching triple digits across cen la and East Texas. Not going with a 
heat advisory due to dewpoints staying low enough where heat 
indices should only get above 105 for maybe an hour or two in the 
afternoon. Rain chances will be minimal today. 


Sunday begins the transition to a wet week ahead. With the 500 mb 
ridge building to our west...several shortwaves are forecast to 
move northwest to southeast across our region...beginning late 
Sunday. With respect to that...threw in low probability of precipitation for cen la and East Texas 
for Sunday afternoon...but confidence is low at this point. 


However...by Monday...everything is pointing at scattered 
thunderstorms...thanks to the middle-level shortwaves. Early thinking 
is we will see an isolated severe storm...but will have to 
continue to watch the pattern to see if a more widespread severe 
weather event can develop. 


This scenario basically repeats itself Tuesday...Wednesday...and 
Thursday. Hard to pick out specific timing of showers and thunderstorms 
could see some morning activity along the coast...transitioning 
to I-10 corridor by mid-morning...and north of Highway 190 in the 
afternoon. Current thinking is carrying 40-50 probability of precipitation...but may be 
bumping this up to 60-70 if wet pattern continues. 


As for temperatures Monday through Friday...will see a Little Break from the 
heat...with highs expected to be around 90 along I-10 and lower 
90s north thanks to cloud cover and rain cooled air. 


&& 


Preliminary point temps/pops... 
klch 97 78 94 77 92 / 0 0 10 10 30 
kbpt 96 78 94 78 92 / 0 0 10 10 30 
kaex 102 75 97 74 93 / 0 0 20 20 40 
klft 98 78 96 77 92 / 0 0 10 10 30 


&& 


Lch watches/warnings/advisories... 
la...heat advisory until 7 PM CDT this evening for the following 
zones: Acadia...Allen...Avoyelles...Beauregard... 
Calcasieu...Cameron...Evangeline...Iberia...Jefferson 
Davis...Lafayette...lower St. Martin...Rapides...St. 
Landry...St. Mary...upper St. Martin...Vermilion...Vernon. 


Texas...heat advisory until 7 PM CDT this evening for the following 
zones: Hardin...Jasper...Jefferson...Newton...Orange... 
Tyler. 


GM...none. 
&& 


$$