Weather

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fxus64 klch 072107 
afdlch 


Area forecast discussion 
National Weather Service Lake Charles la 
407 PM CDT Thursday Aug 7 2008 


Synopsis... 
water vapor imagery this afternoon shows an upper level ridge of high 
pressure west of the region providing northwesterly to northerly 
flow over the area. At the surface...a cold front north of the area is 
producing showers and thunderstorms from eastern OK across southern Arkansas into 
northern MS. Closer to SW la and southeast Texas...high pressure is located over 
the northwest Gulf and its associated anticyclonic wind field is evident 
on the latest surface analysis and vsbl Sat images. 


Klch radar show very isolated showers and thunderstorms across the 
area...with most of the activity close to the coast near the seabreeze. 


&& 


Discussion... 
not many changes to the forecast. Upper ridge still expected to 
stay west of the area as an upper trough amplifies over the eastern 
Continental U.S.. this will enhance the northerly flow aloft and help push 
the weak frontal boundary closer to the area on Friday. Latest model 
runs show front settling slowly south...eventually stalling along 
the coast late Friday into early Saturday. Shower and thunderstorm 
complexes associated with the front will move south and expect 
increasing probability of precipitation beginning tonight over northestern zones. Kept chance probability of precipitation 
over the inland zones for Friday...with greatest chances again 
over the NE zones closer to the expected location of the front. 


The front will gradually stall near the coast or over nearshore 
coastal waters Saturday morning...then wash out by late Saturday. 
Maintained slt chance to low end chance probability of precipitation Saturday into Sunday due to 
the vicinity of the decaying boundary. Forecast soundings show precipitable waters  
above 2 inches by early Saturday along with weak storm 
motions...which could result in heavy rains and localized 
flooding. Will hold off on mention of heavy rain in zones at this 
time and let future shifts monitor the situation. 


By early next week...high pressure returns to the area and the 
upper ridge will flatten over the area. Disturbances in the upper 
flow are prognosticated to remain north of the area...and have kept 20 
probability of precipitation for mainly afternoon convection. 


Afternoon temperatures will be near or slightly below normal 
Friday as increasing clouds and shower activity will help to keep 
temperatures in check. Temperatures will gradually rebound back to normal 
or above normal early next week as the upper ridge begins to 
influence our weather again. 


&& 


Aviation... 
VFR conditions to last through much of the coming 24 hours. 
Monitoring ongoing convection (what little there is) in case any 
of this activity finds its way near any of our taf sites. Could be 
some restrictions to visibility similar to this morning toward 
sunrise as lingering low-level moisture works with good radiative 
conditions. Should be a bit more in the way of precipitation tomorrow as 
weak front approaches and combines with some prognosticated shortwave 
energy aloft. 


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&& 


Marine... 
high pressure across the northern Gulf tonight will maintain a light 
to moderate southwesterly or westerly flow. A weak front will 
approach the coast late Friday into early Saturday with increasing 
chances for showers and thunderstorms. Light to moderate southerly 
flow will return by early next week as high pressure builds over 
the Gulf. 


&& 


Hydrology... 
issued the first drought statement of the year for our area this 
afternoon. The latest drought monitor indicated d2 (severe) drought 
conditions across portions of central Louisiana while d0-d1 
conditions persist over the remainder of the area. Rainfall 
deficits continue to increase over the area...despite the close 
call with Tropical Storm Edouard. Departures since June 1 range 
from nearly 2 inches below normal to 6.5 inches below normal. 


Some relief is possible the next few days as a weak cold front 
settles over the area. With deep moisture over the area...the 
potential is there for possible heavy rains...but expect areawide 
amounts to average around one half to one inch. 


&& 


Preliminary point temps/pops... 
klch 76 92 73 92 75 / 20 30 30 30 20 
kbpt 75 94 74 90 75 / 10 30 30 30 20 
kaex 74 90 72 92 72 / 30 50 20 30 20 
klft 76 90 72 91 74 / 20 40 30 30 20 


&& 


Lch watches/warnings/advisories... 
la...none. 
Texas...none. 
GM...none. 
&& 


$$ 


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