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Area forecast discussion 
National Weather Service Shreveport la 
352 am CDT Sat Mar 20 2010 


Short term /today through Monday night/... 
line of convection across central Texas pushing east this morning. 
Most of this precipitation looks to be Post-frontal which will help 
to mitigate severe weather threat. Additionally...dewpoints across 
the region remain in the upper 40s. However...rainfall will be 
widespread today at this line slides across the four state region. 


Big changes in store tonight as high pressure surges east in 
behind the front. Winds are prognosticated to increase to above 20 miles per hour 
across most areas...prompting a lake Wind Advisory. This advisory 
will likely be extended into Sunday. 


Upper-low forecast to continue to deepen through the weekend 
squeezing out any available moisture as it tracks across the deep 
south. First day of Spring looks to be introduced with snow across 
locations north of Interstate 20. In fact...the I-30 corridor may 
see up to 5 inches of snow by Sunday afternoon. This is all 
related to wrap around moisture on the back side of the low. The 
previous Winter Storm Watch has been upgraded to a warning with 
advisories posted along the periphery of the warned area. 
Snow...combined with strong winds could make for significant 
travel concerns. 


Snow should transition to rain late Sunday afternoon as 
temperatures rebound. However...slight chances of a rain and snow 
mix will be possible across the eastern zones late Sunday night as 
the upper-low continues eastward. Snowfall...if any...will be 
very insignificant. 




Long term /Tuesday through Friday/... 
it looks like rather progressive weather pattern will continue 
across the forecast area into the day 4 through 7 period. Medium 
range models are in general agreement with regard to the overall 
weather pattern...with only minor differences in timing. The major 
difference revolves around the strength of ridging...especially 
mid-week...and its effects on the next storm system. 


Right now...it looks like we should see a rather quick warmup for 
the middle of the week as shortwave ridging builds across the 
forecast area. The quiet weather is expected to be rather 
short-lived though...as the next upper-level low dives southeast and 
deepens near The Four Corners region Tuesday night/Wednesday 
morning. This will result in a return to southwesterly flow aloft 
across our region as the ridge axis slides east toward the Tennessee 
Valley. 


There is some debate as to when the odds of seeing precipitation 
will return to our area. We currently have shower and thunderstorm 
probabilities returning Wednesday morning. However...with the 
somewhat slower progression /relatively speaking...of course/ of 
this next storm system...it does not look as if isentropic upglide 
will commence in our region until Wednesday night or so. As 
such...I plan on reducing shower and thunderstorm probabilities over 
our region for the day Wednesday. 


The upper low is expected to push a cold front into the eastern 
parts of Oklahoma and Texas late Wednesday night/early Thursday 
morning. Showers and thunderstorms will likely increase in coverage 
in advance of the front Wednesday night and continue through much of 
the day Thursday. I plan on remaining above guidance values for 
precipitation probabilities through this period...then taper from 
the west Thursday night as drier air works its way down into the 
boundary layer. 


Friday...at least for now...looks to be a dry day across the 
forecast area as the last bit of shortwave energy departs the 
region. Temperatures...even in wake of this storm system...should 
largely remain near normal for early Spring. /21/ 




&& 


Aviation... 
an upper-level disturbance will push a strong cold front across 
the four state region today. Thunderstorms and rain conditions can be expected 
across area terminals along with MVFR ceilings and visibilities. 
West winds will increase to around 20 kts after 18z across East 
Texas and by 00z across north Louisiana and southern Arkansas. Snow 
conditions expected across area terminals...with the exception of 
lfk...by 06z. /05/ 


&& 


Preliminary point temps/pops... 
shv 62 34 45 33 60 / 100 60 70 20 10 
mlu 71 37 46 36 56 / 80 100 60 40 10 
deq 53 32 41 33 58 / 100 90 70 40 10 
txk 57 34 41 34 57 / 100 90 70 40 10 
eld 68 35 43 35 56 / 80 100 70 40 10 
tyr 53 33 44 33 61 / 100 50 60 10 10 
ggg 54 32 46 34 62 / 100 60 70 20 10 
lfk 59 34 49 34 63 / 100 30 40 10 10 


&& 


Shv watches/warnings/advisories... 
Arkansas...lake Wind Advisory from noon today to 6 am CDT Sunday for the 
following zones: arz050-051-059>061-070>073. 


Winter Weather Advisory from midnight tonight to 4 PM CDT Sunday 
for the following zones: arz060-061-071>073. 


Winter Storm Warning from midnight tonight to 4 PM CDT Sunday 
for the following zones: arz050-051-059-070. 


La...Lake Wind Advisory from noon today to 6 am CDT Sunday for the 
following zones: laz001>006-010>014-017>022. 


Winter Weather Advisory from midnight tonight to 4 PM CDT Sunday 
for the following zones: laz001>004-006. 


OK...lake Wind Advisory from noon today to 6 am CDT Sunday for the 
following zones: okz077. 


Winter Storm Warning from midnight tonight to 4 PM CDT Sunday 
for the following zones: okz077. 


Texas...Lake Wind Advisory from noon today to 6 am CDT Sunday for the 
following zones: 
txz096-097-108>112-124>126-136>138-149>153-165>167. 


Winter Weather Advisory from midnight tonight to 4 PM CDT Sunday 
for the following zones: txz108>112-124>126-137-138. 


Winter Storm Warning from midnight tonight to 4 PM CDT Sunday 
for the following zones: txz096-097. 


&& 


$$ 


05/21