961 
fxus64 klub 211147 
afdlub 


Area forecast discussion 
National Weather Service Lubbock Texas 
547 am CST Sat Nov 21 2009 


Aviation... 
only impacts of concern will be dealt to cds this period. Layer 
of IFR ceilings currently stretches from the extreme eastern 
Panhandle south to the eastern rolling plains...however 
indications are VFR criteria will return to cds around 14z as 
light and variable winds turn southwesterly ushering in drier air. Winds 
will back from southwest to south by this evening at both lbb and 
cds...with a return of IFR stratus and possibly fog expected at 
cds late in the forecast period. 


&& 


Previous discussion... /issued 415 am CST Sat Nov 21 2009/ 


Short term... 
middle-level low in central Texas will translate slowly east into the 
lower Mississippi Valley today ahead of a progressive ridge. Said 
ridge is already undergoing deamplification ahead of a trough 
approaching The Rockies...so westerly flow aloft will deepen 
markedly this afternoon and in turn help push a Lee trough close 
to our western zones. Presence of already low dewpoints on The 
Caprock will assist low-level momentum transport by midday and 
secure above normal high temperatures. These conditions should breed 
elevated fire weather conditions primarily for our northwest zones where 
stronger 20 foot winds are expected. See fire weather discussion 
for more details. 


Main challenge involves threat for a round of low clouds and 
perhaps some fog later tonight in the eastern rolling plains. Western 
extent of a vast pool of Richer moisture in OK did manage to creep 
into our northestern zones early this morning behind a surface ridge 
axis...although light downsloping flow in the western Rollin plains 
has thwarted a faster westward expansion of this stratus and fog. 
This is not expected to be the case tonight as widespread southerly flow 
should secure a ribbon of low dewpoint depressions in the eastern 
rolling plains and southeast Panhandle. Consequently low temperatures 
look rather mild for a change off The Caprock...however areas on 
The Caprock may still see freezing temperatures as winds diminish late in 
advance of a dry cold front. 


Long term... 
again...little change in the extended portion of the forecast from 
previous couple of shifts. Models still show a weak front for 
Sunday before a stronger front pushes across the area Monday. 
Still are subtle differences in the timing of the front Monday and 
this could impact temperatures forecasts all the way into Tuesday. 
European model (ecmwf) continues with strong northerly flow into Tuesday morning 
which may result in cooler temperatures than currently forecast. GFS 
has started to trend towards the European model (ecmwf) solution so we will need to 
watch and see how this evolves. 


GFS is also a bit more aggressive with the next trough pushing out 
of the Great Lakes into the upper Midwest compared to the European model (ecmwf) 
which is more progressive. Both models agree on another weak cold 
front for Wednesday of next week with subtle differences in 
strength and timing. Northwesterly flow will continue through the 
end of the forecast and it sounds like a broken record...near 
seasonable temperatures with dry conditions to continue. 


Jordan 


Fire weather... 
elevated fire weather conditions are expected to materialize this 
afternoon primarily over the extreme southwest Panhandle and 
northwest South Plains. A surface trough will tighten across eastern 
New Mexico today and result in southwest winds at the 20 foot 
level increasing to around 15 miles per hour with higher gusts. This...in 
combination with above normal temperatures and minimum humidities 
falling to around 15 percent...will require more care and 
preparation with any controlled Burns this afternoon. 


&& 


Preliminary point temps/pops... 
Friona 68 30 60 29 61 / 0 0 0 0 0 
Tulia 67 32 64 27 61 / 0 0 0 0 0 
Plainview 67 33 67 30 64 / 0 0 0 0 0 
Levelland 69 29 68 30 68 / 0 0 0 0 0 
Lubbock 69 33 69 34 68 / 0 0 0 0 0 
Denver City 69 32 69 34 69 / 0 0 0 0 0 
Brownfield 70 32 71 30 70 / 0 0 0 0 0 
Childress 69 40 67 41 64 / 0 0 0 0 0 
spur 68 37 70 38 68 / 0 0 0 0 0 
Aspermont 68 41 71 41 70 / 0 0 0 0 0 


&& 


Lub watches/warnings/advisories... 
none. 
&& 


$$ 


93/14/93