904 
fxus64 kfwd 212323 
afdfwd 


Area forecast discussion 
National Weather Service Fort Worth Texas 
623 PM CDT sun Mar 21 2010 


Aviation... 
surface/upper level cyclone continues to move slowly east away 
from North Texas and associated cloud deck will also translate 
east this evening. Ceilings at metroplex taf sites are expected to become 
scattered and winds will diminish to around 12 knots by 04z. Generally 
light westerly surface winds during the day Monday will become southerly 
after 00z Tuesday and this is reflected in the extended portion of 
the kdfw taf. 


07 


&& 


Update... 
northwest winds will continue to gust between 30 and 40 miles per hour for 
another hour or so...but sustained speeds are already coming down 
and will continue this trend. Have allowed the Wind Advisory to 
expire on schedule. Winds will fall into the 10 to 15 miles per hour range by 
9 or 10 PM. 


Lingering wrap around precipitation has exited our eastern County Warning Area...and have 
removed the slight chance probability of precipitation accordingly. Also made a few other 
minor adjustments to hourly trends. 


Full suite of updated products available shortly. 


&& 


Previous discussion... /issued 350 PM CDT sun Mar 21 2010/ 
upper level low continues its slow trek eastward and precipitation 
is gradually coming to an end over the eastern zones. Only some 
light snow and rain sprinkles are expected this evening in the 
east. Clouds will be more stubborn to vacate the region...and 
expect them to remain in their current location for the next 
several hours. By midnight...the clearing line will advance east 
to the metroplex...and should finally reach the Paris area by 
sunrise. Otherwise...the very strong northwest winds will diminish 
gradually this evening as the boundary layer decouples. These 
winds will continue into the overnight hours generally in the 5 to 
15 miles per hour range...as surface ridge axis remains to the west of the 
area. Low temperature forecast is more difficult tonight than a 
quick glance might suggest. Warm advection has been occurring in 
the low levels and temperatures off the surface will be several degrees 
warmer during the overnight hours. With the winds continuing to 
aide in mixing of this warmer air down...this will limit the temperatures 
from dropping off too much...but most looks much too warm. The 
western zones will have the lightest winds...and thus will have 
the coldest lows forecast there. Some locations...especially in 
the valleys where winds will be lightest...will drop below 32. 


Warmer and more Spring-like weather is expected again by tomorrow 
with lots of sunshine. South winds will return Tuesday and temperatures 
will reach the middle 70s with continued warm advection. More clouds 
and moisture will return by Wednesday ahead of the next upper 
level trough that will move in from the Pacific. Dynamic lift 
looks strong with this system...but instability should be limited. 
Do not expect severe weather with this system...but a round of 
widespread...perhaps heavy rain appears to be in play Wednesday 
night and into early Thursday. Slightly cooler and dry weather is 
expected by Thursday night and into Friday. Models are in good 
agreement on another trough moving through the plains on Saturday. 
All models do not develop much quantitative precipitation forecast with this trough...but it looks 
like a classic Spring dry line set up. Instability will probably 
be a limiting factor...and the cap should be in place. Only expect 
isolated convection Saturday afternoon/evening at this time. 


Tr.92 






&& 




Preliminary point temps/pops... 
Dallas-ft. Worth, Texas 33 67 44 76 51 / 5 0 0 0 5 
Waco, Texas 33 70 41 77 50 / 0 0 0 0 5 
Paris, Texas 34 57 36 73 46 / 10 0 0 0 5 
Denton, Texas 32 67 41 76 49 / 5 0 0 0 5 
McKinney, Texas 32 63 36 74 48 / 5 0 0 0 5 
Dallas, Texas 35 66 45 76 52 / 5 0 0 0 5 
Terrell, Texas 34 63 39 75 49 / 10 0 0 0 5 
Corsicana, Texas 33 66 42 75 50 / 5 0 0 0 5 
Temple, Texas 33 71 39 77 50 / 0 0 0 0 5 


&& 


Forward watches/warnings/advisories... 
none. 


&& 


$$ 


07/21