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Area forecast discussion...updated 
National Weather Service Midland/Odessa Texas 
649 PM CDT Wednesday Jul 23 2008 


Discussion... 
see aviation discussion below. 


&& 


Aviation... 
the latest visible satellite loop shows the cumulus field across the 
region is in the process of dissipating. We expect this trend to 
continue this evening with the loss of daytime heating. Winds 
through the evening and overnight hours will generally remain from 
the east and southeast at or below 10kts. Cloud cover will be on 
the increase tomorrow as moisture associated with tropical system 
Dolly moves into the area. Currently...we expect VFR conditions to 
prevail through the current taf period. We will also hold off on 
mentioning any precipitation in this taf forecast as the track of 
the remnants of Dolly is still uncertain. 


&& 


Previous discussion... /issued 242 PM CDT Wednesday Jul 23 2008/ 


Discussion... 
models have trended a bit farther north in the 12z model runs this 
morning...taking the remnants of Hurricane Dolly into New Mexico. 
It appears that the models are picking up on a weakness in the 
upper ridge as a shortwave moves through the central Continental U.S.... 
allowing for Dolly/S remnants to take the more northerly track. 
Depending on which model you believe...this could bring increased 
rain chances to more of our area. Right now the GFS is the 
definite outlier...taking the most northerly path into southeast 
New Mexico. The Euro and NAM/WRF are still trending a little more 
westerly and into the Desert Southwest/southwest New Mexico by 0z 
Saturday. Also noting that the 0z Euro has actually handled the 
current location...23/15z...of Dolly better than both the NAM and 
GFS. With all this in mind...leaned a lot heavier on the Euro for 
precipitation/weather grids...blending slightly with the NAM since it lines up 
well with current trends as well as HPC guidance. 


If the forecast pans out...expect to see greatest chances and 
heaviest rainfall across the lower trans Pecos and Big Bend regions 
initially...then translating more into the mountains of southwest 
Texas as Dolly moves towards the Desert Southwest. In general... 
tropical systems Don/T usually have a whole lot of thunderstorm 
activity associated with them...but given the enhanced orographic 
effects of the mountains ... ahead with mainly showers and 
added isolated thunder in weather grids for this event. Although this 
will continue to be monitored for increased convective activity 
with the modified activity as Dolly moves this way. Areas east of 
the Pecos River and north of Interstate 10...as rough 
markers...will see precipitation chances drop off substantially as this 
event unfolds during the latter part of the week. However... 
locations as far north as Interstate 20 could see some rainfall 
out of this system...especially if the track does trend farther 
north and east. After Dolly exits the area this weekend...we will 
return to a fairly diurnal type pattern with best rain chances 
west across the mountains. Stuck fairly close to guidance for days 
4 through 8 given the increased activity due to Hurricane Dolly. 


Temperature forecasts may be a little interesting as they will 
largely depend on how much cloud cover is around from Dolly as well 
as the ultimate track. In this case...stuck closer to a blend of 
the GFS and NAM as the Euro looked a little too cool in some 
places. Will definitely see a significant dip in temperatures on Friday 
but then a warming trend will quickly begin later during the 
weekend. Highs across the area will be back into the upper 90s to 
low 100s for most locations by early next week. 


&& 


Maf watches/warnings/advisories... 
nm...none. 
Texas...none. 


&& 


$$ 


06