Weather

364 
fxus64 kepz 281928 
afdepz 


Area forecast discussion 
National Weather Service El Paso Texas/Santa Teresa nm 
128 PM MDT Thursday Aug 28 2008 


Synopsis... 
east and southeast winds will transport moist unstable air into 
southern New Mexico and western Texas while upper level 
disturbances move into the region. This weather pattern will bring 
scattered showers and thunderstorms to the region through the 
weekend locally heavy rain possible. High pressure will result in 
warm drier weather later next week. 


&& 


Discussion... 
evolving weather pattern still appears favorable for convection 
with locally heavy rainfalls into early next week. Currently 
elongated east-west upper ridge extends across the New Mexico- 
Colorado border vicinity while large upper low remains almost 
stationary across northwest Mexico and Baja California. At low levels little 
has changed as Summer thermal low covers Arizona with high 
pressure extending into central Texas. This overall pattern not 
expected to change much through Friday afternoon with height- 
pressure alignments generating deep lower and middle tropospheric 
east and southeast winds. An examination of regional flow shows 
trajectory from the Gulf of Mexico into the County Warning Area with moisture 
remaining abundant and precipitable water sustained above 1.3 
inches into Friday afternoon. Instability will be moderate during 
the afternoon and evening with convective available potential energy around 1000 j/kg so deep 
convection seems possible. Main uncertainty is deeper forcing 
mechanisms as models suggest weak waves aloft embedded in flow and 
approaching from the east and southeast. These features difficult 
to detect in data void areas so more precise timing and location 
of stronger storms difficult. However forecast soundings show 
little speed or directional shear through the middle levels with 
weaker flow higher up indicating some back building may occur with 
associated heavy rains. 


Models have been rather consistent in moving high amplitude slow 
moving trough across the Pacific into the western U.S. With 
system phasing with upper low over Baja California by Saturday. Approach of this 
trough will also result upper ridge axis reforming further east on 
a north-south alignment into the middle west. These trends will 
deepen southerly wind component through the County Warning Area with precipitable 
water increasing even further to near 1.5. Thus heavy rain 
potential will continue into the weekend as models continue to 
move weak embedded waves into the area. Risk of severe weather may 
increase on Monday as primary upper trough moves across the Rocky 
Mountains providing deeper lift and stronger shear. 


Latest guidance still infers warm drier weather Tuesday 
through Wednesday as more westerly winds and surface high 
pressure become established behind the trough. GFS shows back 
door front increasing rain threat Thursday but will keep slight 
chances in for now. 


&& 


Aviation... 
scattered areas of MVFR and isolated IFR ceilings and 
visibilities in showers and thunderstorms through Friday. 


&& 


Fire weather... 
south to southeast winds will push moist unstable air into New 
Mexico and western Texas into early next week while weak upper 
disturbances move ito the region. This pattern will bring 
scattered showers and thunderstorms with locally heavy rains 
through Monday. Thus the fire danger should become lower over the 
next several days due to widespread rains and high humidities. 


&& 


Preliminary point temps/pops... 
El Paso 69 85 67 83 64 / 40 40 30 30 50 
Sierra Blanca Texas 60 83 61 79 57 / 40 40 30 30 50 
Las Cruces 68 85 67 83 64 / 30 30 30 30 50 
Alamogordo 65 84 63 82 61 / 20 20 20 30 50 
Cloudcroft 47 66 45 64 43 / 30 30 20 40 50 
Truth or Consequences 65 84 64 80 62 / 20 20 20 30 50 
Silver City 59 78 58 75 56 / 30 30 30 30 40 
Deming 65 85 64 82 62 / 30 30 30 30 50 
Lordsburg 64 84 63 81 62 / 40 30 30 30 50 


&& 


Epz watches/warnings/advisories... 
nm...none. 
Texas...none. 
&& 


$$ 


05 rogash/Adair