Weather

564 
fxus64 kepz 062055 
afdepz 


Area forecast discussion 
National Weather Service El Paso Texas/Santa Teresa nm 
255 PM MDT Sat Sep 6 2008 


Synopsis... 
after a couple of dry days across the Borderland moisture will 
begin to work back into the area tonight. A southerly flow at low 
and middle levels between low pressure west and high pressure east 
will bring moisture north back over our region out of northern 
Mexico. The moisture increases coupled with daytime heating and 
weak disturbances aloft will result in chances for isolated to 
scattered showers and thunderstorms each afternoon and evening 
through the upcoming week. 


&& 


Discussion... 
dry northwest flow aloft and resulting lower precipitable waters were short-lived 
for the region. Synoptically our area resides between high 
pressure aloft to the east and low pressure aloft to the west. 
Both of these features are proged to nudge towards the area. The 
flow that develops between the two will be southerly in nature. 
Satellite imagery and model data indicate abundant moisture to our 
south. Thus a low level southeast flow and a middle level S flow with upper 
flow backing to SW will result in an advection of moisture into 
the County warning forecast area tonight. GFS rushes the moisture and combines it with 
dynamics aloft in the form of a shortwave. I believe it is too 
aggressive (too quick) in bringing high probability of precipitation back to the area. But 
do see slight chance probability for evening precipitation in the Texas zones 
late this evening and potentially overnight. 


Sunday should be noticeably more moist on the epz sounding and 
expect precipitable waters back over an inch. Both the NAM and GFS models show 
upper-level low pressure moving over with embedded vorticity lobes 
for sun aftn/eve. Thus the increase in moisture combined with daytime 
heating and upper-level help should bring US back into shower and 
thunderstorm potential area wide after middle day. 


For the rest of the week we remain under a fairly consistent 
pattern of deep southerly low- and middle-level flow due to our 
location between ridging over the areas east of US and troughing 
to our west. The resulting southerly flow will keep moisture over 
the area. Thus we have to keep the probability of precipitation in for each day. 


&& 


Aviation...valid 07/0000z-08/0000z 
low pressure slowly developing off California coast...will begin to send more 
moisture back into the area from Mexico this evening. Look for VFR 
conditions over much of the area...except in isolated -tsra possible 
near the international border through 07/04z. Isolated to scattered thunderstorms and rain/MVFR 
ceilings/visibilities psble areawide Sunday after 07/20z...as deeper moisture 
continues to work its way northward across our flying areas. Isolated 
IFR visibilities possible in heavier rain shafts. 


&& 


Fire weather... 
moisture from the Gulf of Mexico and Gulf of California will 
flow across the area from the south this week...as circulation 
around deepening low pressure off the West Coast...works to 
strengthen our tap from the subtropics. Look for increasing chances 
of afternoon and early night-time shower and storm activity 
area-wide through the end of this week. Nighttime relative humidity 
recoveries will diminish as a result over most areas...with least amount 
of improvement expected over inter-Mountain Valley locations. Look 
for generally light winds through Wednesday. On Thursday...a weak 
back-door cold front may provide a wind shift to the 
northeast-east...however speeds do not appear to increase 
significantly for that time at this time. 


&& 


Preliminary point temps/pops... 
El Paso 67 90 66 91 67 / 10 20 20 20 20 
Sierra Blanca Texas 60 87 61 88 60 / 10 30 30 20 20 
Las Cruces 65 90 63 90 65 / 0 10 20 20 20 
Alamogordo 63 87 62 89 63 / 0 10 20 20 20 
Cloudcroft 47 69 48 70 46 / 10 10 20 30 30 
Truth or Consequences 63 90 62 90 59 / 0 10 20 20 20 
Silver City 57 84 57 83 56 / 0 10 20 10 20 
Deming 62 91 61 90 63 / 0 10 20 10 10 
Lordsburg 63 91 62 91 62 / 0 10 20 10 10 


&& 


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


$$ 


14/22