036 
fxus64 khgx 151211 
afdhgx 


Area forecast discussion 
National Weather Service Houston/Galveston Texas 
711 am CDT Monday Mar 15 2010 


Discussion... 
extended dense fog advsy until 9 am for locations S of I-10. Drier 
air is gradually filtering in from the NE...so anticipate 
improving conditions through the period. 47 


&& 


Previous discussion... /issued 636 am CDT Monday Mar 15 2010/ 
aviation... 
fog continues to affect most taf sites across 
southeast Texas this morning with the exception of cll and uts. 
Satellite fog imagery showing that drier air continues to push 
into the region from the northeast and conditions should begin to 
improve at cxo and iah shortly after sunrise. Closer to the coast 
improvement will probably not come until middle morning but once the 
fog lifts VFR conditions expected again under high clouds. Middle and 
low clouds will build in this afternoon and evening as upper level 
system currently over nm moves closer. Showers will likely be 
moving into the region from the west at the end of the current 
forecast period. For now will only add vcsh for cll before 12z and 
iah by 14z and allow later shifts to refine timing of precipitation 
onset. 38 


Previous discussion... /issued 339 am CDT Monday Mar 15 2010/ 
discussion... 
light srly flow has brought dewpoints up into the 
upper 50s and lower 60s across the southern parts of the region...quite 
a bit higher than model depictions. Widespread dense fog has 
formed in this area. Weak cool front has edged into extreme NE 
parts of the County Warning Area lowering dewpoints into the lower 40s. Though 
winds should gradually back to the east/NE across the remainder of 
the area this morning...not confident in timing - hence when the 
fog will dissipate. Will let the advsy ride until 7 am...but will 
likely need to update once trends are observed. 


Upper low over New Mexico should drop into West Texas today then 
gradually open up as it moves over the remainder of the state 
tonight & Tuesday. Available moisture isn't all that impressive (pw's 
peaking close to 1") but large scale lift associated with the 
upper low/trough should be enough to generate some scattered rain showers and isolated 
elevated thunderstorms and rain as it moves through. Nudged probability of precipitation up another 10% or 
so with models showing a bit more coverage over southeast Texas than before. Still 
anticipate more widespread coverage west of the County Warning Area. 


Mostly dry northwest flow aloft then takes shape in the wake of the 
departing trough as upper ridge builds in from the west. That being 
said...may need to monitor moisture availability Wednesday nt/Thursday 
morning as a potent short wave dives southward through the Midwest and into east 
TX/la. Atmos looks pretty dry at this time...but NAM 12 noting some 
potential precipitation. 


Onshore flow resumes late Thursday ahead of the next front that is 
scheduled to push through southeast Texas Sat morning. Started lowering temperatures 
next weekend - and maybe not enough - as the front looks fairly 
impressive as of now. 47 


Marine... 
easterly winds will persist across the marine zones today before 
becoming offshore Tuesday afternoon as a weak frontal boundary 
clears the coast. Offshore winds will continue through middle week 
before becoming onshore late Thursday ahead of another approaching 
weather system for next weekend. 38 


&& 


Preliminary point temps/pops... 
College Station (cll) 73 51 62 46 70 / 0 30 40 10 0 
Houston (iah) 75 51 65 48 71 / 0 20 40 20 0 
Galveston (gls) 70 55 64 53 67 / 0 20 30 20 0 


&& 


Hgx watches/warnings/advisories... 
Texas...dense fog advisory until 9 am CDT this morning for the following 
zones: Austin...Brazoria...Chambers...Colorado...Fort 
Bend...Galveston...Harris...Jackson...Matagorda...Waller... 
Wharton. 


GM...dense fog advisory until 9 am CDT this morning for the following 
zones: Galveston Bay...Matagorda Bay...waters from Freeport 
to the Matagorda Ship Channel out 20 nm...waters from High 
Island to Freeport out 20 nm. 


&& 


$$