133 
FXUS64 KHGX 171002
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
502 AM CDT Fri Mar 17 2017

.DISCUSSION...
Ridging over the eastern Gulf and surface low in the OK panhandle
and cold front over KS/MO this morning will maintain the moderate
onshore flow today across SETX which has given the area a warm 
start to the day. Temperatures are already about 8-10 degrees 
warmer than normal and expect with the breezy conditions across 
the south and western areas today to still allow afternoon 
temperatures to rise to 4-7 degrees above normal for highs. Rain 
chances look fairly slim at 20 percent or less mainly lined up 
north to south this morning through the center of the region then 
expanding inland this afternoon. Strong cap in place so mostly 
just sprinkles or light showers. Some patchy fog possible for
inland areas overnight. Saturday could be a bit more 
interesting...the previously mentioned cold front sags south and 
may reach extreme NETX and stalling there leaving SETX in a coll 
at the surface with the tail end of the upper shear axis swinging 
southeastward through the region. Daytime heating will destabilize
the airmass and may do so sufficiently to overcome the cap. 
GFS/NAM differ on the strength of the cap and the flow around 
height of the cap...given the stalling front and potential for 
stronger heating and warmer start have boosted rain chances a 
little for the southern areas...differential heating may even come
into play with 20 degree T-SST differences (just seems odd to be 
talking seabreeze in the middle of March). If...the cap erodes 
then can't rule out pulsey type strong thunderstorms that are slow
moving outflow dominated types. Then Saturday night the cap 
returns with a vengeance and the area should be rain free with 
well above normal temperatures Sunday through Wednesday. Gradient 
tightens up Wednesday night/Thursday as pressures fall in the lee 
of the Central Rockies with the approach of a deep upper trough. 
Of course the GFS/ECMWF differ on timing and track of the upper 
low but given the overall consistency of the ECMWF think that most
of system will pass by too far north and only the tail end of the
front reaches the area next Friday - SETX area may be too capped 
for much rainfall...GFS is much more bullish for rain but am 
leaning the forecast in favor the ECMWF solution for now with much
warmer temps and higher rain chances north and west on Friday.

45


&&
.MARINE...
Elevated winds and waves will continue across the bays and coastal 
waters this morning, but are expected to decrease through the day as 
the surface pressure gradient relaxes. Have extended the Small Craft 
Advisory through mid-morning before 7 ft waves subside, with caution 
flags in effect for the bays and nearshore waters. Light to 
occasionally moderate onshore flow is expected to persist over the 
next several days, strengthening late next week ahead of an 
approaching frontal system.

Huffman


&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      81  63  82  61  82 /  20  10  20  10  10 
Houston (IAH)              80  64  82  61  84 /  20  10  20  10   0 
Galveston (GLS)            77  66  76  66  77 /  20  20  20  10   0 

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 7 AM CDT this morning 
     for the following zones: Galveston Bay...Matagorda Bay.

     SMALL CRAFT SHOULD EXERCISE CAUTION until 11 AM CDT this morning 
     for the following zones: Coastal waters from Freeport to 
     the Matagorda Ship Channel out 20 NM...Coastal waters from 
     High Island to Freeport out 20 NM.

     Small Craft Advisory until 11 AM CDT this morning for the 
     following zones: Waters from Freeport to the Matagorda Ship 
     Channel from 20 to 60 NM...Waters from High Island to 
     Freeport from 20 to 60 NM.

&&

$$

Discussion...45
Aviation/Marine...14