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