282 FXUS64 KHGX 160948 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 348 AM CST Wed Dec 16 2020 .SHORT TERM... (Today through Thursday night) High pressure over West Texas will move east today and be centered over SE TX tonight. Some wrap around moisture/clouds are progged to move across the area this morning but not seeing an expansion of the cloud field upstream just yet. Will mention morning clouds in the Sky grids. Skies will clear after 18z as drier air aloft mixes toward the surface. 850 mb temps have cooled from yesterday and MaxT values will struggle to reach the mid 50's today. Skies will remain clear tonight with high pressure overhead. Clear skies, light winds and dry air will allow temps to radiate efficiently and MinT values will be cold. Most of the area north of I-10 will probably fall to freezing or even a bit cooler. and local cold spots south of I-10 will probably hit the freezing mark around sunrise. The surface high will move east of the region on Thursday. Onshore winds will return as will slightly warmer temperatures. 850 mb temps warm several degrees and MaxT values should reach 60 degrees or so. Soundings don't show much in the way of saturation so will keep skies generally sunny. The onshore flow will strengthen late Thursday into Thursday night as low pressure deepens over the TX panhandle. Should start to get some clouds developing near Matagorda Bay Thursday night as moisture levels increase. Low temperatures by Friday morning will remain cool but should be about 10 degrees warmer than the previous night. 43 && .LONG TERM [Friday Through Wednesday]... Onshore flow will help increase temperatures, humidity, and cloud coverage before the next front expected to move through this upcoming weekend. Models place a surface low over the rolling plains of TX late Friday night with a cold front expected to begin to push through. The GFS and Canadian show the onset of precip occurring slightly more early on late Friday night when compared to the Euro which has precip beginning early Saturday morning. The most noticeable difference between the 00Z model run tonight versus last night is how both GFS/Euro models show the front and precip lingering in the Gulf longer. Initially, the Euro shows precip developing inland, then pushing offshore by late Saturday night. The Euro also shows the cold front getting stronger offshore than the GFS while in the Gulf, with a stronger jet stream, and a surface low developing over the FL panhandle. Leaned slightly more towards Euro guidance since the model trends have been consistent with the cold front not moving as fast and precip lingering longer. By Sunday, high pressure will move in over Texas and settle in allowing skies to clear and temperatures to drop due to CAA. Sometime on Tuesday or Wednesday, models are suggesting another surge of precip as increasing southerly winds in advance of a broad surface trough over the central plains helps draw in moisture before another front pushes through the Northern Plains. Once again, model discrepancies leave the timing, location, and intensity somewhat uncertain. KBL && .MARINE... A few marine hazards will persist this morning. Strong NW winds in the wake of a cold front will gradually diminish this afternoon. Will maintain the SCA for the Gulf waters through 18z. The other issue today is the potential for low water hazards. Water levels could fall to between 1.0 and 1.5 feet below MLLW today. Winds are NW but the speeds have not been of the magnitude to drive water from the Bays. Will watch trends but think its best to maintain the Low Water Advisory for now. The surface high will move east on Thursday and onshore winds will return. The onshore flow will strengthen on Fri/Fri Night as low pressure develops over SE CO and strengthens as it moves into the TX panhandle. Shelf waters have cooled and the warmer and more moist air flowing over the cooler waters will have the potential to produce sea fog. As the low moves east, it will drag a cold front across the state and across the coastal waters on Saturday morning. An offshore flow will develop in the wake of the front. Winds will veer to the NE on Sunday as high pressure settles over East TX. 43 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 52 33 61 39 65 / 0 0 0 0 10 Houston (IAH) 54 33 60 39 65 / 0 0 0 0 0 Galveston (GLS) 55 41 57 51 66 / 0 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...Low Water Advisory until 6 PM CST this evening for the following zones: Galveston Bay...Matagorda Bay. Small Craft Advisory until noon CST today for the following zones: Coastal waters from Freeport to Matagorda Ship Channel TX out 20 NM...Coastal waters from High Island to Freeport TX out 20 NM...Waters from Freeport to Matagorda Ship Channel TX from 20 to 60 NM...Waters from High Island to Freeport TX from 20 to 60 NM. && $$