184 FXUS64 KHGX 261110 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 610 AM CDT Fri Jun 26 2020 .AVIATION... Patchy light rain continues to move across SE TX with strong activity just off to the east and west. 09z HRRR shows a cluster of shra/tsra east of the Houston terminals this morning and then nothing for much of the day with additional shra/tsra inching toward western TAF sites late this afternoon. Fcst soundings show weak capping near 850 mb and some dry air in the 900-600 mb layer. Have leaned toward the drier HRRR/TT WRF solution for TAFs today. Mvfr cigs should mix out by 15z with generally VFR conds through the day with MVFR cigs later tonight - mainly affecting northern TAF sites. 43 && .PREV DISCUSSION... /ISSUED 412 AM CDT Fri Jun 26 2020/ SHORT TERM...(Today through Saturday) Skies are cloudy over much of SE TX early this morning and radar is considerably calmer than the past few nights. A weak disturbance will approach the Matagorda Bay region today and push north. This feature will bring a a good chance of shra/tsra to mainly the western half of the CWA today. Upper level ridging over the Gulf will be slowly expanding to the west and this should shunt some of the higher PW air to the west toward Central Texas. PW values are highest this morning ranging between 2.00 and 2.25 inches. PW values drop to around 1.65 inches over the east by evening and 1.85 inches over the west. There could be some additional lift provided by the jet as upper level winds show a broad split over SE TX and a weak speed max approaching the western part of the CWA in the aftn. Fcst soundings show some capping near 850 mb in the east along with a wedge of dry air between 900-600 mb. Have tapered PoPs higher west, lower to the east. WPC has outlooked the extreme western part of the CWA in a Slight Risk for excessive rainfall and parts of SE TX in a Marginal Risk. At this time, feel the excessive rain threat will be west of the area but soil moisture is very high and any additional rainfall will likely lead to rapid run off. Temperatures are tricky today as MOS guidance and blends keep MaxT in the lower/middle 80s. Even with rain and cloud cover yesterday, high temps reached the upper 80's. Went more with persistence and tapered temps cooler in the west under clouds/rain and warmer to the east closer to the building ridge. With the loss of heating and jet dynamics, expect showers to end early in the evening with partly to mostly cloudy skies lingering. PW values increase again on Saturday but forecast soundings show a fairly dry profile. Fcst soundings again show some weak capping near 850 mb and this should be overcome by mid afternoon with modest heating. Not expecting widespread activity on Saturday but there should be a few showers and storms around. Will carry chance PoPs for now. Fcst soundings show saturation around 14,000 feet and there may be a cirrus shield for much of the day. Probably get some Saharan dust into the area as well but latest satellite imagery overnight doesn't look all that impressive with the dust. Leaned toward a blend of persistence/climo for MaxT on Saturday. 43 LONG TERM [Saturday Night through Friday]... Activity across the local area will be dissipating Saturday evening and early night. A few passing isolated showers are possible over the Gulf waters and portions of the coasts overnight into early Sunday morning. Sub-tropical ridge is expected to build and expand across Mexico and could extend into our general area Sunday. However, another upper level shortwave exiting the Southern Rockies Sunday morning and moving eastward across Northern TX Sunday afternoon, may keep the northeastern edge of the ridge to our south southwest. Along the surface, another pulse of low level moisture traveling northeast from the Gulf will make its way across the local area throughout the day. If the ridge is able to expand into Southeast TX, then rainfall activity would be a bit limited by the subsidence aloft, but if the shortwave digs a bit more south, then it would provide a better environment for shower and thunderstorm development. Skies may still be a bit hazy Sunday from the remaining Saharan dust (SAL), however, if we receive enough showers Saturday and Sunday, the amount of particulate in the atmosphere will be reduced. The sub-tropical high will likely be the main dominant weather feature next week and subdue rainfall chances across Southeast TX. Continuos onshore flow will bring a few pulses of low level moisture across the local area, however, subsidence aloft will limit development. Activity, if any, should develop mainly during the late morning and afternoon hours with peak heating and the influence of a few local outflow boundaries. Temperatures will be on the rise Monday through Wednesday, with highs ranging between the low and mid 90s each day. Heat indices will also increase to the low to mid 100s. The GFS and EC retreat the subtropical ridge to the southwest in response to an upper level trough moving eastward from the Rockies Wednesday through the end of the work week, which allow for indices to slightly decrease. How much of an influence we will have from this trough is yet unknown as model solutions continue to vary slightly. Have kept PoPs of 30% or less through the entire week for now. 24 MARINE... Low pressure in the lee of the Rockies and high pressure over the eastern US will maintain a moderate onshore wind through early next week. Mariners in small craft should exercise caution today. A SCEC may be required at various times through the weekend. The general weather pattern doesn't change through mid week with a light to moderate onshore flow continuing. Toward the end of next week, surface high pressure will settle over the central Gulf of Mexico and lighter winds are expected. 43 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 87 74 90 75 92 / 60 40 20 10 30 Houston (IAH) 87 77 90 77 92 / 40 30 30 20 40 Galveston (GLS) 87 81 89 80 91 / 30 20 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 1 PM CDT this afternoon 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. && $$ Discussion...43 Aviation/Marine...43