313 FXUS64 KHGX 012054 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 354 PM CDT Mon Apr 1 2019 .DISCUSSION... April begins chilly as we have yet to pull out of an early spring post-frontal airmass. Indeed, north of Houston, sporadic reports of a few sleet pellets have been reported today. Fortunately, more spring-like conditions are expected later this week. We'll also see the chance of showers and storms return, with a first opportunity centered around Thursday, and another centered around Saturday. We'll want to keep an eye on Thursday for severe weather, though the main action will likely be to our east. This weekend looks to have the heavier rainfall of the two rounds of active weather. .NEAR TERM [Through Tonight]... A shortwave trough is rounding the base of a closed upper low over Oklahoma, and while it's beginning to exit the area now, it's getting its last swipe in across Southeast Texas with light showers and - yes - even some sporadic sleet. So far, the southernmost report has come from Huntsville, but they have been rather broad, ranging from College Station to Crockett. The back end of the precip appears to be crossing the Brazos River about now, so this should wrap itself up from west to east this afternoon and evening. With video of frozen precip seen with temps around/above 50 degrees at Huntsville, it seems likely further pellets will fall across the north. Finally, once the influence of the shortwave fully exits the area, look for clouds to scatter out, and for winds to go light and variable as broad high pressure drops into Southeast Texas overnight. This should set up a good night for radiational cooling, and I go nearly as cold as last night. Given how poorly the guidance handled last night, I chose to undercut most locations away from the coast by 2-3 degrees. This may not be enough, but there is a bit of uncertainty in how low we'll race due to the fact that it is still overcast over the vast majority of the area. .SHORT TERM [Tuesday Through Wednesday Night]... Tuesday through Wednesday night will be a story of a warming trend. Look for winds to come back to onshore by Tuesday evening. And, though the influx of moisture on these winds will likely increase cloudiness and even bring in potential for showers on Wednesday, we'll look for afternoon highs to be progressively warmer, likely because overnight lows will be kept much higher than recent nights, giving us a high floor to start from. Any precip we manage on Wednesday should mainly be streamer showers from onshore flow's isentropic lift. That said, we do have a modest amount of CAPE available, a not completely terrible placement of the upper jet, and (for now) a well-timed midlevel vort max that may be just enough to get the support for an isolated thunderstorm. But, for all intents and purposes, we should be waiting for Thursday to get our best chance at some action. .LONG TERM [Thursday Through Monday]... Thursday will be a day to watch for thunderstorms. An upper trough will drop to around or south of the Red River, and we'll be building considerably more CAPE available to fuel storms on this day, while solid onshore flow continues. Couple arguments against anything occurring in our area as well, though. With the exception of the Euro, which is backing off its earlier frontal push as well, no guidance brings the surface front into Southeast Texas anymore, reducing surface convergence. Additionally, upper jet placement is not ideal, as the angle and curve of the jet streak makes things look fairly confluent for us in the right exit region. From the data available to me now, I'd put my money to our east in Lousiana under the left exit region and a curve that looks to enhance diffluence. Still, SPC has a Day 4, 15 percent contour that nicks the eastern edge of our area of responsibility (Looking at you, H-T-P counties). Translated to a Day 1-3 paradigm, this would put at least a decent chunk of our area in a marginal risk area. Given the uncertainties at this range, this seems appropriate. Rest assured both us and SPC will be continually evaluating the situation with the latest information in the coming days to solidify the true potential. A stronger upper trough still looks to cross deeper in our area Saturday into early Sunday. Additionally, there's some suggestion from the guidance that another upper trough dropping off the Rockies may be moving quickly enough to get a little phasing going with the lead trough. This is a super fragile setup at long range, so it's nothing to count on, but it's something to pay attention to. Instability looks a bit more muted than Thursday, and wind structure looks less than impressive for severe weather, but with continued onshore flow, we may have plenty of moisture in place to get some locally heavy rainfall. Not a real strong signal at this point, but we'll be keeping an eye on things in the coming days. && .AVIATION [18Z TAF Issuance]... Closely watching some radar echoes moving to the ENE across our northern sites (mainly CLL and UTS) and will continue to carry VCSH at those sites through 20Z-21Z. Also monitoring some MVFR ceilings well to the south of our TAF sites that are expected to stay to our south. Still expecting to see the current 6000-8000 foot BKN/OVC deck to work its way eastward this afternoon and east of our TAF sites this evening. For winds, looking at mainly N to NE this afternoon below 10 knots becoming light and variable tonight. SE to S winds tomorrow around to 10 knots. 42 && .MARINE... Light to occasionally moderate north to northeast winds are still expected to become east on Tuesday and southeast Tuesday night and Wednesday as surface high pressure moves off to the east. This developing onshore flow will be strengthening and seas will be rising Wednesday and Wednesday night in response to a tightening pressure gradient (caution flags might be needed). Look for a decreasing trend in both winds and seas Thursday through Friday as a weak front stalls near the area. Southeast winds will be strengthening over the weekend as a storm system moves across the state (caution flags are likely, and some advisories might be needed), and rising shower and thunderstorm chances can be expected too (especially on Satur- day). The next cold front is currently expected to move through the coastal waters on Monday. 42 && .CLIMATE... As of 3 PM, the City of Houston (at IAH) has at least tied its record low for today, and may have broken the record. More details with the 4:30 pm climate report. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 37 70 48 72 64 / 0 0 0 30 50 Houston (IAH) 39 70 50 73 65 / 0 0 0 30 50 Galveston (GLS) 53 65 59 70 67 / 0 0 0 30 40 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ NEAR TERM...Luchs SHORT TERM...Luchs LONG TERM...Luchs AVIATION...42 MARINE...42 CLIMATE...Luchs