Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
Issued by NWS Houston/Galveston, TX
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767 FXUS64 KHGX 022035 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 335 PM CDT Tue Jul 2 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE, TROPICAL... .SYNOPSIS... Issued at 334 PM CDT Tue Jul 2 2024 Major Hurricane Beryl is getting a whole lot of attention, and there is good reason for that. However, in the near term, we also have to pay attention to another bout of unseasonably high heat. Both are potential threats and need some attention - and while hurricanes are eye-grabbing and command attention, heat doesn`t often do that. That heat is real, potentially deadly, and it is here now. So, some key messages to remember for the next week or so: - Heat advisories continue through at least this evening around the Houston metro and points north and northwest. While tomorrow may be a touch cooler, it also looks a touch more humid, and advisories may still be needed. At night, there will be little relief to be found with lows in the upper 70s and lower 80s expected. - Given the conditions, it`s important to keep heat safety front of mind if you have outdoor plans, especially if you will be exerting yourself. In addition to high heat index values, the wet bulb globe temperature, an index particularly useful for heavy exertion, looks to rise into the extreme range for a handful of hours tomorrow afternoon. - Continue to monitor the latest forecast information on Hurricane Beryl. Uncertainty in the forecast grows significantly beyond a few days from now, and will have a significant influence on potential impacts - if any - for our area. Arming yourself with the latest info from our office and the National Hurricane Center is needed to stay prepared. && .SHORT TERM... (This evening through Wednesday Night) Issued at 334 PM CDT Tue Jul 2 2024 Today is a summery day if ever there was one; although really, we have so many summery days. But today is definitely one of them with 3pm temperatures solidly up into the middle 90s across Southeast Texas, and heat index values ranging from around 100 degrees on the low end to 110 degrees on the high end. This well describes the range for established, well-maintained airport sensors. When it comes to other, informal weather sensors, many heat index values are higher. Though the specific values have to be taken with a whole shakerful of salt (no, Willis, the heat index is not really 130 there), it`s a pretty strong indication that it is very hot, right around or over the threshold for a heat advisory. We can expect something very similar tomorrow. While the numerical guidance seems keen on knocking high temperatures down to around 90 degrees, it also does so while keeping 850 mb temps steady as well as 500 mb heights. If anything, the mid-level ridge looks like it may be slightly stronger tomorrow. Because of this, I opted to stick with something virtually identical to the existing high temperature forecast I inherited from the overnight shift. Though this is ever-so-slightly "cooler", it`s only a degree or two, and looks to be offset by dewpoints that look slightly higher thanks to a slightly more established bit of onshore flow. As a result, forecast heat index values are expected to change very little, if at all, and another heat advisory may be needed tomorrow. For those who are physically exerting themselves tomorrow, it may also be worth noting the wet bulb globe temperature forecast for tomorrow. While today, WBGT peak values look to be in the high risk bin in the advisory area, it appears that we may see an area of extreme risk emerge for a few hours in the early afternoon. If you`re looking for overnight relief...please don`t. With such high dewpoints, the temperature floor is very high. Lows in the lower 80s should be expected near the coast, and while those far inland away from the Gulf may see a little better temperature drop, even there we`re only looking for lows in the upper 70s. For true heat relief, it will take access to air conditioning, even at night. In addition to the heat, we are seeing a little bit of activity on the seabreeze, but with the big emphasis on the word "little". Because of subsidence from the strong ridging aloft, most updrafts fail to really get going, but we have seen a few weak showers spring up on the seabreeze around Angleton. We may see a couple more today before the sun starts to go down. Tomorrow, we can expect more of the same, largely. Isolated to widely scattered showers, maybe a storm or two, focused mainly along the convergence of the seabreeze boundary. Okay, this part of the forecast covers a lot of the heat threat. Now you may move on to the long term, and take a look at what Beryl may (or may not) have in store for our area. && .LONG TERM... (Thursday through next Monday) Issued at 334 PM CDT Tue Jul 2 2024 Thursday begins with high pressure aloft over the SE CONUS with an upper level trough digging into the North/Central Plains. NAEFS and GEFS indicate that 500mb heights will be approaching the 90th percentile for this time of the year on Thursday, with deterministic models suggesting heights will reach around 593-594 dam. 850mb temperatures will be around 18-21C, though NAEFS and GEFS would suggest that this is relatively "on-par" for what typically occurs in the summertime. Deep moisture of 1.8-2.0" PWs and isentropic lifting should bring daily chances of showers/storms through the end of the week. This particularly so during the afternoon in areas along and south of I-10, with modest instability present for any developing showers/storms. Steep low level lapse rates may allow for some of these storms to produce gusty winds. Overall, we`re still looking at highs in the 90s with isolated spots reaching triple digits. Heat indices of 105-111 could warrant another Heat Advisory for Thursday, and maybe even Friday depending on how things trend. The aforementioned upper level trough will dig through the Great Lakes on Friday, weakening ridging/high pressure aloft over SE Texas and thus providing mild relief from the heat. Additionally, this feature will attempt to push a weak frontal boundary across the ArkLaTex area late Friday and into SE Texas on Saturday. This, along with weakening in the midlevel ridge, would indicate better chances for rain, and even more relief from the heat. Though, these factors may be of little importance in the grand scheme of things, as conditions over the weekend are expected to be largely contingent on the behavior of Hurricane Beryl. By Saturday, Beryl is currently expected to be over the Southwestern Gulf of Mexico. Current track guidance suggests that Beryl will take a slight northerly turn during this period, making landfall somewhere along the Mexico to Southern/Central Texas coastline on Sunday/Monday. At minimum, we could see elevated surf and stronger winds across the Gulf waters. However, uncertainty on the full extent of it`s impacts remains high, so please watch the forecast closely this next several days as we monitor Beryl. && .AVIATION... (18Z TAF Issuance) Issued at 1249 PM CDT Tue Jul 2 2024 VFR with light winds throughout. With generally light winds, expect to see the diurnal landbreeze/seabreeze pattern play a greater role in wind direction, particularly closer to the coast. Expect to see an isolated shower today, but confidence in anything impacting a particular terminal is too low to mention in the TAF. Perhaps LBX has the best chance of needing an amendment, as a shower has cropped up 12ish miles SW of the site. Perhaps a slightly better potential for isolated to widely scattered showers tomorrow, but still not enough confidence to justify mention in any TAFs. && .MARINE... Issued at 334 PM CDT Tue Jul 2 2024 Light to moderate onshore winds and seas of 2-4 feet will prevail across the SE Texas coast through the end of the work week. Isolated showers and storms will be possible daily, mainly along the sea breeze. Over the weekend, Tropical Cyclone Beryl is expected to enter the Southwestern Gulf of Mexico. This system is currently expected to track West to Northwesterly over the weekend into next week. At minimum, strong winds and high seas will be possible across the Gulf waters. The elevated surf will also result in a high risk of rip currents across Gulf-facing beaches. The full extent of this system`s impacts remain uncertain, so stay tuned over the next several days as we monitor Beryl. && .TROPICAL... Issued at 334 PM CDT Tue Jul 2 2024 Hurricane Beryl is at major hurricane strength (category 3 or higher) and is currently making it`s way across the Carribean Sea. Beryl is expected to weaken Thursday/Fridays as it passes over the Yucatan Peninsula, encountering stronger vertical wind shear. Despite the relatively hostile environment, model consensus suggests that Beryl will survive it`s journey over land, and enter the Southwestern Gulf of Mexico as a Tropical Storm on Saturday. SSTs are currently around 28-29C, conducive for strengthening this system. Current track guidance suggests that Beryl will take a slight northerly turn during this period, making landfall somewhere along the Mexico to Southern/Central Texas coastline on Sunday/Monday. The full extent of the impacts from Beryl remain uncertain at this time. At minimum, we could see elevated surf and stronger winds across the Gulf waters. However, we cannot rule out the potential for Tropical Storm Conditions, especially for areas near Matagorda Bay. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 77 98 77 99 / 0 10 0 0 Houston (IAH) 80 96 80 97 / 0 40 0 20 Galveston (GLS) 85 91 83 90 / 0 20 10 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Heat Advisory until 7 PM CDT this evening for TXZ163-164-176>179- 196-198>200-212>214-227-237-238-300-313-338-438-439. GM...None. && $$ SHORT TERM...Luchs LONG TERM....03 AVIATION...Luchs MARINE...03