Area Forecast Discussion
Issued by NWS Houston/Galveston, TXVersions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
617 FXUS64 KHGX 042348 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 648 PM CDT Sun Apr 4 2021 .AVIATION [00Z TAF Issuance]... Some light SHRA continues to impact the northern terminal, and have maintained TEMPO groups for precip at CLL and UTS over the next couple of hours as a result. In general, conditions should remain largely within VFR thresholds through the duration of the 00Z TAF period. Model soundings continue to indicate the formation of a BKN to OVC deck at around 10 kft, as we have seen the past few nights. However, a complicating factor will be increasing saturation in the lower levels which will lead to the formation of cloud decks at MVFR to IFR levels by around 09Z. Have not included any sub-VFR cigs for the time being, but the next round of forecast soundings may warrant a change. Furthermore, should clearing be more widespread than anticipated, we could see some patchy fog at normally prone sites (CXO, UTS, etc.) overnight. High-resolution guidance has so far been much less aggressive in depicting any precipitation associated with the next upper-level disturbance tomorrow so have opted to leave any mention of rain tomorrow out of the current package. Cady && .PREV DISCUSSION... /ISSUED 347 PM CDT Sun Apr 4 2021/ SHORT TERM [Through Monday Night]... A few upper level disturbances will continue to move over the SE Texas region through the next few days. Today`s disturbance produced ongoing light rain mostly over the NW quadrant of the CWA, but due to the much drier air in place along the 850 to 700 MB levels, most of has been evaporating before reaching the surface. Thus, accumulations so far have been none to minimal. For tonight, low temperatures will be a couple of degrees warmer as the onshore flow and subtle low level moisture transport persists. Look for lows in the mid to upper 50s along I-10 northward and in the upper 50s to mid 60s along areas south of I-10 including the coastline. Skies may scatter out tonight into early Monday morning, which could allow for some patchy fog to develop briefly during this time frame over portions of SE Texas. The patchy fog, if any, will burn off quickly shortly after sunrise. A similar weather pattern can be expected Monday as another disturbance moves overhead and brings in slight chances of rain. Hi-Res models currently hint at showers starting along the SW quadrant of the CWA early morning, spreading into the central and northern sectors during the afternoon hours. However, forecast soundings continue to show sufficient drier air in the 850 to 700 MB levels mainly in the afternoon, which could very well end up evaporating most of the rainfall before it reaches the surface yet again. Partly sunny to partly cloudy skies along with ongoing onshore flow, will bring up the temperatures to the mid to upper 70s in the afternoon. Lows on Monday night will generally be in the 60s areawide. 24 LONG TERM [Tuesday Through Sunday]... On Tuesday, the surface high pressure remain situated over SE CONUS providing south-southeasterly flow into SE Texas. Meanwhile, a low amplitude upper level ridge is located over the central US with an embedded shortwave moving through Texas. This shortwave will mean there is another day of isolated light rain showers. A closed upper level low will be entering the Central Plains Wednesday morning, however there is some disagreement in the guidance on how far south this system will dig. GFS has the upper level low and associated developing surface low over Kansas/Nebraska border Wednesday afternoon while the EC is further south on the Oklahoma/Kansas border. This difference in location will determine how far south showers and thunderstorms will be possible Wednesday afternoon. The further north GFS solution has precipitation reaching down to Houston, Trinity, Polk counties, but the southern EC solution has precipitation chances down to the coast. Split the difference in the forecast with PoPs down into Harris County with the highest PoPs over the northeastern counties. The weak cold front that will be bringing these showers and thunderstorms will stall out somewhere along southeast Texas on Friday- but like the precipitation chances, there is quite the disagreement in the guidance. Trended toward the weaker, further north stalled boundary as cold fronts this time of year can begin to struggle to make it off the coast. Either way with the boundary nearby with PWATs between 1.25 and 1.50", scattered showers and thunderstorms are possible on Friday. Another upper level low will swing through Friday night into Saturday morning continuing the chance of precipitation. Temperatures through the week will be climbing with high temperatures in the low to mid 80s Tuesday and Wednesday, and then into upper 80s on Thursday/Friday with even a few spots hitting 90 west of the Brazos River. Temperatures will be dropping a few degrees next weekend after the disturbance swings through. Lows through the week will be fairly stable in the mid to upper 60s as persistent cloud cover keeps radiational cooling at bay. Fowler Marine... Light to moderate south-southeasterly flow will continue through midweek as high pressure builds to the east. A weak upper level low will swing through the Gulf waters on Tuesday bringing a chance of showers and thunderstorms for the Bays and near shore waters Tuesday afternoon. The southerly flow will increase overnight Tuesday into Wednesday to 15 to 20kts along with increasing wave heights 5 to 7 feet. So caution flags or small craft advisories may be necessary starting late Tuesday night through Wednesday. At the same time, increasing moisture will bring the potential for some patchy fog near the coastal areas - but uncertainty remains due to increasing sea surface temperatures. A weak cold front will approach the coastal waters Friday into Saturday bringing a chance for showers and thunderstorms. Fowler && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 71 56 77 62 84 / 20 10 20 10 10 Houston (IAH) 75 59 77 63 83 / 20 10 10 10 20 Galveston (GLS) 74 65 75 67 77 / 20 10 0 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...High Rip Current Risk until 1 AM CDT Monday for the following zones: Bolivar Peninsula...Brazoria Islands...Galveston Island...Matagorda Islands. GM...NONE. && $$
No comments:
Post a Comment