Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 11/01/16


Area Forecast Discussion
National Weather Service Honolulu HI
345 PM HST Mon Oct 31 2016 .SYNOPSIS... A surface ridge north of the state will drive breezy and gusty trade winds into Tuesday, followed by a slight decrease in the trades for the remainder of the week. A somewhat dry and stable air mass will produce modest windward rainfall through the week, and aside from a few afternoon showers across the Kona slopes of the Big Island, leeward areas will be rather dry. && .DISCUSSION... Breezy and gusty trade winds will persist into Tuesday. A strong north Pacific jet stream has pushed a relatively strong subtropical ridge to nearly 500 miles north of the state along 29N. The low level pressure gradient remains tight, and a gradually building mid level ridge over the islands has caused a robust inversion to develop between 5000 to 7500 ft according to the afternoon soundings and recent aircraft data. As a result, breezy trade winds have held today, and although gusts have mainly been in the 30s, a few locations over and downwind of terrain on the Big Island and portions of Maui County have been gusting over 40 mph. Expect a slight decrease tonight and Tuesday as the surface ridge is pushed closer to the state. A drier airmass is settling over the islands. Precipitable water (PW) at the afternoon Lihue sounding decreased to less than 0.9 of an inch, while the last bit of a band of moisture hung up on the Big Island kept PW at nearly 1.25 inches at Hilo. Satellite imagery shows a vast field of mainly stable stratocumulus clouds with PW values of an inch or less to the east and northeast of the state. Expect modest rainfall to be focused on windward slopes of the smaller islands tonight, with only a slight chance of a brief leeward shower. Lingering moisture will keep windward Big Island a bit wetter, though shower activity will continue to diminish. A sharp upper level trough stalled over the state will have little effect on local weather. This feature will produce thin high clouds over mainly the Big Island tonight, followed by diminishing high clouds on Tuesday. Breezy trade winds will decrease a notch late Tuesday and Wednesday. A strong jet stream running across the north Pacific will keep the subtropical ridge slightly weakened and displaced a bit south of normal over the central Pacific. This will cause trades to back off slightly into the moderate to locally breezy range through much of the week. Drier trade wind weather is due for much of the upcoming week. The ECMWF and GFS show PW values hovering around an inch, roughly 25 percent below normal, and mid level ridging will build overhead, creating stable conditions. This should result in decreased shower activity, with modest rainfall limited to windward slopes and mainly dry conditions leeward. && .AVIATION... The breezy trade winds will continue to focus clouds and showers along the windward and mountain areas tonight. Conditions for the most part should remain VFR with only scattered showers briefly introducing periods of MVFR. Mountain obscurations are not expected for tonight. AIRMET TANGO for low level turbulence over and immediately south through west of the mountains remains posted. AIRMET TANGO for strong surface winds 30 KT or great is posted over the Pailolo and Alenuihaha Channels and the waters south of the Big Island. This will continuously be monitored, and may be able to be cancelled as trade winds are expected to ease up a bit heading into Tuesday. Trade winds, however, should remain strong enough for the need to continue the low level turbulence airmet. AIRMET TANGO for upper level turbulence has also been posted for light to moderate turbulence between FL250 and FL400 due to a jet stream over the islands. Model guidance suggested the upper level turbulence not increasing until tonight, however a PIREP noted light to moderate turb between FL280 and FL400 30 miles north of PHOG at 0045Z, therefore the airmet has been issued this afternoon. Expect this airmet to continue into Tuesday. && .MARINE... Strong trade winds will continue into Tuesday, with trade winds remaining at near gale strength over the typically windy waters around the Big Island and Maui tonight. A morning ASCAT pass missed the eastern half of the islands but showed widespread 25 kt winds holding around Kauai and Oahu. With only a slight decrease in winds expected tonight, the Small Craft Advisory (SCA) for all waters has been extended through the night. The SCA will remain in place for most waters on Tuesday and will likely be trimmed back to the typical windier locations by mid to late week as the trades ease a notch. A High Surf Advisory remains posted for most east facing shores. Windward PacIOOS buoys have yet to show a significant decline in the trade wind driven seas, which have held at 7 to 9 ft at 8 seconds today. NOAA buoy 51000, located a couple hundred miles northeast of the islands, has shown a decrease in seas, which should be seen locally overnight. As a result, the High Surf Advisory has been extended through the night. A gradual decline will occur during the next couple of days, with trade wind energy holding at 5 to 7 ft at 8 seconds from Tuesday through the weekend. A moderate northwest swell arriving on Tuesday will be reinforced late Wednesday and late Thursday by a pair of large north- northwest swells. Resulting north shore surf will be well above advisory levels late Wednesday through Friday, and at its short- lived peak, warning level surf will be possible Wednesday night and Thursday. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 AM HST Tuesday for East facing shores of Kauai, Oahu, Molokai, Maui, and the Big Island. Small Craft Advisory until 6 PM HST Tuesday for Oahu Leeward Waters-Kaiwi Channel-Maui County Windward Waters-Maui County Leeward Waters-Maalaea Bay-Pailolo Channel-Alenuihaha Channel- Big Island Windward Waters-Big Island Leeward Waters-Big Island Southeast Waters. Small Craft Advisory until 6 AM HST Tuesday for Kauai Northwest Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel- Oahu Windward Waters. && $$ Public and Marine...Wroe Aviation...Eaton
Area Forecast Discussion
National Weather Service Houston/Galveston TX
432 AM CDT Tue Nov 1 2016 .DISCUSSION... Beginning to moisten up out there. Light onshore flow will continue early this morning and will lead to patchy fog across the area but with the arrival of high clouds and even some stratus the the mixing may hamper the widespread fog formation that has occurred the last few mornings. Will be watching the obs and webcams closely and may issue a dense fog advisory and preliminarily for areas along and north of the I-10 corridor where slightly better radiational cool could occur. Showers and thunderstorms working north across the Western Gulf and some of these may remain intact into the southwestern counties near Matagorda Bay early this morning. CRP 00z sounding showing the low levels moistening up but FWD sounding was very dry and LCH was dry as well. Early morning AMDAR temp profiles look more like LCH and guidance looks about on par with these. During the late morning and afternoon hours moisture deepens and the remains of yesterday`s Coastal Bend upper circulation will move up through the northwestern tier of counties with a weak subtropical jet speed max riding up over the coastal waters...this may help with initiating scattered showers and a few thunderstorms mainly over the areas west of I-45. Rainfall should not be particularly heavy - more of the garden variety showers/thunderstorms given the marginal instability and weak shear. Easterly flow tonight increases and may lead to elevated tide levels along with beach flooding. Fog may return again but not very confident yet that it will so have held off on anything other than a mention of patchy fog. Weak ridging noses into the area Wednesday and rain chances look a little slimmer and more showery. Thursday a cold front sags south into the area (probably late afternoon or evening) but with winds backing the low level focus may be lacking and instability may be lacking as mid/high clouds spreads over the region retarding the low level destabilization. The dry air expands across the area Friday and Saturday which should make for some pleasant weather. Then Saturday night or Sunday the moisture increases again with a shortwave trough swinging through NM/TX which should tap into Pacific moisture and abundant Gulf moisture bringing a good shot at showers/thunderstorms to the SETX region Monday/Tuesday. 45 && .MARINE... Stronger winds above the surface early this morning and high clouds streaming overhead from the Gulf have resulted in fog being slower to develop this morning. While patchy fog may develop for areas inland of Galveston Bay again this morning, not currently anticipating any impacts for marine interests in Galveston Bay given current conditions. Otherwise, surface high pressure over the southeastern US and lee troughing along the Front Range will allow for light to occasionally moderate onshore flow to persist through the end of the week. Expect winds slightly stronger across the coastal waters during the overnight hours in response to the tightening thermal gradient along the coast, with caution flags possibly needed each night through Friday morning as a result for both winds and waves. The long east to southeast fetch in place across the Gulf will also continue to result in long period swells, with waves and tides remaining elevated. These elevated tides may cause wave run-up issues for Upper Texas coastal highways and beaches around times of high tide, with tidal guidance continuing to advertise tides possibly climbing into the 3-3.3 feet range tonight and Wednesday night. A frontal boundary is expected to reach the northwest Gulf this weekend, resulting in a period of northeast flow. Caution flags may be needed for elevated winds and waves associated with the front Friday and Saturday. Huffman && && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 86 71 84 67 82 / 20 10 20 20 30 Houston (IAH) 84 70 84 69 84 / 20 10 20 20 20 Galveston (GLS) 83 74 83 74 80 / 20 10 20 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...45 Aviation/Marine...14