Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/19/20

Area Forecast Discussion...UPDATED
National Weather Service Corpus Christi TX
1059 PM CDT Fri Sep 18 2020 .DISCUSSION... Latest aircraft measurements indicate that Tropical Storm Beta`s max sustained winds has strengthened to near 60 mph. Tropical Storm Beta`s track has slightly shifted to the north from the previous forecast. Beta is currently moving toward the north- northeast across the western Gulf with a slow westward motion expected to begin late Saturday. Beta is expected to reach hurricane status Sunday morning and continue to slowly approach the northwestern Gulf Coast. Due to the increase in winds, a Hurricane Watch has been issued for the coastal regions and over portions of the Gulf waters north of Port Aransas. South of Port Aransas, a Tropical Storm Watch has been issued. In addition, seas will also build to hazardous levels and tides are expected to run well above normal. For this, a Storm Surge Watch has been issued from Baffin Bay to Port O`Connor with 2-4 feet inundation possible. && .PREV DISCUSSION... /Issued 621 PM CDT Fri Sep 18 2020/ DISCUSSION... Update for 00Z Aviation. AVIATION... VFR conditions will persist through the period. Rain chances will continue to diminish this evening with a slim chance for developed around LRD for the next hour or two. Otherwise, light northeasterly winds will continue tonight with winds picking up throughout the day tomorrow across ALI, CRP and VCT. PREV DISCUSSION... /Issued 239 PM CDT Fri Sep 18 2020/ SHORT TERM (Tonight through Saturday Night)... This afternoon/evening should be similar to yesterday with an upper level trough remaining in the area and PWATs above 2 inches. Isolated to scattered showers and thunderstorms will form and move southwest through the area. A few storms could be strong. Drier air will move in later tonight as the trough drifts away from the area giving us a brief respite from the rain. Saturday should be fairly pleasant, with normal temperatures for mid-September, partly cloudy skies, and only a slight chance of showers over the Coastal Bend and over the waters. Cloud cover and the chances for precipitation will begin to creep back in Saturday night as moisture from Tropical Depression 22 pours into the area. A Coastal Flood Advisory remains in effect through Saturday morning as tide levels continue to run high with persistent, moderate to strong northeast flow. A Coastal Flood Watch has been issued in response to the approach of TD22. Moderate coastal flooding will be possible with inundation values up to 2 to 4 feet MHHW. LONG TERM (Sunday through Friday)... The NHC forecast of current Tropical Depression Twenty-Two (TD22) essentially controls the long-term forecast. The official track of the tropical cyclone (TC)is based on the expectation of an upper ridge over the SRN Plains/SERN CONUS, resulting in a westward movement of the TC Sunday/Monday toward the TX coast, followed by a developing quasi-zonal upper pattern, resulting in the northward movement of the TC Tuesday/Wednesday. Satellite-based PWAT values depict the copious moisture associated with the TC. The GFS predicts this moisture to advect onshore Sunday. Expect copious moisture to contribute to scattered/numerous convection Sunday. Expect rainbands associated with the TC to result in numerous/widespread precipitation Monday/Tuesday over the ERN CWA. Assuming the TC continues to move NWD, anticipate isolated/scattered convection over the CWA Wednesday-Friday. The track/scale of the TC, along with deterministic WaveWatch output, suggest an enhanced risk of rip currents/coastal flooding at least Sunday-Tuesday. MARINE... Moderate to strong north to northeast winds will continue through Saturday night. Wave heights will rapidly build as Tropical Depression 22 approaches the area, with seas reaching near 16 feet by late Saturday night. A Small Craft Advisory has been issued for both winds and hazardous seas through Saturday afternoon. Tropical storm conditions may be possible beginning as early as Saturday night. The tropical cyclone is expected to maintain numerous/widespread showers, and isolated/scattered thunderstorms, during the Sunday- Tuesday period. A gradual decrease in the coverage/intensity of convection expected Wednesday-Friday. Wind forecast Sunday-Wednesday reflects the NHC forecast. Wave height forecast Sunday-Wednesday for the coastal waters primarily reflects Wavewatch output. && .PRELIMINARY POINT TEMPS/POPS... Corpus Christi 71 88 69 80 71 / 10 20 60 60 80 Victoria 68 87 66 80 70 / 0 20 50 50 70 Laredo 69 88 66 83 69 / 20 0 20 20 50 Alice 69 88 67 83 69 / 10 20 50 50 70 Rockport 74 90 72 80 74 / 10 20 60 70 90 Cotulla 68 88 66 84 69 / 0 0 20 20 50 Kingsville 69 87 67 83 70 / 20 20 60 60 80 Navy Corpus 77 89 72 79 74 / 20 30 70 70 80 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...Tropical Storm Watch For the following zones: Coastal Kleberg... Coastal Nueces...Coastal San Patricio...Kleberg Islands... Nueces Islands. Storm Surge Watch For the following zones: Aransas Islands... Calhoun Islands...Coastal Aransas...Coastal Calhoun... Coastal Kleberg...Kleberg Islands...Nueces Islands. Hurricane Watch For the following zones: Aransas Islands... Calhoun Islands...Coastal Aransas...Coastal Calhoun... Coastal Refugio. GM...Tropical Storm Watch For the following zones: Bays and Waterways from Baffin Bay to Port Aransas...Coastal waters from Baffin Bay to Port Aransas out 20 NM...Waters from Baffin Bay to Port Aransas from 20 to 60 NM. Small Craft Advisory until 4 PM CDT Saturday For the following zones: Coastal waters from Baffin Bay to Port Aransas out 20 NM...Coastal waters from Port Aransas to Matagorda Ship Channel out 20 NM...Waters from Baffin Bay to Port Aransas from 20 to 60 NM...Waters from Port Aransas to Matagorda Ship Channel from 20 to 60 NM. Hurricane Watch For the following zones: Bays and Waterways from Port Aransas to Port O`Connor...Coastal waters from Port Aransas to Matagorda Ship Channel out 20 NM...Waters from Port Aransas to Matagorda Ship Channel from 20 to 60 NM. && $$ EMF/94...SHORT TERM
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
827 PM PDT Fri Sep 18 2020 .SYNOPSIS...18/627 PM. Temperatures will cool through Monday then warm again into next weekend. There will be gusty northerly winds across southern Santa Barbara County through Saturday morning. Overnight and morning low clouds and fog will expand into most coastal and lower valley areas by Monday. && .SHORT TERM (FRI-MON)...18/823 PM. ***UPDATE*** The marine inversion early this evening ranged from near 500 ft deep at LAX to near 800 ft deep at VBG. Low clouds were expanding along the Central Coast this evening and should push into the Santa Ynez Vly later tonight. Low clouds should also develop over the SoCal Bight later tonight and move into the immediate coast of L.A.County by daybreak or so. With the shallow marine inversion, there should also be patchy dense fog with any low clouds overnight. Otherwise, mostly clear skies can be expected across the region thru the night. Good northerly pressure gradients this evening across SBA County (NAM fcst SBA-SMX -3.6 mb at 06Z) will continue strong and gusty NW to N canyon winds across the SBA County S coast and Santa Ynez Mtns mainly from San Marcos Pass westward. Gusts up to 50 mph have been observed at the SCE San Augustin automated wx station west of Gaviota, with gusts up to 48 mph at the Refugio RAWS. These wind gusts will likely persist overnight into early Sat. A Wind Advisory is in effect for this area overnight thru mid- morning Sat. Please see the latest Non-Precipitation Weather Message (LAXNPWLOX) for further details. ***From Previous Discussion*** A cooling trend will continue through the weekend and into Monday along with a deepening marine layer. The latest AMDAR soundings from KLAX indicate a marine layer depth closer to 600 feet deep. The marine layer depth should deepen to near 1000 feet deep by Saturday morning, possibly thinning slightly for Sunday morning, then deepening again on Monday. Middle and high level cloudiness from what used to be tropical storm Karina will continue to thin out across the region tonight which should allow for better stratus formation. With the trough moving over the region, the smoke that has been in place the last couple of weeks will clear out over a majority of the area. Increasing southwest flow in the boundary layer will increase transport winds and the trough should enhance mixing. The smoky skies should continue to improve across the area, except for portions of Los Angeles County where the Bobcat Fire is still actively burning at this time. A dying boundary north of the region will move south and tighten the northerly pressure gradient through Sunday. Marginally gusty Sundowner winds are already occurring this afternoon and will increase across southern Santa Barbara County later and linger into Saturday morning. A wind advisory remains in effect from 4 pm PDT this afternoon through 9 am PDT Saturday morning. Gusts up to 45 mph are possible, especially west of Goleta out toward the Gaviota area. If traveling across this area, gusty cross winds are possible on Highways 101 and 154 this afternoon and tonight. If planning any outdoor recreational activities this afternoon and evening, such as kayaking out near Gaviota and Refugio, it might be best to delay these activities when these winds may not present hazardous weather and/or sea conditions. A tricky cloud forecast is on tap for tonight. Cold air advection could make for little marine layer induced stratus south of Point Conception. The previous forecast was scaled back for a later arrival. Little, if any stratus should make into the Ventura County Coast or the Santa Barbara South Coast. Better confidence exists for the Central Coast and the Santa Ynez Valley. Night through morning low clouds and fog should start to expand into Saturday night and Sunday as the eddy circulation should allow for better coverage. Zonal flow should setup for Sunday between troughs as the trough along the southern Oregon coast lifts out and another trough dips in behind it. The marine influence should continue to win out for the coast and lower valley, keeping a cooling trend going. Less confidence for the mountains and desert as these areas could end warming. .LONG TERM (TUE-FRI)...18/138 PM. The influence of the trough should linger into Tuesday and keep cooler temperatures in place. The deepest marine layer of the week should be in place between Monday and Tuesday, then ridging aloft should start to build into the region and thin the marine layer. A warming trend will develop for the latter half of the week. By Thursday or Friday, stratus coverage could be minimal as weak offshore flow develops. For the current time, no gusty offshore winds are expected, but this will need to be monitored closely for development. && .AVIATION...18/2343Z. At 2330Z at KLAX...The inversion was about 500 feet deep. The top of the inversion was around 2500 feet with a temperature of about 28 degrees C. Moderate confidence in the 00Z TAFs for KPRB, KSBP, KSMX and KLGB due to uncertainties with regard to the timing and extent of low clouds and LIFR/IFR conditions at these airfields from this evening along the Central Coast to late tonight into Sat morning elsewhere. The timing of the onset and dissipation of the low clouds may be off +/- an hour or two. There is also a 20%-30% chance of no low clouds and fog development at KPRB and KLGB. Otherwise and elsewhere, there is hi confidence in VFR conditions thru Sat afternoon. KLAX...Generally hi confidence in the 00Z TAF with VFR conditions expected thru Sat evening. However, there is still a 10%-20% chance of low clouds and LIFR conditions late tonight and early Sat. KBUR...Hi confidence in the 00Z TAF with VFR conditions expected through Sat afternoon. && .MARINE...18/826 PM. Across the outer waters... Small Craft Advisory (SCA) level wind will continue through Saturday night and there is a forty percent chance of it continuing through Sunday night. SCA level winds will develop again Tuesday and Wednesday. The strongest winds will be in the afternoon and evening hours. Otherwise, conditions will remain below SCA level through the forecast period. Across the nearshore waters of the Central Coast... There is a forty percent chance of SCA level wind during the afternoon and evening hours through Saturday night. Otherwise, conditions will remain below SCA level through the forecast period. Across the inner waters south of Point Conception... SCA level wind will continue across the western portion of the Santa Barbara Channel through Saturday night. Otherwise and elsewhere, conditions will remain below SCA level through the forecast period. Patchy fog will continue into next week across the coastal waters. The poorest visibility and most widely spread conditions will occur in the overnight and morning hours. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory in effect until 9 AM PDT Saturday for zones 39-52. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for zones 650-670-673-676. (See LAXMWWLOX). && .HAZARD POTENTIAL OUTLOOK (MON-FRI). No significant hazards expected. && $$ PUBLIC...Hall/Sirard AVIATION...Sirard MARINE...Kj SYNOPSIS...Kj
Area Forecast Discussion
National Weather Service Phoenix AZ
425 PM MST Fri Sep 18 2020 .UPDATE... Updated Aviation && .SYNOPSIS... A gradual cooling trend begins today persisting into the weekend with highs dipping below 105 across most desert areas. A weak disturbance moving through the area early next week will be on the dry side, but an isolated shower or thunderstorm over high terrain north and east of Globe is possible. High temperatures will continue to fall off early next week with some desert locations approaching only 100 degrees Monday and Tuesday. && .DISCUSSION... The UL plots show lingering elevated heights at H5 although the ridge is already starting to flatten and shift east with the anticyclonic circulation seen to the east, and cyclonic flow noted across N Baja. 850mb temperatures were still elevated, around 27C, within a BL thermal ridge lingering across the area. The BL also remained dry in spite of the southeasterly flow. The stable Phx 12Z sounding and recent ACARs also indicated a more moist airmass than yesterday with PW`s near 0.7" due to moistening in the mid to upper levels. Satellite imagery also confirmed this uptick in mid and upper level WV. With early afternoon temperatures running up to 3 degrees cooler than yesterday, the gradual cooldown into early next week is now underway with highs expected from 104-107 degrees today for the Phoenix and nearby deserts. The NE PAC progressive low pressure system will push across the PAC NW and through the N Rockies into the weekend. As it passes to the north it will continue to flatten the ridge and shift it even further south and east. This pattern shift will support the current gradual cooling trend through early next week as heights continue to decrease and moisture slightly increases. Models still show slightly below normal PWs approaching seasonal norms tonight and tomorrow, but this will not prevent mostly dry conditions from prevailing. Early next week ensembles bring a fairly dry and weak shortwave disturbance in from the west as PW`s once again trend slightly higher and possibly closer to, or slightly above seasonal norms of 0.8-0.9", and maybe even near 1.0". Again it appears that conditions will remain marginally too dry for any significant chance of rain as supported by ensembles and NCEP/WPC cluster 24H QPF. Although a slight chance of isolated showers and thunderstorms across the Mogollon rim and the eastern and southeastern high country are possible for early next week. However there continues to be much better confidence that temperatures will bottom out in the low 100s, only slightly above seasonal norms around Tuesday with very little model spread. The 5 and 6 day NCEP/WPC 500 mb heights clusters indicate similar variations on a theme of strong high pressure returning to the Southwest and Central US by Wednesday and Thursday next week. They also suggest a minor rebound of high temperatures of only 2 or 3 degrees going into midweek. && .AVIATION...Updated at 1725Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Only minor aviation weather concerns will exist through Saturday as a thin layer of lofted smoke remains positioned across the area and could create slantwise visibility issues. Winds this evening will be highly variable potentially not truly complete the traditional westerly switch and remaining 140v210 before returning back to an easterly configuration mid/late evening. Towards sunrise, a stronger pressure gradient should create some 25kt SE winds above the boundary later around 2K ft AGL, albeit well below LLWS criteria. Some of this momentum may be mixed to the sfc late morning in the form of gusty east winds. Confidence is good east winds will prevail much of the day, with lower confidence in the ability for the typical westerly wind shift to occur Saturday afternoon. Southeast California/Southwest Arizona including KIPL and KBLH: No major weather concerns through Saturday other than some wafting high level smoke that could create slantwise visibility issues. Wind trends will be nearly identical to the past couple days with directions switching to SW at KIPL later this evening before returning to easterly by sunrise. The typical period of light northerly drainage wind is likely at KBLH Saturday morning with afternoon southerly winds likely somewhat stronger than today. && .FIRE WEATHER... Monday through Friday: Cooler high temperatures will remain a few degrees above normal through the period. Minimum humidities will mostly be in the 10 to 15 percent range across the lower deserts through the period. Higher terrain areas will also stay below 20 percent. Max RH will see a slightly better upward trend of roughly 10% most places and reach about 30-50% by the middle of next week before dropping back down again late in the week. Thunderstorms are expected to remain outside of the forecast area. However, the Mogollon Rim and the eastern and southeastern high terrain areas will have a slight chance of storms for early next week. Winds will generally be light except for some modest afternoon breeziness. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Sawtelle AVIATION...MO/Rogers/AD FIRE WEATHER...Sawtelle/CB