####018004323#### FXUS64 KMAF 240520 AFDMAF Area Forecast Discussion National Weather Service Midland/Odessa TX 1220 AM CDT Wed Apr 24 2024 ...New AVIATION... .SHORT TERM... (This afternoon through Wednesday night) Issued at 224 PM CDT Tue Apr 23 2024 Temperatures are warming up quickly this afternoon with weak ridging overhead and westerly winds at the surface. Along with some afternoon heating, we are seeing some moisture convergence near and east of Davis Mountains. As a result, a few storms have developed near the Glass Mountains and Stockton Plateau early this afternoon. One or two stronger storms could produce large hail and damaging winds. Also starting to see some activity developing near the dryline in the northern Permian Basin. As the dryline pushes east this afternoon, a cold front will continue to push south, approaching the northern Permian Basin early this evening. Convection looks to develop ahead of this front, east of the dryline, affecting the northern Permian Basin region through this evening. A couple of these storms could be severe but best chances for very large hail will be far northeastern areas. Thunderstorm chances rapidly come to an end with the loss of daytime heating. The warm temperatures continue Wednesday with highs generally in the 80s and 90s once again. Temperatures around 100 are likely along/near the Rio Grande in the Big Bend. Low thunderstorm chances return Wednesday afternoon as the dryline sharpens near the NM/TX state line. Upper ridging will remain in place tomorrow so thunderstorm coverage looks to be isolated at best, if at all. Highest chances (10-15 percent) are generally confined to the northeastern Permian Basin where better moisture resides. IF we see storms develop, one or two could become severe, potentially producing large hail and/or damaging wind. Again, chances are very low at this time. && .LONG TERM... (Thursday through Monday) Issued at 224 PM CDT Tue Apr 23 2024 A deep upper level trough arrives in the area on Thursday. Ahead of the trough a dryline forms in the eastern Permian Basin that will serve as the focus for thunderstorms. Behind the dryline will be windy and dry with strong winds in the Guadalupe Mountains and very windy conditions extending east into the adjacent plains. Friday the trough lifts northeast then north into the northern Great Plains preventing much of an eastward push to the dryline and leaving it in the Permian Basin. The trough is quickly replaced by a second that keeps the windy conditions going into the weekend as well as the threat for storms forming along the dryline. && .AVIATION... (06Z TAFS) Issued at 1219 AM CDT Wed Apr 24 2024 VFR conditions are expected to remain through the period. Winds will generally be south to southeast at all terminals through the majority of the period. && .FIRE WEATHER... Issued at 224 PM CDT Tue Apr 23 2024 The fire weather threat remains low tomorrow before stronger winds and very dry air create near critical to critical fire weather conditions Thursday into the weekend. The main threat area will be from southeastern New Mexico to the Big Bend where winds will be strongest. These areas also did not receive much rain recently as other areas to the east and have lower fuel moisture levels. Overnight recovery will be good in the east, poor farther west. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 66 87 59 86 / 10 10 50 0 Carlsbad 58 89 54 82 / 0 0 0 0 Dryden 66 90 64 93 / 0 10 20 0 Fort Stockton 64 93 58 88 / 0 10 10 0 Guadalupe Pass 59 80 52 74 / 0 0 0 0 Hobbs 60 88 52 81 / 0 0 10 0 Marfa 52 86 46 82 / 0 0 0 0 Midland Intl Airport 66 89 58 85 / 10 10 40 0 Odessa 66 89 59 85 / 0 10 30 0 Wink 64 94 56 88 / 0 0 10 0 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...27 LONG TERM....10 AVIATION...91 ####018003291#### FXUS63 KTOP 240521 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1221 AM CDT Wed Apr 24 2024 .KEY MESSAGES... - Many chances for showers and thunderstorms through the weekend with severe weather potential during several of them && .DISCUSSION... Issued at 245 PM CDT Tue Apr 23 2024 Elevated shower and thunderstorm activity has shifted east as the upper wave and associated weak cold front moved east and south respectively. Benign conditions are expected for the rest of the day into early Wednesday with modified surface high pressure nosing in. Northwest flow aloft under easterly surface winds bring small chances for more high based showers and perhaps a few thunderstorms Wednesday afternoon into Wednesday night via mid-level isentropic lift. Coverage of precipitation should increase Thursday into Thursday night as low levels saturate on south to southeast low level flow under a moderate elevated mixed layer as upper ridging exits. Cloud cover may be more scattered early in the day so highs in the 60s may still be reachable and NBM temps are slightly cooler than guidance means. Deep moist convection is likely to form well to the west and southwest late in the day Thursday but the depth of the EML may be enough to keep much severe activity in check this far east. Precipitation may persist into at least Friday morning as an upper trough moves into western Nebraska then northeast into the upper Mississippi Valley into Friday night. A dryline/Pacific front gets dragged through eastern Kansas through the day Friday though height falls are limited this far south and convergence along the dryline is not impressive. NBM PoPs look a bit aggressive especially for the afternoon. The main impact from this system could end up being synoptic winds with deep southwest flow developing in the dry air and some guidance suggesting Warning-level winds in deep mixing. CAPE and shear will be supportive of severe storms Thursday night into late Friday if CIN can be overcome. Moisture doesn't stray far Saturday as the next upper wave approaches. Instability will ramp up again during the day with moisture advection likely leading to at least scattered showers and storms with afternoon and evening CAPE again supporting severe potential. Unidirectional flow could give rise to some training storms with precipitable water values around 1.5 inches for some local heavy rain potential Saturday night into Sunday. Precipitation chances back off into the late weekend though a weaker trailing upper wave suggests small chances even Sunday night and Monday. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1218 AM CDT Wed Apr 24 2024 VFR at terminals as high clouds are expected to increase overnight, accompanied by a 12-15 kft mid level cloud deck developing aft 14Z. Light north winds gradually veer to the east below 10 kts through the period. As next system arrives, may see a <10 kft stratus deck lift northeastward at the end of forecast period. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Poage AVIATION...Prieto ####018008062#### FXUS66 KMFR 240523 AAA AFDMFR Area Forecast Discussion National Weather Service Medford OR 1020 PM PDT Tue Apr 23 2024 Updated Aviation Discussion .DISCUSSION...Thunderstorm activity is a few hours behind us now and conditions will remain relatively calm overnight. Zonal large scale flow will allow a weak boundary to drift in off the pacific tomorrow. This will initiate another round of pop-up style thunderstorms across NorCal and east of the Cascades. Storms are not expected to be any stronger than today, though; with winds generally being 40 mph or less and hail around pea size as a result of these storms. For areas that don't receive thunderstorm activity, skies are expected to still be partly cloudy as some higher level clouds move through the area as we swap a warm airmass for a cool-ish one. Temperatures may not even get into the 70s for most areas, with the Lower Klamath river valley being the exception. The pattern is expected to remain active into the weekend with rain and snow becoming more widespread in the forecast. && .AVIATION...24/00Z TAFs...VFR ceilings and visibilities are most likely across the forecast area outside of lower stratus (with MVFR and IFR ceilings) along the coast from Cape Blanco northward. Areas of MVFR/IFR may also develop late tonight and early Wednesday morning in the southern Umpqua, south of Roseburg. Elsewhere expect mainly VFR. Wednesday afternoon and evening, isolated to scattered showers and thunderstorms are expected again over southern/eastern Siskiyou, Modoc, southeast Klamath and southern Lake counties. L Gusty winds are possible near thunderstorms that develop Wednesday afternoon and evening. -CC && .MARINE...Updated 800 PM Tuesday, April 23, 2024...Winds and seas will continue to lower tonight into Wednesday. Then a front will arrive on Thursday followed by additional fronts Saturday into early next week. Westerly fresh swell and gusty southerly winds could rebuild steep seas by late Thursday or early Friday, especially in outer waters. However, current guidance suggests that waves only have a 10-20% of exceeding 9 feet through the weekend. So while steep seas and gusty winds up to small craft advisory level are possible, more hazardous conditions are not expected. -Hermansen/CC && .PREV DISCUSSION... /Issued 252 PM PDT Tue Apr 23 2024/ SHORT TERM...Tonight through Wednesday night. It will be at least a couple of weeks before it is quite as warm again inland as it is today. This shift back to cool, frequently wet, more typically spring-like weather will be more readily apparent beginning on Thursday. But, the cooling trend will begin Wednesday, with highs around 5 to 10 degrees lower than today. The most notable aspects of the short term are areas of coastal low clouds, and a chance of afternoon and evening showers and thunderstorms for northern California, northward into the Siskiyou Mountains of far southern Jackson County, and northeastward into south central Oregon..Klamath and Lake counties. This includes Fort Jones, Yreka, Weed, Mt. Shasta, Tennant, Lava Beds, Alturas, and Lakeview. Our area of activity will be a bit larger today with an area of deformation and instability between areas of low pressure offshore from Canada and California. The pattern will shift very slightly southeastward for Wednesday with a late day slight chance to chance of thunderstorms again for southern, central, and eastern Siskiyou County eastward and northeastward across Modoc and southern portions of Klamath and Lake counties. This includes Tennant, Alturas, and Lakeview. By the end of Wednesday night, a wet cold front is expected to be just west of the coastal waters, with rain developing at the coast Thursday morning. -DW LONG TERM...Thursday morning through Tuesday night. The warm and dry weather comes to an end on Thursday as the next wave and frontal system hits the region. We're expecting rain along the coast and west of the Cascades. The NBM is predicting a 100% chance of precipitation late Thursday morning through late Thursday evening with chances of precipitation lowering to around 60% east of the Cascades. Snow levels will be around 5000 to 7000 feet depending where one is located with the higher snow levels east of the Cascades. Like always, snow over the higher Cascades is expected and Crater Lake will see accumulating snow fall Thursday into Friday morning. The forecast for Crater Lake is showing between 4 and 8 inches of snow accumulating and perhaps 1 inch over Mt. Ashland. 1 to 3 inches are also anticipated in the Warners through Friday morning. Overall, impacts here are pretty minimal, although one traveling to Crater Lake on Friday morning could be caught off guard with snow accumulation in late April. The atmosphere shows some instability by later Friday, so thunderstorms were inserted into the forecast around that time. The probability of thunder is around 15% and covers large swaths of the forecast area. Given that an upper level wave is starting to depart the region, thunderstorms that do form will likely be weak and a few cloud to ground flashes seems the most likely scenario. Another shortwave and warm front will push into the forecast area around Saturday. The chance of precipitation is only about 50% west of the Cascades as the ensembles might have some issues with timing or perhaps moisture content. Those probabilities drop off in northern California and east of the Cascades down to 20 percent. So some of the forecast area as a modest chance of rain, other areas will likely stay dry. Finally, the ECMWF and GFS are both showing a stronger low in the Gulf of the Alaska, although the ensemble anomalies are not as excited about how unusual it is for this time of year. In general, it looks like zonal flow is setting up under a strong west to east mid level jet, which will likely keep Spring like temperatures in check with a cooler moist flow for the weekend into next week. There is a small set of ensemble members(15%), which show a stronger ridge building in southern Oregon between Sunday evening and Monday evening, which would lead to warmer temperatures and drier weather than what is currently in the forecast. -Smith AVIATION...23/18Z TAFs...VFR ceilings and visibilities are most likely across the forecast area this afternoon and evening as lower stratus has burnt off along the coast. Thunderstorms will build over northern California this afternoon with ceilings around 6000 to 8000 feet above ground level. It also appears the storms will stay far enough away from all our TAF locations, although the storms will impact smaller airports in northern California. The lower LIFR and IFR ceilings will push back into the coast later tonight. -Smith MARINE...Updated 115 PM Tuesday, April 23, 2024...The strongest winds remain south of Cape Blanco but will be easing through this afternoon. The thermal trough will weaken through the day, but a Small Craft Advisory will be in place for all waters through 5 PM today, then will continue for waters south of Cape Blanco until 8 PM. Seas will remain calm through Wednesday and into Thursday morning before active weather returns to the area. Westerly fresh swell and gusty southerly winds could rebuild steep seas by late Thursday or early Friday, especially in outer waters. However, current guidance suggests that waves only have a 10-20% of exceeding 9 feet through the weekend. So while steep seas are possible, more hazardous conditions are not expected. -TAD/Hermansen && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...None. && $$