####018005570#### FXUS64 KAMA 151023 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 523 AM CDT Mon Apr 15 2024 ...New SHORT TERM, LONG TERM, FIRE WEATHER... .SHORT TERM... (Today through Tuesday night) Issued at 446 AM CDT Mon Apr 15 2024 For today and tonight, a vigorous upper level low pressure system initially progged to be centered around the vicinity of southern Utah and northern Arizona at 12Z this morning is forecast to move to around northwestern or north central Kansas by 12Z Tuesday. A surface dryline is expected to be located across the far eastern zones this afternoon, then retreat westward some this evening before being overtaken by a Pacific cold front later tonight. Despite some moisture return east of where the dryline sets up, the quality and depth of this moisture return does not appear to look as good as was progged several days ago. Also, high uncertainty exists regarding whether or not thunderstorms will form east of the dryline due to a significant elevated mixed layer in place across the area. High level cloud cover seen on satellite imagery may inhibit maximum daytime heating needed to break any mid level capping inversion. That said, NBM pops for this afternoon are restricted to only the very far southeast TX Panhandle and appear plausible based on concerns outlined above. Low pops offered by the NBM for tonight across only the far eastern zones also look reasonable based on the expected location of the Pacific cold front overtaking the retreating dryline. If any storms manage to develop, they will have the potential to become severe given favorable wind shear with large hail, damaging winds, and perhaps an isolated tornado possible before these storms move into Oklahoma. The upper level storm system is expected to move north and east of the region towards eastern Nebraska by late Tuesday afternoon. However, the pressure gradient will remain tight such that breezy to windy conditions will develop across the area on Tuesday. It appears the overall strongest winds will likely occur across the Oklahoma Panhandle. A Wind Advisory may eventually need to be considered for at least the Oklahoma Panhandle on Tuesday if these progged winds are to materialize. Winds will rapidly diminish early Tuesday evening as the gradient relaxes. 02 && .LONG TERM... (Wednesday through Sunday) Issued at 446 AM CDT Mon Apr 15 2024 A cold front is forecast to move across the region late Wednesday night into Thursday morning with cooler temperatures anticipated Thursday into the weekend. Another upper level shortwave trof may impact the area Friday night through Saturday night and may bring the next chance for precipitation. Specific details concerning this next storm system remain problematic this far out in time. Nevertheless, medium range deterministic models and associated ensembles are in general agreement and were accepted. Dry weather returns for Sunday as the upper level shortwave trof heads east of the area. 02 && .AVIATION... (06Z TAFS) Issued at 103 AM CDT Mon Apr 15 2024 For the 06Z TAFs, southwest winds will increase and become gusty at the terminal sites later today before diminishing late Monday evening. Patchy blowing dust is also expected along with periods of high level clouds. 02 && .FIRE WEATHER... Issued at 446 AM CDT Mon Apr 15 2024 Critical fire weather conditions will develop late this morning through this evening across the Oklahoma Panhandle as well as most of the northern and western sections of the Texas Panhandle due to strong twenty foot southwest winds of 20 to 30 mph with higher gusts along with minimum relative humidity values of 5 to 9 percent. Elevated fire weather conditions are expected to develop across the remainder of the Texas Panhandle except the southeast section from late this morning through this evening. Elevated to critical fire weather conditions are possible Tuesday across the Oklahoma Panhandle as well as northern and western sections of the Texas Panhandle due to strong northwest winds and low relative humidity values. 02 && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 85 50 81 46 / 0 0 0 0 Beaver OK 89 49 80 44 / 0 20 0 0 Boise City OK 81 44 77 42 / 0 0 0 0 Borger TX 90 53 84 47 / 0 10 0 0 Boys Ranch TX 86 49 84 45 / 0 0 0 0 Canyon TX 85 49 81 44 / 0 0 0 0 Clarendon TX 84 52 83 49 / 10 10 0 0 Dalhart TX 82 43 80 40 / 0 0 0 0 Guymon OK 87 46 78 42 / 0 10 0 0 Hereford TX 85 48 82 43 / 0 0 0 0 Lipscomb TX 87 53 82 47 / 0 20 0 0 Pampa TX 86 51 82 47 / 0 10 0 0 Shamrock TX 83 53 84 49 / 10 20 0 0 Wellington TX 83 52 84 49 / 20 20 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning from 11 AM this morning to 11 PM CDT this evening for TXZ001>004-006>008-011-016. OK...Red Flag Warning from 11 AM this morning to 11 PM CDT this evening for OKZ001>003. && $$ SHORT TERM...02 LONG TERM....02 AVIATION...02 ####018006488#### FXUS63 KUNR 151023 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 423 AM MDT Mon Apr 15 2024 .KEY MESSAGES... - Warm weather continues today, with threat for strong to severe storms later this afternoon and evening across much of the area. - Showery and windy on Tuesday, with strong winds expected from southern portions of northeast Wyoming to the southwest South Dakota plains. - Unsettled, windy, and colder weather expected for the rest of the week and into the weekend. && .DISCUSSION...(Today Through Sunday) Issued at 423 AM MDT Mon Apr 15 2024 Current surface analysis shows low pressure over north central WY, with frontal boundary/warm front extending south- southeast across eastern WY into southwest NE and northeast CO. Pacific cold front extends south-southwest across the Rockies. Tight pressure gradient across the Dakotas and strong low level southerly jet is helping to produce gusty winds across portions of the western SD plains, and in particular along the Pine Ridge, where gusts to around 45 mph are noted. Upper level analysis shows negatively tilted ridge across the plains, with trough across the western US and embedded low pressure over northwest AZ early this morning. Skies are variably cloudy across the area with a few showers noted on KUDX radar across northwest into central SD on edge of low level jet. Temps are in the 40s and 50s. An active couple of days ahead as the upper low moves quickly east- northeast across the southern Rockies today and through the central Plains later tonight into Tuesday night. Warm weather will persist today in most areas as frontal boundaries only move slowly east into the high Plains today. Highs will range from the upper 60s over parts of northeast WY and the higher Black Hills to the 80s south and east of the Black Hills. By later this afternoon, main area of low pressure along the cold front should develop across the NE panhandle, with warm front setting up across northern NE. Southeasterly flow will persist across most of the area into the afternoon, with the strongest winds east of the Black Hills and especially over south central SD, where gusts to near 45 mph are expected. Moisture will increase across the area as well, with dewpoints rising through the 40s and into the lower 50s to the east- southeast of the Black Hills. This will help to produce MLCAPE values of 500 to around 1500 j/kg, highest toward south central SD. Shear will increase later today, with a corridor of more favorable shear progged from near the Black Hills to south central SD, north of the warm front. Robust shortwave energy should push north- northeast through the area this afternoon and evening as the upper low moves across CO. Showers and thunderstorms will develop and increase in coverage generally from southwest to northeast by mid to late afternoon. Parameters support at least isolated strong to severe storms later this afternoon and evening across much of the forecast area, with supercell potential and large hail most favorable to the east and southeast of the Black Hills. Strong wind gusts will be a primary threat as well for the marginal and slight risk areas. Would not rule out an isolated tornado threat with stronger storms that develop closer to the warm front near the NE border. Precipitable water values will be above average, near or above one inch across much of western and south central SD, so at least locally heavier rainfall can be expected, with many areas having high potential (above 50 percent) of a half inch or more of beneficial rainfall later today into Tuesday. Severe storm threat should diminish by late evening in most areas, but could linger into the overnight over south central SD as the low tracks east across NE. The main concern after this evening will be strong N-NW winds on the back side of the system as the surface low tracks across NE and into IA by Tuesday evening. Winds will increase initially across northeast WY late tonight and then across western SD Tuesday morning. Most of the forecast area will see wind gusts ranging from 40 to 55 mph on Tuesday, with areas along the eastern foothills and west central plains having potential for wind gusts to 65 mph during the midday and afternoon hours. Have issued a high wind watch for these areas. Winds should drop off fairly quickly by early evening. Showers can be expected across most of the area on Tuesday, with isolated thunderstorms expected, mainly east of the Black Hills. Upslope enhanced rainfall will develop for a period across the northern Black Hills. Highs will mostly be in the 50s and lower 60s, with 40s over the higher Black Hills. Threat for severe storms should remain east of the forecast area. Pcpn with the upper low will dissipate from west to east during the afternoon and evening hours. The rest of the week looks to be unsettled, cool, and windy at times. A Canadian upper low passes well north of the region midweek, with northwest flow aloft developing across the region by late week. A disturbance rotating well southwest of the Canadian low will bring chances for rain and snow Wednesday and Wednesday night, mainly from northeast WY to the Black Hills and southern SD. Some minor snow accumulations are possible, especially across the higher Black Hills and over Campbell County. Blustery winds can be expected Wednesday and Thursday, with below average temperatures Wednesday through at least Saturday. Drier weather expected late week into the weekend, but a couple of disturbances could bring low chances for rain/snow Friday and over the weekend. && .AVIATION...(For the 06Z TAFS Through 06Z Monday Night) Issued At 1208 AM MDT Mon Apr 15 2024 VFR is expected northeast Wyoming and wrn SD overnight through 23z today. Thereafter, scattered thunderstorms and MVFR ceilings are expected to develop from 23z through 06z Monday evening. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...High Wind Watch from Tuesday morning through Tuesday afternoon for SDZ026-030-031-042-072>074. WY...None. && $$ DISCUSSION/KEY MESSAGES...26 AVIATION...WFO LBF ####018005796#### FXUS66 KLOX 151024 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 324 AM PDT Mon Apr 15 2024 .SYNOPSIS...15/228 AM. Dry and warmer conditions will kick in today and continue through next weekend. Low clouds and fog should also affect portions of the coast and valleys during the night and morning hours through the period. && .SHORT TERM (TDY-WED)...15/303 AM. After an atypical cold and wet mid April weekend, the weather will begin to trend back to normal this week. Today dry NW flow will set up between the departing upper low to the east and a building ridge to the NW. North flow will bring plenty of clouds to the north slopes around the Kern County line. Decent onshore flow and residual moisture have teamed up to bring areas of low clouds to portions of the coasts and vlys. The low clouds will not last past mid morning and then after they have dissipated the mid April sunshine and rising hgts will bring 6 to 12 degrees of warming to the area. Ydy's max temps were so cool, however, that today's highs will still end up 4 to 8 degrees blo normal. Sfc high pressure will build in to the north of the area tonight and the offshore push from the north will increase to about 4 mb. Since there is no upper support this will only support sub advisory level winds through the northerly passages from the SBA south coast through the VTA mtns and then as far east as the I-5 corridor. The offshore flow from the N and neutral flow in the E/W direction will prevent any low clouds from forming. Hgts will continue to rise and max temps will leap another 5 to 10 degrees. This warming will push almost all areas to above normal. The ridge flattens out some on Wednesday and onshore flow to the east increases while the offshore flow from the north relaxes. This should allow some low clouds to develop across the Central Coast and the Paso Robles area. Max temps will continue to rise across the mtns and interior but the weaker offshore flow will bring an earlier cooling sea breeze and the csts/vlys will cool 1 or 2 degrees. .LONG TERM (THU-SUN)...15/322 AM. The ridge really flattens on Thursday and onshore flow increases to the east. A grip of mid and high clouds will move over the area and a deep marine layer will cover the coasts and vlys. The clouds and onshore flow will conspire to lower max temps by 2 to 5 degrees. The mid and upper level clouds will clear out for Friday but the marine layer clouds will still cover most of the coasts and vlys in the morning. A 7.2 mb onshore push in the afternoon will bring breezy westerly winds to the Antelope Vly in the afternoon. The onshore flow and slightly lower hgts will bring 2 to 4 degrees of cooling to the area. This will bring max temps across the csts and vlys down to 3 to 6 degrees under normals. The night through morning low cloud pattern will continue Friday and into the weekend. Long range temperature guidance indicates some warming each day but given the 6 to 7 mbs of onshore flow each afternoon would not be surprises if temps near the coast change little day to day. && .AVIATION...14/2241Z. At 2230Z, there was no marine inversion or marine layer at KLAX. Overall, low to moderate confidence in 00Z TAF package. Scattered showers will end this evening. Overnight, there is a 30-50% chance of MVFR/IFR conditions developing at most coastal and valley sites (with highest chances at KSBP and KSMX) in the 09Z-18Z time frame. The only exception will be KPRB where there is moderate confidence in VLIFR conditions in the 10Z-17Z time frame. There is a 15-20% chance of thunderstorms for all sites through early this evening. KLAX...Overall, low confidence in 00Z TAF. There is a 40% chance that MVFR CIGs/VSBYs will develop overnight. No significant easterly wind component is expected. KBUR...Overall, moderate confidence in 00Z TAF. There is a 40% chance that MVFR/IFR CIGs/VSBYs could develop overnight. && .MARINE...14/1227 PM. For the Outer Waters, moderate to high confidence in current forecast. Tonight through Tuesday, high confidence in a combination of Small Craft Advisory (SCA) level winds and seas. On Monday afternoon and evening, there is a 20-30% chance of Gale force winds around Point Conception. For Wednesday through Friday, there is a 20-30% chance of SCA level winds. For the Inner Waters north of Point Sal, high confidence in current forecast. Tonight through Tuesday, there is a 60-80% chance of SCA level winds, mainly in the afternoon and evening hours. For Wednesday through Friday, winds and seas will remain below SCA levels. For the Inner Waters south of Point Conception, moderate to high confidence in current forecast. Tonight through Tuesday, there is a 60-80% chance of SCA level winds across the western half of the Santa Barbara Channel...with winds and seas remaining below SCA levels elsewhere. For Wednesday through Friday, high confidence in winds and seas remaining below SCA levels. There is a slight chance of thunderstorms for all the coastal waters waters today. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Wednesday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Rorke AVIATION...RAT MARINE...RAT SYNOPSIS...30 weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox