Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/27/23

Area Forecast Discussion
National Weather Service Amarillo TX
613 PM CDT Fri May 26 2023 ...New AVIATION... .SHORT TERM... (This evening through Saturday night) Issued at 229 PM CDT Fri May 26 2023 Potential for thunderstorms bringing the possibility of severe hail, damaging winds, and flooding continues in the short term. Today, latest ridge riding shortwave looks to potentially generate another round of convection in NM which may spread into the western Panhandles this evening into the overnight hours. Similar to yesterday, effects of the extensive morning convection have temporarily stabilized the atmosphere across the Panhandles, as evidenced by the abundant but flat cumulus, particularly in the east, where subtle subsidence on the back side of last night`s shortwave is favored. Due to aforementioned stabilization, expect the bulk of today`s thunderstorms to once again occur after 7pm. Best bet for generation looks to be a remnant outflow boundary from last night`s MCS, somewhat apparent as a thin line of agitated cumulus in NE NM. Have once again leaned heavily on the HRRR given the good performance of this guidance yesterday and the trend toward a later start time in line with expectations based on observational data. On the whole, expect less overall coverage compared to yesterday given the issues with destabilization. With a trend toward stronger winds aloft, expect a bit more wind shear compared to yesterday, with 0-6km bulk shear values in the 30- 40 knot range as MLCAPE once again builds into the 1000-2000 J/kg range. Resulting long hodographs are mostly straight however, so do expect some splitting supercells and subsequent upscale growth as the evening goes on. Given these parameters, hail and damaging winds once again look to be in play, with a bit higher of a top end hail risk compared to yesterday, which featured paltry shear. Finally, given the later start time and the expectation for splitting supercells, the tornado risk appears very low. Flash flooding will once again be a big concern given our climatologically high antecedent rainfall and expected storm motions around 25 mph. Saturday, as the main upper trough to our west finally begins to move eastward, next notable shortwave looks to arrive during the earlier afternoon. Thus, expect a more typical afternoon initiation time unless convection overachieves Friday night. Upper level winds look to be more modest with resulting deep shear struggling to surpass 25 knots. Thus, only expect lower end severe hail and winds, with flooding issues returning to the forefront given crawling favored storm motions. Ferguson && .LONG TERM... (Sunday through next Thursday) Issued at 248 PM CDT Fri May 26 2023 Sunday, main portion of the current western upper trough finally shifts eastward. Yet another shot at afternoon through nighttime showers and thunderstorms will result as moisture remains broadly supportive. Flooding concerns look to be the primary concern with any thunderstorms Sunday, as upper winds aloft take another small step downward, resulting in paltry shear and sluggish storm motions. That said, instability alone would be supportive of a stray severe hail report, so cannot rule out severe thunderstorms. Monday and Tuesday look to feature a relative respite from our active weather pattern as a weak upper ridge builds over the southern High Plains. That said, cannot rule out additional convection each day as southerly flow at the surface helps maintain sufficient moisture for a couple thunderstorms. Wednesday and Thursday, High Plains upper ridge breaks down as our next round of western troughiness takes over. While presence and magnitude of severe and flooding risks will depend on each day`s details, at this time Thursday could feature some more notable severe thunderstorms as some guidance does favor more robust winds aloft compared to what we`ve seen recently. Ferguson && .AVIATION... (00Z TAFS) Issued at 606 PM CDT Fri May 26 2023 A somewhat messy TAF period is in store with the chances of thunderstorms to continue across the combined OK/TX Panhandles. VFR conditions to start could diminish to MVFR with broken CIGs just under 3k ft going into the hours of darkness. If a terminal is impacted by a thunderstorm some brief IFR conditions may be possible. Have mostly stayed positive with timing and conditions of impactful weather for each terminal. However, amendments may very well be needed through the 00Z TAF period. 36 && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 59 72 58 77 / 70 60 40 30 Beaver OK 59 76 58 79 / 30 50 40 30 Boise City OK 55 72 55 79 / 60 40 30 30 Borger TX 61 75 60 81 / 50 60 30 30 Boys Ranch TX 59 75 58 81 / 70 50 30 20 Canyon TX 58 71 57 78 / 70 60 40 40 Clarendon TX 60 72 58 74 / 50 60 50 50 Dalhart TX 56 72 54 78 / 70 40 30 30 Guymon OK 58 74 57 79 / 50 50 30 20 Hereford TX 58 72 57 79 / 60 50 40 40 Lipscomb TX 60 75 58 77 / 20 50 40 40 Pampa TX 59 72 58 76 / 40 60 40 30 Shamrock TX 60 74 58 75 / 30 40 40 40 Wellington TX 62 77 60 75 / 30 50 50 50 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$ SHORT TERM...77 LONG TERM....77 AVIATION...36
National Weather Service Bismarck ND
1021 PM CDT Fri May 26 2023 .UPDATE... Issued at 1016 PM CDT Fri May 26 2023 Strong low level moisture transport pointing into a surface trough that coincides with thunderstorm outflow is maintaining convective activity from north central to southwest North Dakota late this evening. Excessive rainfall from training convection remains a concern, though radar suggests a decreasing trend in rainfall rate intensity over the past hour. The main area of concern is from north central Dunn to northeast Billings Counties, where a narrow band of 3 to 6 inches of rain has been estimated by MRMS. A secondary area that has not received as much rain but where some moderate rain continues to fall is across southern Ward County. Due to the rainfall rates becoming less intense, there is only a very low probability for any flash flooding to develop through the remainder of this event. But ponding of water in urban and low lying areas is certainly remains a potential impact. Though some CAMs have already begun dissipating the convection too quickly, the moisture transport is forecast to make a slight tilt to the east later tonight, which should allow showers and storms to diminish. UPDATE Issued at 726 PM CDT Fri May 26 2023 At 7 PM CDT, a surface trough was located from Bottineau to Golden Valley Counties and slowly advancing east. Numerous pieces of shortwave energy ejecting off higher terrain to our south and west will promote showers and thunderstorms from western into north central North Dakota this evening into the overnight hours. Early evening activity is likely to remain tied to the surface boundary. Training convection may cause localized areas of flooding, especially from near Killdeer to Minot where MRMS has already estimated pockets of 2 to 4 inches of rain. Cell mergers and boundary collisions may briefly cause storms to pulse near severe limits, but the overall threat of severe weather is low and will likely continue to diminish through the evening as MLCIN increases. && .SHORT TERM...(This Evening through Saturday) Issued at 151 PM CDT Fri May 26 2023 The main forecast issues in the short term period include winds over the east for the rest of this afternoon and early evening, and thunderstorm chances and severe potential west and north central later this afternoon and tonight. Currently, surface low pressure was situated over southeast Saskatchewan with a cold front through northwest and portions of west central ND. A strong southerly flow was situated over central and eastern North Dakota. Winds over eastern portions of central ND are near advisory criteria, with a few obs up into low advisory, but given the small areal extent and low end criteria, will hold off on an advisory. Will take a last look before publishing. It will be windy though over eastern portions of central ND through the afternoon. The focus then shifts to the west later this afternoon and tonight. Currently, MLCape values are are around 500-1000J/KG just ahead of the aforementioned cold front (north central ND) and back south southwest through western ND and into northwest SD. Shear is not real strong over this area, with 20-30 knots of effective shear over northwest and north central ND. There are some strong low level lapse rates over much of western and central ND, especially just ahead of the cold front (there is also an area of congested CU development over the far south central attim) Mid level lapse rates are pretty meager however, and based on the EMC RAP analysis, are not forecast to increase much over western and central ND this afternoon/evening. Thus it seems like the best chances for severe weather later this afternoon/this evening would be right along/ahead of the cold front from north central into west central ND. Later tonight convection over the northern High Plains could poke into the far southwest, but the threat would seem to be pretty limited by then. Also, late tonight there could be some convection over the south central along the nose of a developing low level jet. This also looks to be uncertain given the limited instability aloft. However a stronger storm or two over either of these two areas can be completely ruled out. On Saturday we see another warm day with highs generally in the 80s. Will discuss Saturday`s convection in the long term section. .LONG TERM...(Saturday Night through Friday) Issued at 151 PM CDT Fri May 26 2023 Overall, the general synoptic setup changes little on Saturday, with a slight shift eastward in the marginal severe weather threat. Latest CAMS are hinting at convection moving into western ND early Saturday evening, so daytime May not be too eventful storm wise. However, whether convection hold off until then, or starts earlier, there is a broader area of 1000-2000J/kg of CAPE and perhaps some slightly better shear over the western third of ND. A few strong to severe storms will be possible Saturday night. At this time we will stick with the 60 mph winds and quarter size hail, but depending on how things develop Saturday, threats could be a little higher than this. Sunday and Monday, the threat shifts more over central ND as the western upper trough finally pushes into the region. A unique and stagnant pattern still looks to set up for the work week next week. Each day will have ample moisture and instability to work with. The zonal flow followed by a shift back to southwest flow could also provide weak disturbances at times. The overall result will be chances for showers and thunderstorms almost each day through the week. The surface gradient does not look to be as sharp as this week, thus strong winds are not expected at this time, although some breezy winds may return later next week. Temperatures will also remain warm through next week and generally in the 80s for highs and 50s to 60s for lows. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 1016 PM CDT Fri May 26 2023 Thunderstorms will continue to impact KMOT into the early overnight hours, with visibility falling to IFR levels at times. The storms should gradually diminish at KMOT after 06Z. Additional storms are still possible at KXWA later tonight, but the probability there has decreased. A few showers and possibly a thunderstorm are also possible at KBIS later tonight. A period of drier weather is expected for all terminals Saturday morning and into the afternoon, but another round of thunderstorms is likely across western North Dakota by Saturday evening. Southerly winds will become stronger once again on Saturday. The probability of low-level wind shear criteria being reached tonight at KJMS has decreased, but a 25 kt difference between the surface and 1-2 km above the ground with a slight directional shift is still expected. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hollan SHORT TERM...TWH LONG TERM...TWH AVIATION...Hollan
Area Forecast Discussion
National Weather Service Cheyenne WY
529 PM MDT Fri May 26 2023 .SHORT TERM...(This evening through Saturday) Issued at 345 PM MDT Fri May 26 2023 Today is the first day of a potentially active weekend across the area. Earlier, a Severe Thunderstorm Watch was issued across the region, encompassing all counties in the CWA with the exception of Carbon County. Currently, convection is ongoing across Carbon and Albany Counties and is expected to expand further eastward into far eastern Wyoming and the Nebraska panhandle by later this afternoon and into the evening hours. The more favorable environment for severe storms exists east of the Laramie Range, so this is where the strongest storms are expected. Dewpoints in the 50s, steep 700-500 mb lapse rates, and MLCAPE values of 1000 to 2000 J/kg will likely trigger severe convection later today. Although shear values are modest with 0-6 km shear of 20 to 25 kts, storms to the south of our CWA already look to be producing severe weather. Initial threat will most likely be large hail with more discrete cells. During the evening, storms look to transition to a more linear mode, which will lead to more of a wind threat. Storms looks to vacate the CWA by midnight tonight. Heading into the weekend, the severe weather potential continues. A Rex Block parked over the eastern part of the country will keep an upper-level trough near stationary over western CONUS. Daily precipitation chances will be likely as the CWA sits under the downstream side of the trough. Saturday looks as though it will be a repeat of today with severe storms possible in the same area. Model soundings from the RAP and GFS indicate similar conditions with dewpoints in the 50s and 60s, steep 700-500 mb lapse rates, and MLCAPE around 1500 J/kg. 0-6 km shear values are better at 25 to 30 kts. Hi-Res models also seem to hint at the potential for storms tomorrow to be a bit stronger than today, but perhaps not as widespread in coverage. Again, initial threat looks to be hail in discrete cells, but transitioning to a wind threat as convection turns to more linear clusters of storms by the evening hours. Model soundings continue to indicate PW values above climatology with moist low-levels. This will mainly lead to a heavy rain concern. Because of the Rex Block, severe storm chances look locked in place through at least Sunday. Severe storm threat for Sunday looks the greatest in the Nebraska panhandle where dewpoints stay in the 50s and instability looks strongest. However, storm coverage on Sunday looks much less and more scattered compared to today and Saturday. The upper-level trough shifts slowly eastward, pushing the better plume of mid-level moisture further off to the east over central Nebraska. This will lead to a bit of a drier day across the CWA with less numerous storms. .LONG TERM...(Saturday night through Friday) Issued at 225 PM MDT Fri May 26 2023 Monday...Although a low amplitude ridge aloft will lie across Colorado, it looks like a shortwave trough aloft will be moving across our counties near peak heating, and will combine with adequate low and mid level moisture to produce scattered afternoon and evening showers and thunderstorms mainly along and east of Interstate 25. Tuesday-Friday...With a longwave trough aloft over the Great Basin states and southwest flow aloft over our counties ejecting various shortwave troughs, along with adequate low and mid level moisture to fuel thunderstorms, we will be in a favorable pattern for scattered afternoon and evening showers and thunderstorms, most numerous Wednesday through Friday when moisture will be more plentiful. Temperatures will be moderated by the widespread late day cloudiness and precipitation coverage. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 523 PM MDT Fri May 26 2023 Wyoming TAFS...As a weather disturbance moves near the region, isolated thunderstorms will be in the vicinity until 02Z this evening with scattered to broken clouds from 5000 to 10000 feet AGL. Thunderstorms will also be in the vicinity at Laramie and Cheyenne after 18Z on Saturday, when broken ceilings from 5000 to 10000 feet will occur. Sufficient pressure gradients will produce wind gusts to 32 knots at all terminals until 02Z, and to 25 knots after 15Z Saturday. Nebraska TAFS...As a weather disturbance moves near the region, occasional thunderstorms will occur through 03Z producing wind gusts to 40 knots along with visibilities from 3 to 4 miles and ceilings around 3500 feet AGL. From 07Z to 15Z, ceilings will be near 2000 feet AGL, then improve to 5000 feet after 15Z. Winds will gust to 35 knots through the forecast period. && .FIRE WEATHER... Issued at 225 PM MDT Fri May 26 2023 Minimal fire weather concerns continue over the next several days due to daily chances for showers and storms and fuels in green-up status across the area. Widespread storms with wetting rains are likely on Friday and Saturday. Storms may contain strong gusty winds with gusts in excess of 60 MPH. Conditions will gradually dry out Sunday into the beginning of next week with minimum RHs across the area falling into the 20s and teens by Tuesday. && .HYDROLOGY... Issued at 330 AM MDT Fri May 26 2023 Warm temperatures continue into the holiday weekend, leading to additional snowmelt runoff in areas where substantial snowpack lingers, mainly above 9000 ft. Minor flood stage continues to be reached each morning along the Little Snake River near Baggs/Dixon. Forecasts from the RFC show this continuing for Friday and Saturday, but crests may potentially fail to reach minor flood stage by Sunday. Will continue to monitor through the weekend. The latest forecasts continue to show the North Platte River near Saratoga remaining below flood stage, so the Flood Watch was cancelled yesterday. The river remains at action stage. Action stage has also been reached on the Encampment River, and could be reached by Monday on the Laramie river in Laramie. Forecasts do not show flood stage being reached on either river at this time. Daily chances for afternoon showers and thunderstorms continue this weekend. Slightly faster storm motion is expected Friday and Saturday, but substantial atmospheric moisture will continue to produce a locally heavy rainfall threat. Most of this should stay && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...SF LONG TERM...RUBIN AVIATION...RUBIN FIRE WEATHER...SF HYDROLOGY...MN
Area Forecast Discussion
National Weather Service Wilmington NC
1002 PM EDT Fri May 26 2023 .SYNOPSIS... Strengthening low pressure off the Georgia coast will move inland across the Carolinas Saturday bringing gusty winds and heavy rain, especially along the coast. Some drier air will arrive Sunday. After a cool holiday weekend, more seasonable temperatures will return next week. && .UPDATE... After reviewing the latest HRRR and ensemble heavy precipitation probabilities, we`ve issued a Flash Flood Watch for the three coastal Cape Fear counties in NC through 9 PM Saturday evening. Widespread rainfall amounts of 3-5 inches will likely have mesoscale enhancements producing streaks of 7+ inches of rain by this time tomorrow evening. Given significant rainfall that occurred in this area a week ago, soils are not nearly as dry here as they are in other parts of the eastern Carolinas. We`re also continuing to monitor storm surge anomalies which have not changed over the past three hours. It appears tonight`s high tide will pass without coastal flooding occurring. Earlier updates from 730 PM follow... Radar and surface obs reveal the shield of isentropic rain is spreading onshore as deep and moist easterly winds overrun colder and drier air in place at the surface inland. Although dry air inland is eroding/evaporating the western periphery of radar echoes across the Pee Dee region, it`s only a matter of time before rain reaches the surface here. High res models continue to paint a variety of positions and intensities of precip maxes associated with convective enhancement within the broader zone of overrunning precipitation Saturday. The potential for flooding rain is low most places, except a little higher across Brunswick and New Hanover counties where soils are a little wetter and HREF probs for 6+ inches show a relative maximum. If higher certainty in large rainfall were to appear with 00z models I could see a small Flash Flood Watch for this area. Changes made with this update include raising PoPs and sky cover to 100 percent for all areas late tonight and Saturday and changing the precip type descriptor to "rain" rather than "showers" tonight. Wind speeds both inland and offshore are verifying nicely and need no changes. Tide gauges at Wrightsville Beach and Myrtle Beach show a storm surge anomaly of +1.4 to +1.7 feet currently. Given that we`re in between the new and full moon it will take a much larger surge of at least +2.4 feet to produce coastal flooding during tonight`s high tide. I`ll keep an eye on those gauges through the evening but don`t anticipate we`ll need to issue an advisory. && .NEAR TERM /THROUGH SATURDAY/... Digging shortwave off the west coast of FL will work in concert with a second shortwave along the SC coast to create significant weather impacts during the next 24 hours. The shortwaves are aiding low pressure developing along a front stalled off the FL coast this afternoon. This low will wobble off the FL/GA coast tonight before starting to move north-northwest Sat morning. Meanwhile, high pressure continues building in from the north, with the pressure gradient growing ever tighter. Winds will continue increasing this afternoon into tonight as the low slowly strengthens. Gusts in excess of 50 mph will be possible across the coastal waters with a brief period of time where gusts may approach 50 mph along the immediate coast. However, no plans for a wind advisory given that forecast speeds end up short of meeting criteria. Farther away from the coast peak gusts overnight into Sat will be on the order of 35 to 40 mph. Light to moderate showers, currently along the coast, will gradually spread inland this evening. Forecast soundings continue to depict low and mid-level dry air inland until around midnight. It may take until then for the I-95 corridor to start seeing any rain of significance. However, coastal areas will start to see moderate to heavy rain much sooner. Precipitable water rises from 1.3-15." this afternoon to over 1.7" by daybreak Sat. Meanwhile the freezing level will also be increasing, growing the warm cloud layer by close to 2k ft by midday Sat. The abundant moisture and the deep warm cloud layer will translate to high efficiency when it comes to rainfall production. Any cells will be capable of producing very heavy rain and with the combination of low level convergence along the coast, isentropic lift and dynamics as the low approaches, there will be no shortage of forcing mechanisms. Periods of heavy rain overnight and Sat could lead to rainfall in excess of 6 inches in some coastal areas with inland areas pushing 3 inches in some places. If showers and any isolated thunderstorms manage to train over the same location in quick succession flooding could become a concern. Lows tonight will range from below normal near the coast to well below normal inland. The slow northward movement of the low late tonight should prevent a scenario with temps rising along the coast in the pre-dawn hours. Highs on Sat will be well below climo with daytime temperatures in some inland areas struggling to hit 60 degrees as the wedge holds on. Closer to the coast highs will be in the upper 60s to lower 70s. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/... The main focus for this forecast period will be the last stage of the area of low pressure meandering offshore and finally moving inland. There is still a lot of uncertainty of where it moves inland but overall the speed seems to have slowed down thus significant rainfall remains possible at least for a few more hours. Mid level dry air and decreased forcing will lead to more scattered pops early Sunday. Once again progress to the north will be slow thus we don`t go with a dry forecast until Monday morning. With the cold air wedge long gone, temperatures will bounce back somewhat moreso Sunday with highs in the lower to perhaps the middle 70s. Lows will be in the 55-60 degree range. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... A mid level low, which will have closed off in the Tennessee Valley this weekend will meander to the east with a brief Rex block developing and basically dissipating through the period. There really is no cleansing feature at the surface or aloft. Chance pops remain in place mainly during the afternoon and evening hours but do trend down as the mid level low finally drifts further enough offshore to become a non factor. Temperatures will drift back to near normal values. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... VFR conditions will begin to degrade as soon as 04z along the coast as rainfall rates increase and cloud bases lower. There is a high potential MVFR conditions will develop at all three coastal airports (KILM, KCRE, and KMYR) no later than 08z, spreading inland to affect KFLO and KLBT before 12z Saturday. Conditions will degrade further Saturday as widespread moderate to heavy rain brings IFR ceilings and a moderate chance for periods of IFR visibility. Precipitation will become more showery after 18-20z when there will be a low to moderate potential for thunderstorms along the coast. With the exception of cool temperatures, the effects from this system will be similar to a weak tropical system with synoptic wind speeds increasing to 20G30 kt from the north and northeast. Extended Outlook...There is a high potential for lingering MVFR to IFR ceilings Saturday night through Sunday as showers continue to circle the weakening low pressure inland. Convection should become more scattered in nature Monday and Tuesday will a low to moderate potential for sub-VFR conditions. && .MARINE... Through Saturday... Treacherous marine conditions continue through Sat with northeast winds in excess of 30 kt sustained and potential for brief period of gusts approaching storm force, especially across portions of the SC waters. Seas already over 6 ft will keep building, likely exceeding 10 ft this evening and potentially approaching 15 ft in places. Low pressure off the FL/GA coast this evening will slowly move north late tonight into Sat. The gradient will start to relax as the low moves closer, with winds dropping below gale force in the afternoon. An SCA headline will be needed once the gale is dropped for both winds and seas and the SCA may potentially be needed for an additional 18 to 24 hours. Saturday Night Through Wednesday... Winds and seas will be on the decline Saturday evening as low pressure moves inland and weakens. It seems a Small Craft Advisory will be necessary at least through about midday Sunday. The headline will be issued later Saturday as the Gale Warning takes precedence. For the remainder of the period which includes much of next winds will be weakly forced and driven somewhat by the sea breeze taking turns with the synoptic flow. Significant seas will be 2-3 feet. && .TIDES/COASTAL FLOODING... For beach hazards, a High Surf Advisory for 5-9 feet breakers is in effect for north of Cape Fear through Saturday due to high waves associated with the low. There is potential for dune erosion at east- facing beaches with tonight`s high tide. High rip current risk is forecasted north of Cape Fear today, and forecasted for east-facing beaches Saturday Sunday, along with strong north to south longshore current. Elevated rip risk at south and southeast facing beaches possible over the weekend. Conditions will improve further late Sunday into Monday. && .CLIMATE... Unseasonable chilly air on the west side of the coastal low is threatening records for the coldest daily high temperatures at several locations. Here`s the list: Coldest Observed Daily High Temps on Record Location Fri May 26 Sat May 27 Wilmington NC 60 in 1972 64 in 1961 Lumberton NC 66 in 1963 *60 in 1972 N. Myrtle Beach SC *68 in 1963 65 in 1961 Florence SC 66 in 1972 *66 in 1961 * indicates this record is threatened && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Beach Hazards Statement from 6 AM EDT Saturday through Saturday evening for SCZ054-056. NC...Flood Watch from 6 AM EDT Saturday through Saturday evening for NCZ105>110. High Surf Advisory until 8 PM EDT Saturday for NCZ106-108. High Rip Current Risk from 6 AM EDT Saturday through Saturday evening for NCZ106-108. MARINE...Gale Warning until 2 PM EDT Saturday for AMZ250-252-254-256. && $$ SYNOPSIS...ILM UPDATE...TRA NEAR TERM...III SHORT TERM...SHK LONG TERM...SHK AVIATION...TRA MARINE...III/SHK TIDES/COASTAL FLOODING...III CLIMATE...TRA
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
659 PM CDT Fri May 26 2023 ...New AVIATION... .DISCUSSION... Issued at 221 PM CDT Fri May 26 2023 Tonight and Tomorrow... A surface low stationed over the Lower Miss Valley will help initiate light rain chances across the north this afternoon through this evening along and north of the HWY 82 corridor. Though there is ample amount of dry air across the region, as this low tracks E/NE, moisture will wrap around and when met with peak heating, light rain will be possible. The rest of the region today has and will remain dry through tonight. Mostly clear to partly cloudy skies will prevail this evening with lows near seasonable values. Expect temperatures in the 60s area-wide. The previous mentioned low will continue to deepen across the Mid and Deep south Saturday. While there won`t be a lot of flow at the surface, there will be some flow aloft along with cooler temperatures aloft. With the lack of surface instability, severe weather is not expected however, during the afternoon and early evening hours storms and rain chances will be possible across north- central and northeastern areas of the region. It is worth the mention that the 12z HRRR sounding model indicated a inverted V with deep high vertical totals. Meaning any storms that have a chance to become surface based could produce gusty winds. High temperatures will be in the 80s Saturday across the region. /JNE/ Saturday night through next Friday... A broad upper level low propagating from the southeastern region into the mid-Atlantic coast will push out of the lower Mississippi Valley by Sunday. This will filter drier and warmer low level air into the ArkLaMiss region through the weekend into mid-week. Weekend highs will remain in the lower to upper 80s, while overnight lows range in the upper 50s to middle 60s. By mid-week, an upper low spinning up off of the Texas coast, progged to make its way into the Lower Mississippi Valley by Wednesday will supply the next possibility for rain chances. An influx of southerly flow and instability will allow for isolated to scattered showers and storms Wednesday and Thursday afternoon. These storms are expected to be diurnal in nature, so precipitation chances should decrease by the early evening. Temperatures will be warmer, with highs in the upper 80s to low 90s, while lows remain in the middle 60s to low 70s. /AJ/ && .AVIATION... (00Z TAFS) Issued at 656 PM CDT Fri May 26 2023 VFR conditions with winds generally out of the northeast less than 10 kts should prevail at all TAF sites through the period. Isolates SHRA or TSRA are possible before 02Z Saturday and again after 19Z Saturday, but confidence in impacts to any TAF site was too low to mention at this time. /NF/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 62 84 61 84 / 10 20 10 0 Meridian 60 83 58 84 / 0 10 10 0 Vicksburg 64 85 61 86 / 10 30 0 0 Hattiesburg 62 85 61 87 / 0 0 0 0 Natchez 64 85 62 86 / 0 20 0 0 Greenville 64 83 61 84 / 20 30 0 0 Greenwood 64 82 60 83 / 20 40 10 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ JNE/AJ/NF
...Update to aviation forecast discussion...

.DISCUSSION... Issued at 242 PM CDT Fri May 26 2023 Key Points: - Warm temperatures continue this weekend into next week - Mainly afternoon/early evening chances (10-30%) of showers and thunderstorms Sunday through Thursday 19Z water vapor imagery depicts broad low pressure over the eastern US and another upper trough over the west, leaving ridging over the central CONUS. Sfc high pressure is centered over WI and MI and extends into northeast KS. A diffuse boundary can be seen along a line from Emporia to Manhattan to Washington, with diurnal cumulus having developed west of that boundary and clear skies remaining east of it. While a few of the 12Z CAMs are still trying to develop isolated shower and storm activity in north central KS this afternoon, the HRRR and RAP have backed off on this potential with the better instability still well to our west. Would expect most, if not all, locations to stay dry for today. The influence of the sfc high should keep mainly clear skies around tonight, allowing for temperatures to fall back to the 50s for most, perhaps upper 40s in far northeast KS. Heading into Saturday, models prog the upper low in the southeastern US to retrograde slightly while lee sfc troughing deepens in the eastern Rockies. Still, precipitation is favored toward western and central KS with locations within the CWA staying dry. Highs look similar to today in the 80s area-wide. Precipitation chances improve somewhat into early Sunday as the lee trough moves a little closer to the CWA, although large-scale forcing for ascent still looks weak. This will remain the case through much of next week as the main upper trough stays out west with weaker perturbations being ejected out of that trough to bring 10-30% chances for showers and thunderstorms each day through Thursday. This type of set-up brings low predictability in regard to timing and placement of precip associated with these waves, and will likely need to take it day by day, but at this time storms look to be mainly diurnally driven. There are signs of the upper ridge starting to break down late in the week, and details on that should become more clear in the coming days. Temperatures look to hold steady with highs in the 80s, warming about a degree or two each day in the forecast period with low 90s in some locations by mid-week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 555 PM CDT Fri May 26 2023 VFR conditions will continue. Dry air moving in from the east has pushed crossover temperatures below even the coldest low temperature forecast from guidance, and with some boundary layer mixing returning, the chance for any diurnal ground fog are very low despite modest winds and clear skies. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Picha AVIATION...65