####018009708#### FXUS63 KJKL 030345 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 1145 PM EDT Thu May 2 2024 .KEY MESSAGES... - Shower and thunderstorm chances return to the forecast Friday through Wednesday. - Cooler this weekend, though temperatures remaining above normal by 5 to 10 degrees on average from the weekend well into next week. && .UPDATE... Issued at 1145 PM EDT THU MAY 2 2024 No significant changes to the forecast with just the inclusion of the latest obs and trends for the T/Td/Sky grids with this update. These minor adjustments have been sent to the NDFD and web servers along with a freshening of zones and SAFs. UPDATE Issued at 750 PM EDT THU MAY 2 2024 23Z sfc analysis shows weak high pressure holding on over eastern Kentucky for one last evening as low pressure is advancing from the west. This pressure pattern helped push temperatures to record and near record highs on account of mostly sunny skies. Now the readings are only slowly backing down - ranging from the mid 70s to lower 80s. Meanwhile, amid light west to southwest winds, dewpoints are holding in the mid 50s to lower 60s most spots. Have mainly updated the forecast to include the latest obs and trends for the T/Td/Sky grids. These minor adjustments have been sent to the NDFD and web servers. && .SHORT TERM...(This evening through Friday night) Issued at 322 PM EDT THU MAY 2 2024 Upper ridging and surface high pressure remain the dominant weather features this afternoon, but this will begin to slowly change through the short term period. Mid-latitude cyclonic jet stream remains well northwest of the region from the Central Plains to the Upper Great Lakes region, and will remain that way through Saturday night. Meanwhile, stout and persistent upper ridging will begin to slide slowly east and weaken as persistent weak shortwaves move from the Southern Plains to the Mid-Atlantic region through Saturday night. A pronounced shortwave currently over the Arklatex region will move toward the area tonight, bringing increasing cloud cover, with shower chances toward dawn west and southwest of Somerset. Big question mark is how much does the increasing cloud cover impact tonight's low temperatures. Overall, the trend in forecast lows tonight is warmer given the warm air and moisture advection into the region, but COOP MOS still suggests lower to mid 50s for a lot of the sheltered eastern valleys. Decided to stick close to the NBM with primarily 60s outside the sheltered valleys, with local effects in the typically cooler areas given the uncertainty, though this is still a much warmer forecast than the previous shift. Showers increase through the morning from west to east, with thunderstorms becoming more likely from late morning into the afternoon especially for western and southwestern areas as instability increases. This will introduce a continuous period of high-end chance to categorical (i.e., 50 to 90 PoPs) Friday afternoon into Friday evening decreasing to high-end chance to low- end likely (50 to 60) PoPs Saturday morning. The warmest locations in our CWA will be toward Pike County Friday as this area will remain closer to the downstream ridging plus have a bit of downslope drying from light southerly flow. Highs in this area may reach well into the 80s, while highs trail off to the upper 70s across western parts of the CWA where more persistent shower and thunderstorm activity is expected. By Friday night, PoPs will be more uniform across the area, which will yield lows in the mid 50s to 60s. .LONG TERM...(Saturday through Thursday) Issued at 322 PM EDT THU MAY 2 2024 The period is expected to begin with an upper level ridge extending from the Bahamas into the Northeast Conus, an upper level low just south of Hudson Bay in northern Ontario with a shortwave trough trailing into the Upper MS to portions of the northern to central Plains. Additional weaker shortwaves should extend from the Central Plains to the Ozarks and another moving through the OH Valley to southern Appalachian region. Further west, another upper level low will be nearing the Northwest Conus with weak ridging in between this feature and trough that extending into the Central Conus. Meanwhile, a wavy frontal zone is expected to extend into the Lower OH Valley from low pressure over the eastern Great Lakes as the period begins with another sfc low southwest of Hudson Bay south to the upper MS Valley to the southern Plain to southwestern Conus. Saturday to Sunday night, the axis of the upper level ridge initially near the east coast will shift east into the western Atlantic while the upper level low initially centered in the vicinity of the southwest portion of Hudson Bay moves to Quebec. Meanwhile, the shortwave initially tracking across the Lower OH Valley and southern Appalachians should shift east of the area with another shortwave moving across the Lower OH Valley late Sat night into Sunday and another perhaps stronger shortwave that will have moved across the Southern Plains and Ozark vicinity should near the Lower OH Valley by late Sunday night. Further west, the upper level low initially near the Northwest Conus is expected to move across the western Conus/Great Basin and begin to weaken/open up as it near the Rockies Sunday night. At the sfc, the first wavy front zone is expected to cross eastern KY to begin the weekend, with the next boundary moving to the Central Great Lakes to Lower OH Valley to Southern Plains during that time as well. However, this boundary should tend to slow down and stall as it nears the OH Valley while the the western to northwest extent of this becomes warm front into eastern MT. Chances for convection should be highest on Saturday with the first passing wave and boundary with secondary peaks in convection possible with daytime heating on Sunday and perhaps late Sunday night ahead of a shortwave approaching form the southeast. Monday to Tuesday night, the consensus of the guidance is for a 500 mb shortwave trough to cross the OH Valley region Monday to Monday evening followed by shortwave rigging moving form the MS and across the Great Lakes to OH Valley and Appalachians on Tuesday. Meanwhile, the upper level low moves across portions of the Rockies and into portions of the northern Plains and an upper level trough encompasses much of the Western to Central Conus. At the sfc, a wavy boundary that may initially be stalled out near the OH River is expected to lift north as a warm front as warm front into the Great Lakes east of the sfc low as guidance suggest it moves east near the US/Canadian border to the upper MS Valley while a triple point low may reach the western Great Lakes with the trailing front should track across the Plains/portions of the Central Conus to the western Great Lakes to mid MS Valley to Southern Plains. A rather warm and moist airmass should be across the region, with passing weak shortwaves and diurnal heating leading to peaks in chances for convection each afternoon and evening with confidence greater on a peak during Monday with a passing shortwave. Wednesday to Thursday, the axis of the shortwave ridge is generally expected to shift east and southeast to a position from the Gulf of Mexico to parts of the western Atlantic with southwest flow from the Southwest Conus across the Plains/Central Conus into the OH Valley region, Southeast and Appalachians downstream of rather broad troughing. Multiple weak shortwaves could move from the Plains across the OH Valley/Southeast and across the Commonwealth during this time. Meanwhile, the sfc low well to the north of the Commonwealth should move gradually from the Great Lakes toward portions of the Great Lakes to mid Atlantic with the trailing frontal zone shearing from northeast to southwest and perhaps stalling or nearly stalling from the OH Valley to the Southern Plains regions. This boundary should interact with the passing shortwaves and heating each day with a diurnal peak in chances for convection each afternoon and evening. Temperatures will begin the period about 5 degrees above normal on Saturday even after the possible passage of the rather weak front. Then, from Monday to Thursday, the region will be in the warm sector much of the time with temperatures likely to be above normal by around 5 to 10 degrees above normal && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 800 PM EDT THU MAY 2 2024 VFR conditions continue under mostly clear skies. Later this evening high BKN to OVC skies spread in over the area, west to east. An area of showers with a few thunderstorms then approach western TAF sites from the after 12Z Friday. Have kept VCSH into the TAFs at various times between 12 and 18Z Fri, with more continuing into the afternoon further east, but these will likely be further refined as we get a better handle on timing, as well as whether a mention of CB and VCTS will be warranted. Winds will be light and variable overnight then favor the south to southwest at 5 to 10 kts throughout the day, Friday. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...CMC LONG TERM...JP AVIATION...CMC/GREIF ####018003382#### FXUS63 KFGF 030347 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 1047 PM CDT Thu May 2 2024 .KEY MESSAGES... - Several rounds of rain are expected through the remainder of the week and into next week. Isolated thunderstorms are possible, especially the first half of next week. && .UPDATE... Issued at 1045 PM CDT Thu May 2 2024 Forecast and timing of rain on track. Low is right over Grand Forks at 03z. East wind at KGFK and west wind at KRDR. Rain area moving north with backedge of the rain approaching Grand Forks area. Rain in the eastern fcst area (Bemidji) remains less than desired as that area up to Baudette keeps missing the higher rain totals. Other than minor tweeks to grids no further weather issues noted overnight. . UPDATE Issued at 724 PM CDT Thu May 2 2024 Low pressure is moving north-northeast and near Mayville ND at 00z. Sfc front located from low to Fargo then to Fergus Falls to Alexandria. WSW to west winds behind it and south-southeast winds ahead of it. Area of moderate rain ahead of the low moving north and into the northern valley. Scattered showers and a few t-storms western and central ND will weaken as they move east but still worth watching. Otherwise trend overnight will be to watch clearing line and pop trends. && .DISCUSSION... Issued at 350 PM CDT Thu May 2 2024 Active H5 pattern persists through much of the forecast period, with multiple chances to see rain and isolated thunderstorms. Shortwave troughing exits the region this evening and overnight, with a break in shower activity overnight for most areas. Another, slow moving, upper low traverses the Northern Plains Friday into Saturday, bringing a chance for showers and isolated thunderstorms to portions of the region Friday afternoon through around midday Saturday. The best chance for thunderstorm activity will be along and just south of the International Border. This will gradually work to the east, with a period of dry weather starting Saturday afternoon and evening. H5 shortwave ridging builds into the area Sunday ahead of our next system. Look for warmer and relatively dry weather through much of the day, with increasing rain chances late Sunday evening. A relatively deep upper low is being picked up by multiple ensembles heading into Monday. Thunderstorm chances will be slightly higher with this system, along with a better chance for increased instability as moisture return is well-supported. Troughing will favor negative tilting ahead of the upper low, and a strong storm or two cannot be ruled out on both Monday and Tuesday afternoons respectively. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 724 PM CDT Thu May 2 2024 MVFR cigs in many areas in rain as system moves north-northeast thru the area. But seeing clearing and rising ceilings moving into DVL and SE ND/WC MN early this evening with that translating northeast thru the night. Winds turning southwest to west as this system moves through and a windy/gusty day on Friday with gusts from the west 30 kts. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Riddle DISCUSSION...Lynch AVIATION...Riddle ####018007878#### FXUS64 KSHV 030348 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 1048 PM CDT Thu May 2 2024 ...New UPDATE... .UPDATE... Issued at 1024 PM CDT Thu May 2 2024 A moist and somewhat unstable environment remains in place across the Four State Region. This can make for challenging forecast, as any remnant boundary, remnant MCV/MCS, or weak disturbance could ignite convection across the region. For this update, decided to lean heavy on HRRR for modifications, as it has done a decent job with current convection across the Southern Plains. Not expecting much in the way of precip in the area for a large portion of evening into the overnight hours. However, decided to keep 20 POPs over the area, as an isolated shower or thunderstorm can't be ruled out in this type of environment. The last several runs of the HRRR have been very consistent with developing and MCS across Eastern Oklahoma overnight, and shifting it southward into our zones north of I-30 after 3am or so. Because of this, decided to increase POPs between 1am and daybreak for the aforementioned area to chance and high chance, with high chance across SE Oklahoma and adjacent SW Arkansas. Otherwise, the remainder of the forecast remains on track, with overnight lows in the mid to upper 60s. /20/ && .SHORT TERM... (This evening through Friday Night) Issued at 313 PM CDT Thu May 2 2024 A few scattered showers will continue to move northeast across portions of Northern/Northeast Louisiana and Southwest Arkansas through early this evening in the wake of the departing shortwave trough that brought this morning's MCS to the area. Additional scattered convection may develop this evening along and north of Interstate 20 along a remnant outflow boundary from the aforementioned convective complex. The forecast becomes increasingly uncertain during the overnight hours. For the last couple of days, model guidance has generally been in decent agreement that another convective complex will form across Texas and Southern Oklahoma before diving east-southeast and into our CWA early Friday morning, in a very similar situation to what we had today. The latest models introduce considerable uncertainty regarding rain chances for Friday. The 12z NAM continues to be far more aggressive than the remainder of the guidance. The GFS and ECMWF also depict convection moving east-southeast into the area but have trended downward regarding coverage, intensity, and QPF amounts. Meanwhile, the vast majority of the CAMs depict very little in the way of thunderstorms. Some of them either keep the next MCS to our west and southwest, or don't even show one developing. The NSSL-WRF is the most supportive of another convective complex, but has it quickly weakening with eastward extent into the ArkLaTex by 09z-12z. Most of the guidance tends to struggle in this type of pattern with a persistent southwest flow and a surface boundary well to our northwest. The trends in the CAMs are likely due to today's convection overturning the environment and lack of recovery of diurnal instability. However, with low-level southerly flow and warm air advection some surface- based CAPE could still recover tonight. If a convective complex does develop to our west, the key factor in its survival into our CWA will likely center around something that can help propagate the complex eastward like a mature cold pool or the development of a MCV. Unfortunately, as mentioned, model guidance struggles greatly in these scenarios. Based on the trends in the models, rain chances were lowered somewhat after midnight tonight through much of Friday. This also lowers forecast QPF amounts a great deal, as most locations are generally expected to see an inch or less of additional rainfall through Friday evening. Since the heavy rain threat has already diminished for today, the Flood Watch was cancelled early. The surface front that the next round of thunderstorms is expected to develop along should stall near or north of I-30 Friday morning before lifting back northward during the day. As a result, PoPs should diminish Friday afternoon and become increasingly confined to areas north of I-20 before falling below mentionable levels in most areas by midnight Saturday morning. CN && .LONG TERM... (Saturday through next Wednesday) Issued at 313 PM CDT Thu May 2 2024 Saturday is likely to be a very similar situation to today and Friday. Another weak disturbance in the southwesterly flow aloft will trigger thunderstorms along the frontal boundary across the Plains well to our north late Friday. What's left of this complex is expected to move into our area during the day Friday. Redevelopment along a residual outflow boundary Saturday afternoon should bring scattered showers and thunderstorms to much of the northwest half of the CWA. The front should sag farther south Saturday with yet another round of strong convection developing along the front and dryline over Texas and Oklahoma. This batch of storms should initiate farther south and should have a better chance of reach our CWA during the day Sunday. In addition, the shortwave trough moving across the Southern Plains appears to be more defined than previous days, which should result in increase lift helping to sustain the showers and thunderstorms. Thus, widespread high PoPs in the forecast for Sunday, especially in the morning. Daily chances for showers and thunderstorms in the forecast through at least Monday and Tuesday. The biggest change early next week is that a much stronger longwave trough is forecast to lift from the Southern/Central Rockies and into the Northern Plains. This should keep the best large scale forcing well to our north Monday and Tuesday. However, with strong low-level southerly flow and southwesterly flow aloft, there will be plenty of instability to fuel more convective development especially as a front finally begins to move into and across the area on Thursday. Rain chances are currently expected to be lower than in the short- term forecast period and more scattered in nature. Combined with strong southerly winds and warm air advection, perhaps the bigger story will be the building heat and humidity next week. Daytime high temperatures should be warming into the 90s in several locations by Tuesday and may be into the mid 90s in many locations by Wednesday and Thursday. Very humid conditions are also expected. This will likely push peak heat index values near or over the century mark across much of the area south of I-20. CN && .AVIATION... (00Z TAFS) Issued at 632 PM CDT Thu May 2 2024 A very complicated TAF forecast is anticipated over the next 24-hours, as uncertainties remain regarding overnight precipitation. In the event a line of thunderstorms moves into the region, TSRA will likely become much more widespread in FM groups. Regardless, look for IFR and LIFR VIS and CIGS as low clouds return by 03/10z, with SHRA/-RA following shortly thereafter. /44/ && .PRELIMINARY POINT TEMPS/POPS... SHV 69 81 68 86 / 20 50 20 40 MLU 69 81 65 86 / 20 60 30 30 DEQ 65 81 64 82 / 50 40 20 50 TXK 66 81 66 83 / 40 50 30 50 ELD 66 80 63 84 / 20 60 30 30 TYR 70 82 68 84 / 20 40 20 40 GGG 69 81 67 84 / 20 50 20 40 LFK 70 81 68 84 / 20 60 10 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...09 LONG TERM....09 AVIATION...44