####018006321#### FXUS64 KSHV 260821 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 321 AM CDT Fri Apr 26 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Friday through Saturday) Issued at 320 AM CDT Fri Apr 26 2024 The weather story and hazard outlooks remain largely unchanged from recent forecasts as of this writing. As a series of upper level lows eject east from the Intermountain West and veer along a northeasterly track up the Great Plains and towards the Great Lakes, this persistent unsettled pattern will result in several days worth of showers and storms bringing rainfall to much of the ArkLaTex, and some chances of severe weather, particularly to our northwestern half. Showers have already begun to move into our southeastern Oklahoma zones as of the 08Z hour, and will increase in coverage and intensity while gradually trekking south and east after daybreak today. Showers and storms will impact all but the southeasternmost reaches of the ArkLaTex through this afternoon, receding in coverage back to the north of the I-30 corridor overnight into Saturday. The severe weather outlook today remains much the same as previous iterations, with a Slight Risk covering our northwestern zones from Tyler up to Texarkana and along I-30, extending just far enough south to clip the northwestern corner of Louisiana. The chief modes of severe weather expected will be damaging wind and especially large hail, but a tornado or two cannot be ruled out entirely. Simultaneously, these same zones are included in a slight risk of excessive rainfall leading to flash flooding, particularly in areas of training torrential rainfall. 1-2 inches of accumulation today look easily possible, particularly north of I-30. Today's highs will range from the middle 70s northwest to middle 80s southeast, followed by a night of lows in the upper 60s to near 70 degrees, and a warmer Saturday as more sites reach the mid to upper 80s. Saturday continues to look like the "in-between" day of this stretch, where we will not see a defined line of storms associated with one of the aforementioned lows move into the region. Nevertheless, conditions will remain ripe for renewed showers and storms across the northern half of the Four State Region through the course of the day, accompanied by a Marginal Risk for severe weather and a sliver of Slight Risk on our northwestern corner, accompanied by a similar distribution of ERO risks. All modes of severe weather will again be possible, but at reduced confidence compared to Friday and Sunday. /26/ && .LONG TERM... (Saturday Night through Friday) Issued at 320 AM CDT Fri Apr 26 2024 During the day Saturday and into Saturday night, the second of the upper level lows will begin to make its northeastward journey up the Plains, swinging its frontal boundary and attendant convection into the ArkLaTex. There is little in the way of a defined break between Saturday's showers and storms and Sunday's convection, thus it remains to be seen how worked over the environment may be ahead of the arrival of Sunday's storms. That being said, the outlook continues to highlight a sizable swath encompassing the northwestern two-thirds of the region in a Slight Risk for Sunday into Sunday night. All modes of severe weather are being considered likely, with emphasis once again on damaging winds and large hail. The third straight day of severe weather impacts will indeed also be the third straight day of flash flooding impacts. By the time all is said and done, storm total accumulations look to range from 1-2 inches in north central Louisiana to as high as 4+ inches in extreme southeast Oklahoma. Given the recent substantial flooding event across the region, and with many area waterways still quite full, a return to flood stages cloud be quickly achieved, and this potential hazard necessitates as much vigilance as the severe threat. After the upper level low departs and synoptic flow becomes more zonal, conditions will remain unsettled into next week, as southerly flow funnels continued moisture and showers and storms remain possible through the end of this extended forecast period. Temperatures will be mitigated somewhat by the ongoing rainfall but will remain warm in the low to mid 80s throughout, with lows in the upper 60s to lower 70s. /26/ && .AVIATION... (06Z TAFS) Issued at 100 AM CDT Fri Apr 26 2024 MVFR cigs have begun to develop across E TX to begin the 06Z TAF period, with these cigs expected to develop farther E into Wrn LA/SW AR during the overnight hours. ELD/MLU should remain VFR through at least 12Z, before MVFR cigs develop after daybreak. Should see a gradual improvement to cigs by late morning/early afternoon, with VFR cigs returning areawide. However, scattered to numerous areas of convection are expected to spread into portions of NE TX/SE OK/SW AR by late morning to early afternoon, primarily affecting the TYR/GGG/TXK terminals, before possibly affecting SHV by late afternoon. This convection should diminish during the evening, with MVFR cigs expected to develop by mid to late evening over Deep E TX/Cntrl LA, and quickly spread N across E TX/N LA by the end of the TAF period, and into SW AR after 06Z Saturday. These cigs will persist through mid to late morning Saturday before lifting/returning to VFR. SSE winds 5-10kts overnight, except 10-15kts with occasional higher gusts over E TX, will increase to 12-20kts with gusts to 30kts after 15Z. /15/ && .PRELIMINARY POINT TEMPS/POPS... SHV 85 72 88 71 / 20 30 10 10 MLU 85 69 87 67 / 0 20 10 0 DEQ 76 65 81 65 / 80 40 60 40 TXK 81 70 85 69 / 50 40 40 20 ELD 83 66 86 66 / 20 30 20 10 TYR 80 70 85 70 / 70 30 20 30 GGG 82 70 86 70 / 50 30 20 20 LFK 84 70 87 70 / 30 20 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ SHORT TERM...26 LONG TERM....26 AVIATION...15 ####018004635#### FXUS63 KOAX 260822 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 322 AM CDT Fri Apr 26 2024 .KEY MESSAGES... - Several rounds of showers and thunderstorms are expected through the weekend. - Severe weather appears likely (>80% chance) during the afternoon and evening hours on both Friday, Saturday, and perhaps Sunday. - Flash flooding is also a concern due to the potential for repeated thunderstorm activity over the same areas. && .DISCUSSION... Issued at 319 AM CDT Fri Apr 26 2024 Today... Multiple rounds of showers and thunderstorms traversed eastern Nebraska and southwest Iowa overnight, fueled by a robust southerly low-level jet. Heavy rain with these storms required the issuance of a handful of flood advisories over parts of northeast Nebraska. Despite the dreary start to the day, expect clouds to begin to thin across parts of southeast Nebraska by early Friday afternoon. Moderate instability will blossom in this region, ahead of an approaching dry line. Strong bulk shear vectors of 40-55kts are possible across much of the forecast area late Friday morning and into the early afternoon, as a low pressure system begins to move through northeast Nebraska. Supercells will become the most likely storm mode Friday afternoon. Given the steep lapse rates, and robust low level jet. Very large hail will be the primary threat, along with a few tornadoes (some of which may be strong). Heavy rain and strong winds would also be possible with any supercell that forms. The current CAM solutions have storms developing around 2 PM and moving out of southwest Iowa around 8 PM. One potentially limiting factor to the Friday afternoon/evening event would be how far north the narrow channel of sufficient instability reaches. Even the latest model solutions vary on how much clearing and atmospheric recovery we will see after noon today. However, it is clear that any supercells that do become established will be capable of producing damage. Friday Night through Saturday... Once the rain shuts down Friday evening, the remainder of the night Friday night into Saturday morning looks quiet, especially for those participating in outdoor activities Saturday morning. However, that break will be short-lived as another round of severe weather potential develops Saturday afternoon by 4 PM and beyond, as a frontal boundary from the first system is reinvigorated by the next closed low moving out of the Rockies. This allows widespread showers/storms to redevelop across the region Saturday night, with the next round of severe storms possible along/south of Interstate 80. Once again, all modes of severe storms would be possible, including another round of supercells with potential tornadoes and very large hail. Given the multiple rounds of storms Saturday night, compounded with the rainfall we received overnight tonight and will receive this evening, we will have to keep a close watch on flooding potential with an increasing risk for flash flooding. Sunday and Beyond... Another round of storms will close out our weekend on Sunday, as the second low pressure system passes through the forecast area. While the best chance for more well-developed/stronger storms will likely remain off to our east, the passage of the surface low through the heart of our CWA brings concerns for a few low-topped supercells with tornadic potential. We finally receive a break from the active weather pattern on Monday and into early next week, with just a few minor showers and storms possible Tuesday and Wednesday. Temperatures will generally top out in the 70s next week, with a few locations reaching the low 80s on Tuesday. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1231 AM CDT Fri Apr 26 2024 Our first round of thunderstorms continues to move through eastern Nebraska and western Iowa tonight. Expect periods of reduced visibilities, down to 1 mile in the strongest storms. Ceilings will dip to IFR at all three sites tonight and into early Friday morning before lifting to MVFR around 18Z. Our next round of storms will arrive between 20-23Z Friday afternoon. While a few of these storms are expected to be severe, the exact timing and location remains questionable at this time. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...KG AVIATION...KG