977 FXUS64 KSHV 201534 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 1034 AM CDT Mon May 20 2019 .UPDATE... Low level southerly flow has become fully established across the region. Low ceilings forecast to gradually diminish with diurnal heating allowing temperatures to climb into the upper 80s. Could see airmass driven diurnal convection today with best chances along and north of I-30 within the vicinity of a frontal boundary across central Arkansas. Otherwise, a Lake Wind Advisory remains in effect for portions of east Texas and southeast Oklahoma and will likely be expanded eastward and through the overnight hours with the afternoon package update. && .PREV DISCUSSION... /issued 700 AM CDT Mon May 20 2019/ AVIATION... For the 20/12Z TAF period, MVFR/IFR cigs plaguing all sites this morning with a few spots seeing LIFR conditions with patchy fog also being observed. A slow but gradual improvement is expected through the rest of this morning with most sites seeing a return to VFR by very late morning into early this afternoon. A warm front lifting back northward along the I-30 corridor will be the primary focus for convection today, but some isolated to widely scattered showers and a few thunderstorms will also be possible farther south. The terminals most likely to see any convection today are ELD/TXK/SHV and possibly MLU. Any convection should diminish after sunset with heating loss followed by a return of low stratus MVFR cigs after midnight. Otherwise, the other main concern will be the increasing S/SE winds across our East Texas sites and extending eastward toward SHV/TXK where wind speeds will be approaching 15 kts or higher with gusts near or in excess of 25 kts through much of the period, especially across East Texas. /19/ PREV DISCUSSION... /issued 438 AM CDT Mon May 20 2019/ SHORT TERM.../Today through Tuesday Night/ A surface boundary continues to hold up stationary near I-30 in NE Texas and snaking eastward along the Arkansas/Louisiana border. It will gradually lift northward through the remainder of the morning and be completely north of the region by this afternoon. Meanwhile a developing surface low well to our NW will induce an enhanced pressure gradient later this afternoon, especially across our far western counties. Therefore, a Lake Wind Advisory has been issued for SE Oklahoma and the western two-thirds of NE Texas from early this afternoon through late this evening with a likely extension and possible eastward expansion forthcoming with future forecast updates. All that said, expect another warm and muggy day with increasing WAA via the strengthening southerly flow. As far as any convection is concerned today, initial forcing will be rather weak but lift will increase later today as the upper trough out west propels farther eastward from the Four Corners Region across the Rockies. Upper forcing will increase dramatically across the Plains with a very volatile day expected across much of Oklahoma and NW Texas. Farther east across our region, instability will be peaking this afternoon near 3000 J/kg for MUCAPE values once again with scattered convection expected to develop over much of the region. The area of greatest concern for strong to severe storms will be across our far NW tier including McCurtain County in SE Oklahoma and the adjacent sections in SW Arkansas where the warm front will be lifting back northward and coinciding with increased upper forcing ahead of the ejecting trough to the west. Damaging winds and large hail will be the primary concerns with any storms that develop and spread into these NW tier areas. Any convection farther south and east is not expected to be severe through today and tonight. Shifting ahead to Tuesday, the aforementioned upper trough will be spilling out into the mid-section of the country with a closed low ejecting NE across the Plains. Increased forcing along and ahead of the upper trough axis will induce a line of convection from central Texas eastward into our region through the afternoon and early evening. Intensification of this line with peak heating could induce strong to severe storms with damaging winds becoming the primary threat along this line as it shifts into our region. A Slight Risk is already highlighted for areas north of I-20 in NE Texas, extreme NW Louisiana, and points north in Arkansas and SE Oklahoma. Large hail and isolated tornadoes are lower end threats but cannot be completed ruled out. The severe threat should slowly wind down through the evening and overnight hours with the primary forcing shifting farther NE into northern Arkansas and Missouri through Tuesday night. As far as our temperatures are concerned, expect them to generally maintain near to slightly above normal readings through mid-week. /19/ LONG TERM.../Wednesday through Sunday/ The long term portion of the forecast can be summed up easily: Warm (some might say hot) and dry. Model consensus is quite good that the Four State Region will be on the western side of a dogged Deep South subtropical upper level ridge through the bulk of the period while a long-wave trough in the western CONUS sends pulses of energy occasionally through the Intermountain West and Central Plains. The official forecast does have some slight chances of showers and thunderstorms north of I-20 on Wednesday in associated with the prior boundary retreating north through the day. Most of the period our region will be in prevailing southerly flow with perhaps enough moisture depth in western zones to allow for isolated afternoon/early evening shower and thunderstorm development. However, the suppressive influence of the nearby ridge center will be vast and thus confidence in even slight rain chances after Wednesday is not currently enough to include in the official forecast. Otherwise, anticipate temperatures running about 5 degrees above normal through the period, meaning max temperatures will generally be around 90 degrees with min temps close to 70 degrees. Peak heat index values will be peaking in the low to mid 90s most days owing to moderate humidity. Some may hate to see this forecast of consistent heat before June, but we should be glad we are not farther east; underneath and east of the ridge center atmospheric suppression and related heat anomalies will be much more significant. Model consensus suggests the ridge center may start breaking down or getting squashed more to our east early next week, which should likely allow for some rain chances to start creeping back in next week. However, it is not likely a wetter trend will start before the upcoming Memorial Day weekend is over. /50/ && .PRELIMINARY POINT TEMPS/POPS... SHV 88 73 87 72 / 30 10 30 40 MLU 88 71 89 74 / 30 0 10 20 DEQ 83 70 80 63 / 50 20 80 20 TXK 85 71 82 69 / 40 10 60 50 ELD 86 72 87 71 / 30 10 20 40 TYR 87 73 83 69 / 20 20 60 20 GGG 88 73 84 71 / 20 10 60 40 LFK 89 74 87 74 / 20 10 30 30 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...Lake Wind Advisory until 10 PM CDT this evening for OKZ077. TX...Lake Wind Advisory until 10 PM CDT this evening for TXZ096- 108>111-124-125-136-137-149-150-152-165. && $$ 05/19/50