886 FXUS64 KSHV 111438 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 938 AM CDT Mon Mar 11 2019 .UPDATE... Widespread showers with isolated embedded thunder continue across mainly southern Arkansas and north Louisiana, shifting east. Conditions to gradually improve as upper-level ridging becomes better established across the region this afternoon. Current forecast reflects an improving trend. At this time no update is necessary. /05/ && .PREV DISCUSSION... /issued 709 AM CDT Mon Mar 11 2019/ AVIATION... For the 11/12Z TAF period, mostly MVFR/low VFR cigs observed this morning as showers continue to increase in areal coverage with SW flow aloft lifting warmer air above the relatively cool sfc temps. Showers will continually spread farther south and east through mid to late morning into early afternoon before gradually diminishing as an upper level disturbance shifts east of the region. Embedded thunderstorms will also accompany showers, but confidence is low on placing them at any individual TAF site. Cigs/vsbys could drop to IFR within some of the heavier convection, but generally look for MVFR/low VFR cigs to be maintained through much of the period. NE winds between 6-14 kts will be common with occasional higher gusts near 18-22 kts through the daytime hours, then speeds will drop off slightly overnight. /19/ PREV DISCUSSION... /issued 415 AM CDT Mon Mar 11 2019/ SHORT TERM.../Today through Tuesday/ Stalled frontal boundary remains perched just to our south with increased isentropic forcing as warmer SW flow just above the cooler sfc continues to induce showers this morning, especially across the northern half of our region where embedded shortwave energy is also contributing to the convection. Look for coverage to increase once again farther south as we move through the day today with this shortwave traversing SE across the remainder of the area. Therefore, continue to advertise high chance to likely POPs areawide with temperatures primarily in the 50s for highs this afternoon. Warmer readings will be observed across our far southern tier closer to the stalled boundary. Although prospects of thunderstorms are low, cannot rule some isolated activity embedded within the more widespread showers as the shortwave shifts eastward. Rain chances will fall off sharply overnight as the shortwave exits with mainly isolated to scattered coverage ahead of yet another shortwave, which is expected to primarily shift to our north and west across the Southern Plains. Therefore, continue to favor lower POPs through Tuesday as warmer temperatures return to the area. Expect highs mainly ranging through the 60s with some 70s down across our southern sections as the weak boundary begins lifting back northward as a warm front. /19/ LONG TERM.../Tuesday Night through Sunday Night/ Scattered showers and a few thunderstorms are possible late Tuesday, especially along and north of Interstate 30, as a warm front continues to move north across Oklahoma. Meanwhile, a strong upper trough over Southern Arizona/New Mexico and Northern Mexico will begin to eject to the northeast during the overnight hours. The trough should be taking on a negative tilt at this time, and rapid surface lee cyclogenesis will occur over the High Plains. A Pacific cold front/dryline will also rapidly sharpen from the surface low trailing southward across the Southern High Plains. Strong to severe convection is expected to develop along this front/dryline. The resulting QLCS will move across Oklahoma and Texas and should approach the western fringes of Southeast Oklahoma and East Texas just before noon Wednesday. The potential for severe weather still exists with the QLCS on Wednesday. Shear profiles, combined with the probable development of bowing segments along the line, suggest that a damaging wind threat will likely exist. An isolated tornado embedded within the QLCS also cannot be ruled out. However, instability will be very limited, likely less than 1000 J/kg. The primary time frame for strong to severe convection across the area will be from noon through the evening hours. The strongest convection should exit to the east and across the Mississippi River by midnight Thursday morning. Southwesterly flow aloft will provide ample deep layer moisture, so these storms should be efficient rain producers. The models are in good agreement showing the potential for up to three inches of rain across South Central Arkansas and North Central/Northeast Louisiana. Many locations in this area are already two to four inches above normal for rainfall this year, so flash flooding could be a concern on Wednesday. As the upper level shortwave moves through Kansas, it will merge with a northern stream trough and become much broader and very positively-tilted. The vertically stacked system will slow down considerably. The Pacific cold front will likely stall across our area, which will keep scattered showers and a few thunderstorms in the forecast for much of Thursday, mainly southeast of a line from Lufkin TX, to Shreveport, to Magnolia AR. The upper trough will finally lift towards the Great Lakes by late Thursday, which should bring a cold front through the area from the northwest ushering considerably drier and cooler air into the region. No precipitation is expected after midnight Friday morning. Medium range models suggest a few showers are possible during the day Sunday as a weak shortwave trough moves across the Southern Plains. However, deep layer moisture availability is questionable, especially in the lowest levels. Thus, a dry forecast was maintained for now. Well below normal temperatures can be expected for Friday and next weekend before we slowly begin to moderate heading in the beginning of next week. Most locations will fall below 40 degrees F for overnight lows, and below freezing temperatures are possible Friday night/Saturday morning in Southeast Oklahoma and extreme Southwest Arkansas. CN && .PRELIMINARY POINT TEMPS/POPS... SHV 60 53 68 62 / 70 30 20 30 MLU 59 52 69 62 / 70 30 20 10 DEQ 57 50 60 57 / 60 50 40 50 TXK 57 50 63 59 / 70 40 30 40 ELD 58 51 66 60 / 70 40 20 20 TYR 58 53 69 61 / 50 40 30 50 GGG 58 53 68 62 / 50 30 30 40 LFK 69 57 75 64 / 50 20 20 40 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 05/09/19