Sunrise 6:24 AM   Sunset 7:59 PM Moonrise 2:42 AM   Moonset 2:13 PM

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FXUS64 KSHV 030552 AFDSHV

Area Forecast Discussion National Weather Service Shreveport LA 1252 AM CDT Fri May 3 2024

New AVIATION

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
(06Z TAFS)
Issued at 1243 AM CDT Fri May 3 2024

Plenty of disagreement to work with tonight as 00z CAMs have struggled to promote a collective convective decision across the airspace through the morning. Currently, thunderstorms are present west of the airspace, with upper level cirrus associated with the convection working west to east, and into the airspace. As a result, have prevailed high level OVC for many, along with any low level CIGs advertised in area ASOS/AWOS. Plan for now is to not stray far from the previous TAF package convection through the morning, and monitor trends through the overnight, with the goal of adjusting for the 12z package later this morning. Aviation interests will need to closely monitor overnight trends given how fluid the forecast is at this time.

RK

PRELIMINARY POINT TEMPS/POPS
SHV 81 68 86 69 / 50 20 40 20 MLU 81 65 86 67 / 60 30 30 20 DEQ 81 64 82 63 / 40 20 50 40 TXK 81 66 83 66 / 50 30 50 30 ELD 80 63 84 64 / 60 30 30 20 TYR 82 68 84 67 / 40 20 40 40 GGG 81 67 84 67 / 50 20 40 30 LFK 81 68 84 68 / 60 10 30 20

SHV WATCHES/WARNINGS/ADVISORIES
AR...None.
LA...None.
OK...None.
TX...None.

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