Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
640 FXUS64 KMEG 261721 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1221 PM CDT Sun May 26 2024 ...New AVIATION... .UPDATE... Issued at 936 AM CDT Sun May 26 2024 Updated to cancel the remainder of Tornado Watch #314. Additional showers and sub-severe thunderstorms continue to track across northeast Arkansas, the Missouri Bootheel and the northern half of west Tennessee. Our severe threat should be minimal for the next several hours but another round of severe thunderstorms is still expected later this evening into early Monday morning. && .SYNOPSIS... Issued at 316 AM CDT Sun May 26 2024 Severe weather is possible tonight with damaging winds, large hail, a few tornadoes, and heavy rainfall are all possible. The most likely timing for this event is 9 PM tonight to 5 AM Monday. After storms exit the region Monday morning, warm and dry conditions are expected. Afternoon thunderstorms are possible each day until the next chance of widespread rain later this week. && .DISCUSSION... (Today through Saturday) Issued at 316 AM CDT Sun May 26 2024 A shortwave trough is currently over western Arkansas as of 215 AM. This shortwave will push east in the coming hours and bring a few strong to severe thunderstorms to the northern tier of counties of our County Warning Area (CWA). A very moist and unstable air mass will allow plenty of storm fuel for the trough to initiate convection very soon. Latest mesoanalysis depicts steep mid-level lapse rates (7-8 C/km), 2000-3000 J/kg of MLCAPE, 40-50 kts of effective shear, and 150-200 m^2/s^2 of 0-1km of SRH. This type of atmosphere has all weather hazards on the table. As the shortwave pushes east, it will be interesting to see where the remnant outflow boundaries will set up. The outflow boundaries may result in some afternoon isolated convection, but confidence is low in afternoon convection. It appears some weak shortwave ridging resides behind this shortwave which should keep updrafts to a minimum. The ridging also means clearing skies allowing ample atmospheric recovery and enhancement to surface based instability. During this potential down time, the pressure gradient will begin to tighten as the low and associated cold front approach. Breezy and gusty conditions can be expected in northeast Arkansas, the Missouri Bootheel, and northwest Tennessee. Winds for this area will increase to around 20 mph with gusts up to 35 mph this afternoon. Later this evening a line of storms along a cold front will bring severe weather chances back to the area. Once again all hazards are on the table. Recent CAM runs show this line breaking into a few broken line segments. As with a linear storm mode, damaging winds are the primary threat. MLCAPE values and mid-level lapse rates are a bit concerning on deterministic soundings with 3000-3500 J/kg and 8-8.5 C/km respectively. The tornado threat really seems to ramp up after dark as 0-1km SRH values exceed 200m^2/s^2 in our northern most portion of the CWA, where an Enhanced Risk for severe weather is in effect. Please have your severe weather plan in place, multiple ways to receive warnings, and a way for a warning to wake you up when you are sleeping. Most likely timing for this round appears to 9 PM tonight until 5 AM tomorrow morning as this line of storms tracks southeast. In addition to the severe weather threat, a Flood Watch is in place until 7 AM Monday morning. The Mid-South has seen several rounds of rain over the last several days and PWs are looking to hang around 1.5-1.75". Very saturated soils will not be able to absorb quick rainfall rates or any training storms. West Tennessee, northeast Arkansas, and the Missouri Bootheel will see the most rain today around 1-2" after the rounds of rain today. Locally higher amounts are possible. After the line of storms pushes out of the Mid-South, Memorial Day should be pleasant. A few diurnally driven thunderstorms are possible, but mostly dry conditions are expected. High pressure will slowly slide in to encompass the region. A ~1020mb high will encompass the region by Tuesday morning and will slowly be pushed out by our next chance of widespread rain late week. Diurnally driven, pop-up thunderstorms are possible each day, but nothing widespread or severe is expected at this time. DNM && .AVIATION... (18Z TAFS) Issued at 1220 AM CDT Sun May 26 2024 CAMS continue to show very little activity across the Midsouth this afternoon despite ongoing storms along the Tennessee/Kentucky state line. Will not included any mention this afternoon at any TAF site, but an isolated storm cannot be ruled out. Overnight, a line of showers and thunderstorms will likely impact all TAF sites. MVFR ceilings are possible in the vicinity of thunderstorms. Convection should exit the Midsouth shortly after sunrise. South winds today at 10 to 15 knots with gusts over 25kt will shift to the southwest behind the thunderstorms overnight. Low level wind shear is likely tonight, but TS in the TAF will preclude any mention. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Flood Watch through Monday morning for ARZ009-018-026>028-035- 036-048. MO...Flood Watch through Monday morning for MOZ113-115. MS...None. TN...Flood Watch through Monday morning for TNZ001>004-019>022- 048>055-088>092. && $$ PUBLIC FORECAST...JDS AVIATION...JDS