Area Forecast Discussion
Issued by NWS Nashville, TN
Issued by NWS Nashville, 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
290 FXUS64 KOHX 221823 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 123 PM CDT Sun Sep 22 2024 ...New AVIATION... .SHORT TERM... (Rest of today through Monday) Issued at 1136 AM CDT Sun Sep 22 2024 An upper-level high pressure remains centered to our south, but with plenty of instability and moisture, some storms have already begun developing late this morning. Low confidence in how widespread this activity will become through the remainder of today as convection will likely be dependent on outflow boundaries that push out of storms over KY. Storms will be hit-and-miss, but with an unstable atmosphere of SBCAPE values around 1500-2000 J/kg, bulk shear values of 25 to 30 knots, and high PWAT values approaching 2 inches, the ingredients are there to allow for a pulsy storm that can produce gusty winds and heavy rain. Any storm activity will diminish after sunset with the loss of daytime heating. By Monday, the high pressure gets suppressed as a trough digs into the Great Plains. Storm chances increase on Monday ahead of this feature, and with better forcing present from this trough, activity won`t be so outflow-dependent as is the case today. The latest SPC Day 2 Outlook also places roughly the northern half of Middle TN in a marginal risk for strong to severe storms. This is likely due to increased mid-level winds from a jet that passes through, allowing for increased wind shear near 40 knots Monday afternoon. While small hail can`t be ruled out, large hail is unlikely with mid-level lapse rates at only 6 to 6.5 C/km. Gusty winds will be the main threat with stronger storms. && .LONG TERM... (Monday Night through next Sunday) Issued at 1136 AM CDT Sun Sep 22 2024 The trough sends a cold front through the area on Tuesday, allowing for the best rain chances of this forecast so far. This Tuesday event is still not looking like a big rain-maker. Rain amounts are still generally expected to be around a quarter of an inch or less, but areas north of I-40 could get closer to half an inch where forcing is better from the trough. But chances of exceeding half an inch is currently less than 20 percent. It`s still an uncertain forecast Wednesday and beyond as models are struggling with a developing low to our west and a developing tropical system in the Gulf. What these two systems do and how much rain we may or may not get is uncertain. Rain chances have trended up slightly late week into the 30 to 50 percent range as model solutions are trending wetter, but confidence remains low as to any specifics regarding timing or amounts. && .AVIATION... (18Z TAFS) Issued at 123 PM CDT Sun Sep 22 2024 Isolated convection developing for locations across mid state region, especially for locations around and east of I-65 Corridor Region. Continued 23/12Z aviation forecast discussion reasoning with VCTS possible 22/21Z - 23/00Z with VFR BKN 3-4 Kft. LIFR fog development possible 23/12Z-23/14Z SRB. Again, another round of shwrs and even potential tstms approaching once again mid state terminals around 23/15Z-23/18Z, but not enough to mention prevailing. && .PRELIMINARY POINT TEMPS/POPS... Nashville 72 91 70 86 / 20 40 50 70 Clarksville 70 87 68 83 / 30 50 70 70 Crossville 64 85 62 83 / 10 50 40 70 Columbia 69 91 68 87 / 10 30 50 70 Cookeville 67 86 66 83 / 20 60 40 70 Jamestown 65 84 64 81 / 20 60 50 80 Lawrenceburg 68 90 68 87 / 10 30 30 60 Murfreesboro 69 92 69 88 / 10 40 40 70 Waverly 69 88 67 82 / 10 30 70 70 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Clements LONG TERM....Clements AVIATION.....JB Wright