Area Forecast Discussion
Issued by NWS Nashville, TN
Issued by NWS Nashville, TN
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534 FXUS64 KOHX 221649 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 1149 AM CDT Sun Sep 22 2024 ...New SHORT TERM, LONG TERM... .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... (12Z TAFS) Issued at 624 AM CDT Sun Sep 22 2024 Some MVFR/IFR/LIFR patchy fog continues at KCKV and KSRB while all other terminals maintain VFR conditions. Think -TSRA/VCTS will be possible after 21Z but pinpointing arrival time and impacts is too difficult to put too much detail in the forecast at this time. Another night of mostly VFR expected tonight with exception of some locally dense fog that will once again develop in the fog prone areas. && .PRELIMINARY POINT TEMPS/POPS... Nashville 93 72 91 70 / 20 20 40 50 Clarksville 90 70 87 68 / 40 30 50 70 Crossville 86 64 85 62 / 30 10 50 40 Columbia 93 69 91 68 / 20 10 30 50 Cookeville 87 67 86 66 / 30 20 60 40 Jamestown 87 65 84 64 / 30 20 60 50 Lawrenceburg 92 68 90 68 / 20 10 30 30 Murfreesboro 93 69 92 69 / 20 10 40 40 Waverly 91 69 88 67 / 20 10 30 70 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Clements LONG TERM....Clements AVIATION.....Hurley