textproduct: Morristown

UPDATE

Issued at 930 PM EDT Wed Apr 2 2025

Storms and rain will remain west of the region tonight for the most part. Early tomorrow morning some showers may move into the Plateau counties but confidence is low. Upped the cloud cover for tonight. Obs are clear but high clouds can be seen on satellite overhead and upstream. Lows will be mild in the 60s for the Tennessee Valley due to cloud cover and continued WAA.

SHORT TERM

(This evening through Thursday) Issued at 312 PM EDT Wed Apr 2 2025

Key Messages:

1. Windy conditions will continue across the area through this evening, especially the far east Tennessee mountains and foothills through Thursday morning. Please refer to the High Wind Warning and Wind Advisory Products.

2. Most of the area will remain dry but best chance of showers and storms will be across the northern Plateau late tonight and Thursday.

3. Near record to record high temperatures are likely across much of the area for Thursday. Temperatures will be 15 to 20 degrees above normal.

Discussion:

Tight pressure gradient across the Tennessee valley and southern Appalachians will continue to produce 850mb jet of 40-50 knots. Gusts at Cove Mountain has peaked thus far at 69 mph with 64 mph at Camp Creek. Strong and gusty winds will continue across the far east Tennessee mountains and foothills through Thursday morning. Winds across the valley will subside toward sunset.

Convection has not been allowed to develop given the mid-level cap.

For tonight, a line of showers and thunderstorms will move across Tennessee overnight into Thursday morning. HREF and HRRR suggest this line may move into the northern Plateau toward daybreak. The low-level moisture has been slow to erode across the Plateau and southeast Tennessee. Overall expect partly to mostly cloudy sky over the area overnight.

For Thursday, the mid-level cap will remain across much of the area along with upper ridging. This will keep any chances of convection limited at best and mainly across the Plateau counties. The upper ridge and abnormally warm 850mb temperatures will produce an unseasonably very warm day. Near record to record high temperatures are anticipated.

Date Chattanooga Knoxville Tri-Cities Oak Ridge 04-03 89(1999) 85(1946) 82(2012) 87(1963)

LONG TERM

(Thursday night through next Wednesday) Issued at 312 PM EDT Wed Apr 2 2025

Key Messages:

1. Abnormally warm weather pattern continues Friday and Saturday, with temperatures around 20 degrees above normal; record-breaking highs are likely.

2. Showers and thunderstorms affect the area Sunday, with potential for strong storms with heavy rainfall.

3. Much colder temperatures Monday through Wednesday, with lows near to below freezing Tuesday and Wednesday mornings.

Discussion:

Thursday night begins with strong ridging aloft centered over the SE coast as well as surface high pressure over the western Atlantic. The pattern will seemingly become locked as deep troughing dominates the west and ridging over the east. This set up will stall the front and storm system to our west and northwest, where the MS to OH Valley regions are expecting 4 to 10 or so inches of rainfall over the next 5 days. We will remain under the "high and dry" sector until the pattern gets moving again and the system finally passes over us this weekend. With really high heights and southerly flow, high temperatures will max out around 20 degrees above normal with readings in the upper 80s across the valley Friday and Saturday. 90 degrees may be possible somewhere. Our climate sites will ultimately be flirting with breaking record highs or tying them.

Daily Record High Maximum Temperatures

Date Chattanooga Knoxville Tri-Cities Oak Ridge 04-04 88(1934) 87(1934) 83(2023) 84(1999) 04-05 89(2023) 89(2023) 86(2023) 88(2023)

By Saturday, troughing will start shifting our direction, suppressing the SE ridge. There will essentially be a tight gradient of precipitation to none at all, which will lie across our northern Plateau counties and southwest Virginia; the best chance of seeing any precipitation in the first day or so of the long term. By late Saturday and into the early hours of Sunday, the mass precipitation axis that essentially parks over the aforementioned regions in the first paragraph, will finally reach us, bringing the possibility of severe storms, and especially heavy rainfall. Latest totals from Saturday night to early Monday, place many locations in the 2 inch range. Currently, lesser amounts of below 2 inches for far NE TN and SW VA. SPC Day 4 issued this morning, has the 15% chance of severe enveloping our western half of the CWA, so will need to watch for the potential of severe weather.

Following the front's passing, the last couple days of the long term will be night and day compared to the first half. Drastic height falls under the trough, NW flow, and 850 temperatures dipping below 0C, will provide a couple days of below normal conditions, especially the low temperatures anticipated Tuesday and Wednesday morning. Wednesday may be the coldest with many values around or below freezing. Heads up to those who may have planted sensitive plants early. The long term also ends dry with ridging building in behind the trough and surface high pressure aiming for the Mid- Atlantic from Canada.

AVIATION

(06Z TAFS) Issued at 103 AM EDT Thu Apr 3 2025

The main aviation impact again tonight will be LLWS, which is currently included for CHA and TRI. Winds of around 35 to 40 kts around 2,000 feet AGL will persist area-wide, but gusty surface winds at TYS will limit LLWS potential. There will also be additional MVFR moving into CHA over the next couple of hours and continuing into the late morning. Regarding the severe convection to the west, the current trends continue to suggest everything to fall apart before it reaches the terminals. There is a very low- end chance that rain reaches TRI, but aviation impacts would be limited if this does happen. Winds will be gusty again through the day on Thursday but not quite as strong as yesterday.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 67 88 66 88 / 0 10 0 0 Knoxville McGhee Tyson Airport, TN 66 87 66 88 / 10 10 10 10 Oak Ridge, TN 66 86 65 87 / 10 20 0 10 Tri Cities Airport, TN 63 85 62 87 / 10 20 0 10

MRX WATCHES/WARNINGS/ADVISORIES

NC...NONE. TN...Wind Advisory until 8 AM EDT this morning for Johnson-Southeast Carter-Southeast Monroe-Unicoi.

High Wind Warning until 11 AM EDT this morning for Blount Smoky Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains- Southeast Greene.

VA...NONE.