SHORT TERM
(This evening through Saturday)
Issued at 221 PM EDT Fri Jul 26 2024

Key Messages:

1. Showers and thunderstorms continue this afternoon with the greatest coverage likely to be south of I-40.

2. Another round of showers and possibly thunderstorms will occur tomorrow.

Discussion:

Currently the initial round of light showers moving through the central valley is running into the drier airmass in northeast TN and southwest VA. Expect this trend to continue with only isolated drizzle expected north of Interstate 40. More robust convection is moving along near the southern TN border. There is some enhanced moisture convergence and slightly better synoptic forcing on the southern edge of the trough moving through. With some clearing in the clouds across southeast TN this afternoon these storms could move into some enhanced instability as they move further to the east. MLCAPE values could exceed 1,000 J/kg in this area. Biggest threats with the strongest storms would likely be gusty winds and brief heavy downpours leading to localized flooding of poor drainage areas.

Moving into the overnight hours expect the convection to quickly die off once the sun begins to set leading to a fairly calm overnight period. Expect another round of patchy fog in our region with the higher dew points and recent rainfalls. Tomorrow will see another warm and humid day with afternoon showers and thunderstorms possible once again.

LONG TERM
(Saturday night through next Friday)
Issued at 221 PM EDT Fri Jul 26 2024

LONG TERM
(Saturday Night through Friday)

Key Messages:

1. An unsettled pattern with daily chances of showers and storms is expected through the long term.

2. Localized flooding is possible due to repeated, potentially heavy rainfall, especially Monday.

Discussion:

Come Sunday, we will find ourselves under brief ridging squished between shortwave troughing to our west and a developing cutoff low off the east coast. This will allow for increasing moisture advection into the region with PWAT increasing to upwards of 2 inches in portions of the central and southern valley. Vort maxima and isentropic lift will lead to numerous to widespread showers and storms Sunday and Monday. Model derived soundings suggest tall & skinny CAPE profiles with freezing levels between to 13 to 14kft may very well promote periods of efficient warm rain processes. This will lead to increased flooding potential, especially for Monday, in which a large portion of our area of responsibility remains highlighted in a slight risk ERO. A limiting factor to the flooding threat may be fairly meager MLCAPE values less than 1000J/kg, however, soundings also suggest corfidi upshear values less than 10kts are possible and potential for slow moving or back building storms will need to be monitored.

Quasi-zonal flow with bouts of upper level disturbances is expected Tuesday onwards. This will promote continued daily chances of showers and storms through the extended period. A continued threat of flooding is a little less clear given a lack of real significant upper level features but poor antecedent conditions may allow the flooding threat to persist throughout the week as well. Temperatures mid to late week will also be trending warming, with thermodynamic profiles becoming increasingly favorable for more thunderstorm activity and potential gusty winds and small hail with stronger storms. Slightly above normal temperatures are expected to return in

AVIATION
(00Z TAFS)
Issued at 721 PM EDT Fri Jul 26 2024

Mostly VFR conditions are expected this TAF cycle. Some fog development is possible in the early morning hours, mainly near TRI where clearing is expected. High clouds will hang around longer for TYS/CHA. Hit and miss showers are likely mainly near TYS/CHA in the afternoon.

PRELIMINARY POINT TEMPS/POPS
Chattanooga Airport, TN 71 88 73 87 / 20 50 10 70 Knoxville McGhee Tyson Airport, TN 68 88 71 88 / 20 40 10 60 Oak Ridge, TN 68 88 70 86 / 10 40 10 60 Tri Cities Airport, TN 65 87 65 88 / 10 20 0 30

MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.