textproduct: Columbia

WHAT HAS CHANGED

Removal of afternoon verbiage and minor adjustments to Key Messages. Aviation discussion updated.

KEY MESSAGES

- 1. Chances for showers/storms continue into Tuesday before drier conditions begin to move in.

- 2. Below normal temperatures Tuesday behind a front before a warming trend is expected into this weekend.

DISCUSSION

Key Message 1: Chances for showers/storms continue into Tuesday before drier conditions begin to move in.

An upper trough over the Great Lakes is expected to sharpen and dig through the eastern US. An associated front is expected to accompany this sharper trough, passing over the area tonight into Tuesday morning. This will bring another round of scattered showers and isolated thunderstorms to the region. While PWATs remain high, the risk of flash flooding is low outside of any training cells. While the overall severe risk is limited due to the loss of daytime heating, an isolated stronger thunderstorm or two cannot be ruled out as depicted in some of the CAMs.

This front moving in from the northwest should bring cooler/drier air into Tuesday, though it may stall out near the southern FA, bringing continued scattered rain chances through at least the first half of the day. PWAT's then likely drop to under 1" Tuesday evening as a surge of dry air moves, leading to drier conditions that likely hold the remainder of the week.

Key Message 2: Below normal temperatures Tuesday behind a front before a warming trend is expected into this weekend.

Temperatures are then expected to fall below normal Tuesday as a push of CAA moves in behind the front. Current NBM guidance has high temperatures Tuesday in the mid to upper 70s, but depending on how far south the front pushes and the timing of the onset of 850mb CAA, temperatures, could trend toward somewhat lower than currently forecast. There is limited change in the temperature outlook through this weekend. The latest LREF cluster analysis remains is decent agreement that the upper ridge currently over the Central US will shift overhead with surface high pressure building in as well. This should bring temperatures that remain below normal Wednesday, but begin steadily raising closer to normal Thursday and into this weekend.

AVIATION /01Z TUESDAY THROUGH SATURDAY/

Shower Activity Increasing in Coverage in the Midlands....

While the main line of showers and thunderstorms has moved away from the terminals this evening, renewed shower activity has developed during the last 30 minutes. There are also thunderstorms moving from the Upstate to monitor. Right now will maintain a TEMPO for a passing shower or two at CAE/CUB/OGB and amend as needed. Model guidance continues to suggest showers and thunderstorms will move into the CSRA impacting AIK/AGS/DNL later tonight so maintained the TEMPO for thunder there. Guidance indicates additional low CIGS may develop after sunrise Tuesday morning, with mainly MVFR restrictions occurring. Additionally, winds will become more NELY behind the front at around 10 kts.

EXTENDED AVIATION OUTLOOK...Drier air returns to the region mid to late week with mainly VFR conditions expected.

CAE WATCHES/WARNINGS/ADVISORIES

SC...None. GA...None.