textproduct: Columbia

SYNOPSIS

Cool and mostly dry conditions are expected today, though a few showers are possible along and ahead of a cold front this afternoon and evening. A period of moderate to heavy rainfall is expected with the next storm system Monday night into Tuesday. High pressure then builds back in for Wednesday and Thursday before another system may take aim at the region to end the week.

NEAR TERM /UNTIL 7 AM MONDAY MORNING/

Key message(s):

- Light showers possible throughout the evening as a cold front slides through.

Some light showers continue to move across the western Midlands this evening, with minimal QPF or rates. This will push east this evening but steadily dissipate around midnight or so. The associated surface front will cross the region shortly after, pushing some slightly drier air into the area and flipping winds out of the north-northeast. It is not a terribly strong front, so the temp advection and moisture advection behind it will be quite inconsequential.

SHORT TERM /7 AM MONDAY MORNING THROUGH TUESDAY NIGHT/

Key message(s):

- Cooler and drier on Monday with a low (10 to 20 percent) risk for a few light showers until rain chances rapidly increase towards evening.

- Widespread moderate to heavy rainfall moves in Monday night into Tuesday morning with precipitation tapering off from southwest to northwest in the afternoon.

- Skies clear out Tuesday night as high pressure builds in.

Monday and Monday Night: High pressure passes north of the region pushing cold, dry air down the spine of the Appalachians in a classic in-situ wedge setup. Expect mainly cloudy skies and cooler temperatures. While much of the day should be dry, a bit of drizzle or a few light showers cannot be ruled out, especially in the CSRA. Temperatures will be cooler than today with forecast highs generally in the 50s, with some upper 40s possible in the far northern CWA. Low pressure in the Western Gulf rapidly moves northeast and ends up near or off the South Carolina coast by daybreak Monday. The rain may be heavy at times towards daybreak. The clouds and rain limit cooling with lows ranging from the mid-30s to mid-40s.

Tuesday and Tuesday Night: Widespread moderate to locally heavy rainfall should be ongoing at the start of the day aided by an approaching upper trough, deep isentropic lift, and a robust low-level jet. While the forecasts is calling for rainfall amounts between 1 and 2 inches, the overall flood threat is low though some minor flooding cannot be ruled out in locations where the heaviest rainfall occurs. Rain chances diminish from southwest to northeast during the afternoon and evening hours. Skies clear out at night as high pressure builds in from the west. Daytime temperatures should once again end up in the 50s in most locations, with a few lower 60s possible across the southeastern CWA. Clearing skies at night should promote radiational cooling allowing temperatures to drop into the upper 20s to mid-30s.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Key message(s):

- Mainly sunny but cool on Wednesday.

- Warmer Thursday with increasing cloudiness.

- Rain chances return to close out the extended.

High pressure passes overhead on Wednesday bring cool, dry weather conditions to the FA. The anticyclone will pass offshore by daybreak Thursday promoting moisture and warm air advection across the FA, though temperatures will likely remain below seasonal values. Clouds should increase during the day ahead of the next storm system, which will begin to take shape over the Western Gulf. Rain chances increase Thursday night into Friday and there is the potential for another round of moderate rainfall to close out the extended, though confidence in timing is low. Temperatures should warm enough Friday morning to prevent any frozen precipitation at the onset of the event, though trends will be monitored. Below normal temperatures are likely to persist through the long term.

AVIATION /00Z MONDAY THROUGH FRIDAY/

Some restrictions possible late tonight or early Monday morning as a weak front moves through the region.

A cold front continues to approach the area this evening and will move through overnight. Isolated light showers may impact the terminals ahead of the front, with the main impacts being brief MVFR CIGS/VSBYS. Lower confidence in impacts at OGB. Precip chances generally end after 07z-09z with VFR CIGS returning. Guidance then continues to indicate the return of MVFR CIGS at AGS/DNL in the 12z-16z time frame Monday morning, with some potential improvement by Monday afternoon. Otherwise, the terminals should generally remain VFR tomorrow.

Generally light and variable winds around 5 kts or less through this evening until the front passes, then winds should shift more NELY by morning and increase to 5 to 10 knots after 15z.

EXTENDED AVIATION OUTLOOK...The next weather system will keep the potential for restrictions in rain Monday night through Tuesday, with highest likelihood of rain on Tuesday. Additional restrictions possible late in the week.

CAE WATCHES/WARNINGS/ADVISORIES

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