textproduct: Columbia

WHAT HAS CHANGED

Adjusted aviation discussion.

Next chance of rain Tuesday night into Wednesday is trending wetter for the area, especially south of I-20.

KEY MESSAGES

- 1) Below average temperatures continue through tonight with warm up tomorrow. Patchy black ice tonight where there is lingering snow or liquid on roads.

- 2) Rain chances ramp up mid week ahead of a cold front.

DISCUSSION

KEY MESSAGE #1: Below average temperatures continue through tonight with warm up tomorrow. Patchy black ice tonight where there is lingering snow or liquid on roads.

Surface high pressure is in place to the south of the area, along the Gulf coast. This air mass continues to moderate today with temperatures expected to be about 5-10 degrees warmer today compared to yesterday. Below average temperatures expected to continue tonight, although radiational cooling will be limited by a strengthening low level jet aloft. Blended guidance still favors temperatures generally in the low to mid 20s, and even into the teens in the northeastern-most portion of the forecast. While the black ice threat tonight into Tuesday morning will likely be much more limited with significant melting and drying today, there remains some concern where the heaviest snow fell, mostly in shady spots northeast of Columbia. Tomorrow the warming trend continues as surface high pressure moves offshore and winds increase out of the southwest leading to warm advection ahead of a cold front.

KEY MESSAGE #2: Rain chances ramp up mid week ahead of a cold front.

A cold front will approach the area with mostly zonal flow aloft but as it moves in models favor a deepening 500mb trough to the west leading to strengthening southwest flow. This will lead to a slower progression of the system through the forecast area which with increasing PWATs (HREF mean indicating approaching an inch) and low level convergence, expect widespread rain developing across the area Tuesday night into Wednesday. Generally trend has been wetter among blended model guidance with highest amounts favored south of I-20 where PWATs will likely increase the most. This would amount to some beneficial rain for the area, but hazardous weather is not expected. Just a note that while there have been some rumors of snow with this next system, forecast soundings are consistent in showing dry air moving in aloft before colder air arrives. Even if there was precipitation associated with the colder air, it is unlikely that there would be ice in the cloud with the moisture remaining too shallow.

AVIATION /20Z MONDAY THROUGH SATURDAY/

VFR Conditions Continue.

A weak shortwave moving across the region could bring a few mid-level clouds across the area this afternoon. Otherwise, skies will be mostly clear and conditions vfr the next 24 hours. As for surface winds, much better mixing has occurred this afternoon across the area, allowing winds to increase a little more that previously expected. Winds will again become light and variable to calm by sunset. Winds on Tuesday will become more southwesterly around 5 knots by late morning as high pressure moves east.

EXTENDED AVIATION OUTLOOK...Another system and front moving into the area Tuesday night and Wednesday could bring restrictions back to the region.

CAE WATCHES/WARNINGS/ADVISORIES

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