textproduct: Columbia

WHAT HAS CHANGED

No significant changes made to the key messages. A warming trend culminates in record high temperatures on Friday with increasing fire weather concerns this weekend following a dry cold frontal passage. Aviation discussion updated for 18Z TAFs.

KEY MESSAGES

- 1. Temperatures warm through Friday, before a cold front brings back cooler conditions to the region this weekend. Temperatures likely rebound again early next week.

- 2. Fire weather concerns increase this weekend behind the cold front with very dry air and breezy winds moving in.

DISCUSSION

KEY MESSAGE 1: Temperatures warm through Friday, before a cold front brings back cooler conditions to the region this weekend. Temperatures likely rebound again early next week.

Afternoon satellite imagery shows widespread stratocumulus from this morning has broken up significantly allowing for partial sunshine across much of the forecast area. While temperatures have struggle to warm thus far, the sunshine should allow highs to approach seasonal values with readings in the mid to upper 60s. Temperatures are forecast to continue warming during the next few days as upper ridging builds in from the west. The combination of strong ridging aloft with increasing southwesterly flow at the surface should allow temperatures to reach the upper 70s to lower 80s on Thursday, before topping out in the upper 80s to near 90 degrees on Friday. The current forecast high of 89 degrees at CAE and AGS would break the daily high temperature of 88 degrees at both locations.

There remains fairly good agreement across ensemble guidance and global models on the timing of the strong cold front moving through late Friday and into early Saturday. The front continues to look mostly dry, with slight chance to chance PoP's mainly across the Pee Dee region. Behind the front, much cooler and drier air moves in as strong surface high pressure (near the NAEFS climatological max) moves into the region. Temperatures are expected to be a touch below normal this weekend before followed by warming temperatures into the start of next week.

KEY MESSAGE 2: Fire weather concerns increase this weekend behind the cold front with very dry air and breezy winds moving in.

As the strong cold front moves in late Friday, a tightening pressure gradient takes shape as robust 1036-1038mb high pressure moves into Midwest. This is expected to bring breezy winds by Friday afternoon that ramp up further Friday night into Saturday as the gradient tightens even further with the surface high moving closer. The latest EC Ensemble mean solution shows a swath of 25-30 mph gusts during this period, while the GEFS is a bit less aggressive, but still showing gusts exceeding 20-25 mph. This surface high originating from western Canada brings a very dry airmass where LREF probabilities for RH values under 25% exceed 60% for much of the FA. The latest EC Ensemble is a bit more aggressive, but in general displays a similar story. Overall, confidence is increasing that breezy northeasterly winds will be seen behind the front, coinciding with minimum RH values that near or fall below critical values Saturday afternoon. When this is coupled with dry fuels from the prolonged drought conditions across much of the area, enhanced fire weather concerns are expected especially Saturday. The Storm Prediction Center has already highlighted the FA in critical fire weather conditions on their latest fire weather outlook on Saturday. Near to below critical RH values seem likely again Sunday, but winds look to be much weaker.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

VFR Conditions Expected for much of the TAF Period, Low Ceilings may Return Towards Daybreak....

The low ceilings that were impacting OGB/AGS/DNL earlier in the day have transitioned to VFR decks at all terminals this afternoon. SCT to BKN VFR ceilings are expected at the terminals for the remainder of the daytime hours with generally light and variable winds. For tonight, guidance shows clouds lowering and thickening, especially after midnight. Ceilings may fall to MVFR or IFR levels towards daybreak. A TEMPO was added at AGS/DNL where confidence in restrictions is the highest. Expect improvement in ceilings towards the end of the current TAF period.

EXTENDED AVIATION OUTLOOK...Mainly VFR conditions are expected for the second half of the week. Another cold front will move through Friday night, ushering in another reinforcing cool and dry air mass for the weekend. Some gusty winds are possible Saturday behind the front.

CAE WATCHES/WARNINGS/ADVISORIES

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