textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12z TAF.

KEY MESSAGES

- 1) A warming trend this week will lead to well above normal temperatures, especially Wednesday through Friday.

- 2) Rain chances look to increase again late this week or this weekend.

DISCUSSION

KEY MESSAGE #1: A warming trend this week will lead to well above normal temperatures, especially Wednesday through Friday.

LREF 500 mb height interquartile range remains less than 3 dam through Thursday, indicating good ensemble agreement in the overall synoptic pattern. Given this pattern features surface high pressure offshore and strong upper ridging for this period, confidence is high for a period of well above normal to near record high temperatures. LREF max T interquartile ranges are between 1 and 4 degrees for CAE through Thursday, and only slightly greater at 5 degrees on Friday. NBM temperatures show highs reaching around 70 by Tuesday, then increasing by 2 or 3 degrees each afternoon through Friday. Record highs by the end of the week are generally in the low 80s, and NBM probabilities of 80 degrees or higher are notably 50% to 75% southeast of I-20 on Friday. Lower confidence in temperatures returns by the weekend with the potential for rain chances increasing and the upper ridge breaking down.

KEY MESSAGE #2: Rain chances look to increase again late this week or this weekend.

The overall synoptic pattern depicted by the global ensembles suggests the next decent shot of rain to be late this week or perhaps this weekend. Deterministic solutions have been inconsistent over the last several runs, so have little confidence that we'll see much if any precip around the middle of the week, especially given a lack of forcing and persistent upper ridging. There may be a bit more potential by Thursday as a weak frontal boundary tries to sink into the northern forecast area, and PW values will be slightly higher by then as well. However, a more significant pattern shift in the way of an upper trough and preceding deeper southwest flow aloft appears most likely toward the upcoming weekend.

AVIATION /12Z MONDAY THROUGH FRIDAY/

VFR conditions reappearing with lingering MVFR ceilings near OGB for next couple hours.

Satellite imagery this morning shows the stratus deck continuing to shift south of the Columbia and Augusta terminals with VFR conditions returning here. OGB is nearing the edge of this deck and should see VFR ceilings prevail, but some more stratus may pivot in over the coming hours, bringing intermittent periods of MVFR ceilings. The VAD profile from KCAE has consistently shown 37-40 kts of flow around 2000 ft and with northeasterly surface winds between 5-9 kts, have left mention of LLWS in the TAF at CAE/CUB/AGS/DNL until 14z when surface winds increase to 8-12 kts with gusts up to 20 kts possible until 16-18z. After this, northeasterly winds relax and mostly clear skies are seen the remainder of the day. Tonight, winds become light and variable to calm, where guidance is indicating some fog potential, but uncertainty still exists.

EXTENDED AVIATION OUTLOOK...VFR conditions expected much of the extended period outside of potential fog Tuesday morning.

CAE WATCHES/WARNINGS/ADVISORIES

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