Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
031 FXUS62 KCAE 111838 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 238 PM EDT Sat May 11 2024 .SYNOPSIS... High pressure keeps the area dry through the weekend and into the beginning of next week. The high then moves offshore Monday and increasing moisture supports an unsettled week with chances for showers and thunderstorms for much of the week. && .NEAR TERM /THROUGH TONIGHT/... A well-developed cyclone is moving through the Great Lakes region today, while surface high pressure is building over the southeast. Satellite imagery and a look out the window reveals a scattered fair- weather cu deck across much of the Midlands with some lingering moisture in the atmosphere. Surface observations show west to northwest winds continue to usher in a drier airmass with dewpoints in the low to mid 40s, while temperatures have warmed into the low to mid 70s. Fair weather continues the remainder of today as the upper trough north of us continues to move east into New England, reinforcing northwest flow aloft. A weak surface trough and front associated with this upper low will then move through the region tonight, but with PW values only around 0.5", no precip is expected. Main effect will be another slight wind shift from the west to the northwest late tonight into Sunday morning. Dry surface regime will generally preclude any fog concerns for tonight, and lows are expected to be cool once again, generally in the low to mid 50s. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... High pressure continues to ridge over the forecast area Sunday with heights rising as weak upper ridging to the west shifts over the forecast area. This will lead to temperatures a few degrees warmer for Sunday which will be the only noticeable difference in weather for tomorrow compared to today. Low temperatures also expected to be a degree or two warmer but still remaining in the mid 50s. Monday, an upper low pressure system over the Four Corners region will eject and push across the CONUS. This will lead to increasing southwesterly flow with strong moisture transport in the upper and mid levels as PWATs increase through the day. This will lead to increasing clouds, first over the CSRA and then into the rest of the forecast area. As a result, expect cooler highs in the CSRA, in the mid-70s and low 80s, in the eastern portion of the area. Forecast soundings do indicate a layer of near surface dry air and so while isentropic lift is expected to increase towards the end of the day on Monday, any precipitation should be light. With isentropic lift increasing overnight Monday, rain chances will continue to increase. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Ensemble suites show high probability (around 80 percent) that by Tuesday PWATs will increase to above an inch and a half. With a fairly robust shortwave moving through the area, expect widespread showers, although there is some question as to the exact evolution as models are indicating some drier air behind this shortwave and uncertainty to its timing as it will result from the ejection from the previously mentioned upper low. As far as an ingredient perspective, there remains at least some concern of the potential for severe weather, especially across the southern area where there is higher potential for destabilization but the overall shear profile would support organized storms. As we start to approach the timing for convective allowing models, there is also the potential for an upstream MCS to develop in the Deep South and move east, riding along the highest instability near the Gulf Coast, which may miss us to the south. While some drier air likely moves in Wednesday, ensemble means indicate moisture remains high enough to support scattered showers and storms, especially in the Pee Dee. Brief ridging expected to build back in briefly Thursday before another moisture surge expected Friday with LREF probability showing highest probability of destabilization in the CSRA. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... VFR conditions expected through the TAF period. Mostly clear skies with some fair weather cumulus at 5-7k ft MSL during this afternoon which will diminish overnight. SFC winds north to northeast between 5 and 10 kts shift to more westerly after about 11/18z. Winds then decrease to light and variable overnight into Sunday morning. Dry conditions and a low level jet should hinder any fog development overnight. EXTENDED AVIATION OUTLOOK...Showers and thunderstorms and associated restrictions are possible late Monday through Wednesday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$