textproduct: Columbia

WHAT HAS CHANGED

No significant changes to the forecast. Updated aviation discussion for the 06z TAFs.

KEY MESSAGES

- 1. Fire weather concerns remain elevated this week.

- 2. Increasing rain chances this weekend into early next week.

DISCUSSION

Key Message 1: Fire weather concerns remain elevated this week.

Elevated fire weather concerns continue this week as a dry air mass remains over the region with much of the area in severe to extreme drought. Temperatures will continue to rise to well above average through the end of the week into the weekend. While winds will generally be light due to high pressure ridging into the area, there remains a high probability of relative humidity dropping below 30 percent, potentially as low as 20 percent each afternoon through Friday. Winds could be a bit stronger today and Friday but likely remain below Fire Danger Statement criteria with gusts into the teens. The SC Forestry Commission continues a Burn Ban for South Carolina until further notice.

Key Message 2: Increasing rain chances this weekend into early next week.

The highly amplified 500mb pattern over the CONUS will begin to breakdown this weekend as a more progressive pattern takes place beginning with a cold front moving through this weekend. Ensemble mean PWATs generally rising to 125 to 150 percent of normal will favor increasing chances for rain associated with this front. Blended guidance also indicates moderate confidence in sbCAPE greater than 500 J/kg with thunderstorms possible Saturday as a result. With this progressive pattern in place, additional shortwaves will be possible into early next week leading to additional chances for rain and slight chance for thunderstorms. We will still likely have a ways to go to break the drought with only around 10 percent of GEFS members showing greater than an inch of rain through Tuesday (and we will need more than that). The longer term pattern favor a more active (wetter) pattern through the end of the month and into early May with teleconections such as the NAO, favoring general troughing over the eastern CONUS.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

VFR conditions should continue through the TAF period. Potential LLWS through 14z.

With dry high pressure in control, no significant weather expected. Some upper level broken clouds will stream across the region through the morning, then scatter out by the afternoon hours. Although those upper clouds should be the majority of the cloud cover today, can not rule out a few mid-level cumulus developing in the afternoon. VFR conditions will remain.

Bigger issue through the morning will revolve around potential for llws at all sites. Current surface obs showing generally light and variable winds. Meanwhile the kcae vertical wind profile (VWP) product is consistently showing 35-40 knot winds 1-2kft off the surface. Surrounding radars not quite as strong off the surface, but still strong enough to warrant at least a mention of llws overnight until 14z this morning. Mixing after 14z will limit llws, but bring a few wind gusts at the surface from late morning through the afternoon. Surface winds winds will be south to southwesterly through the majority of the period.

With the cirrus clouds, strong low-level jet, and drier air in place, not really expecting much in the way of fog through the morning. Only impact could be brief patchy shallow ground fog at ags/ogb near the rivers.

EXTENDED AVIATION OUTLOOK...Widespread restrictions are not expected through at least Friday. Possible rain chance move in this weekend, but confidence in any restrictions is low at the moment.

CAE WATCHES/WARNINGS/ADVISORIES

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