textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Increased Fire Danger Statement in effect for Northeast Georgia today.

Rainfall amounts for the precipitation event Saturday night through Sunday night have come down slightly.

KEY MESSAGES

1. Increased Fire Danger across northeast Georgia through 6 PM. Dry conditions persist through Saturday allowing low relative humidity to develop each afternoon, mainly east of the mountains. 2. Widespread rain is expected over the weekend, with precipitation most likely early Sunday morning through Sunday evening. The QPF has trended downward with this cycle, so the rain is more likely to be beneficial than malevolent for most of the area. Localized heavier rainfall is possible, which could lead to nuisance flooding of poorly drained areas, and/or isolated bankfull conditions on area streams.

DISCUSSION

Key message 1: Increased Fire Danger across northeast Georgia through 6 PM. Dry conditions persist through Saturday allowing low relative humidity to develop each afternoon, mainly east of the mountains.

High pressure remains over the region through Saturday, keeping the area free of any significant weather. The main concern today and into Friday is the dry relative humidity as dewpoints remain low. A mix of RH in the upper teens to low 20% range for today and 20-30% for Friday. Winds are expected to be light with an occasional gust for a few areas east of the mountains. Wind direction is mostly out of the N/NW before turning NE east of the mountains overnight. The lack of winds, especially at the top of the boundary layer should help offset too much mixing, resulting in even drier dewpoints today. Regardless, fuel moisture east of the mountains fall into the 8-10% range and RH less than the 25% critical threshold. For this, an SPS for Increased Fire Danger is in place for northeast Georgia through 6 PM this evening. Given similar conditions for Friday with only a small improvement on RH, an SPS may be needed. Other than fire concerns, weather stays quiet with mild temperatures through Saturday.

Key message 2: Widespread rain is expected over the weekend, with precipitation most likely early Sunday morning through Sunday evening. The QPF has trended downward with this cycle, so the rain is more likely to be beneficial than malevolent for most of the area. Localized heavier rainfall is possible, which could lead to nuisance flooding of poorly drained areas, and/or isolated bankfull conditions on area streams.

After a quiet first half of the weekend with temperatures generally staying at or as much as five degrees above normal, we are still expecting a dynamic-looking srn stream system to move in from the west Saturday night followed by widespread rain on Sunday. There does not appear to be much, if any, chance for anything other than rain as this system moves in because of the increasing cloud cover Saturday evening and the warm advection that takes hold before the precip starts. Fcst soundings look to be safely above 32F in a deep sfc-based layer. If anything, the pattern looks more like it would favor a possible non-zero severe threat developing up from the south during the day with a warm sector pushing against an in-situ cold air damming wedge enough to possibly uncover the lower Piedmont later in the day. This will be monitored. For now, thunder will appear in the forecast on our southern fringe.

Getting back to the rain potential...a categorical precip prob is a given, what with deep layer forcing acting upon deep layer moisture and an open Gulf. However, one gets the impression that the better mid/upper forcing was shifting northward with better frontogenesis along the NC/VA border. This might play into the small downward bump to the overall precip amts in this fcst cycle. We shall see if this trend continues and how things look once the CAMs go out far enough, but for now the flooding rain threat looks no better at any rate. While it may be true that as of yesterday, the soils across the nrn mountains were frozen, but the latest fcst gives that area at least 48 hrs prior to onset where the average temperature will be above 32F, so that should help to mitigate that concern somewhat. For now, this means the expected rain looks more beneficial than anything, but we will continue to monitor. The rain should move out early Monday.

The rest of the period looks relatively benign, with a warming trend through the middle of next week that takes us well above normal once again.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

At KCLT and elsewhere: VFR conditions prevail through the TAF period. A few SCT clouds this afternoon and may linger into the overnight hours. No cigs/vsby restrictions at this time. Winds prevail out of the N/NW through the evening before turning more NE overnight. KHKY and KAND become VRB and may even have periods of calm winds Friday morning and through the end of the period. A few low-end gusts of 15-20kts at KCLT and KGSP through 00z before diminishing. KCLT could also see more light and VRB winds for Friday, but will keep the NE direction for now.

Outlook: Dry and VFR through Saturday before precipitation chances and associated restrictions return Saturday night into Sunday. Drier conditions and VFR should return for the beginning of the week.

GSP WATCHES/WARNINGS/ADVISORIES

GA...INCREASED FIRE DANGER until 6 PM EST this evening for GAZ010- 017-018-026-028-029. NC...None. SC...None.