textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Updated aviation discussion for the 12Z TAFs.

KEY MESSAGES

1. A Red Flag Warning remains in effect for the mountains of northeast Georgia and a Special Weather Statement for Increased Fire Danger remains in effect elsewhere across northeast Georgia from 12 PM to 8 PM today. Any fire that develops will catch and spread quickly. Outdoor burning is not recommended. 2. Gusty winds are expected today in association with a cold front. A Wind Advisory is in effect for the majority of the North Carolina mountains and the Greenville mountains through 2 PM. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. 3. Rain chances return this morning as a cold front tracks across the forecast area. Dry conditions return behind the front later this morning into much of next week, resulting in elevated fire danger. Much cooler air will also filter in behind the front, allowing below normal temperatures to return today through Tuesday. Some patchy frost may develop tonight, and especially Monday night in areas sheltered from the wind but confidence is low with such a dry airmass in place. 4. Very warm conditions return for the middle-to-latter part of the week, while conditions are expected to remain very dry through at least Friday. Fire Danger will remain unusually high for mid-spring while drought conditions will continue to gradually deteriorate. A potential front then brings the next hope for rain Friday night/Saturday.

DISCUSSION

Key message 1: A Red Flag Warning remains in effect for the mountains of northeast Georgia and a Special Weather Statement for Increased Fire Danger remains in effect elsewhere across northeast Georgia from 12 PM to 8 PM today. Any fire that develops will catch and spread quickly. Outdoor burning is not recommended.

Gusty northwest winds (20-30 mph) combined with much lower relative humidity (<25%) developing this afternoon behind a departing cold front will lead to critical fire weather conditions this afternoon and early evening. Any rain that manages to fall in association with the cold front this morning will have very little impact on dry fuels across the region. With very dry fuels and ongoing drought in place, both relative humidity (30%, typically 25%) and wind gust (25 mph, typically 30 mph) criteria have been raised slightly for both Red Flag and Increased Fire Danger across northeast Georgia. Thus, a Red Flag Warning remains in effect for Rabun and Habersham counties, with a Special Weather Statement for Increased Fire Dangers in place for Stephens, Franklin, Hart, and Elbert counties from 12 PM to 8 PM. Outdoor burning is not recommended, especially for Rabun and Habersham Counties. Any fire that develops will catch and spread quickly. Burn Bans remain in effect until further notice across the Carolinas.

Key message 2: Gusty winds are expected today in association with a cold front. A Wind Advisory is in effect for the majority of the North Carolina mountains and the Greenville mountains through 2 PM. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.

Gusty winds will develop along and behind a cold front today, with gusts expected to peak around daybreak. Most locations across the North Carolina mountains, will have the potential to see gusts reach advisory criteria (>45 mph). The Wind Advisory was expanded to all elevations across Buncombe and McDowell, as well as the Greenville mountains, Henderson County, and the Polk, Rutherford, Burke and Caldwell mountains. The Wind Advisory is in effect for these locations through 2 PM. Elsewhere, gusts will remain below advisory criteria (<45 mph). Winds should peak around daybreak, but will remain gusty through much of the day before gradually tapering off this evening. Wind gusts will remain elevated through tonight, mainly across the northern North Carolina mountains. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.

Key message 3: Rain chances return this morning as a cold front tracks across the forecast area. Dry conditions return behind the front later this morning into much of next week, resulting in elevated fire danger. Much cooler air will also filter in behind the front, allowing below normal temperatures to return today through Tuesday. Some patchy frost may develop tonight, and especially Monday night in areas sheltered from the wind but confidence is low with such a dry airmass in place.

A cold front will bring much needed rain back to the region this morning. However, activity will gradually break apart as it tracks across the mountains so confidence on rain holding together east of the mountains remains low. Unfortunately, rainfall amounts are expected to remain light and will have little impact on the ongoing drought. Dry conditions will gradually return from west to east behind the front from mid to late morning. A much cooler and much drier airmass will filter in behind the front today into tonight, allowing for the return of below normal temperatures. Highs this afternoon will only reach into the mid 60s to lower 70s east of the mountains and the upper 40s to lower 60s across the mountains. Lows tonight will fall into the upper 30s to lower 40s east of the mountains and the mid 30s to lower 40s across the mountains. Although temps are expected to remain above freezing tonight, with the exception of Mount Mitchell, patchy frost could develop in areas sheltered from the wind. However, confidence on frost development remains very low with such a dry airmass in place.

The cool and dry air mass will continue through Tuesday, as a short wave trough digging into the Mid-Atlantic sends a re-inforcing front through the region Monday afternoon. NW winds will resurge in the wake of this feature during the afternoon, coincident with RH in the 20-30% range. Although winds will be gusty, they are expected to fall short of critical levels in terms of fire weather concerns. Nevertheless, fire danger will be very much elevated in light of the ongoing drought/dire fuels conditions. With surface high pressure settling near the region Monday night, chances for frost will be a little higher across sheltered areas of the mountain valleys and northern zones Tue morning. While winds will be much lighter on Tuesday, widespread afternoon RH of 20-30% will continue to enhance the fire danger.

Key message 4: Very warm conditions return for the middle-to-latter part of the week, while conditions are expected to remain very dry through at least Friday. Fire Danger will remain unusually high for mid-spring while drought conditions will continue to gradually deteriorate. A potential front then brings the next hope for rain Friday night/Saturday.

An upper ridge will progress into the central Conus by mid-week...then gradually build into the East through week's end. Sprawling low level high pressure between the ridge and confluent flow off into the East Coast will maintain a dry, albeit gradually modifying air mass across the southern Appalachians and vicinity through Friday. Temperatures will also be modifying under the mid-spring sun and in response to rising heights aloft, with max temps expected to warm to 5+ degrees above normal by Wednesday...with maxes likely remaining in the +5-10 range with respect to climo through the end of the week. The lack of substantive moisture flux will likely result in very low...if not critical afternoon RH each day Wed-Fri. Fuels will continue to dry out in the very warm/low RH conditions, and fire danger will remain unusually high for mid-spring, despite the rapid green-up that is underway. By Saturday, a consensus of global models suggest the ridge will break down in response to large scale/major height falls across the western half of the county, possibly allowing a frontal zone to make its way into the Southeast. Likely PoPs are advertised across the mountains Saturday, with mainly 40-50% chances elsewhere. Having said that, the likelihood that this event will put so much as a dent in ongoing drought conditions is very small.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

At KCLT and elsewhere: -RA is currently pushing eastward across the western Carolinas this morning as a cold front tracks across the terminals. -RA and restrictions are impacting KAVL as of 10Z with MVFR cigs noted at the terminal. -RA should hold together enough to track over the terminals east of the mountains early this morning so have TEMPOs in place for the 12Z TAF period. KAVL should see -RA end by the start of the 12Z TAF period so have dry conditions returning by then. Dry conditions return east of the mountains by mid to late morning. Winds are already NW at KAVL and will turn NW behind the front east of the mountains around sunrise. Wind speeds will gradually increase through sunrise, becoming gusty. Gusts at KAVL should range from mostly 25-35 kts, with gusts east of the mountains ranging mostly from 20-28 kts. Wind speeds and gusts will peak around daybreak before gradually decreasing in speed throughout the rest of the day. Gusts should finally diminish by late this evening. Wind direction will gradually turn more W'ly across the terminals late tonight into daybreak Monday, with lighter wind speeds expected. Cigs will remain BKN to OVC before gradually becoming SKC behind the front from west to east late this afternoon into early this evening.

Outlook: Breezy winds return Monday. Dry and VFR through most of the week.

GSP WATCHES/WARNINGS/ADVISORIES

GA...Red Flag Warning from noon today to 8 PM EDT this evening for GAZ010-017. INCREASED FIRE DANGER from noon EDT today through this evening for GAZ018-026-028-029. NC...Wind Advisory until 2 PM EDT this afternoon for NCZ033-049-050- 052-053-059-062>065-501-503-505-507-509. SC...Wind Advisory until 2 PM EDT this afternoon for SCZ103.