textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

No significant changes for this update.

Updated for 06Z Aviation Discussion.

KEY MESSAGES

1. A Frost Advisory remains in effect for all of our NC counties, except the northern mountains and adjacent Blue Ridge area where the growing season hasn't officially begun, through 9 AM this morning. Patchy frost is possible over Upstate SC and northeast GA. 2. Fire weather concerns continue through this weekend, with relative humidity falling to near-critical levels each afternoon. A Fire Danger Statement has been issued for northeast Georgia for Thursday. Permission from local officials and extreme caution are both advised if attempting outdoor burning.

DISCUSSION

Key message 1: A Frost Advisory remains in effect for all of our NC counties, except the northern mountains and adjacent Blue Ridge area where the growing season hasn't officially begun, through 9 AM this morning. Patchy frost is possible over Upstate SC and northeast GA.

The Frost Advisory still looks viable at this hour, with observed temps generally in line with the forecast trend, so no changes were made. Temps should warm quickly up through the 40s an hour or two after sunrise, ending the threat. Otherwise, sfc high pressure ridging down across the region from a position off the New England Coast and Canadian Maritimes should bring us another nice spring day with temps a few degrees on the cool side of normal. Once again, there is some indication that a chunk of the retreating sfc high will break off and remain over the southern Appalachians tonight, providing for another good night of radiational cooling. At the same time, however, the air mass continues to modify and fcst low temps are on the order of five degrees warmer than what is expected this morning. This will probably obviate the need for another Frost Advisory for tonight in most places and the new fcst keeps frost patchy at best in the I-40 corridor and the mtn valleys. There remains a small chance that the fcst could trend back colder tonight, so keep an eye on the next forecast to see if the frost potential increases, but for now no additional advisories are planned.

Each successive night for the next several days should be a little warmer, eventually resulting in low temps well above normal by early next week.

Key message 2: Fire weather concerns continue through this weekend, with relative humidity falling to near-critical levels each afternoon. A Fire Danger Statement has been issued for northeast Georgia for Thursday. Permission from local officials and extreme caution are both advised if attempting outdoor burning.

The aforementioned sfc high ridging down from the northeast will keep a dry air mass in place at least through the weekend. Deep mixing will probably allow for afternoon RH to drop into the middle 20 percents each afternoon through at least Sunday, increasing the danger for wildfires, even though wind will not be nearly as strong as it was yesterday. A Fire Danger Statement remains in effect from noon to 8 PM in our northeast GA zones--see the Special Weather Statement for more details. The SC Forestry Commission has issued a Red Flag Fire Alert for all of Upstate SC until further notice. Further coordination with land management agencies may result in additional Fire Danger Statements through the weekend across northeast GA and western NC.

Dewpoints will begin to climb again on Monday, as surface high pressure retreats into the Atlantic, and southwesterly winds begin to usher in some Gulf moisture.

AVIATION /06Z THURSDAY THROUGH MONDAY/

At KCLT and elsewhere: VFR should prevail at all terminals through the period. That being said, we will be in the lookout for another round of stealthy low cloud development around daybreak near the Blue Ridge Escarpment, as long was we maintain a light easterly low level flow. Satellite imagery shows plenty of high thin cirrus for the morning, but that is expected to move east as well. The air mass looks too dry for anything else, probably not even any high based stratocu. That leaves us with a wind forecast. Opted for light ENE at KCLT thru daybreak, after which the direction should become more northeasterly. Won't rule out a few low end gusts this morning with deeper mixing. Otherwise, the light NE wind will go light/variable again this evening with sunset.

Outlook: VFR thru the late part of the week courtesy of high pressure. A developing easterly low level flow could eventually bring a return of low clouds over the weekend. VFR with a more southwesterly flow Monday.

GSP WATCHES/WARNINGS/ADVISORIES

GA...INCREASED FIRE DANGER from noon EDT today through this evening for GAZ010-017-018-026-028-029. NC...Frost Advisory until 9 AM EDT this morning for NCZ035>037-048- 051>053-056>059-062>065-068>072-082-502-504-506>510. SC...None.