textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Updated aviation discussion for the 00Z TAFs.

KEY MESSAGES

1. Well-above normal temperatures continue with slightly higher humidity returning briefly on Sunday and Monday. 2. Dry and hot most of next week with no drought relief in sight. Daily record highs could be in jeopardy Tuesday through the end of next week, mainly east of the mountains, but confidence on breaking records is low at this time.

DISCUSSION

Key message 1: Well-above normal temperatures continue with slightly higher humidity returning briefly on Sunday and Monday.

A broad upper ridge builds into the area Sunday then flattens on Monday. A weak frontal boundary drops south across the area this evening then washes out on Sunday with high pressure over the area Monday. Low clouds do move in from the NE overnight but don't get too far south of the I-40 corridor or west of the I-77 corridor. This low level moisture will lead help keep dewpoints from bottoming out on Sunday with mixing taking place into this layer. Even with that, have RH near 25 percent for much of the area. If dewpoints are lower, then lower RH would be more common. RH on Monday could remain above critical levels, but that's more uncertain given the continued above normal temps.

Key message 2: Dry and hot most of next week with no drought relief in sight. Daily record highs could be in jeopardy Tuesday through the end of next week, mainly east of the mountains, but confidence on breaking records is low at this time.

Upper ridging continues building across the Southeast through Wednesday before gradually breaking down Thursday into Saturday as an upper trough approaches out of the west. Meanwhile, the southwestern periphery of a surface high centered over the western Atlantic will remain parked over the Southeast through Saturday as a cold front slowly approaches out of the west. This surface ridge will keep dry conditions around for most locations with the exception of the North Carolina mountains Friday and Saturday as moisture well ahead of the cold front increases. However, confidence on rain chances remains very low as global models have been gradually pushing rain chances later in the period. Thus, NBM chance PoPs over the mountains on Friday and Saturday appear warranted for now. With no real wetting rain expected in the foreseeable future, drought conditions are likely to worsen.

In addition to the lack of rainfall, the heat will gradually crank up Tuesday through Saturday. Highs are likely to reach into the upper 80s and lower 90s east of the mountains each afternoon starting Wednesday. The probability of reaching the 90 degree mark east of the mountains will continue to increase each day through Saturday. Thus, locations east of the mountains on both Friday afternoon and Saturday afternoon are most likely to see highs climb into the lower 90s. At this time, confidence remains low on breaking any record highs across the climate sites (KAVL, KGSP, and KCLT). KAVL looks the least likely to break any daily record highs next week with chances looking slightly better for both KGSP and KCLT. KGSP will have roughly a 50% chance of breaking the record high on Thursday, while KCLT will have roughly a 50% chance to break the record high on both Wednesday and Thursday.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

At KCLT and elsewhere: Dry and VFR across the terminals outside of KHKY which has the potential to see MVFR cigs develop from 12Z to 16Z Sunday. Winds will go light and VRB to calm this evening into tonight before picking up out of the NE east of the mountains around daybreak. Winds will then gradually turn S'ly Sunday afternoon while increasing in speed. Wind speeds will range from 5-10 kts and low- end intermittent gusts cannot be entirely ruled out during the afternoon hours. At this time, KAVL looks to have the best potential to see low-end gusts develop so only have gusts mentioned at this terminal for now. Could see BKN to OVC cirrus develop on Sunday but limited cigs to SCT for now.

Outlook: Expect dry and VFR conditions to persist into the middle of next week.

CLIMATE

RECORDS FOR 04-14

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 86 2006 36 1907 62 1922 24 1950 KCLT 89 1941 46 1907 69 1922 27 1950 KGSP 92 1916 48 1901 67 1922 22 1907

RECORDS FOR 04-15

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 89 1972 42 1943 64 1887 23 1907 KCLT 89 1936 46 1889 66 2006 28 1907 KGSP 91 2006 45 1913 69 1922 22 1907

RECORDS FOR 04-16

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 87 2006 42 1905 62 1945 26 1943 KCLT 89 2006 49 1890 64 1998 29 2008 1896 1991 1962 1945 KGSP 88 1888 54 1903 64 1945 24 1907

RECORDS FOR 04-17

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 89 1896 45 1890 63 1927 26 1904 KCLT 94 1896 47 1890 66 1896 30 2018 1949 KGSP 92 2006 51 1904 63 1927 25 1905

GSP WATCHES/WARNINGS/ADVISORIES

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