textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Fire Danger Statement has been issued for all of our NC and GA counties again for Thursday afternoon into early evening.

Fire danger continues to increase through the weekend.

The aviation discussion was updated for the 00Z TAFs.

KEY MESSAGES

1. Fire weather concerns continue amid a dry and stagnant weather pattern. A Fire Danger Statement has been issued for Thursday afternoon for all of western North Carolina and northeast Georgia. Critically low relative humidity and breezy conditions are likely to occur each of the next several afternoons through the weekend. 2. Hot and dry through Saturday with high temperatures near daily records in some locations outside the mountains. A cold front may bring some rainfall to our area on Sunday, but any accumulations will likely be too small to improve drought conditions. Near-normal temperatures are expected early next week.

DISCUSSION

Key message 1: Fire weather concerns continue amid a dry and stagnant weather pattern. A Fire Danger Statement has been issued for Thursday afternoon for all of western North Carolina and northeast Georgia. Critically low relative humidity and breezy conditions are likely to occur each of the next several afternoons through the weekend.

The synoptic pattern remains largely unchanged with stout upper ridging centered over the Gulf into Florida with well above average heights extending north into the southeast states. Farther west, a series of shortwave troughs within an active southern stream flow will lift over the ridge across the Midwest into the Great Lakes and Ohio Valley. This will continue to leave the Southern Appalachians high and dry with surface high pressure locked in as well. The main focus over the next several days will be a threat for fire danger each afternoon as temperatures warm into the upper 80s to low 90s. Forecast soundings reveal a deep well mixed boundary layer extending up to nearly 800mb. Relative humidity values are already crashing this afternoon with dewpoints mixing out a good bit below NBM forecast values. Have adjusted dewpoints down considerably both this afternoon and again the next several days heading into the weekend. This results in critical values of 25-30%. Occasional wind gusts will also be possible with modest flow within and at the top of the mixed layer. Momentum transport will help realize gusts around 20 mph, perhaps a hair higher. The low humidity combined with winds and very dry fuels will result in increased fire danger. A special weather statement has been issued for Thursday afternoon. A red flag warning cannot be completely ruled out for tomorrow either should wind gusts increase more than currently forecast.

Key message 2: Hot and dry through Saturday with high temperatures near daily records in some locations outside the mountains. A cold front may bring some rainfall to our area on Sunday, but any accumulations will likely be too small to improve drought conditions. Near-normal temperatures are expected early next week.

Stout upper ridging across the Southeast from an upper anticylone over the northeast Gulf/FL peninsula should start to break down tomorrow as a lead short wave trof drifts across the Ozark Plateau/Mid-MS Valley regions. Not that it will have much of an effect on our region just yet, as temps will climb well above normal each day through Saturday after the initial wave passes. High temps for Thursday have probably the best chance to break records east of the mountains based on the continued drought conditions and the new forecast, which is very close to record values. By Friday and Saturday, the records are several degrees warmer, so perhaps not quite as good a chance. Either way, it will be a dry heat for mid-April.

Guidance still has a cold front on track to move in from the west Saturday night as a robust mid/upper trof swings across the Great Lakes/Midwest. Ahead of the front, the upper flow across the Deep South is more west-southwesterly, which doesn't provide an ideal setup for moisture return. It stands to reason that areas along the TN border will stand the best chance for some precip because of loosely organized convection moving in from the west before weakening in the evening. East of the mtns, however, it would be best to not get your hopes up. The modest moisture transport, ongoing dry conditions, and weakening forcing suggest limiting precip probs to the chance range at best. Except for the TN border region, the QPF from the models is more of an insult at this point, and would provide no relief.

The front is expected to move east of the area by midday Sunday, and should usher in temperatures much more reasonable for this time of year. It might almost feel like a backwards change of seasons, with lows and highs at or slightly under normal for the first part of next week. Unfortunately, the new air mass will be very dry, so expect another round of high fire danger.

AVIATION /00Z THURSDAY THROUGH MONDAY/

At KCLT and elsewhere: VFR conditions will prevail through the TAF period at all terminals. Southwest winds with periods of mainly thin, high clouds streaming overhead. Winds go light tonight with gusts returning again tomorrow afternoon along with additional high clouds. KAVL winds will be tricky due to a cross-valley (and cross-runway) flow. The majority of the guidance has winds staying SW to WSW, but there is a chance it could favor a NW direction thru much of the day Thursday, with periodic gusts.

Outlook: VFR prevails the rest of the week and into the weekend.

CLIMATE

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

RECORDS FOR 04-18

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 90 1896 44 1921 60 1927 28 1905 1891 KCLT 93 1896 45 1983 66 1896 32 2001 KGSP 89 2002 51 1983 66 1927 28 1905 1967

GSP WATCHES/WARNINGS/ADVISORIES

GA...INCREASED FIRE DANGER from Thursday afternoon through Thursday evening for GAZ010-017-018-026-028-029. NC...INCREASED FIRE DANGER from Thursday afternoon through Thursday evening for NCZ033-035>037-048>053-056>059-062>065- 068>072-082-501>510. SC...None.