930 
FXUS62 KFFC 050004
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
804 PM EDT Sun Apr 4 2021


...00Z Aviation Area Forecast Discussion with Small Update...

.UPDATE...
Minor update to hourly temps as they are hanging on to the
afternoon warmth a bit longer than forecast. Otherwise, no
frost/freeze concerns tonight as low temps should stay in the 40s.
Another beautiful day on tap tomorrow.

Lusk

&&

.PREV DISCUSSION... /Issued 250 PM EDT Sun Apr 4 2021/ 

..Sunday Afternoon Forecast Discussion...

SHORT TERM /Tonight through Monday Night/...

High pressure regime continues, need we really say more? Afternoon 
temperatures continue to increase with each day with low 70s today 
giving way to highs in the mid to upper 70s tomorrow. Overnight, 
radiational cooling will once again be strong with clear skies and 
calm winds but should stay in the low 40s, which mean no more frost 
or freeze threat. The trickiest part of the forecast continues to be 
the afternoon dewpoints and relative humidities as guidance 
continues to struggle with deep atmospheric mixing entraining very 
dry low-level air into the mixing layer, and eventually reaching the 
ground. A spread of 10-18 degrees exists between the 12Z runs of the 
HRRR and the NAM3km, with the NBM and other blends splitting the 
difference. But day after day, we've seen models like the HRRR and 
ARW perform well under blue sky conditions and so have lowered 
dewpoints to match resulting in RHs tomorrow afternoon between 20-30 
percent.

Thiem

LONG TERM /Tuesday through Sunday/...

Dry conditions will be ongoing to start the forecast period on 
Tuesday. The center of surface high pressure will be pushing farther 
off the Florida Atlantic coastline, bringing a return to southerly 
flow with continued warming temperatures and gradually increasing 
moisture levels. By Wednesday, a closed upper low will be dropping 
southeastward through the Central Plains while shortwave ridging 
will build over the forecast area ahead of it. At the surface, the 
associated surface low will be occluding over the Plains with the 
cold front making gradual eastward progress into the Mid South. 
Wednesday should remain mostly dry locally with temperatures warming 
near or above 80 degrees across most of the area. 

While the cold front's forward progress slows to our west, rain 
chances will increase appreciably by Wednesday night into Thursday 
as shortwave energy swings eastward. Instability will be limited as 
convection approaches Wednesday night into Thursday morning, so 
intensity may be on a downswing at that time. This activity will 
push eastward across the area through the day Thursday. By Thursday 
night into Friday, the forecast begins to become less certain. 
Additional convection may develop to our west near the surface front 
in association with another shortwave. At this point, chance PoPs 
were maintained into Friday given uncertainties on finer details. 
Forecast uncertainty increases further by the end of the period with 
general consensus that the upper low will remain lingering in the 
Great Lakes region but less agreement on frontal placement and 
subsequent shortwave energy. Therefore, chance PoPs remain the rule 
on Day 7.

RW

AVIATION... 
18Z Update... 
VFR under SKC will prevail through the period. Winds are light 
and generally westerly between 4-10kts, but have some variability 
and very isolated gusts at different sites around the area. Winds 
should go mostly calm tonight, and be light out of the WSW, below 
7 kts, tomorrow in the late morning and afternoon.

//ATL Confidence...18Z Update...
High on all elements.

Thiem

&&

.AVIATION...
00Z Update...
VFR conditions continue through the TAF period with SKC. Winds 
will go variable to calm at most sites tonight. West winds again 
tomorrow from 4-8 kts, with some slightly higher gusts possible, 
but not expected to pick up until 16-17Z.

//ATL Confidence...00Z Update...
High confidence all elements.

Lusk

&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          43  76  49  79 /   0   0   0   0 
Atlanta         45  75  50  76 /   0   0   0   0 
Blairsville     40  71  45  73 /   0   0   0   0 
Cartersville    40  75  46  77 /   0   0   0   0 
Columbus        43  76  48  79 /   0   0   0   0 
Gainesville     44  74  50  76 /   0   0   0   0 
Macon           41  77  46  81 /   0   0   0   0 
Rome            40  75  47  78 /   0   0   0   0 
Peachtree City  40  75  46  78 /   0   0   0   0 
Vidalia         43  78  50  81 /   0   0   0   0 

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Thiem
LONG TERM....RW
AVIATION...Lusk