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FXUS62 KFFC 171140

Area Forecast Discussion
National Weather Service Peachtree City GA
640 AM EST Tue Jan 17 2017

.PREV DISCUSSION... /Issued 348 AM EST Tue Jan 17 2017/ 

SHORT TERM /Today through Wednesday/...
Water vapor analysis reveals a broad trough across the SW US and 
into Mexico with several notable perturbations rotating 
within...while downstream of this feature flow becomes more 
anticyclonic...with center of ridge across the Yucatan and quasi-
zonal to SW flow across the SE. At the sfc...low pressure was 
centered across the Midwest/associated with a strong H5 shortwave/ 
and its cold front draped S into Arklatex...while sfc wedge has held 
on a little longer/stronger than previously thought across Georgia. 
Will see wedge front retreat while the cold front pushes south and 
east during the short term.

Low cloud cover and fog associated with wedge front has been slowly 
creeping west from NE Ga over towards the ATL metro. This should 
persist into mid morning across this general area. All other 
locations will experience increased cloudiness today with temps 
continued warm /upper 60s north to upper 70s central/. Rain chances 
will be confined to mainly north Georgia today and will increase as 
the day wears on with aforementioned cold front moving towards 
the state. By early to mid-afternoon...instability will increase 
enough across N Georgia to warrant mention of general thunder. 

Overnight Tuesday the cold front will push through north Georgia. 
With the best dynamics displaced well to the north...most of the 
precip will diminish...but enough forcing along front itself along 
with moist airmass in place... chance for rain and thunder will 
continue across north Ga. 

Wednesday...A few showers will persist along the front as it 
continues to push slowly across the state. Not seeing enough 
instability to carry thunder on Wednesday. The front will stall near 
metro ATL and areas west and east of the city by Wednesday evening. 
Temps will continue well above normal. With weak sfc high pushing 
into north counties behind the front on Wed...kept highs a touch 
cooler in the low-mid 60s. Areas near and south of the front will 
see highs in the lower-upper 70s.


LONG TERM /Wednesday Night through Monday/...
Unsettled weather still on tap for the long term portion of the 
forecast. Fast flow will dominate aloft, so expect several systems 
to impact the area through the end of the week into early next week. 

An old frontal boundary will begin pushing back northward as a warm 
front Wednesday night into Thursday as a low pressure system moves 
into the Lower Mississippi River Valley. Pops will be on the 
increase during the day Thursday as the boundary pushes north and 
the low pressure system/front approaches from the west. Models are 
progging some minimal instability with this system, so thunder still 
looks appropriate. The front briefly settles across southern 
GA/northern FL before beginning to push back north late on Saturday 
ahead of the next low pressure/frontal system.

Copious moisture is expected ahead of the late weekend/early next 
week system. Pops remain high. The parent low with this system 
rapidly moves east from the center of the country to the TN valley 
by early Sunday, dragging a frontal boundary through the CWFA later 
Sunday/early Monday. This is a potent system...strong mid level 
energy aloft will give support for widespread showers and 
thunderstorms. Currently, good shear and very steep lapse rates are 
progged, so there is good potential for severe thunderstorms. Now, 
this is still Day 5/Day 6, so the forecast could change, stay tuned!



12Z Update...
Expansive area of LIFR/IFR/MVFR visibilities still exist across 
all TAF sites except CSG. Expect these conditions to continue for 
another hour or two...sticking around AHN the longest...but still 
think most sites will hold steady with MVFR ceilings for most of 
the day today after fog erodes/visibilities rise. Could see VFR 
ceilings this evening before conditions rapidly deteriorate again 
Wednesday morning. Shower and thunder activity looks to stay north
of all TAF sites...though could see an isolated shower pop up 
near northern sites. Winds will shift to the SW this morning with 
speeds generally between 5-10kts. 

//ATL Confidence...12Z Update...
Low on duration of low vsbys.
High on wind speed and direction.
Medium on all other elements.



Athens          71  57  70  49 /  20  30  30  20 
Atlanta         71  58  68  53 /  20  30  30  20 
Blairsville     64  52  62  46 /  50  60  40  30 
Cartersville    70  55  65  50 /  40  50  40  30 
Columbus        75  59  74  55 /  10  20  20  20 
Gainesville     68  57  67  51 /  30  50  40  20 
Macon           75  57  74  54 /  10  20  20  20 
Rome            70  55  65  50 /  50  60  40  30 
Peachtree City  72  57  70  52 /  20  30  30  20 
Vidalia         77  57  76  56 /  10  20  20  10 




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