FXUS64 KMEG 040504
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
1104 PM CST Tue Dec 3 2024

...New AVIATION...

.SYNOPSIS...
Issued at 228 PM CST Tue Dec 3 2024

Temperatures won't be quite as cold tonight, but low temperatures
will still average 8 to 12 degrees below normal. Under increasing
cloudiness, highs across the Midsouth will range from the lower 
to mid 50s Wednesday afternoon. A few light rain showers are 
expected south of Interstate 40 Wednesday afternoon.

An Arctic cold front will pass through the Midsouth Wednesday 
night. The coldest air will lag behind the front a bit. For the 
Midsouth, our coldest temperatures are expected Friday morning, 
with lows ranging from the mid teens over northwest Mississippi 
to the mid 20s over northwest Tennessee.

Mild and rainy conditions will settle in to the Midsouth late next
weekend into early next week. 

&&

.DISCUSSION...
(This evening through next Monday)
Issued at 228 PM CST Tue Dec 3 2024

We're about five days out from an upper level pattern change 
across North America. The persistent longwave trough over the 
eastern U.S. and southeast Canada will lift out over the Atlantic 
by Sunday, allowing a progressive split flow upper level pattern 
to develop over the lower 48 states. 

In the interim, northwest flow will persist over the Midsouth.
Another strong Arctic cold front will pass through Wednesday 
night. At that time, the core of Arctic air, a 1041mb pressure 
ridge, will be centered over the Dakotas. This high will settle 
into the Midsouth by late Friday afternoon. Though Friday morning 
will likely bring the coldest temperatures of the week, Thursday 
morning's apparent temperatures (wind chills) will be equally low 
to Friday's due to gusty winds immediately behind the Arctic 
front. 

By Saturday morning, southerly low level flow will commence 
behind the departing Arctic high pressure. Earlier model runs from
a few days ago were depicting a potential freezing rain scenario 
Saturday morning, with southern branch moisture overspreading 
modified Arctic air near the surface. However, guidance has come 
into better consensus in developing an upstream ridge over east TX
during this period. Midlevel moisture and QPF will be mainly 
confined to the diffluent flow west of the ridge axis over TX. 
Eventually, the ridge will deamplify and translate east, with rain
edging into eastern AR Saturday night. By such time, thermal 
profiles will favor rain. 

In response to steep northern branch height falls over the Pacific
Northwest, a southern branch cutoff upper low over northwest 
Mexico will eject into the southern plains on Sunday. A plume of 
moisture will develop through the lower and middle MS River Valley
in advance of this feature. PWAT values will range from 1.4 to 
1.8 inches by Monday morning across the Midsouth, nearing the 99th
percentile of climatology. A Pacific cold front will bring cooler
temperatures early next week. There is some question as to where 
this front may stall, which will impact rain chances toward the 
middle of next week. 

PWB

&&

.AVIATION...
(06Z TAFS)
Issued at 1104 PM CST Tue Dec 3 2024

VFR conditions continue through most of the TAF period. Current 
light winds will become southwesterly and gusty by mid morning, 
with 20 to 25 kts gusts thereafter. Winds will fall back below 10
kts after 02Z, becoming west/northwest near the end of the 
current TAF period. Frontal boundary will bring low cigs to north 
MS and the potential for some -SHRA after 00Z. Low cigs could 
approach MEM for a few hours, mainly between 02Z and 05Z.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

$$

PUBLIC FORECAST...PWB
AVIATION...CMA