802 
fxus64 kmeg 191623 
afdmeg 


Area forecast discussion 
National Weather Service Memphis Tennessee 
1023 am CST Wednesday Nov 19 2008 


Discussion... 


Canadian high pressure at the surface that allowed for the cold 
temperatures last night continues to shift eastward. This has 
allowed for a return to southerly flow and an increase in 
temperatures. Although low level warm air advection will continue 
in earnest with 925mb temperatures warming...still think surface 
temperatures will be slower to respond and current forecast high 
temperatures appear a few degrees too warm. Have updated high 
temperatures to trim a few degrees and bump highs down a category 
along and east of the Mississippi River. Otherwise all other 
forecast elements look good. Sunny skies will remain the rule 
today. 


Updated grids and zones have already been sent. 


Jlh 


&& 


Previous discussion... /issued 536 am CST Wednesday Nov 19 2008/ 


Update... 
updated for aviation discussion. 


Discussion... 
/issued 432 am CST Wednesday Nov 19 2008/ 


Discussion...10z surface analysis places 1031 mb high pressure 
across the southeast United States while the next Alberta clipper cold 
front to affect the middle south is located from Minnesota back to 
the northern rockies. Temperatures across the middle south this 
morning remain quite cold with readings in the upper 20s to lower 
30s in the Mississippi River Delta and teens to lower 2os along 
the Tennessee River. Main challenge in this forecast package is 
precipitation chances in the long range forecast. 


Short term...(today through friday)...surface and upper level 
ridging will gradually shift southeast today towards the Florida 
Peninsula as an Alberta clipper embedded within northwest flow 
aloft dives southeast into the middle Mississippi Valley late this 
afternoon into early evening and into the middle south late tonight 
into Thursday morning. Ahead of the cold front...southerly winds on 
the backside of high pressure and warmer temperatures aloft will 
mix down to the surface this afternoon to produce high 
temperatures in the upper 50s to around 60 along and west of the 
Mississippi River and lower to middle 50s east. No precipitation 
is expected with the passage of the cold front due to a dry 
atmosphere and lack of instability. A return of very cold air will 
return by Thursday night with low temperatures falling back into 
the 20s and highs only recovering into the 40s on Friday. (Similar 
to yesterday/S high temperatures) 


Long term...(saturday through tuesday)...despite some minor 
differences in placement of upper level synoptic features...00z 
long range models showing better agreement than in previous runs. 
Upper level trough just beginning to enter the Pacific northwest 
this morning will move across the northern rockies at the start of 
the period and move into the Mississippi Valley by the end of the 
weekend into early next week. Adjusted probability of precipitation up a bit as long range 
models agree on a cold front moving through the forecast area 
Sunday night into Monday with precipitation chances tapering off 
into Monday night. 


Cjc 


Aviation... 
12z taf cycle 
11z surface map showed high pressure centered along the Gulf 
Coast. Expect occasionally gusty winds along the periphery of this 
ridge following sunrise. Winds should to decrease to below 10kts 
all terminals by 23z and remain light this evening. A surface 
front is expected through the midsouth late tonight...with passage 
through kmem in the 09z to 11z timeframe. 


Pwb 


&& 


Aviation... 




&& 


Preliminary point temps/pops... 
mem 57 39 52 27 / 0 0 0 0 
mkl 54 34 48 22 / 0 0 0 0 
jbr 57 37 49 25 / 0 0 0 0 
tup 55 34 55 26 / 0 0 0 0 


&& 


Meg watches/warnings/advisories... 
Arkansas...none. 
MO...none. 
MS...none. 
Tennessee...none. 
&& 


$$