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fxus64 kjan 081631 aaa 
afdjan 


Area forecast discussion...updated 
National Weather Service Jackson MS 
1031 am CST Thursday Jan 8 2009 


Update...dry forecast continuing through most of Friday will be the 
nicest of days we'll have for the next week or so. A weakening trough 
axis passing through central portions of the County warning forecast area with a wind shift 
to the north-northwest. Current temperatures running a little ahead of our forecast and 
have adjusted upward in most locations for the early afternoon maxes. 
Drying airmass and winds dying off quickly this evening should result 
in a rapid drop in readings back into the 40s before midnight. 
Updates to grids/graphics/and texts should be available./40/ 


Rest of forecast remains on track with previous discussion: a 
moderately strong cold front moves towards our area Friday night. The 
combination of the departing surface high and developing surface low to our 
west will help winds quickly back around to the S/SW causing ll 
moisture and temperatures to increase on Friday. As our cold front approaches... 
rain showers may be possible across the extreme northwest late Friday afternoon but in all 
likelihood everyone will probably remain dry until Friday night or Sat. 
The only other thing to really talk about are winds Friday. The pressure 
gradient will tighten through the day and ll winds will also pick 
up...just how much on Friday is the question. The GFS is the fastest of 
the models and thus has stronger winds during the afternoon which could lead 
to a breezy day across the northwest. 


High pressure will be departing to the east through tonight so the 
coldest temperatures will be across the east likely ranging from middle/upper 
30s in the NE to Lower/Middle 40s in the SW and this is in good 
agreement with the mav gui. As for highs Friday h925 temperatures will increase 
to around 13-14c and this should lead to highs mainly in the upper 
60s to lower 70s and the gui agrees with this. /Cab/ 


Long term...Friday night through Thursday...overall a return to 
colder and drier weather is expected for the long term as an 
amplification of a mean upper ridge over the West Coast and 
troughing in the eastern Continental U.S. Sets up. Friday night and Saturday 
will be the exception though as warm air advection strengthens Friday night ahead 
of an approaching middle level trough and associated cold front. The 
GFS is still the fastest in moving the cold front into the County warning forecast area 
Saturday morning but the cold front should be over the Delta by 
sunrise Saturday and be south of our southeast zones by sunset 
Saturday. The increasing southerly winds and moisture will hold 
morning lows in the 50s over much of the area. Although this should 
be a fast moving system have gone slightly above guidance with 
likely to categorical probability of precipitation. The fast moving nature of the system 
should limit heavy rainfall so not expecting additional flooding 
potential over our area. Skies will clear Saturday evening and a 
cold center of high pressure will drop over the Southern Plains. 
This will help our temperatures drop to around freezing by Sunday 
morning for much of the area. Sunday should be sunny and dry but 
temperature will top out several degrees below normal and mainly in 
the lower 50s. 


Several weak short waves will move through the eastern trough Sunday 
night and Monday as the surface high over the Southern Plains shifts 
south and weakens. Low level southerly flow Sunday night and Monday 
will do little to increase moisture over the region and no rain is 
expected with the shortwaves. The shortwaves will help deepen the 
upper trough and help send a weak cold front across our County warning forecast area Monday 
night. Will carry slight chance probability of precipitation with this feature only over the 
northeast. A more potent shortwave will help send a reinforcing shot 
of cold air across our County warning forecast area Tuesday. There are still significant 
differences between the GFS and Euro in the strength and timing with 
the center of the Arctic airmass that will be dropping south over our 
region but...very cold air on gusty northwest winds could make for a 
rather cold Tuesday with temperatures dropping through the day. Models 
do agree that the upper trough axis and the surface high will be 
shifting east across our County warning forecast area Tuesday night. Winds will likely play a 
major role in overnight lows...but lower 20s are expected over most 
of the northeast half of the area Wednesday morning. Temperatures and 
moisture will begin to moderate Wednesday and Wednesday night but the 
Euro and GFS show another quick hitting surge of Arctic air on 
Thursday along with some precipitation. This system will need to be 
watched for wintry potential. /22/ 


&& 


Aviation...VFR conditions will persist at all taf sites over the 
next 24 hours. /19/ 


&& 


Preliminary point temps/pops... 
Jackson 65 39 70 53 / 0 0 0 59 
Meridian 64 34 68 54 / 0 0 0 48 
Vicksburg 67 43 71 51 / 0 0 4 67 
Hattiesburg 67 40 73 55 / 0 0 0 32 
Natchez 67 45 73 55 / 0 0 1 58 
Greenville 60 40 67 46 / 0 0 15 76 
Greenwood 58 38 69 48 / 0 0 9 74 


&& 


Jan watches/warnings/advisories... 
MS...none. 
La...none. 
Arkansas...none. 
&& 


$$