Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus64 kjan 090934 

Area forecast discussion
National Weather Service Jackson MS
334 am CST Fri Dec 9 2016 and tonight: cold and dry through the next 24
hours. Early morning surface analysis had a >1040mb north-south
oriented ridge axis over the plains. This ridge will shift east
through tonight and become centered over the Ohio and Tennessee
valleys by Saturday morning. Our flow aloft will remain
northwesterly. Together, these features will bring a cold and very
dry airmass across our area. Although record cold is not expected,
afternoon highs today will be around 15 degrees below normal and
lows tonight will be around 15 degrees below normal. The winds
tonight will be much lighter than the winds early this morning.
This will result in warmer wind chill values in the lower 20s
versus the teens. /22/

Saturday through Thursday...00z models and ensembles continue the
general progressive zonal pattern through the period. We will start
with a cool Saturday morning with lows in the lower to middle 20s
with the cold surface high centered over Kentucky. As we push further
into the day the surface high will retreat to the eastern Seaboard.
This will bring back more humid low level return flow to the region
as high temps quickly rebound back to the 50s and 60s on Sunday
afternoon. There will be enough moisture convergence on Sunday to
squeeze out some isolated showers in the northwest Delta Region for
Sunday afternoon. A series of shortwaves will come across the region
with several cold fronts for Sunday through the middle of next week.
Once again models are having timing issues with the shortwaves and
the amount of return moisture with each one. On Sunday night
scattered showers will spread across the region as pwats build to
around 1.3 inches ahead of the first cold front. As we go into next
week guidance have continued the trend to warmer Spring like
afternoon highs and milder nighttime lows for the upcoming week
before the strong cold front. For Monday models continue to show some
surface and low level CAPES for some isolated convective potential.
So have kept isolated thunder in for Monday. The first front should
move through the region during the day before it hangs up across our
southern counties. Models shows that surface and low level CAPES will
continue across the south half for Monday night. So have introduced
some isolated thunder in the south half. For Tuesday into Wednesday
our chances of rain will continue as models have a difference of
opinion on surface and low level instability. So will keep it all
showers with basically lower end pops with moisture availability
issues among the models. For Wednesday a stronger cold front will
push into the region. There are different model opinions on how the
cold air will Chase after the departing rainfall on Wednesday night.
The GFS and Euro gets the rain out of the there before the cold air
arrives, while the Canadian tries slow the exit of the rains out of
the region. Have opted to go with the faster Euro and GFS. So have
moved the rain completely out of the region by Wednesday night per
the Euro. The GFS was a little slower in exiting the rain out
Wednesday night before the colder air arrives. So do not see any
winter weather at this time for Wednesday night. For Wednesday night
in the wake of the front temps will cool down into the 20s and 30s,
while on Thursday highs will be in the 40s and 50s. /17/


non convective low level wind shear was added to all tafs as the sfc
winds have become light enough combined with the winds through 2 kft
greater than 30kts on average. This will last until after 13z.
Otherwise, mid and high level clouds will continue to decrease across
the south and VFR conditions are expected through Friday evening. /22/


Preliminary point temps/pops...
Jackson 45 25 50 35 / 0 0 0 3
Meridian 44 23 49 30 / 0 0 0 2
Vicksburg 44 24 50 36 / 0 0 0 3
Hattiesburg 48 25 52 32 / 0 0 0 3
Natchez 45 25 53 39 / 0 0 0 4
Greenville 40 24 47 36 / 0 0 0 6
Greenwood 42 21 48 34 / 0 0 0 4


Jan watches/warnings/advisories...

National Weather Service Glossary of Abbreviations