Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Jackson MS
435 PM CST Tuesday Mar 3 2015
Short term...tonight through Friday morning...it has been a rather
warm day across the arklamiss region as a warm front moved through.
Temperatures this afternoon have reached the lower to middle 70s almost
areawide with middle 60s in the Delta. These temperatures are some 20 to
even 30 degrees warmer than yesterday. With the passage of the warm
front...dewpoints have climbed into the lower to middle 60s...making
conditions feel rather muggy. Some light to occasionally moderate
showers are occurring up the I-55 corridor but overall most locations
have been on the drier side. This is due to the effects of the large
upper level anticyclone centered over the northern Gulf of Mexico.
A rather warm 24 hours or so will occur for much of the area ahead
of another strong cold front that will move through the region
tomorrow. Warm overnight lows will occur tonight given our location
in the warm sector and we could drop only into the lower 60s. Some
light warm advective showers will be possible tonight but many
locations should be dry as we remain under some influence of the
upper ridge and in a negative Theta-E advection regime. However we
should still see another night of fog across the area.
The primary period of concern for weather continues to be Wednesday
through Thursday as a strong cold front heads toward our region. The
upper ridge will be shunted to the east in response to another
trough swinging southeast through the northern plains. Models
continue to trend slightly slower with the passage of this front.
Temperatures should be able to warm decently ahead of this front
into the 70s and even some 80s across southern Mississippi despite
clouds and some rain. Enough instability should exist across the
southern portions of the area to support some thunderstorms but most
other locations look to be just showers. Once the cold front passes
and the colder air is able to move into the region...temperatures
should drop and a changeover to some sleet and eventually freezing
rain should occur across the Delta. This looks to start after 00z
Thursday and progress southeastward across the County Warning Area through the night.
Locations south of the Natchez trace roughly will likely remain just
rain until after 12z Thursday. Just above everyone in the County Warning Area should
see some potential for freezing rain...even if it is just light
icing...except for the Pine belt. Model soundings show enough warm
air lingering here with the precipitation for it to remain rain. In
addition...bufr soundings show the potential for a changeover to
light snow through the morning before precipitation ends there. All
precipitation should exit the County Warning Area by around or after 18z Thursday. At
this point we have not made any adjustments to watches/hwo/graphics
as it seems covered well at this point.
After the frontal passage...northerly winds will be rather gusty
particularly across the Delta Region through early Thursday with
sustained speeds around 25-30mph and possible gust to near 40mph
based on some guidance. Elsewhere...northerly winds will be breezy
but with some more terrain they should not be quite as high.
Temperatures behind the front will drop off drastically particularly
in the Delta/flatter terrain. With highs on Wednesday in the
70s...we could definitely see a drop of about 40 degrees by
Wednesday night. Highs on Thursday wont be very warm given
clouds...cold advection...precipitation early in the day. It is
feasbile we could only be a few degrees warmer than the overnight
low. Forecasted highs will be in the middle to lower 30s for most
locations. Lows on Thursday night will be on teh chilly side with
readings in the 20s and possibly some upper teens across the north.
Long term...Friday through next Tuesday...cool and dry conditions
continue on Friday as highs range from the middle 30s in the
Delta...to the upper 40s across southeast Mississippi. Heading into
the weekend and the start of the next work week...aside from a rain
free Saturday and a warming trend through this forecast period...
models remain at odds Sunday through next Tuesday with the timing of
a coastal low prognosticated to affect mainly southern portions of the
forecast area. /19/
Aviation...a mix of MVFR/VFR flight statuses is expected to
continue at sites through the rest of the afternoon and into
tonight. Flight statuses will again fall to at least MVFR/IFR
conditions...with LIFR conditions possible at namely kmei and
khbg...late tonight into early Wednesday morning as the result of
low ceilings and degraded visibilities from fog...a chance of
showers possible through the forecast period. Winds this evening
and overnight will be southerly between 7-10 knots. Rain chances
will also be on the increase after midnight tonight...and through
the day Wednesday as a cold front begins to impede upon the area
from the northwest. /19/
Preliminary point temps/pops...
Jackson 64 79 32 33 / 32 71 99 77
Meridian 63 80 37 36 / 27 58 97 80
Vicksburg 65 73 30 33 / 18 80 100 74
Hattiesburg 65 82 46 41 / 14 51 92 80
Natchez 66 80 32 34 / 13 55 100 80
Greenville 60 64 25 31 / 27 99 100 56
Greenwood 62 66 29 32 / 42 94 100 58
MS...Winter Storm Watch from Wednesday evening through late Wednesday
night for msz018-019-025>030-034-035-040-041.
La...Winter Storm Watch from Wednesday evening through late Wednesday
night for laz007>009-015.
Arkansas...Winter Storm Watch from Wednesday evening through late Wednesday
night for arz074-075.