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Area forecast discussion...updated 
National Weather Service Jackson MS
1016 am CDT Thursday Oct 2 2014

Update...latest satellite and upper air analysis...showed an upper
trough advancing across the plains. Upper jet energy was digging
into the back side of this feature for a negative tilted feature
later. There was some good upper divergence ahead of the trough for
the strong convection in the middle MS valley region. Over our region
flat mean riding was noted where dry midlevel air(vapor imagery) was
pushing over the region. In the lower levels a good moisture surge
was noted across the region as area 12z soundings showed precipitable waters from
1.8 to around 2 inches. Warm advection showers was noted across the
region this morning where moisture convergent transport vectors were
at maximum. This was aided by good inflow of Gulf moisture in the
low levels. On the surface a warm front was draped over the
northeast portion of the arklamiss with lower to middle 70s
dewpoints in its wake. At 850-025 mb we had teen dewpoints for rich
moisture values. The showers were pretty efficient with the
Bienville Forest reporting 0.48 inch and National Weather Service Jan had 0.40 inch as of
late morning.

Short range WRF models shows that the maximum moisture convergence will
shift north of region for this afternoon. So have opted to cut probability of precipitation slightly
with the loss of maximum convergence. Still expecting scattered
coverage for today for warm advection activity. It will be another
warm day with highs 88-90 with heat indices from lower to middle
90s. So will keep current temperatures for this afternoon./17/



/previous discussion...507 am CDT Thursday Oct 2 2014

Discussion...

Today through Friday night...

The threat for severe weather continues for northwest portions of the
arklamiss late tonight. A fairly strong shortwave trough is currently
moving east across the Southern Plains. This trough and associated
cold front will help to initiate a linear convective system west of
the arklamiss this afternoon and evening in a moist and unstable
airmass. The line of storms is forecast by most higher-res guidance
to approach and possibly move into the upper arklamiss Delta Region
shortly after midnight.

Guidance strongly suggests that peak convective intensity will occur
before this time as instability and forcing wane are expected to wane
during the evening...but with organized convection and west-southwest 0-3 km
shear vectors nearly normal to the line...will keep the mention of
severe weather going in the hazard products for the Delta Region
including the mention of damaging winds and a few tornadoes.
Instability/forcing and the lcs will continue to diminish farther
east across during the early morning hours. This should result in a
quick decrease in severe potential for locations east of the Delta
Region. The caveat will be to watch for quicker system speed and
earlier approach of convection that could result in greater storm
intensity.

Ahead of the severe threat today...a warm advection pattern with a moist
and unstable airmass will support scattered shower/thunderstorm
development given daytime heating. Temperatures will be very warm
with some readings approaching 90 degree f while heat indices reach the
lower to middle 90s. Convection should diminish some during the early
evening before increasing again ahead of the approaching cold front.
/Ec/

Saturday through next Thursday...

A very pleasant early fall weekend is expected across the forecast
area Saturday and Sunday as high pressure builds east into and
through the forecast area. With sunny skies prevailing...highs on
Saturday will struggle to climb out of the middle 70s on
Saturday...with middle 70s to around 80 expected Sunday. Conditions
Saturday night under mostly clear skies will be quite chilly as lows
fall into the low and middle 40s. Then for Sunday night...lows will
be a tad warmer as they fall into the low and middle 50s.

High pressure east of the region Monday will result in subtle
southerly flow across the region and slightly warmer conditions. A
weak front is prognosticated to swing east into and through the forecast
area from the early morning hours of Tuesday into early Tuesday
afternoon. This will bring some small rain chances to the forecast
area during that time. High pressure quickly building back into the
region Tuesday night behind the front...and remain in control of our
weather Wednesday into Thursday. /19/

&&

Aviation...MVFR conditions prevail this morning with low stratus
deck over most of region. A patch of rain showers and thunderstorms and rain between kjan and
kmei is moving northeast towards kgtr and kgwo and will monitor
timing for direct rain showers taf inclusion. Conditions will improve to
more widespread VFR by early afternoon with scattered thunderstorms and rain developing through
00z. A quick down trend in activity expected late afternoon to early
evening before a stronger line of thunderstorms pushes into the
region from northwest as a cold front moves through. Thunderstorms and rain with pockets of
30-50 knots wind gusts will be possible in Delta Region 03-07z. A
weakening trend is expected through 12z as line approaches kjan and
sites farther east but continued rain showers/thunderstorms and rain is expected. Winds will
be south today near 10 knots and turn west with front and then northwest
behind front overnight through Friday morning./Ja/



&&

Preliminary point temps/pops...
Jackson 88 70 84 47 / 37 83 35 0
Meridian 89 68 83 45 / 38 76 60 8
Vicksburg 92 68 85 46 / 36 87 21 0
Hattiesburg 89 72 88 55 / 38 52 60 7
Natchez 88 69 80 50 / 38 83 24 0
Greenville 90 67 82 47 / 35 88 16 0
Greenwood 90 66 80 44 / 38 90 29 0

&&

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

$$

17/ec/19/ja

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