Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Jackson MS
416 PM CDT Sat Jul 4 2015

Discussion...complex forecast on tap for the next 48 hours as a
couple more early morning storm complexes appear possible in this northwest
flow regime. Additionally...the Thermo env will be supportive of
severe storms and depending on how the morning cold pools
evolve...some threat for severe weather will also exist.

What is left after morning and afternoon convection is a well
defined mesoscale convective vortex over north MS. The leading edge of the deep convection has
shifted east with some additional storms back to the SW and west
along the stalled cold pool. Indications are the precipitation over the southeast
will push east while the activity to our west/SW will diminish by early
evening. The focus will shift to after midnight where another nocturnal
round of storms appears possible. There is strong support from the
GFS/Euro while other guidance is not as supportive. This sort of pattern
is one that fits the overnight redevelopment of storms as well as
supports heavy rainfall from the training of storm cells. Most near
term guidance shows a lull in the activity followed by a recovery of the
Theta-E axis a top the old cold pool. This looks to support storms
after midnight as the ll jet gets established. The key is where may
this form. Too much uncertainty exists to pinpoint an area...but we
feel somewhere north of I-20 has the best potential. While a severe
storm can't be ruled out...the main threat looks to be from heavy
rainfall. We cancelled the previous Flash Flood Watch as the threat had
diminished. We will hold off on issuing a new one at this time due
to the uncertainty in location of where the heaviest activity will
develop later tonight. Later shifts will evaluate this threat and
issue updates as needed. Something similar may again be possible
early Monday morning...but this will hing on how activity develops on
sun and we will evaluate this threat during later shifts.

As for the severe storm risk...steep lapse rates will exist into Tuesday
as cold temperatures aloft will remain over the area. Locations that can
remain uncontaminated from morning outflow boundaries and have an
opportunity to destabilize...will have some risk each day.
However...will not opt to highlight a location at this time due to
all the uncertainty on location as morning activity will highly
dictate where afternoon storms will be possible. We will update
often and highlight risk areas as our confidence grows in any
particular location.

As for temps/weather...probability of precipitation were focused for after midnight tonight
and mainly across the north half. For sun-Mon...tried to show the north
having the better chances during the overnight periods with the rest
of the area mainly during the day periods. Temperatures will be tricky on
sun and I showed central sections cooler as they will be highly
influenced by clouds/precipitation (similar to today). Look for a warming
trend as we head into middle/late week with 90-95 degree readings
common. /Cme/

&&

Aviation...showers and storms have cleared most of the taf sites so
have updated accordingly. Expect some activity to redevelop later
tonight and have indicated so in tafs but timing will likely need
adjusting. Otherwise...there are some MVFR ceilings scattered around
which are expected to be temporary. /SW/

&&

Preliminary point temps/pops...
Jackson 72 84 72 89 / 77 59 60 23
Meridian 70 83 69 89 / 80 58 64 37
Vicksburg 72 85 73 91 / 72 59 52 16
Hattiesburg 73 84 73 91 / 63 66 34 18
Natchez 73 87 73 90 / 42 61 22 15
Greenville 71 86 72 90 / 77 46 60 23
Greenwood 71 85 71 89 / 76 47 53 30

&&

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

$$

Cme/SW/

National Weather Service Glossary of Abbreviations