Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Jackson MS
1036 am CDT Tuesday Jul 29 2014
Update...reduced probability of precipitation even further to near 0-5% and removed light
sprinkle wording for today.
Discussion...below normal temperatures and near 50-60% of normal
moisture content is paving the way for a comfortable late July day
with current readings as of 10am in the upper 70s to low 80s. Highs
will top out in the middle to upper 80s north and central with a couple
sporadic 90f degree readings towards the Highway 84 corridor. A weak
secondary boundary is located across north MS this morning as it moves
southward could help initiate some very shallow isolated sprinkles
this afternoon. However, 12z kjan sounding indicates decent capping near
6-8 kft and should limit overall light shower development/coverage.
Thus, removed light sprinkle wording for today.
Updates are out and an updated aviation discussion can be found
directly below. /Allen/
Aviation...quiet conditions for 95 percent of the taf period as VFR
conditions will prevail. The only issues that may arise will be in
the morning where some MVFR visible conditions may develop between
Previous discussion... /issued 337 am CDT Tuesday Jul 29 2014/
Short term...today through Wednesday night...cold front has cleared
the area and dry/cool air continues to ooze into the forecast area
this morning. Some cumulus noted in infrared imagery this morning over far north MS
and latest hrrr data showing some possibility of sprinkles with
these today...especially during the limited heat of this afternoon.
Temperatures will be markedly cooler today with maximums not making
out of the 80s over the northern two thirds and around 90
elsewhere. High level moisture looks to begin spreading into the
region tonight...but at the moment the resulting cirrus looks to be
thin and scattered in nature. Widespread record lows...therefore...
look probable...especially in the east. Current records... some long
standing...are in the lower 60s. These values look to easily be
broken in the east with middle/upper 50s expected. Records in the west
will be a little harder to break with expected mins around 60.
Approaching middle level shortwave in the northwest flow will begin moving out
of the plains into the lower MS valley by Wednesday afternoon. An
increasing/thickening veil of cirrus will overspread the forecast
area by afternoon/evening. Middle/high level moisture will continue
increasing during the evening with showers breaking out after
midnight from the northwest as isentropic lift above 310k Theta increases.
Not looking for much...if any...thunder at the onset as lapse rates
remain meager and showalters well above zero./26/
Long term...Thursday through Tuesday...a long wave trough will be
in place across the eastern half of the country for the extended
forecast period...a very unusual situation for late July and early
August. This will lead to below normal highs and lows through the
Models bring significant moisture back into the entire forecast area
on Thursday and Thursday night as a middle level wave crosses the
region. Instability will be lacking with this feature so will keep
thunder out of the forecast. The lead wave will pull east of the
area for Friday and the weekend. However...abundant moisture...
instability and more weak low pressure waves will lead to scattered
storms each day. The most likely timeframe for rainfall will return
to the afternoon and evening by this weekend. /SW/
Preliminary point temps/pops...
Jackson 88 60 87 66 / 5 2 5 13
Meridian 89 57 87 62 / 5 2 5 10
Vicksburg 88 59 87 64 / 5 2 5 19
Hattiesburg 91 64 89 65 / 5 2 2 6
Natchez 87 61 86 66 / 5 2 2 11
Greenville 85 60 85 65 / 5 2 13 32
Greenwood 85 56 84 63 / 5 2 8 22