Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion...corrected 
National Weather Service Jackson MS
1044 am CDT Sat Aug 1 2015

Update...

The short term forecast is on track and no significant adjustments
are being made in this update. Observed precipitable water is
generally below an inch for the arklamiss as a dry airmass remains
entrenched over the region. As expected...full sun is leading to
strong mixing with unseasonably low relative humidity values forecast this
afternoon along with occasional wind gusts above 20 miles per hour.

As discussed earlier...the recent very hot and dry weather has
contributed to an unusual degree of vegetative Browning and this is
depicted well in latest usfs wafs analyses. Kbdi values are in
excess of 600...and the combination of the hot/dry/breezy conditions
continues to support a limited fire danger threat...but explicit
relative humidity/winds values are near marginal thresholds so not expecting any
increase in the fire danger threat this weekend. /Ec/

&&

Previous discussion... /issued 326 am CDT Sat Aug 1 2015/

Short term...today through Sunday night...a pleasantly dry airmass
continues to pour into the County Warning Area this morning under northeasterly winds
of around 10 knots which have not decoupled. This has prevented temperatures
from falling off into the 60s and have instead remained in the 70s.

Deep mixing will get underway quickly this morning as the August sun
takes full advantage of the dry air and allows temperatures to shoot up
into the middle 90s across the County Warning Area today. Bufr data is showing winds
averaging from 10 to 15 knots through the mixed layer and will
expect to see breezy conditions at the surface.

The heat of the last couple of weeks has served to Brown out a lot
of the vegetation over the area...especially grass. With dewpoints
falling into the 50s during maximum mixing...minimum relative humidities
today and Sunday will fall into the 25 to 35 percent range. These
humidities combined with the expected winds will lead to increasing
fire danger...thus will continue the limited fire danger threat in
the severe weather potential statement./26/

Long term...Monday through Friday night...the dry conditions will
continue for the most part on Monday with precipitable waters below 1.4 inches
over most of the area. Afternoon highs will be a little warmer
climbing into the middle/upper 90s once again. Moisture will begin to
increase from the south as the surface flow does become more
southerly Monday into Monday night. With more moisture across the
area on Tuesday there will be an increase in isolated thunderstorms
along with a return of the humid conditions.

Upper troughing will deepen over the area on Wednesday as northwest
flow returns. Moisture will also increase along with increased
chances for showers and thunderstorms. Both the GFS/European model (ecmwf) indicate
that a frontal boundary will move into the area Wednesday night into
Thursday bringing with it more chances for showers and
thunderstorms. Hopefully this system will bring some much needed
rainfall across the region. Both the GFS/European model (ecmwf) keep plenty of
moisture across the area on Friday into Saturday with afternoon and
evening scattered thunderstorms./15/

&&

Aviation...VFR conditions will prevail across the region through
the period. NE winds from 10-15 knots with gusts near 20 knots will
be common between 01/18z and 01/23z. /26/28/

&&

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

$$

National Weather Service Glossary of Abbreviations