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Area forecast discussion...updated 
National Weather Service Jackson MS
941 PM CDT Friday Jul 31 2015

Update...
overall forecast is generally on track. Precipitable waters have fallen to less
than an inch in 00z kjan sounding with drier air just to the
NE...near just a quarter of an inch. North/NE flow aloft due to upper
ridge center to the west and deep trough over the middle MS valley/Great
Lakes region will aid in this very dry air...near record level
precipitable waters ...to advect in overnight. Expect very cool conditions for this
time of the year in the middle 60s with some top 5 record lows
possible...mainly in east/NE MS. Only adjusted hourly temperatures/dewpoints to
account for previous trends. Rest of the forecast is on track. /DC/

&&

Aviation...VFR conditions will prevail through the period with sky clear.
North to NE winds around 5-15kts are possible through the next 24 hours.
/Bb/DC/

&&

Previous discussion... /issued 310 PM CDT Friday Jul 31 2015/

Short term...(tonight through Sunday night) the main issue for the
short term is the layer of drier air over the region which will make
the heat of the afternoon and muggy nights little less oppressive
through Saturday night. However this will have an impact on fire
weather conditions across the region through Saturday. As of middle
afternoon dewpoints range from the middle 50s at Jan to around 70 at
hbg. There have been some wind gusts of around 20 to 25 miles per hour mainly
in open areas...which has help relative humidity values to dip to near 30 percent.
Models shows 925 mb winds will be around 20 knots again for
Saturday. So look for some gusty winds of 15 to 20 miles per hour to mix down
from the north on Saturday. Expect precipitable waters to dip to below 1 inch for
tonight and Saturday which will increase fire danger conditions
across the region. So with this dry air expecting sunny days and
clear nights for the period. As far as temperatures are concern the drier
air will bring middle to upper 60s across the region for tonight as
well as upper 60s to around 70 on Saturday night. Low level moisture
will start to return to the region with lows 70 to 74 for Sunday
night. We will get another day of slightly milder highs with
readings 91 to 95 for Saturday before warming to the middle 90s on
Sunday.

With the drier air and lower relative humidity values (30-40%)...the fire danger
will continue be on the increase through Saturday. Combine that with
the lack of precipitation over the past 3 weeks...some burn bans in effect
and increased winds today and Saturday...will continue the limited
threat to bring attention to this risk and mention burning is
discouraged for this afternoon and Saturday. For Sunday humidity
will be low again...but winds will not be an issue for any
significant fire danger risk./17/

Long term...Monday through Friday... GFS/European model (ecmwf) along with their
ensembles were in general agreement with the overall pattern during
the period. At the beginning of the period with middle/upper level
pattern characterized by ridging in the western US and a general
troffiness over the northeast and east central portions of the
nation. Shifting surface high pressure will allow surface winds to
become more southerly by Monday and begin tapping into the higher
dewpoints just to the south of the County Warning Area. A few isolated storms look
possible in the far south in the afternoon as lower 70s dewpoints
move back in. Tuesday will have similar scenario with isolated
storms in the south and west in the afternoon. By late Tuesday night
into Wednesday morning...with dewpoints now in the 70s overspreading
the region...a series of shortwaves dropping southeast in the northwest flow will
kick off some isolated convection that will become more scattered
during maximum heating Wednesday afternoon and into Wednesday night.

This convection will serve to moisten up the lower levels as precipitable waters
return to more normal levels by midweek in the 1.7 to 2.0 inch
range. This along with expected highs in the 90s will combine well
for airmass type convection again for Thursday and Friday./17/

&&

Preliminary point temps/pops...
Jackson 68 94 69 97 / 1 1 2 4
Meridian 64 94 67 94 / 1 2 5 9
Vicksburg 66 95 67 97 / 1 1 1 3
Hattiesburg 68 94 71 96 / 4 4 5 9
Natchez 67 93 69 95 / 1 1 2 4
Greenville 67 94 70 95 / 1 0 1 2
Greenwood 66 94 68 95 / 1 1 1 3

&&

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

$$

District of Columbia/bb/17

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