Areal Flood Warning 1, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
1220 PM CST Fri Feb 26 2021

.UPDATE...
Updated for 18Z aviation discussion

&&

.AVIATION...
18Z TAF discussion:
IFR stratus deck from roughly HKS to GTR and points to the NW on
sat imagery. Some improvement in a patch near GLH at least
temporarily supported by only a couple of other obs and some gaps
on visible. Showers to the north and south...less precip through
HKS/JAN/MEI, but cigs bouncing back and forth above and below
3kft. Front invof northern terminals will keep the wind forecast
changing through the evening...but more southerly south of the
boundary. Intermittent gusts through the afternoon until the BL
decouples. Tonight, models persist on dropping the ceilings
everywhere...but considering the mixing out going through the
central portion of the forecast area...have kept MVFR instead.

&&

.DISCUSSION... Cloudiness and some light showers have helped keep
temperatures from rapidly rising in most areas. Rain chances
diminish through the day and temperatures should recover in areas
south of the surface boundary that remains draped roughly along the
Interstate 20 corridor. As showers diminish, the boundary may drift
north a bit with prevailing southerly wind anchored by surface high
pressure to the east. In the forecast, lowered afternoon high
temperatures a degree or two for most areas south of the boundary
given the cloud cover trend with overcast skies still in place. This
will break up some through afternoon and most areas in the south
will rise into the middle and upper 70sF, approaching 80F in the far
southeast. Drier conditions are expected as we head into evening and
overnight with only a few showers possible in the far northern
zones. Lows Saturday morning will fall to the 50sF in the north,
60sF in the south. /86/

Prior discussion below:

Today and Tonight: Satellite imagery and surface observations show
dense fog around Mobile and east across the Florida panhandle that
may spread across our southeast zones toward sunrise. It is possible
that a layer of stratus will develop over our southern zones and
limit dense fog in our area but the Dense Fog Advisory will remain
in effect until 9am for now. Latest surface analysis had a stalled
frontal boundary across our CWA from just north of Meridian to just
south of Jackson and meandering between Vicksburg and Natchez. Water
vapor imagery/RAP analysis showed the circulation around a shortwave
trough from the Red River valley north across western Oklahoma and
western Kansas. This shortwave will weaken as it lifts northeast
across the mid Mississippi river valley today and Ohio valley
tonight. This shortwave trough will continue to draw moisture up
across the stalled boundary through the period resulting in
convection mainly across our northern zones. The most vigorous
convection through the period is expected this morning where a
strong thunderstorm or two capable of small hail will be possible.
Instability looks to remain limited and the storms elevated. It's
also possible that brief runoff issues may develop where the
strongest storms train across the same area, especially in the
upper delta that has seen the most rainfall this past evening. As
the shortwave lifts northeast of the region the stalled boundary
is expected to drift back to the north some. This will result in
the rainfall being more confined to the northern zones. South of
the boundary much warmer than normal temperatures will continue.
Our southeast should see the most sun today and top out near 80
degrees while upper 70s will be common south of Interstate 20.
Morning lows Saturday will be in the lower 60s south of Interstate
20 with mid 50s expected across our northwest. /22/

The wet weather pattern will continue into next week.

This weekend into Monday: The surface front will continue to pull
northward as the upper jets streak shifts northward, with strong
southerly flow kicking in south of the front over the weekend.
Though lighter shower activity and a few storms will remain possible
closer to the front, the axis of heavier precip will shift northward
into the Midsouth Saturday through early Sunday. However, the front
will begin to shift southward again later Sunday into Monday as a
mid/upper low digs across the Four Corners area then shifts eastward
into the Southern Plains. This will bring the main precip axis back
into northern portions of the area late Sunday afternoon into the
evening, shifting southward overnight into early Monday. Sufficient
instability will exist for embedded storms as well.

On Sunday, forecast ensemble mean PW values continue to be in the
90th+ to 99th+ percentile range for this time of year, though they
revert to a more seasonable range as the front shifts farther south
on Monday. We're beginning to get a better grasp on placement of
this rainfall, with much of the early weekend QPF north of our area
then late weekend into Monday shifting back into the area. With
grounds from AR into north MS saturated from prior rains (MRMS
estimates show a few bands of 1-2" roughly along the US 82 corridor
and northward from last night and early this morning), potential
exists for localized flooding in these areas especially with higher
rainfall rates in any convection. In addition, some rivers and
streams are already running above normal and these levels will only
increase with additional rains. Thus, we have added a limited
flooding threat for areas north of a Winnsboro to Columbus line for
Sunday into Monday. It's not impossible a higher threat level may
need to be added as we get into CAM timeframe if greater rain rates
appear more likely.

Also of note for this weekend south of the front, shower activity
will be more isolated and it will be quite warm. Temps in the 80s
are possible Saturday and Sunday as far north as the I-20 corridor
with mid 80s possible in the Pine Belt.

Tuesday through Thursday: Forecast uncertainty remains greater
toward the end of the forecast period with unresolved questions over
how far south the front will push early next week before stalling
again. The best we can say right now is...ensemble consensus
suggests it will remain close by enough for continuing isolated to
scattered showers into the middle of next week. Temperatures are
expected to be more seasonable with lows remaining above freezing
and highs mainly in the 60s. /DL/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       75  62  81  65 /  24  14  20  16
Meridian      75  63  81  64 /  19  10  20  14
Vicksburg     74  61  79  65 /  45  15  22  18
Hattiesburg   78  63  83  63 /  20  10  16  13
Natchez       76  63  80  66 /  30  12  12  12
Greenville    61  54  70  63 /  94  53  50  41
Greenwood     66  58  75  65 /  88  56  46  37

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.

&&

HJS

Hazardous Weather Outlook
National Weather Service Jackson MS
416 AM CST Fri Feb 26 2021

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>061-271030-
Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland-
Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar-
Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-Lowndes-
Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-Winston-
Noxubee-Issaquena-Sharkey-Yazoo-Madison MS-Leake-Neshoba-Kemper-
Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah-
Simpson-Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-
416 AM CST Fri Feb 26 2021

This hazardous weather outlook is for portions of southeast
Arkansas, northeast Louisiana, and central Mississippi.

.DAY ONE...Today and Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Localized flash flooding and minor river flooding will be possible
north of a line from Winnsboro to Bentonia to Columbus from Sunday
evening through Monday.

(https://www.weather.gov/images/jan/graphicast/2.png)

.SPOTTER CALL TO ACTION STATEMENT...
The activation of storm spotters, HAM radio operators, and
emergency management personnel in support of severe weather
operations is not expected through next Thursday.

MSZ062>066-271030-
Lincoln-Lawrence-Jefferson Davis-Covington-Jones-
416 AM CST Fri Feb 26 2021

This hazardous weather outlook is for portions of south central
and southeast Mississippi.

.DAY ONE...Today and Tonight

FOG
THREAT...Limited
TIMING...Through 9 AM

Patchy dense fog, with visibilities potentially down to a quarter
of a mile, is possible this morning.

(https://www.weather.gov/images/jan/graphicast/1.png)

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The probability for widespread hazardous weather is low.

.SPOTTER CALL TO ACTION STATEMENT...
The activation of storm spotters, HAM radio operators, and
emergency management personnel in support of severe weather
operations is not expected through next Thursday.

MSZ072>074-271030-
Marion-Lamar-Forrest-
416 AM CST Fri Feb 26 2021

This hazardous weather outlook is for portions of southeast
Mississippi.

.DAY ONE...Today and Tonight

FOG
THREAT...Elevated
TIMING...Through 9 AM

Areas of dense fog, reducing visibilities to a quarter mile or
less, are likely this morning.

(https://www.weather.gov/images/jan/graphicast/1.png)

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The probability for widespread hazardous weather is low.

.SPOTTER CALL TO ACTION STATEMENT...
The activation of storm spotters, HAM radio operators, and
emergency management personnel in support of severe weather
operations is not expected through next Thursday.

DL

&&

...HAZARD LEGEND...

*FOG*
Extreme...Widespread fog with visibilities near zero.
Significant...Fog with visibilities less than or equal to 1/4
 mile likely.
Elevated...Fog with visibilities less than or equal to 1/4 mile
 possible.
Limited...Patchy fog with visibilities less than or equal to 1/4
 mile possible.

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