River Flood Warning 109, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
638 PM CST Fri Dec 7 2018

.UPDATE...
Updated for 00Z aviation discussion

&&

.AVIATION...
00Z TAF discussion:

Expect the worst conditions in the GLH/GWO area this forecast
period where IFR/MVFR category ceilings will generally prevail in
low stratus and periods of RA, especially from late tonight
through Saturday. These conditions will gradually work their way
to GTR later tonight, and then JAN/HKS by around daybreak. The
MEI to HBG/PIB area will actually experience mostly VFR conditions
tonight, but conditions will deteriorate rapidly Saturday morning.
Another big concern will be increasingly gusty E/NE surface winds,
peaking during the mid morning to early afternoon period. /EC/

&&

.DISCUSSION...
Tonight and Saturday:

The stalled cold front continues to sit over the ArkLaMiss Delta
this afternoon and provide the focus for the continuous isentropic-
induced rain showers. So far, radar estimates show up to an inch has
fallen in the far reaches of Bolivar County today with most other
locations receiving up to 1/2". As the night wears on and the
shortwave trough over the Southwest US pushes towards us, moisture
will increase along the frontal boundary over TX. The progressive
movement of the trough will push the moisture and rain through our
CWA during the day tomorrow. While PWs above 1.5" move into south MS
with this activity, rain rates will be moderate but the system
should move through the area fairly quickly. QPF totals are still
between 2-4" with some locally higher amounts possible, particularly
in the far northwest reaches of the CWA. Still expect any convective
activity to remain south of our area and so no thunder/lightning is
in the forecast through this event.

During the morning tomorrow, as a surface low lifts out of south LA,
the pressure gradient increases over our area and therefore winds
will increase. Some disruptions in the pressure field will yield
sustained winds of 15 mph at times with gusts up to 30 mph possible.

Temperatures tonight will fall into the lower to middle 40s. Highs
tomorrow will only rise maybe 7 degrees at the most (mid 40s to near
50) due to thick cloud cover and the saturated conditions. /10/

Saturday night through Thursday night...By Saturday evening most of
the heavy rain will shift off to the east of the area, but light
rain will continue through much of the night as another upper short
wave moves through. The models are a little faster moving the precip
to the east of the area than previous runs. There could be some
lingering light rain or drizzle in the east Sunday afternoon, but
the bulk of any light rain should be east of the area by early
evening. Currently it looks like the precip will be east of the area
before the airmass is cold enough to support any wintry precip.

The main upper trough axis will drop southeast across the area on
Monday and Monday night, but upper ridging will build in on Tuesday
and continue into Wednesday along with strong surface high pressure.
The cool temperatures will continue through mid-week with highs
generally in the 50s and lows falling into the mid/upper 20s/low
30s. The surface high will shift to the east of the area late
Wednesday, with the surface flow swinging back around the
southeast. With the southerly flow, expect warmer overnight lows
in the 40s Wednesday night.

Things will get active again towards the end of the period with the
potential for thunderstorms and possible some severe storms Thursday
night. The global models diverge in there solutions, but this is
something to keep a close eye on./15/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       42  47  40  44 /  99 100  61  32
Meridian      42  47  41  46 /  79  98  79  40
Vicksburg     44  47  38  44 / 100 100  55  22
Hattiesburg   45  50  43  49 /  42  98  65  21
Natchez       45  49  37  44 / 100 100  43  18
Greenville    42  45  35  42 / 100 100  75  22
Greenwood     43  45  38  43 / 100 100  79  31

&&

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

&&

Hazardous Weather Outlook
National Weather Service Jackson MS
224 PM CST Fri Dec 7 2018

ARZ074-075-LAZ007>009-015-016-023>026-MSZ034-040-041-082030-
Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland-
Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Washington-
Issaquena-Sharkey-
224 PM CST Fri Dec 7 2018

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

.DAY ONE...Tonight and Saturday

FLOODING
THREAT...Limited
TIMING...Tonight through Saturday

NON-THUNDERSTORM WINDS
THREAT...Limited
TIMING...Saturday

Localized flash flooding due to heavy rain is possible,
particularly in low lying and urban areas. This will mainly occur
tonight into all day Saturday. Rainfall totals will be between
2-4 inches, with locally higher amounts possible.

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

Wind gusts up to 30 mph are possible for the entire outlook area
on Saturday.

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

.DAYS TWO THROUGH SEVEN...Saturday night 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.

MSZ018-019-025>029-035>037-042>044-046>066-072>074-082030-
Bolivar-Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-
Humphreys-Holmes-Attala-Yazoo-Madison MS-Leake-Kemper-Warren-
Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah-Simpson-
Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-Lincoln-Lawrence-
Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest-
224 PM CST Fri Dec 7 2018

This hazardous weather outlook is for portions of central
Mississippi, north central Mississippi, northwest Mississippi,
and south central Mississippi.

.DAY ONE...Tonight and Saturday

FLOODING
THREAT...Limited
TIMING...Saturday

NON-THUNDERSTORM WINDS
THREAT...Limited
TIMING...Saturday

Localized flash flooding due to heavy rain is possible,
particularly in low lying and urban areas. This will mainly occur
early Saturday morning and spread eastward across the region
throughout the day. Rainfall totals will be between 2-4 inches,
with locally higher amounts possible.

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

Wind gusts up to 30 mph are possible for the entire outlook area
on Saturday.

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

.DAYS TWO THROUGH SEVEN...Saturday night 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.

MSZ030>033-038-039-045-082030-
Clay-Lowndes-Choctaw-Oktibbeha-Winston-Noxubee-Neshoba-
224 PM CST Fri Dec 7 2018

This hazardous weather outlook is for portions of central
Mississippi, east central Mississippi, and northeast Mississippi.

.DAY ONE...Tonight and Saturday

NON-THUNDERSTORM WINDS
THREAT...Limited
TIMING...Saturday

Wind gusts up to 30 mph are possible for the entire outlook area
on Saturday.

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

.DAYS TWO THROUGH SEVEN...Saturday night 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.

10

&&

...HAZARD LEGEND...

*FLOODING*
Extreme...Confident in significant flooding.
Significant...Significant flooding possible.
Elevated...Confident in flooding.
Limited...Flooding possible.

*NON-THUNDERSTORM WINDS*
Extreme...Sustained winds 50 mph or greater or wind gusts 65 mph
 or greater.
Significant...Sustained winds 40-49 mph or wind gusts 58-64 mph.
Elevated...Sustained winds 30-39 mph or wind gusts 45-57 mph.
Limited...Sustained winds 20-29 mph or wind gusts 30 to 44 mph.

...USEFUL WEATHER WEB PAGES (URLS)...

NWS JAN Home page...
   https://www.weather.gov/jan
Stay Aware, Stay Safe NWS JAN Briefing Page...
   https://www.weather.gov/jan/safe
Latest Weather Briefing...
   https://www.weather.gov/jan/weather_briefing

Find NWS JAN on Facebook...
   https://www.facebook.com/NWSJacksonMS
Follow NWS JAN on Twitter...
   @NWSJacksonMS
Follow NWS JAN on Youtube...
   https://www.youtube.com/user/NWSJacksonMiss

...ADDITIONAL URLS FOR FLOODING ISSUES...

Current Watches and Warnings...
   https://www.weather.gov/jan/safe_HeavyRain

Observed Precipitation Images...
   https://www.weather.gov/jan/precipmaps

River Forecast Center...
   https://www.weather.gov/lmrfc/
Significant River Flood Outlook...
   https://www.wpc.ncep.noaa.gov/nationalfloodoutlook/index.html
Day 1 through 3 Excessive Rainfall...
   https://www.wpc.ncep.noaa.gov/qpf/excess_rain.shtml
Excessive Rainfall Discussion...
   https://www.wpc.ncep.noaa.gov/discussions/qpferd.html
Day 1 through 7 QPF...
   https://www.wpc.ncep.noaa.gov/qpf/qpf2.shtml
QPF Discussion...
   https://www.wpc.ncep.noaa.gov/discussions/qpfpfd.html