Flash Flood Warning 102, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
609 AM CDT Tue Jul 30 2019

.UPDATE...
Updated for 12Z aviation discussion

&&

.AVIATION...
12Z TAF discussion:

Showers and storms continue to increase in coverage this morning
and will continue to be possible in the vicinity of most sites
throughout the day. A deck of IFR CIGs has developed in the MS
Delta this morning, currently impacting conditions at KGLH.
Conditions will also begin to deteriorate at KGWO before the deck
of CIGs begins to fall apart by 14Z. Scattered thunderstorms will
continue to impact the region throughout the day and into the
early evening. Sites that are impacted by these showers and storms
could see reductions in visbys. Confidence is also growing that
some patchy fog could develop late in the forecast period.

&&

.DISCUSSION...

Today and tonight...

The weather pattern will continue to be active and wet on Tuesday
as a frontal boundary remains stalled near the region, helping to
initiate showers and storms throughout the day. The coverage of
showers has been on the decline during the early morning hours as
noted by recent radar scans. However, expect coverage to begin to
increase as the morning progresses, developing along remnant
outflow boundaries from last night's storms.

The coverage of showers and storms will peak during the afternoon
hours as moisture continues to increase in our region ahead of the
slowly moving boundary that will continue to sink south into the
lower Mississippi River Valley. Weak 0-6km shear and modest
instability may support a few strong storms this afternoon with
the best chance of this occuring along and west of the MS River,
closer to the boundary, where these parameters will be the
highest. CLoud cover and storms will help to keep temperatures
below normal today with highs only expected to reach the mid to
upper 80s.

Coverage of storms will begin to wane as we lose daytime heating
but a few showers could linger into the night.

Mid-week through early next week (Wednesday - next Monday):

Northwest flow, lingering trough axis & higher deep layer moisture
will persist through the extended forecast this week. The synoptic
pattern by mid-week will consist of a cold core low cutting off over
the northern Gulf of Mexico. Persistent northwest flow & jet energy
will build on the periphery of anomalous deepening mid-upper ridge
of high pressure over the Intermountain West & Texas Panhandle. This
synoptic pattern, in addition to -NAO high latitude blocking, will
keep the ArkLaMiss locked in for rain & storm chances through the
entire forecast period. In addition, some better lapse rates &
microburst & organized strong diurnal storm potential will be
possible by mid-late this week & into early weekend. However, it is
difficult to pin down a better forced & more favorable time. This
will have to be assessed daily. In addition, any MCS development
late week-early weekend upstream in the Plains to Ozarks could be
something to watch for our area. Right now, it looks as though most
global consensus keeps the ArkLaMiss on the eastern periphery & less
favorable. This will definitely a pattern to watch upstream
convection.

There will be periods of rain & storms each day through the week &
weekend. As the mid-level ridge builds to near 595-596DM, increasing
heat will slowly build in. As a weak frontal boundary moves in or
just north of the area, rain & storms will gradually shift southward
of the Highway 82 corridor by late week. Southerly return flow &
moisture will lift north through the weekend & early next week,
leading to increasing rain & storm coverage areawide. Overall heat
stress will remain lower due to rain, storms & cloudiness, but
humidity will still be higher. Heat indices will remain around the
upper 90s to near 100 degrees. Highs will be near to slightly above
normal through the week in the low-mid 90s & warming into the
weekend. /DC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       85  70  91  71 /  61  23  33   6
Meridian      85  70  93  71 /  57  15  29   7
Vicksburg     85  70  89  72 /  56  23  26   5
Hattiesburg   86  70  92  71 /  42  15  37   4
Natchez       84  71  88  71 /  63  31  47   7
Greenville    87  72  89  70 /  41  21  12   1
Greenwood     86  71  89  70 /  45  22  17   2

&&

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

&&

JPM3

Hazardous Weather Outlook
National Weather Service Jackson MS
336 AM CDT Tue Jul 30 2019

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
310845-
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-Lincoln-
Lawrence-Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest-
336 AM CDT Tue Jul 30 2019

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

.DAY ONE...Today and Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

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 Monday.

23

&&

...HAZARD LEGEND...

No short term hazards expected.

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

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

Tropical page...
   https://www.weather.gov/srh/tropical?office=jan
National Hurricane Center Home Page...
   https://www.nhc.noaa.gov/
Find NWS JAN on Facebook...
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Follow NWS JAN on Twitter...
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Special Weather Statement
National Weather Service Jackson MS
645 AM CDT Tue Jul 30 2019

LAZ024-026-MSZ060-301230-
Concordia-Catahoula-Adams-
645 AM CDT Tue Jul 30 2019

...AN AREA OF STRONG THUNDERSTORMS WITH HEAVY RAINFALL WILL AFFECT
SOUTHWESTERN CONCORDIA...SOUTHWESTERN CATAHOULA PARISHES IN
NORTHEASTERN LOUISIANA AND SOUTHWESTERN ADAMS COUNTIES...

At 643 AM CDT, strong thunderstorms were clustered near Lake Ophelia
National Wildlife Refuge, or near Larto, moving southeast at 10 mph.

Winds in excess of 30 mph are possible with these storms.

Locations impacted include...
Larto, Monterey, Mayna, Acme, New Era, Black Hawk and Slocum.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 3104 9165 3104 9172 3120 9170 3123 9179
      3130 9191 3127 9195 3123 9192 3123 9200
      3124 9201 3153 9201 3157 9175 3129 9147
      3128 9150 3123 9149 3124 9156 3121 9159
      3111 9163 3104 9156 3097 9166
TIME...MOT...LOC 1143Z 337DEG 9KT 3129 9193

DC