Freeze Warning 8, NWS Jackson, MS

Ashley County, AR, Chicot County, AR, East Carroll Parish, LA, Franklin Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Attala County, MS, Bolivar County, MS, Carroll County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Lowndes County, MS, Montgomery County, MS, Noxubee County, MS, Oktibbeha County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1145 PM CST Sun Nov 10 2019

.UPDATE...
Updated for 06Z aviation discussion

&&

.AVIATION...
06Z TAF discussion:
VFR conditions wl prevail through 20Z Monday. After 20Z a strong
cold front will begin moving in from the nw and bring widespread
-RA, gusty nw winds, and reduced flying conditions. Conditions will
drop to MVFR and occasionally IFR with gusts to 30kts in the wake
of the front as it moves se through the area overnight. /22/

&&

.DISCUSSION...
Zonal flow through the base of a mean longwave trough draped
across the northern CONUS will continue across the Gulf Coast
states tonight. At the surface, a sharp arctic cold front over the
Central Plains is progged to be pushing into northern Arkansas by
daybreak. High clouds embedded within the aforementioned zonal
flow are forecast to increase in coverage through the overnight
which will help keep temperatures around 10 degrees warmer
compared to this morning's lows. Temperatures have dropped quickly
ahead of the advancing clouds, however, and overnight lows were
adjusted down a degree in turn. Otherwise, the ongoing forecast
remains on track and no other changes were needed. /TW/

Prior discussion below:

Tonight and Monday: Though dry weather will continue through
tonight, changes are already underway as a potent storm system
begins to build over the central CONUS. The surface high which has
helped maintain quiet and colder weather over the past couple days
is now shifting eastward, with southerly flow now increasing across
the region. The sky is still relatively clear this afternoon, but
high clouds are increasing across the northern portion of the area.
As the mid and lower levels of the atmosphere continue to moisten, a
more pronounced increase in clouds will occur overnight. There is
also some potential for a brief period of advection fog sneaking
into the Pine Belt area around daybreak, though confidence in this
is too low to include in the forecast at this point.

Ahead of the front, rain will approach the ArkLaMiss Delta during
the morning hours Monday. For the areas still ahead of the rain, it
will likely be a relatively warmer day (similar to today) given the
surge of warm advection just ahead of the front. By the afternoon
hours, coverage of rain will increase more substantially across the
area. Though much of this rain will be more stratiform in nature,
limited elevated instability may make it more showery at times, and
rather respectable rainfall amounts of around an inch are possible.
The cold front will begin to enter the Delta by late afternoon/early
evening, with gusty northerly winds resulting from a tightening
pressure gradient hastening a quick drop in temperatures. /DL/

Monday night through the remainder of the week: A highly
impactful arctic air outbreak continues to be expected for the
Monday night through Tuesday night time frame with record-breaking
cold temperatures forecast.

Concerning winter weather potential: An arctic frontal passage
Monday night will be accompanied by rain potentially changing to a
light mix of sleet/freezing rain prior to ending. Typically, cold
air following rain scenarios such as the one expected do not pose
much in the way of impacts, especially so early in the cool
season due to the preceding mild weather, but this is an
especially cold airmass and it may overachieve in terms of cooling
the column sufficiently for a brief change-over. If this does
indeed happen, the latest SREF/HREF/WPC guidance point to the
potential for either sleet or freezing rain as the mid level warm
layer would not support much in the way of -SN potential, although
a few light snow grains could certainly develop in the very cold
lowest level. If any freezing rain develops, would not expect it
to accumulate on any paved surfaces given preceding warmth and
brief period of FZRA, but could see some very light accretion on
elevated objects such as tree limbs. Perhaps the more likely
scenario is that a brief period of sleet could occur given the
intensity of the cold air and sufficient cold layer depth for
liquid to refreeze just above the ground per discussion with WPC
earlier.

Concerning the cold and wind: Expect any precipitation to end
quickly early Tuesday morning with strong gradient winds
persisting as much colder air continues to surge southward. This
scenario is extremely unusual for so early in the cool season.
Not only are we are concerned with the threat to the growing
season, but there is even some concern that this cold event could
pose a threat to life and property in northern portions of the
ArkLaMiss. The combination of wind and cold Tuesday morning could
send wind chill readings well into the teens, while high
temperatures struggle to rise through the 30s in the afternoon.
As we go into Tuesday night, with high pressure settling more
firmly over the forecast area, we expect the wind to drop off
enough so that lows fall well into the 20s, and possibly even the
upper teens over north central MS. For now, will keep messaging
simple and maintained through the HWO/graphics.

As we go through the remainder of the week, expect moderating
temperatures, but readings will continue to be significantly below
average for the most part. Increasing moisture along the Gulf
coast baroclinic zone could support some light rain development
later in the week, but this potential has diminished somewhat
compared to previous days. /EC/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       46  72  30  38 /   0  62  99  18
Meridian      44  71  32  39 /   0  37  96  34
Vicksburg     48  73  29  37 /   0  82  99   9
Hattiesburg   44  72  37  43 /   0  24  93  45
Natchez       48  73  31  39 /   0  52  98  17
Greenville    46  64  25  35 /   1 100  96   2
Greenwood     48  66  25  36 /   0  91  98   3

&&

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

&&

TW/DL/22/EC

Hazardous Weather Outlook
National Weather Service Jackson MS
416 PM CST Sun Nov 10 2019

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
112230-
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-
416 PM CST Sun Nov 10 2019

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

.DAY ONE...Tonight and Monday

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Monday night through Saturday

Arctic air will surge southward into the ArkLaMiss region Monday
night and bring highly impactful weather. Strong northerly winds
behind the cold front could gust up to 35 mph in the Delta region
Monday night into Tuesday. These winds will make for difficult
travel and could raise concerns for falling tree limbs, and will
likely result in very cold wind chill readings, especially Tuesday
morning.

As we go through Tuesday night, a signficant, long duration
freeze is expected. Record low temperatures will be likely as
readings fall into the lower 20s over much of the outlook area,
with even a few readings in the upper teens over north central
Mississippi.

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

21

&&

...HAZARD LEGEND...

No short term hazards expected.

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