FXUS64 KJAN 060327

Area Forecast Discussion
National Weather Service Jackson MS
1027 PM CDT Fri Jun 5 2020

Updated for evening discussion.


Severe MCS has blown through the forecast area, leaving wind
damage in its wake. Some showers are left through the rest of the
evening but these should eventually diminish tonight. Muggy night
in store as lows should only drop into the upper 60s or lower 70s.

Prior discussion below:

Through tomorrow:

As of this afternoon, a severe MCS is pushing south along I-55 in
northern Mississippi. This line of severe storms will continue to
move south through northern and into central Mississippi. 18z JAN
sounding sampled 4600 J/kg of SBCAPE and 1100 J/kg of downdraft
CAPE, which will be supportive of damaging wind gusts of 60-70mph.
The ongoing slight risk in the HWO/graphics remains well placed and
no changes were needed. The MCS will weaken this evening as it
pushes south of I-20 with only a few showers and perhaps an isolated
storm lingering through the overnight hours.

By tomorrow, Tropical Storm Cristobal will continue to move north
across the Gulf of Mexico as upper ridging shifts east into the
Middle Mississippi River Valley. Associated cloud cover will begin
to increase across southeast Mississippi, but the majority of any
rainfall will remain offshore and south of the ArkLaMiss region
through the day tomorrow. A few isolated to scattered diurnally
driven showers and storms will be possible, but coverage is expected
to be lower compared to today. /TW/

Saturday night through next week: The primary focus will be on the
impacts of Tropical Storm Cristobal as we finish up the weekend
and go through early next week. Per latest information from NHC,
we expect "Cristobal" to officially make landfall late Sunday
over the eastern LA coast. Thereafter, the center of the decaying
system will track NNW through western portions of the forecast
area, with impactful wind/rainfall will spread across most of the
forecast area as we go from Sunday night through Tuesday.

The rainfall associated with this system has the chance to the
most significant impact for the ArkLaMiss region. Initially, the
bulk of rainfall is occurring on the north/east side of the track
as it moves through a weakness in the subtropical ridge over the
Gulf of Mexico, but as "Cristobal" approaches the LA coast and
then moves inland, it will begin to make a westward turn in
response to a ridge building to the north. Given greater ridge
influence, ascent and the heaviest rainfall should focus closer
to the center and the bulk of guidance shows the heaviest QPF
shifting to west of the I-55 corridor with time. An HWO graphic
shows the increasing rainfall/flooding threat, but it is also
worth noting that there has been a noticeable eastward shift in
the guidance and this may need to eventually be reflected in the
graphic. Otherwise, there will likely be a threat for brief
tornadoes and strong wind gusts, perhaps near TS strength Monday.

"Cristobal" is expected to get swept up in the westerlies mid week
with a strong upper level trough pushing a cold front through the
forecast area. While convective rainfall will accompany the
front, expect drier conditions to finish up the week behind it.


00Z TAF discussion:
Line of thunderstorms are moving through the I-20 corridor. Behind
this, light to moderate rain is occurring. This is affecting TAF
sites along and north of I-20 and leading to reduced vis in the
strongest storms. Elsewhere VFR conditions continue. This line
will continue south this evening. Light rain will linger behind
this activity through the evening but VFR conditions and quiet
weather expected overnight into tomorrow. /28/


Jackson 70 89 72 88 / 13 24 6 27
Meridian 70 89 70 87 / 13 24 9 28
Vicksburg 72 91 74 90 / 13 22 4 23
Hattiesburg 69 88 71 83 / 23 24 23 60
Natchez 71 89 72 86 / 30 23 7 40
Greenville 72 92 74 93 / 13 18 2 9
Greenwood 70 92 73 93 / 13 20 3 9





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