Funnel Cloud in Arkansas, September 18, 2017

Area Forecast Discussion
National Weather Service Jackson MS
1204 PM CDT Mon Sep 18 2017

.UPDATE...
Updated for 18Z aviation discussion

&&

.AVIATION...
18Z TAF discussion:
A few showers have developed and more scattered activity is
expected south and west through the afternoon. Will add VCTS to
GLH and HBG and maybe JAN/HKS after 20z. Guidance has some fog but
models do not show too much, so may add some MVFR ceilings for a
few hours again for TVR-MEI and south.

&&

.DISCUSSION...

Today through tonight:

Fog has been just a little slower to form so far this morning, but
still expect quick development before sunrise per HRRR guidance,
in similar fashion to the past few mornings. Have expanded the
limited threat for dense fog in the HWO to include the entire area
based on obs/guidance trends, but it is unclear if and where
dense fog may necessitate an advisory, so will hold off on an
issuance for now. Otherwise, expect a summerish weather pattern to
continue with temperatures several degrees above normal.
Hot temperatures combined with precipitable water values
exceeding the 1.5 inch threshold will support isolated to scattered
diurnal convective precipitation mainly over western portions of
the forecast area today with activity quickly diminishing with
nightfall. Another muggy night should follow along with more fog
development in the persistent weather pattern. /EC/

Tuesday through Sunday...Predominately warm muggy conditions will
persist across the region through much of the forecast period. High
temperatures through the period will generally top out from the
upper 80s to lower 90s.  With dew points in the low and middle 70s
each day, afternoon heat indices could top out around the century
mark in some locations through the period.  Otherwise, lows each
night will range from the upper 60s to lower 70s.

Although weak high pressure at the surface will remain over the
forecast area, heights aloft will slightly weaken over much of the
CWA as an upper low to our east is forecast to slowly drop south
southwest through the period. This, in addition to daytime heating
and a moist airmass as precipitable H2O values sit at around 1.75
inches, will result in slightly better chances for mainly afternoon
showers and storms through at least the end of the work week.

While conditions and parameters overall aren't exactly conducive for
severe weather, with some slightly better lapse rates over the
region through Friday, around 7 C/KM, a stray severe storm can't be
ruled out each afternoon.  However, confidence in this is quite low
at the moment. Thus, I'll not introduce this potential into the HWO.
Gusty winds will be the primary concern with any such storm.
Convection will quickly begin to wane after sunset. /19/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       91  71  92  72 /  15  15  32  12
Meridian      91  70  94  71 /  13  13  34  10
Vicksburg     90  71  92  72 /  27  17  30  14
Hattiesburg   90  70  92  71 /  19  17  39  12
Natchez       89  71  90  72 /  29  20  28  11
Greenville    92  71  92  72 /  16  15  30  20
Greenwood     91  71  91  72 /  13  13  31  20

&&

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

&&

07

Hazardous Weather Outlook
National Weather Service Jackson MS
1017 AM CDT Mon Sep 18 2017

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
191530-
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-
1017 AM CDT Mon Sep 18 2017

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

.DAY ONE...The rest of Today and Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

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 Sunday.

21

&&

...HAZARD LEGEND...

No short term hazards expected.

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