993
FXUS64 KJAN 211143 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
643 AM CDT SUN JUN 21 2026
..NEW AVIATION
KEY MESSAGES
- WE WILL BE MONITORING A STORMY WEATHER PATTERN FOR ADDITIONAL
FLASH FLOOD AND SEVERE WEATHER THREATS THIS WEEK.
- DANGEROUS HEAT STRESS WILL RETURN FOR MUCH OF THE AREA MONDAY
AND CONTINUE THROUGH THE UPCOMING WEEK.
DISCUSSION
ISSUED AT 355 AM CDT SUN JUN 21 2026
THE FORECAST AREA WILL REMAIN IN THE INTERFACE REGION BETWEEN A
STRONG SUBTROPICAL RIDGE AXIS CENTERED TO OUR SOUTHWEST AND AN
UNSEASONABLY STRONG LONGWAVE TROUGH OVER THE CENTRAL/EASTERN
CONUS. NORTHWEST FLOW BETWEEN THESE PROMINENT FEATURES WILL
SUPPORT ADDITIONAL ROUNDS OF STORMS AS WE GO THROUGH WORK WEEK.
EXPECT A SIGNIFICANT LONGWAVE PATTERN CHANGE BY NEXT WEEKEND
WITH THE TROUGH SHIFTING TO THE WESTERN CONUS WHILE THE
SUBTROPICAL RIDGE BUILDS NORTHWARD ACROSS MUCH OF THE EASTERN
CONUS. THIS WILL RESULT IN THE POTENTIAL FOR STIFLING HEAT.
FOR TODAY: PATCHY AREAS OF DENSE FOG HAVE DEVELOPED AND WILL
CONTINUE TO AROUND DAYBREAK GIVEN THE VERY MOIST NEAR SURFACE
HUMIDITY, MOSTLY CLEAR SKIES, AND LIGHT WIND. ONCE THE FOG
DISSIPATES, A STRENGTHENING LOW LEVEL WARM ADVECTION PATTERN WILL
SUPPORT HOTTER CONDITIONS ALONG WITH DISORGANIZED, DIURNALLY
ENHANCED SHOWERS AND STORMS.
MONDAY THROUGH SATURDAY: GUIDANCE CONTINUES TO SETTLE ON A
CONSENSUS FOR MORE SUPPRESSED WESTERLIES, AND THIS WILL RESULT IN
CONTINUED STORM THREATS WITH ADDITIONAL CONCERNS FOR FLASH
FLOODING/SEVERE WEATHER THROUGH THIS WEEK. AS OF NOW, IT DOES NOT
APPEAR ANY OF THESE THREATS WILL BE SIGNIFICANT, AND LIMITED/MARGINAL
CATEGORIES SHOULD MOSTLY COVER THE THREATS.
WITH THAT SAID, LOCAL MESOSCALE INFLUENCES AND ANTECEDENT
CONDITIONS WILL DRIVE ANY FLASH FLOOD AND SEVERE WEATHER THREATS
ON A DAILY BASIS, SO MONITOR FOR UPDATES AS WE GO THROUGH TIME
THIS UPCOMING WEEK. WITH UP TO 30 KNOTS OF DEEP LAYER WEST-
NORTHWEST FLOW THAT IS MOSTLY PARALLEL TO WEAK SURFACE BOUNDARIES,
THERE MAYBE A TENDENCY FOR MULTICELL STORM CLUSTERS TO BACK BUILD
AND TRAIN REPEATEDLY FOR A LOCALIZED HEAVIER RAIN FLASH FLOOD
THREAT. DURING PEAK HEATING, EXPECT UPDRAFTS TO BE INTENSE ENOUGH
FOR A MARGINAL SEVERE WIND THREAT.
HEAT IS INCREASINGLY A CONCERN WITH AN ELEVATED THREAT FOR MONDAY
AHEAD OF STORMS THAT MOVE IN LATER IN THE DAY AND EVENING. GOING
BEYOND MONDAY AND THROUGH THE REMAINDER OF THE WORK WEEK, HEAT
STRESS WILL BE A LINGERING ISSUE FOR SOUTHERN PORTIONS OF THE AREA
IN PARTICULAR, WITH AREAS FARTHER NORTH A CONCERN IF THERE IS
JUST A SLIGHT NORTHWARD SHIFT IN THE RIDGE AXIS FROM WHAT IS
CURRENTLY FORECAST. BY THE WEEKEND, THE PREVIOUSLY MENTIONED
PATTERN CHANGE COULD RESULT IN AN ESPECIALLY HOT PERIOD AS UPPER
LEVEL RIDGING STRENGTHENS AND COMBINES WITH THE VERY HUMID
CONDITIONS TO DANGEROUS HEAT INDEX VALUES. WILL BE MONITORING FOR
ADDITIONAL HEAT THREAT MESSAGING. /EC/
AVIATION
(12Z TAFS)
ISSUED AT 643 AM CDT SUN JUN 21 2026
IFR/LIFR FLIGHT CONDITIONS ACROSS EASTERN/SOUTHEASTERN SITES AS FOG
HAS REDUCED CEILINGS; ELSEWHERE, VFR FLIGHT CONDITIONS PREVAIL UNDER
CLEAR SKIES. ADDITIONAL FOG DEVELOPMENT WILL BE POSSIBLE THROUGH
15Z. VFR FLIGHT CONDITIONS WILL PREVAIL THROUGH THE REST OF THE
PERIOD ONCE FOG DIMINISH. AFTERNOON CONVECTION MAY BRIEFLY REDUCTION
IN FLIGHT CONDITIONS AT AFFECTED AREAS. /SW/
PRELIMINARY POINT TEMPS/POPS
JACKSON 88 75 91 75 / 70 10 40 40
MERIDIAN 87 75 92 74 / 70 10 30 30
VICKSBURG 88 76 91 76 / 60 10 30 40
HATTIESBURG 89 76 93 76 / 60 10 10 10
NATCHEZ 89 76 92 76 / 50 0 10 10
GREENVILLE 90 75 90 74 / 30 30 70 70
GREENWOOD 90 75 90 74 / 50 30 80 70
JAN WATCHES/WARNINGS/ADVISORIES
MS...NONE.
LA...NONE.
AR...NONE.
EC/SW
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