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000
FXUS64 KJAN 121917 AAA
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
217 PM CDT WED JUN 12 2013

.SHORT TERM...STEAMY MORNING ACROSS THE AREA AS SFC DEWPTS ARE VERY
HIGH (73-76) AND SFC TEMPS ARE WARMING QUICKLY INTO THE UPPER 80S.
FULL SUNSHINE WILL AID IN THE QUICK WARMUP BUT THE WARMING WILL
TAPER OFF AND SLOW AS DEEPER MIXING OCCURS. LIKE THE PAST TWO
DAYS...SFC MOISTURE WILL HELP KEEP AFTERNOON DEWPTS FROM FALLING OFF
TOO MUCH AND ALSO SERVE TO KEEP MAX TEMPS IN CHECK A BIT AND NOT
ALLOW FOR POTENTIAL UPPER 90S TO BE REALIZED. LOOK FOR HIGHS 1-2
DEGREES WARMER THAN YESTERDAY WITH THE WARMEST READINGS ACROSS THE
NW AREAS. A FEW TWEAKS WERE MADE TO HIGHS ACROSS THE E AS HIGHS WERE
TONED DOWN TO AROUND 94. STILL...HEAT/HUMIDITY COMBINATION WILL
YIELD HEAT INDEX VALUES FROM 100-104 TODAY. SOME MODIFICATIONS WERE
MADE TO THE HOURLY TEMPS/DEWPTS TO CATCH THE LATEST TRENDS AND
THINKING.

THIS WAS THE MORNING UPDATE AFD...FORGOT TO SEND IT OUT. NEW
DISCUSSION FOR THE AFTERNOON PACKAGE WILL OUT BY 300-330PM. /CME/

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL AT TAF SITES TODAY.  WINDS
WILL BE SOUTHWESTERLY AROUND 10 KNOTS THROUGH THE DAY...BUT SUBSIDE
TO LIGHT TO CALM OVERNIGHT.  PATCHY FOG WILL BE POSSIBLE AT SOME
SITES AROUND DAY BREAK THURSDAY. /19/

&&

.PREV DISCUSSION... /ISSUED 357 AM CDT WED JUN 12 2013/

SHORT TERM...TODAY THROUGH THURSDAY NIGHT...HOT DAY ON TAP TODAY AS
SURFACE AND UPPER RIDGING PREVAIL ACROSS THE ARKLAMISS. HIGH
TEMPERATURES WILL CLIMB INTO THE LOW TO MID 90S WITH HEAT INDEX
VALUES RANGING FROM 98-101 WITH THE HOTTEST TEMPS IN THE DELTA. THE
GFS/ECMWF HAVE COME IN DRIER THAN PREVIOUS RUNS ON THURSDAY AS A
COLD FRONT DROPS ACROSS THE AREA THURSDAY AFTERNOON INTO THURSDAY
NIGHT. THE GFS CONTINUES INDICATES A FAIRLY STRONG CAP THURSDAY
AFTERNOON INTO THE EVENING AND THE BIG QUESTION REMAINS WHETHER
CONVECTION WILL DEVELOP. THE BEST CHANCE FOR CONVECTION WILL BE EAST OF
I-55 WITH EVEN BETTER CHANCES ALONG THE MS/AL BORDER. THE ECMWF IS
EVEN DRIER THAN THE GFS AND A LITTLE SLOWER WITH THE BOUNDARY MOVING
SOUTH ACROSS THE AREA. THE LATEST GFS POPS HAVE COME IN QUITE A BIT
LOWER THAN PREVIOUS RUNS...SO WILL BUMP UP ABOVE GUIDANCE THURSDAY
AFTERNOON THROUGH THE EVENING HOURS. IF ANY CONVECTION DOES DEVELOP
THERE WILL BE PLENTY OF INSTABILITY TO WORK WITH 2500-3000 J/KG OF
ML CAPE. WILL CONTINUE TO MENTION THE POSSIBILITY OF STRONG TO
SEVERE IN THE HWO AND GRAPHICAST.

EITHER WAY THURSDAY LOOKS TO BE ONE OF THE HOTTEST DAYS OF THE YEAR
SO FAR WITH HIGHS IN THE MID TO UPPER 90S AND HEAT INDEX VALUES
RANGING FROM 100-105. THE BOUNDARY WILL PUSH SOUTHEAST OF THE AREA BY
FRIDAY MORNING WITH SLIGHTLY COOLER OVERNIGHT LOWS...ESPECIALLY OVER
THE NORTHEAST AND EASTERN PORTIONS OF THE AREA AS DRIER/COOLER AIR
BUILDS IN./15/

LONG TERM...(FRIDAY THROUGH TUESDAY)...

THE PRIMARY CONCERNS WILL BE THE BREAK DOWN OF THE UPPER RIDGE FOR
POSSIBLE CONVECTIVE COMPLEXES CROSSING THE REGION FOR LATE SUNDAY
INTO EARLY NEXT WEEK. SOME OF THOSE STORMS COULD BE ON THE STRONG
SIDE. THIS FOLLOWED BY POPS AND TEMPS.

EXTENDED MODELS AND ENSEMBLES WERE IN GENERAL AGREEMENT WITH THE
UPPER PATTERN WITH SOME MINOR DIFFERENCES. FOR FRIDAY THE UPPER
RIDGE AXIS WILL BE OVER THE ARKLATEX REGION. AREA MODEL CROSS
SECTIONS SHOWS A DRY AIRMASS OVER MOST OF THE REGION. THERE WAS SOME
MOISTURE ACROSS THE WEST AND SOUTHWEST WITH PWATS AROUND 1.6 INCHES.
A WEAK QUASI-STATIONARY FRONTAL BOUNDARY WILL BE ACROSS THE REGION.
MODELS SHOWS ISOLATED POPS ACROSS THE SOUTH DURING THE DAY. AS WE GO
INTO FRIDAY NIGHT PWATS WILL BE LESS THAN 1 INCH ACROSS MOST OF THE REGION
AS DRYER AIR SPREADS IN FROM THE EAST IN THE LOW LEVELS. DURING
SATURDAY THE WEAK FRONTAL BOUNDARY WILL PUSH BACK TO THE NORTH. THE UPPER
RIDGE AXIS WILL PUSH BACK OVER THE REGION DURING THE WEEKEND. DRY
WEATHER WILL CONTINUE THROUGH SATURDAY NIGHT. ON SUNDAY LOW LEVEL
SOUTHERLY FLOW WILL GRADUALLY INCREASE MOISTURE ACROSS THE REGION AS
PWATS INCREASE TO AROUND 1.8 INCHES. THE UPPER RIDGE AXIS WILL
WEAKEN DURING THE DAY SUNDAY AS A SHORTWAVE APPROACHES. THE
SHORTWAVE WILL CROSS THE REGION ON SUNDAY NIGHT. THERE WILL BE
ENOUGH INSTABILITY FOR SOME ISOLATED CONVECTION SPREADING ACROSS THE
REGION FOR SUNDAY AND SUNDAY NIGHT. ON MONDAY AND TUESDAY THERE IS
SOME POTENTIAL FOR A SERIES OF MCS FOR SOME STRONG TO POSSIBLY
SEVERE STORMS WITH THE CONVECTIVE COMPLEXES TO COME IN NORTHWEST
FLOW. LOOKING AT SOME OF THE PARAMETERS. CAPES >3000, MLCAPE >1500,
LI NEAR -4 TO -8, LAPSE RATE 6-7C, SHOWALTER -3 TO -5, MIDLEVEL FLOW
WILL BE ON THE WEAK SIDE FOR ANY GOOD CHANCE OF ORGANIZED STORM
POTENTIAL AND THERE WILL BE SOME MIDLEVEL CAP (700 TEMP AROUND 10C).
A FRONTAL BOUNDARY WILL PUSH INTO THE NORTHERN PORTION OF THE REGION
BY EARLY WEDNESDAY. FOR NOW WILL NOT MENTION ANY STRONG TO POSSIBLY
SEVERE STORM POTENTIAL IN THE HWO THIS FAR OUT.

AS FAR AS TEMPS ARE CONCERN HIGHS WILL BE IN THE LOW TO MID 90S
DURING THE PERIOD. LOWS WILL START WITH SOME LOWER 60S TO AROUND 70
FOR SATURDAY MORNING...THEN PUSHING TO UPPER 60S TO LOWER 70S FOR
THE REST OF THE PERIOD. WENT CLOSE TO MEX AND SOME GMOS GUIDANCE.

AS FAR AS POPS ARE CONCERN MADE SLIGHT ADJUSTMENTS TO MEX POPS ON
FRIDAY...THEN WENT CLOSE TO IT ON SUNDAY THROUGH TUESDAY./17/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       94  71  96  70 /   1   4  16  16
MERIDIAN      93  70  97  67 /   3   5  16  20
VICKSBURG     94  70  95  67 /   1   4  12  11
HATTIESBURG   94  71  97  73 /   5   4   5  19
NATCHEZ       93  71  93  72 /   2   3   5  10
GREENVILLE    95  74  96  69 /   1   3  15   9
GREENWOOD     95  72  96  66 /   1   4  23  10

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$

CME/19/