Area Forecast Discussion

464
FXUS64 KJAN 030205 AAA
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
905 PM CDT WED OCT 2 2013

.UPDATE...
UPPER LEVEL LOW FROM YESTERDAY EVENING HAS BECOME MORE OF AN OPEN
WAVE AND IS LIFTING TO THE NE TONIGHT. 00Z REGIONAL SOUNDINGS/BLENDED
SATELLITE IMAGERY INDICATES PWATS 1.5 TO ~2 INCHES. THE DEEP MOISTURE
COMBINED WITH SOUTHWESTERLY FLOW ALOFT/ISENTROPIC LIFT HAS AIDED IN
SOME SHOWERS CONTINUING IN THE E. INTRODUCED SOME SLIGHT CHANCE POPS
IN THE E AND LEFT SOME IN THE S/W UNTIL 3Z. WENT CLOSE MAV TEMPS
OVERNIGHT BUT BUMPED UP SLIGHTLY IN THE NE/E. LIGHT WINDS AND LOW
LEVEL MOISTURE WILL AID IN SOME PATCHY FOG FORMATION POSSIBLE
TONIGHT. SOME AREAS COULD BE LOCALLY DENSE BUT DUE TO LOW LEVEL WINDS
STAYING UP OVERNIGHT...COULD BE A COMBINATION OF PATCHY FOG/LOW
STRATUS. ONLY MENTIONED PATCHY FOG IN THE GRIDS. HAD TO MODIFY SKY
GRIDS ACCORDING TO CURRENT TRENDS. REST OF THE FORECAST IS ON TRACK. /DC/

&&

.AVIATION...VFR CONDITIONS ONGOING THIS EVENING AND SHOULD CONTINUE
THROUGH THE EARLY PORTIONS OF THE NIGHT. FOR LATE TONIGHT...AT LEAST
MVFR CONDITIONS SHOULD DEVELOP AT MOST TAF SITES WITH POTENTIAL FOR
PATCHY TO AREAS OF FOG. BEST CHANCE FOR IFR CONDITIONS AND FOG SHOULD
BE SOUTH OF INTERSTATE TWENTY. EXPECT CONDITIONS TO IMPROVE TO VFR
CONDITIONS BY 14Z. WINDS WILL BE LIGHT OUT OF THE SOUTHEAST ON
TONIGHT INTO THURSDAY. /28/

&&

.PREV DISCUSSION... /ISSUED 433 PM CDT WED OCT 2 2013/

DISCUSSION...

TONIGHT THROUGH THURSDAY NIGHT...

THE PREVIOUSLY MENTIONED CLOSED UPPER LOW IS SLOWLY DEPARTING THE
ARKLAMISS...AND THIS WILL ALLOW THE MID LEVEL RIDGE TO REBUILD OVER
THE FORECAST AREA AS WE GO THROUGH THURSDAY. THE AIRMASS WILL REMAIN
MOIST SO THAT DAYTIME HEATING AND VERY WARM AFTERNOON TEMPERATURES WILL
WILL LEAD TO ISOLATED SHOWER/THUNDERSTORM ACTIVITY THURSDAY. ANY
CONVECTIVE ACTIVITY WILL DIMINISH QUICKLY WITH SUNSET AND MOSTLY
QUIET WEATHER IS ANTICIPATED THURSDAY NIGHT. NIGHTTIME COOLING OF
THE HUMID BOUNDARY LAYER COULD LEAD TO FOG FORMATION LATE TONIGHT
AND EARLY THURSDAY...AND THEN AGAIN LATE THURSDAY NIGHT. /EC/

FRIDAY THROUGH NEXT WEDNESDAY...

AS OF WEDNESDAY AFTERNOON...VERY LITTLE HAS CHANGED REGARDING THE
POTENTIAL TROPICAL WEATHER INFLUENCES IN THE LONG TERM...WITH THE
PRIMARY FOCUS BEING INCREASED PRECIP POTENTIAL AHEAD OF A SOLID COLD
FRONT DURING THE WEEKEND.

DESPITE CARRYING A PERSISTENT MESSAGE IN THE FORECAST...THE RECENT
TRENDS IS THE MODEL GUIDANCE ARE OFFERING A BIT MORE IN THE WAY OF
DIFFERENCES WITH OVERALL EVOLUTION OF THE WEEKEND SYSTEM. DUE TO
THIS...CONFIDENCE IS NOT AS GREAT...MAINLY WITH TIMING OF THE KEY
FORECAST ELEMENTS (POPS AND COOLER TEMPS IN THE WAKE OF THE FRONT).

THE FORECAST PATTERN FOR FRI-SAT REMAINS SIMILAR TO THE PAST SEVERAL
RUNS WITH A RIDGE OVER THE SE CONUS AND EVOLVING TROUGH OVER THE
WEST. MODELS CONTINUE TO INDICATE A AREA OF DEEP TROPICAL MOISTURE
SOME SOME GUIDANCE DEVELOPING A TROPICAL SYSTEM. THIS IS GENERALLY
SIMILAR TO PREV RUNS AS WELL...BUT HOW THIS POTENTIAL SYSTEM EVOLVES
IS WHERE DIFFERENCES EXIST AND BECOME A BIGGER PLAYER IN FORECAST
SPECIFICS FOR THE WEEKEND. THE GFS DEVELOPS A SYSTEM BUT HAS IT MORE
TO THE EAST. THIS WILL RESULT IN MORE OF A N TO NE FLOW PATTERN ON
THE EDGES OF THE FEATURE WHICH IS TYPICALLY THE DRIER SECTOR. THE
GFS GUIDANCE UNDERSTANDS THIS AND HAS MUCH LESS IN THE WAY OF PRECIP
POTENTIAL FOR FRI AND SAT. THE EURO ON THE OTHER HAND DOESN`T
DEVELOP THE SYSTEM AS MUCH AND IS FURTHER WEST WITH THE CORE OF THE
MOISTURE. THE RESULT IS SOME BETTER RAIN CHANCES ACROSS THE SOUTH
FOR FRI AFTERNOON AND MORE ACTIVITY AREAWIDE SAT. THERE EXIST SOME
SUPPORT FOR THE MORE WESTWARD POSITION OF THE POTENTIAL TROPICAL
ENTITY FROM THE SREF/EURO ENS AND SOME MEMBERS OF THE GFS ENS. DUE
TO THIS...WILL CONTINUE WITH A SIMILAR/PERSISTENT TYPE FORECAST FOR
THE WEEKEND.

AS FOR THE FROPA...THE EURO IS A BIT SLOWER WITH THE COOLER
AIR...BUT THE GFS/NAM ARE IN GOOD AGREEMENT ON THE FROPA SAT NGT. IT
ALSO APPEARS THAT THE AIRMASS BEHIND THE FRONT WILL BE FAIRLY POTENT
AND I LIKE HOW THE NAM MAY BE HANDLING THE SHALLOW NATURE OF THE
CHILLY AIR. DUE TO THIS...TEMPS WERE TAPERED A BIT FOR SUN BASED
OFF THE LATEST GUIDANCE. AS FOR MON-WED...THE GFS SEEMED TO HANDEL
THE SITUATION BEST WITH THE COOL AIRMASS LINGERING OVER THE AREA FOR
THAT PERIOD AND THE GFS GUIDANCE WAS FOLLOWED. /CME/

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       68  88  66  90 /  11  27  15  20
MERIDIAN      65  89  66  91 /  17  18  15  20
VICKSBURG     67  88  68  89 /  12  27  15  20
HATTIESBURG   67  91  69  91 /  15  32  15  20
NATCHEZ       69  88  70  87 /  15  27  15  20
GREENVILLE    66  88  67  89 /  13  27  15  20
GREENWOOD     66  88  67  91 /  11  24  15  20

&&

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

$$

DC/28/EC/CME