619
FXUS64 KJAN 060246
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
945 PM CDT SAT JUL 5 2008
DISCUSSION
CLEANED UP THE PACKAGE SLIGHTLY. ADJUSTED POPS TO
LOWER RAIN CHANCES FOR THE LATTER PART OF THE NIGHT...PER PREVIOUS
FORECAST THINKING. WILL MAINTAIN HIGHER RAIN CHANCES NRN ZONES AS
THE REMNANTS OF THE NEXT CONVECTIVE CLUSTER APPROACH FROM THE NW.
NO CHANGES MADE TO OVERNIGHT LOWS.
PREV DISCUSSION
300 PM CDT SAT JUL 5 2008 TONIGHT THROUGH SUNDAY
NIGHT...A PRETTY GOOD SHORTWAVE LOOKS TO DIVE INTO THE REGION WHILE
A DECENT UPPER LEVEL JET...60-70 KNOTS...POSITIONS ITSELF TO MY WEST
AND LINING THE REGION UP IN ITS LEFT FRONT QUADRANT. WITH ALL OF
THIS IN PLACE...I DON'T THINK RAINFALL CHANCES WILL NECESSARILY FALL
OFF EVERYWHERE THROUGH THE EVENING AND OVERNIGHT HOURS. WITH ALL
THE ABOVE IN PLACE...LOOK FOR THE DISTURBANCE TO TRAVERSE THE
BOUNDARY CURRENTLY OVER THE AREA EARLY SUNDAY MORNING. THIS WILL
RESULT IN SHOWERS AND THUNDERSTORMS AGAIN BREAKING OUT OVER MAINLY
NORTHERN PORTIONS OF THE FORECAST AREA EARLY SUNDAY MORNING.
CONVECTION SHOULD AGAIN BE ONGOING INTO THE AFTERNOON HOURS
SUNDAY...WITH THE BETTER RAIN CHANCES EXISTING IN THE EAST WHERE THE
BOUNDARY REMAINS AND THE UPPER LEVEL DISTURBANCE WILL BE EXITING THE
AREA. THEN BY SUNDAY EVENING...LOOK FOR CONVECTION TO REALLY BEGIN
TO COME TO A HALT AS ALL OF THE DYNAMICS AND FEATURES SHIFT OFF TO
THE EAST. THIS ON TOP OF THE LOSS OF DAYTIME HEATING.
WITH THE WARM MOIST AND UNSTABLE AIRMASS REMAINING IN PLACE OVER THE
REGION...COUPLED WITH THE PRESENCE OF THE UPPER LEVEL
DISTURBANCE...BOUNDARY...AND THE UPPER JET ENERGY...I'LL GO AHEAD
AND KEEP THE MENTION OF AT LEAST ISOLATED STRONG TO SEVERE IN THE
HWO FOR TONIGHT AND INTO SUNDAY. HOWEVER...GIVEN HOW THINGS
TRANSPIRE OVERNIGHT TONIGHT WITH THE DISTURBANCE MOVING ACROSS THE
REGION...IT COULD REALLY WORK OVER THE AIRMASS AND LIMIT ACTIVITY
AND INTENSITY SUNDAY AFTERNOON.
MONDAY THROUGH FRIDAY... NOT A WHOLE LOT OF CHANGES IN THE MODELS
PAST SUNDAY AS THINGS BEGIN TO SETTLE BACK DOWN INTO THE TYPICAL
SUMMER TIME PATTERN. HIGH PRESSURE TO THE EAST BUILDS INTO
THE AREA KEEPING HOT/MUGGY CONDITIONS OVER THE AREA WITH MAINLY
ISOLATED DIURNAL SHOWERS AND THUNDERSTORMS EXPECTED. AS A
RESULT...THE PREVIOUS LONG TERM DISCUSSION FOLLOWS. /19/
MONDAY THROUGH FRIDAY...WESTWARD EXTENSION OF THE BERMUDA HIGH WILL
BE IN CONTROL OF THE WEATHER OVER THE ARKLAMISS REGION AS WE GO
THROUGH THE UPCOMING WORK WEEK. TYPICAL EARLY JULY
CONDITIONS...HOT/MUGGY WITH ISOLATED/ SCATTERED DIURNAL TSTMS...ARE
EXPECTED. WHILE MID/UPPER LEVEL FLOW WILL BE VERY WEAK...PREVAILING
LOW-LEVEL FLOW SHOULD BE FROM THE SOUTH...AND THIS COULD PROMOTE
GREATER CHANCES FOR CONVECTION IN SPITE OF SUBSIDENCE ALOFT. GFS
ENSEMBLE MOS SUGGESTS MEX GUIDANCE POPS ARE A LITTLE TOO LOW...BUT
WILL REFRAIN FROM RAISING POPS GIVEN THAT BOTH THE GFS AND ECMWF
INDICATE A STRONG PRESENCE OF THE SUBTROPICAL RIDGE WHICH COULD
GREATLY LIMIT STORM ORGANIZATION POTENTIAL AND SUBSEQUENT COVERAGE.
TEMPERATURES WILL BE A LITTLE ABOVE EARLY JULY AVERAGE...NOTHING
EXCEPTIONAL. /EC/
AVIATION
CONVECTION HAS DIMINISHED WITH ONE OR TWO SHOWERS
CONTINUING. WILL SEE VFR CONDITIONS WITH CIGS ABOVE 5000FT THROUGH
MIDNIGHT. CIGS WILL DECREASE OVER NORTHERN ZONES AFTER MIDNIGHT WHEN
THE NEXT CLUSTER OF SHOWERS AND TSTMS MOVES ON FROM THE NW BUT WILL
REMAIN ABOVE 3000FT EXCEPT IN AREAS OF RAINFALL. A FEW AREAS OF MVFR
VSBY IN FOG WILL BE POSSIBLE BUT HIGHER CLOUD COVER WILL PREVENT
WIDESPREAD FOG DEVELOPMENT.
JAN WATCHES/WARNINGS/ADVISORIES
MS...NONE.
LA...NONE.
AR...NONE.
19/CME
03
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