FXUS64 KJAN 242142
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
342 PM CST THU DEC 24 2009
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...SQUALL LINE CURRENTLY
WORKING ITS WAY ACROSS THE EASTERN PORTIONS OF THE ARKLAMISS THIS
AFTERNOON AND SHOULD BE MOSTLY THROUGH THE AREA BY EARLY EVENING WITH
ONLY SOME POST FRONTAL SHOWERS REMAINING. THE GFS KEEPS SOME WRAP
AROUND MOISTURE ACROSS THE AREA TONIGHT WITH SOME LIGHT RAIN POSSIBLY
CHANGING OVER TO FLURRIES BEFORE ENDING IN THE EARLY MORNING...WITH
NO MEASURABLE ACCUMULATIONS EXPECTED. SANTA WILL BE ABLE TO MAKE
QUICK WORK ACROSS THE DELTA TONIGHT AS THE WINDS WILL CONTINUE TO BE
GUSTY WITH A STRONG SURFACE GRADIENT CONTINUING TONIGHT BEFORE
WEAKENING A BIT DURING THE EARLY MORNING. WILL ALSO LEAVE A LAKE WIND
ADVISORY IN AFFECT FOR THE REMAINDER OF THE AREA THROUGH FRIDAY
AFTERNOON. SKIES WILL BECOME PARTLY CLOUDY CHRISTMAS WITH VERY COOL
TEMPERATURES RANGING FROM NEAR 40 IN THE NORTH TO THE UPPER 40S IN
THE SOUTH.
TEMPERATURES WILL BE PRETTY COLD TOMORROW NIGHT WITH MOST AREAS
FALLING INTO THE UPPER 20S. THE MODELS DIVERGE A BIT ON SATURDAY
WITH THE GFS DEVELOPING A SHORT WAVE AND ASSOCIATED SURFACE LOW IN
THE GULF AND MOVE IT ACROSS THE NORTHERN GULF SATURDAY NIGHT INTO
SUNDAY MORNING. THE EURO DOES NOT DEVELOP THIS FEATURE AND BUILDS
STRONG HIGH PRESSURE RIDGING OVER THE AREA. WILL JUST BLEND THE MODELS
AND INTRODUCE JUST A SLIGHT CHANCE OF LIGHT RAIN IN THE SOUTH
SATURDAY NIGHT. STUCK PRETTY CLOSE TO GUIDANCE THROUGH THE PERIOD
WITH ONLY SOME MINOR CHANGES TO HIGHS ON SATURDAY AND TO POPS
SATURDAY NIGHT. WILL ATTACH THE APPLICABLE PREVIOUS LONG TERM
DISCUSSION BELOW./15/
.PREVIOUS LONG TERM...SUNDAY INTO MONDAY THE LARGE UPPER VORTEX WILL
FINALLY LIFT OUT TO THE NORTHEAST BUT ANOTHER LARGE CLOSED LOW WILL
BE DROPPING SOUTH DOWN THE WESTERN CONUS. SHORTWAVE RIDGING SURFACE
AND ALOFT IS EXPECTED OVER OUR REGION MONDAY INTO TUESDAY. THIS
SHOULD BRING US SOME WARMER TEMPS TUESDAY ALTHOUGH THE SURFACE HIGH
WILL BE CENTERED NORTH OF OUR REGION KEEPING OUR REGION UNDER A DRY
NORTH FLOW. THE GFS AND ECMWF ARE IN A LITTLE BETTER AGREEMENT THIS
MORNING IN MOVING PRECIPITATION BACK INTO THE REGION LATE
TUESDAY...PROBLEM IS THAT COLD TEMPERATURES ARE EXPECTED IN OUR AREA
WITH THE PRECIPITATION. THE LARGE UPPER LOW THAT WAS DROPPING SOUTH
DOWN THE WESTERN CONUS MONDAY WILL OPEN UP AND SWING EAST THROUGH
MID WEEK. THE ECMWF IS STRONGER WITH THE SHORTWAVE TROUGH THAN THE
GFS BY TUESDAY NIGHT BUT LIGHT RAIN IS EXPECTED TO SPREAD ACROSS OUR
AREA FROM THE SOUTHWEST LATE TUESDAY AND TUESDAY NIGHT. TEMPERATURES
WILL DROP THROUGH THE EVENING AND THERE IS SOME POTENTIAL FOR A
WINTRY MIX OR LIGHT SNOW IN THE NORTH AFTER MIDNIGHT. THERE ARE
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF WEDNESDAY THROUGH
THURSDAY WITH THE POSSIBLE DEVELOPMENT OF A SURFACE LOW OVER THE
NORTHERN GULF AND CONTINUED RAIN CHANCES THROUGH WEDNESDAY INTO
THURSDAY. FOR NOW WL LEAN TOWARD THE GFS WITH SLIGHTLY WARMER
TEMPERATURES AND THE RAIN TAPERING OFF WEDNESDAY NIGHT BEFORE
INCREASING FROM THE SOUTH AGAIN THURSDAY AS ANOTHER SHORTWAVE HELPS
DEVELOP A STRONGER SURFACE LOW OVER THE NORTHERN GULF. THERE MAY
AGAIN BE SOME WINTRY MIX PRECIPITATION WEDNESDAY NIGHT INTO THURSDAY
MORNING. /22/
&&
.AVIATION...IFR CONDITIONS WILL PREVAIL ALONG AND BEHIND A SQUALL
LINE IN ERN MS WHILE A COLD FRONT CROSSING THE ARKLATEX STARTS
RACING EWD OVERNIGHT. SSE SURFACE WINDS OF 25KTS WILL CONTINUE AHEAD
OF THE SQUALL LINE AND THEN SHIFT TO THE SW AT 15-25KTS. WINDS WILL
GRADUALLY BECOME WLY AT 15-25KTS WITH HIGHER GUSTS AS THE THE FRONT
PASSES TONIGHT. THE IFR CEILINGS OF 2-3K FEET SHOULD PERSIST FOR
MUCH OF CHRISTMAS MORNING WITH INCREASING CAA AND NWLY WINDS.
CEILINGS SHOULD BECOME BROKEN AT 4-6K FEET AFTER 17Z ALONG THE MS
RIVER WITH IMPROVING CONDITIONS SPREADING EWD THROUGH THE AFTERNOON.
VFR CONDITIONS WILL RESUME FRIDAY NIGHT AND THROUGH THE WEEKEND./40/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 43 27 51 / 52 9 12 9
MERIDIAN 36 44 26 51 / 73 10 12 10
VICKSBURG 34 44 29 51 / 36 8 11 8
HATTIESBURG 38 48 26 53 / 62 9 10 7
NATCHEZ 35 43 27 52 / 23 7 10 7
GREENVILLE 32 41 28 47 / 56 10 12 10
GREENWOOD 33 39 27 48 / 63 11 13 11
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...LAKE WIND ADVISORY UNTIL 3 PM CST FRIDAY FOR MSZ026>033-036>039-
042>066-072>074.
FLASH FLOOD WATCH UNTIL 6 PM CST THIS EVENING FOR MSZ018-019-
025>052-054>058-062>066-072>074.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MSZ026>033-036>039-
042>066-072>074.
WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR MSZ018-019-025-034-035-
040-041.
LA...LAKE WIND ADVISORY UNTIL 3 PM CST FRIDAY FOR LAZ015-016-023>026.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR LAZ015-016-023>026.
WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR LAZ007>009.
AR...WIND ADVISORY UNTIL 3 AM CST FRIDAY FOR ARZ074-075.
&&
$$
15/40
