[top]
000
FXUS64 KJAN 242011
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
210 PM CST TUE NOV 24 2009
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...SURFACE ANALYSIS
EARLY THIS AFTERNOON SHOWS THE COLD FRONT OVER EASTERN ARKANSAS AND
DROPPING SOUTH ACROSS NORTH CENTRAL LOUISIANA. THE COLD FRONT SHOULD
BE NEAR A GREENVILLE TO MONROE LINE BEFORE THE END OF THE AFTERNOON.
A RATHER NARROW BAND OF CLOUDS WAS NOTED ON VISIBLE SATELLITE
IMAGERY ASSOCIATED WITH THE FRONT AND REGIONAL RADARS WERE SHOWING
AN EVEN NARROWER BAND OF LIGHT RAIN THAT WAS MOVING OVER OUR
NORTHWEST MOST COUNTIES. THIS COLD FRONT WILL PASS THROUGH THE CWA
AS A MOSTLY DRY COLD FRONT. THE GREATEST CHANCE FOR MEASURABLE PCPN
WL BE ALONG AND NORTH OF HIGHWAY 82 THROUGH EARLY EVENING WITH ONLY
A FEW SPRINKLES POSSIBLE ELSEWHERE. MODELS AGREE THAT THE COLD FRONT
SHOULD BE NEAR A MERIDIAN TO BROOKHAVEN LINE BY MIDNIGHT AND
SOUTHEAST OF OUR CWA BEFORE DAYBREAK. THE COOLER AND DRIER AIR
BEHIND THE FRONT WILL MAKE FOR COOLER MORNING LOWS WEDNESDAY WITH
LOWER 40S EXPECTED OVER MUCH OF THE AREA AND MID 40S SOUTH. OUR
WINDS ALOFT WILL BACK TO NEAR ZONAL WEDNESDAY AND SURFACE HIGH
PRESSURE CENTERED OVER THE SOUTHERN PLAINS WILL ONLY PROVIDE A LIGHT
NORTHERLY WIND. THUS CAA WILL NOT BE STRONG WEDNESDAY AND UNDER
MOSTLY SUNNY SKIES...TEMPERATURES WILL WARM BACK NEAR SEASONAL NORMS
FOR AFTERNOON HIGHS WITH LOWER 60S NORTH AND CENTRAL...MID 60S SOUTH.
CLEAR SKIES AND NEAR CALM WINDS WILL ALLOW FOR GOOD RADIATIONAL
COOLING WEDNESDAY EVENING AND ALLOW TEMPERATURES TO DROP OFF
RAPIDLY. HOWEVER A POTENT NORTHERN STREAM SHORTWAVE DROPPING OUT OF
THE NORTHERN PLAINS WEDNESDAY WILL SWING EASTWARD ACROSS THE OHIO
VALLEY AMPLIFYING THE UPPER TROUGH OVER OUR REGION WEDNESDAY NIGHT
AND SEND A REINFORCING SHOT OF COLD DRY AIR ACROSS OUR CWA THURSDAY.
THIS MAY RESULT IN MIXING AFTER MIDNIGHT WEDNESDAY NIGHT AND DISRUPT
THE PRIME RADIATIONAL COOLING BUT MORNING LOWS ARE EXPECTED TO
BOTTOM OUT IN THE 30S AREAWIDE. THE FEW CLOUDS IN OUR AREA WILL BE
LIMITED TO THE NORTH BUT THANKSGIVING DAY WILL BE DRY AND COOLER
THAN NORMAL FOR THE ARKLAMISS AS MOST SITES WL STRUGGLE TO REACH 60
DEGREES. THE UPPER TROUGH WILL BEGIN SHIFTING EAST THURSDAY NIGHT.
WL STILL BE UNDER NORTHWEST FLOW ALOFT AND SURFACE HIGH PRESSURE
WILL SHIFT EAST INTO OUR CWA FROM THE SOUTHERN PLAINS BY FRIDAY
MORNING. THE RESULTING CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR
GOOD RADIATIONAL COOLING OF OUR COOL DRY AIRMASS AND NEAR FREEZING
TEMPERATURES OVER EASTERN MISSISSIPPI. HAVE LEANED TOWARD SLIGHTLY
COOLER NAM MOS LOWS FOR THURSDAY AND FRIDAY MORNINGS. /22/
.LONG TERM...FRIDAY THROUGH TUESDAY...GFS/ECMWF/GEFS ARE IN GOOD
AGREEMENT TO START OUT THIS PERIOD SHOWING A S/WV TRANSITING THE
GREAT LAKES REGION AND RIDGING OVER THE WESTERN PLAINS. THIS WILL
PLACE THE ARKLAMISS IN COOL DRY NORTHWESTERLY FLOW ALOFT. DRY
CONDITIONS WILL CONTINUE THROUGH SATURDAY NIGHT AS COOL/DRY AIR
ASSOCIATED WITH SURFACE HIGH PRESSURE CONTINUES BUILDING OVER THE
REGION AS WELL. UNSEASONABLY COOL TEMPS CAN BE EXPECTED FRI AND SAT
MORNING DUE TO EFFICIENT RADIATIONAL COOLING ASSOCIATED WITH THE
CLEAR SKIES EXPECTED...LIGHT WINDS AND THE COLD AIRMASS THAT WILL BE
IN PLACE. LOW 30S EAST OF I-55 LOOK VERY POSSIBLE BOTH MORNINGS.
USUALLY THIS TIME OF YEAR A FREEZE WILL HAVE OCCURRED MAKING MENTION
OF FROST IN THE FORECAST UNNECESSARY HOWEVER CONSIDERING WE HAVEN`T
SEEN ONE YET THIS YEAR WILL GO AHEAD AND INCLUDE FROST EAST OF I-55
FRI AND SAT MORNINGS. WILL MENTION PATCHY FROST FRI MORNING AS THE
HIGH BUILDS IN AND GO WITH AREAS ON SAT AS WINDS DEFINITELY LOOK TO
GO CALM WITH THE RIDGE SITTING OVERHEAD.
THINGS WILL BEGIN TO CHANGE ON SATURDAY AFTERNOON AS THE HIGH
PRESSURE SHIFTS EAST OF MS DUE TO A DEVELOPING TROUGH OF LOW
PRESSURE OVER THE PLAINS. THE TROUGH LOOKS TO DROP DOWN AND
INTENSIFY THE SOUTHERN STREAM JET OVER TX WITH 200-300MB WIND
SPEEDS INCREASING TO NEAR 100KTS IN THE LEFT EXIT REGION OVER THE
ARKLAMISS LATE SUNDAY MORNING. THIS WILL PROVIDE ENHANCED LIFT TO
THE MOISTENING AIRMASS AND WILL INCREASE RAIN CHANCES FROM WEST TO
EAST SUNDAY. GFS HINTS AT PW VALUES INCREASING TO NEAR 1.25 IN BY
LATE SUNDAY AFTERNOON. THE COMBINATION OF DEEP LAYER LIFT AND
INCREASING MOISTURE WILL MEAN VERY WEAK THUNDERSTORM CHANCES
STARTING SUNDAY AFTERNOON. GFS SHOWS AN AREA OF 100-300J/KG MUCAPE
DEVELOPING OVER FAR SOUTHWESTERN ZONES SOUTH OF I-20 AT THIS TIME AND
HAVE MENTIONED A SLIGHT CHANCE OF THUNDER IN THESE AREAS ACCORDINGLY.
THIS WEAKLY UNSTABLE AREA WILL SLIDE ACROSS SOUTHERN ZONES SUNDAY
NIGHT INTO MONDAY AHEAD OF THE FRONT AND WILL MOVE THE THUNDER
CHANCES ACROSS THE CWA ACCORDINGLY...TAPERING OFF MONDAY AFTERNOON.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST MONDAY NIGHT INTO
TUESDAY AS THE FRONT CLEARS THE AREA. GFS/ECMWF NOT IN THE BEST
AGREEMENT AS TO THE EVOLUTION OF THE UPPER LEVEL S/WV COME TUESDAY
MORNING WITH GFS MOVING IT INTO THE SOUTHERN GREAT LAKES REGION AND
ECMWF HANGING IT BACK IN THE CENTRAL PLAINS. WILL GO WITH THE FASTER
GFS SOLUTION ALTHOUGH THE GEFS DOES NOT SHOW THE WAVE CLEARING THE
AREA AS FAST AS THE GFS SUGGESTS. THIS COULD MEAN SOME HIGHER
POPS...PRIMARILY OVER NORTHERN ZONES...FOR TUES BUT CONSIDERING THE
UNCERTAINTY WILL KEEP LOW POPS GOING FOR NOW.
MEX TEMPS GENERALLY ACCEPTED ALTHOUGH SOME LOWERING TOWARD MEN
GUIDANCE WAS NEEDED...PRIMARILY WITH HIGH TEMPS OVER THE WEEKEND AND
LOW TEMPS EARLY NEXT WEEK. /BK/
&&
.AVIATION...SCATTERED SKIES PREVAIL ACROSS MUCH OF THE AREA THIS
AFTERNOON...BUT A COLD FRONT WILL BEGIN TO MOVE EAST OVER THE AREA
THROUGH THE LATE AFTERNOON AND EVENING HOURS. CEILINGS WILL FALL TO
THE 2-4K FEET RANGE AND ISOLATED SHOWERS ARE POSSIBLE ALONG AND OUT
AHEAD OF THE FRONT AS IT SWEEPS ACROSS THE AREA. THE WINDS WILL
SWING AROUND TO THE NORTHWEST BEHIND THE FRONT AND VFR CONDITIONS
WILL RETURN. IFR CONDITIONS IN FOG IS POSSIBLE OVER THE SOUTHEASTERN
PORTIONS OF THE AREA AFFECTING HBG DURING THE EARLY MORNING
HOURS...BUT WILL CLEAR OUT BY 9AM./15/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 42 63 37 59 / 6 1 2 0
MERIDIAN 41 63 34 60 / 8 3 4 0
VICKSBURG 41 62 35 62 / 5 0 2 0
HATTIESBURG 45 64 37 62 / 8 1 2 0
NATCHEZ 44 62 36 59 / 8 0 2 0
GREENVILLE 42 61 38 59 / 3 0 4 0
GREENWOOD 42 63 35 58 / 5 2 4 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
22/BK/15
000
FXUS64 KJAN 241617
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1000 AM CST TUE NOV 24 2009
.UPDATE...SURFACE ANALYSIS STILL SHOWS A RIDGE OF HIGH PRESSURE
NOSING INTO SOUTHEAST MISSISSIPPI FROM THE SOUTHERN APPALACHIANS AND
A COLD FRONT OVER CENTRAL ARKANSAS AND BACK ACROSS NORTHWEST
LOUISIANA. VISIBLE IMAGERY SHOWS CLOUDS BREAKING UP OVER THE EASTERN
HALF OF MISSISSIPPI AS THE DENSE FOG DISSIPATES. A BAND OF CLOUDS
WAS NOTED OVER OUR LOUISIANA PARISHES AND SE ARKANSAS COUNTIES AHEAD
OF THE COLD FRONT. REGIONAL RADARS WERE ONLY SHOWING A SPARSE
COVERAGE OF VERY LIGHT SHOWERS ALONG AND AHEAD OF THE COLD FRONT.
SOME OF THE SHOWERS WERE EDGING INTO OUR NORTHWEST MOST ZONES. THE
COLD FRONT IS STILL EXPECTED TO SLOWLY APPROACH OUR AREA TODAY AND
MOVE ACROSS OUR AREA THIS EVENING. LIGHT SHOWERS WILL BE POSSIBLE
WITH GREATEST COVERAGE IN THE NORTH. TEMPERATURES WERE RUNNING
WARMER THAN EXPECTED IN THE DELTA THIS MORNING BUT WITH THE CLOUDS
AND LIGHT RAIN MOVING IN...FORECAST HIGHS STILL LOOK OK. HAVE
UPDATED FORECAST TO REMOVE FOG WORDING. MINOR TWEAKS TO INCREASE
TEMPS AND POPS WERE MADE THIS MORNING IN THE NORTHWEST. UPDATES HAVE
BEEN SENT. /22/
&&
.PREV DISCUSSION... /ISSUED 430 AM CST TUE NOV 24 2009/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...UPPER VORT TROUGH
CROSSING ERN KS THIS MORNING AND WILL SWING THROUGH MO INTO IL TODAY.
THE ASSOCIATED SURFACE FRONT FROM THE MO/KS BORDER INTO CENTRAL TX
SWEEPS SEWD INTO THE LOWER MS VALLEY THIS AFTERNOON BRINGING MORE
CLOUDS/A FEW SHRA AS IT CROSSES OUR CWFA BETWEEN NOON AND MIDNIGHT.
THE BOUNDARY STILL HAS VERY LITTLE DEEP LAYER MOISTURE AND WILL MISS
OUT TAPPING INTO THE RICH AIR OVER THE SWRN GULF. ANY QPF WITH THE
FRONT WILL STRUGGLE TO REACH ONE TENTH TO ONE QUARTER OF AN INCH AS
AXIS OF 0.8 INCH PWAT AIR MASS CROSSES THE AREA. INSTABILITY STILL
APPEARS MINIMAL WITH THIS SYSTEM AS DOES LOW LEVEL MOISTURE
CONVERGENCE.
CURRENTLY...VERY PERSISTENT BROKEN STRATUS DECK STILL TRAPPED UNDER
A SUBSIDENCE INVERSION OVER ERN MS WHILE MORE STRATUS STREAMING NWD
THROUGH TX INTO AR AND WRN LA ASSOCIATED WITH THE APPROACHING
FRONTAL BOUNDARY. TEMPERATURES HAVE HELD BETWEEN 48-54F AND WERE
WARMER THAN EXPECTED DUE TO THE CLOUDS REFUSING TO CLEAR. FOG HAS
BECOME A BIT DENSE ALONG THE HIGHWAY 84 CORRIDOR IN PLACES AND MAY
GO WITH AN ADVY UNTIL 15Z IN THOSE AREAS. OTHERWISE...WILL KEEP
MOSTLY CLOUDY CONDITIONS GOING UNTIL THE FRONT PASSES THROUGH WHEN
WE SHOULD FINALLY GET BETTER CLEARING FROM W TO E ON BETTER
DOWNGLIDE REGIME.
HIGH TEMPS THIS AFTERNOON IN PRE FRONTAL FLOW WILL BE WARMER THAN
MONDAY AS MOST AREAS REACH 64-69F...ENOUGH SUN COULD MEAN 70F IN SRN
MS. PLENTY OF LOW LEVEL MIXING TONIGHT AND WILL HELP KEEP LOWS MAINLY
IN THE MID 40S. MODEST CAA AND RETURN OF SUNSHINE HEADING THROUGH
WEDNESDAY SHOULD KEEP HIGHS ONLY 60-65F FOR MOST LOCALES. STRONGER
COOLING BEGINS TO ARRIVE WEDNESDAY NIGHT AS A SECONDARY UPPER TROUGH
RIDES SEWD THROUGH THE TN/OH VALLEYS. WE SHOULD MANAGE TO DROP TO
THE U30S TO AROUND 40F AS THE 850MB ZERO ISOTHERM MAKES A PLUNGE TO
TO AT LEAST THE HIGHWAY 82 CORRIDOR TO OPEN THANKSGIVING DAY./40/
LONG TERM...THANKSGIVING DAY THROUGH TUESDAY...GFS/ECMWF/GEFS IN
GOOD AGREEMENT TO START OUT THIS PERIOD SHOWING A S/WV TRANSITING THE
GREAT LAKES REGION AND RIDGING OVER THE WESTERN PLAINS. THIS WILL
PLACE THE ARKLAMISS IN DRY NORTHWESTERLY FLOW ALOFT ALLOWING CLEAR
SKIES AND SEASONABLE TEMPS FOR THANKSGIVING DAY. THE DRY CONDITIONS
WILL CONTINUE THROUGH SATURDAY NIGHT AS COOL/DRY AIR ASSOCIATED WITH
SURFACE HIGH PRESSURE CONTINUES BUILDING OVER THE REGION.
UNSEASONABLY COOL TEMPS CAN BE EXPECTED FRI AND SAT MORNING DUE TO
EFFICIENT RADIATIONAL COOLING ASSOCIATED WITH THE CLEAR SKIES
EXPECTED...LIGHT WINDS AND THE COLD AIRMASS THAT WILL BE IN PLACE.
LOW 30S EAST OF I-55 LOOK VERY POSSIBLE BOTH MORNINGS. USUALLY THIS
TIME OF YEAR A FREEZE WILL HAVE OCCURRED MAKING MENTION OF FROST IN
THE FORECAST UNNECESSARY HOWEVER CONSIDERING WE HAVEN`T SEEN ONE YET
THIS YEAR WILL GO AHEAD AND INCLUDE FROST EAST OF I-55 FRI AND SAT
MORNINGS. WILL MENTION PATCHY FROST FRI MORNING AS THE HIGH BUILDS
IN AND GO WITH AREAS ON SAT AS WINDS DEFINITELY LOOK TO GO CALM WITH
THE RIDGE SITTING OVERHEAD.
THINGS WILL BEGIN TO CHANGE ON SATURDAY AFTERNOON AS THE HIGH
PRESSURE SHIFTS EAST OF MS DUE TO A DEVELOPING TROUGH OF LOW
PRESSURE OVER THE PLAINS. THE TROUGH LOOKS TO DROP DOWN AND
INTENSIFY THE SOUTHERN STREAM JET OVER TX WITH 200-300MB WIND
SPEEDS INCREASING TO NEAR 100KTS IN THE LEFT EXIT REGION OVER THE
ARKLAMISS LATE SUNDAY MORNING. THIS WILL PROVIDE ENHANCED LIFT TO
THE MOISTENING AIRMASS AND WILL INCREASE RAIN CHANCES FROM WEST TO
EAST SUNDAY. GFS HINTS AT PW VALUES INCREASING TO NEAR 1.25 IN BY
LATE SUNDAY AFTERNOON. THE COMBINATION OF DEEP LAYER LIFT AND
INCREASING MOISTURE WILL MEAN VERY WEAK THUNDERSTORM CHANCES
STARTING SUNDAY AFTERNOON. GFS SHOWS AN AREA OF 100-300J/KG MUCAPE
DEVELOPING OVER FAR SOUTHWESTERN ZONES SOUTH OF I-20 AT THIS TIME AND
HAVE MENTIONED A SLIGHT CHANCE OF THUNDER IN THESE AREAS ACCORDINGLY.
THIS WEAKLY UNSTABLE AREA WILL SLIDE ACROSS SOUTHERN ZONES SUNDAY
NIGHT INTO MONDAY AHEAD OF THE FRONT AND WILL MOVE THE THUNDER
CHANCES ACROSS THE CWA ACCORDINGLY...TAPERING OFF MONDAY AFTERNOON.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST MONDAY NIGHT INTO
TUESDAY AS THE FRONT CLEARS THE AREA. GFS/ECMWF NOT IN THE BEST
AGREEMENT AS TO THE EVOLUTION OF THE UPPER LEVEL S/WV COME TUESDAY
MORNING WITH GFS MOVING IT INTO THE SOUTHERN GREAT LAKES REGION AND
ECMWF HANGING IT BACK IN THE CENTRAL PLAINS. WILL GO WITH THE FASTER
GFS SOLUTION ALTHOUGH THE GEFS DOES NOT SHOW THE WAVE CLEARING THE
AREA AS FAST AS THE GFS SUGGESTS. THIS COULD MEAN SOME HIGHER
POPS...PRIMARILY OVER NORTHERN ZONES...FOR TUES BUT CONSIDERING THE
UNCERTAINTY WILL KEEP LOW POPS GOING FOR NOW.
MEX TEMPS GENERALLY ACCEPTED ALTHOUGH SOME LOWERING TOWARD MEN
GUIDANCE WAS NEEDED...PRIMARILY WITH HIGH TEMPS OVER THE WEEKEND AND
LOW TEMPS EARLY NEXT WEEK. /BK/
&&
.AVIATION...UPDATED...FR CONDITIONS WERE OBSERVED ACROSS MUCH OF THE
AREA WITH BROKEN CLOUDS 500-800FT AND/OR VISIBILITIES BELOW 3SM IN
MIST/FOG THIS MORNING. THE FOG/STRATUS IS BEGINNING TO MIX OUT AS A
COLD FRONT APPROACHES THE ARKLAMISS. CLOUD BASES SHOULD GRADUALLY
LIFT FROM THE SOUTH AND WEST THIS MORNING AS SLY FLOW PICKS UP A
LITTLE ACROSS THE REGION. CLOUD DECKS SHOULD BECOME BROKEN 3-5K FEET
WITH THE FRONT ARRIVING NEAR THE MS RIVER BY 1-3PM...THE NATCHEZ
TRACE PARKWAY 4-6PM...AND I-59 CORRIDOR BY 7-10PM.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 66 43 63 40 / 13 22 2 4
MERIDIAN 66 42 65 38 / 5 21 4 4
VICKSBURG 65 44 63 40 / 19 22 1 3
HATTIESBURG 69 44 67 41 / 4 20 2 2
NATCHEZ 68 44 65 38 / 16 23 1 3
GREENVILLE 64 43 62 39 / 31 19 1 4
GREENWOOD 64 43 63 40 / 24 22 3 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
22/40/BK
000
FXUS64 KJAN 241030
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
430 AM CST TUE NOV 24 2009
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...UPPER VORT TROUGH
CROSSING ERN KS THIS MORNING AND WILL SWING THROUGH MO INTO IL TODAY.
THE ASSOCIATED SURFACE FRONT FROM THE MO/KS BORDER INTO CENTRAL TX
SWEEPS SEWD INTO THE LOWER MS VALLEY THIS AFTERNOON BRINGING MORE
CLOUDS/A FEW SHRA AS IT CROSSES OUR CWFA BETWEEN NOON AND MIDNIGHT.
THE BOUNDARY STILL HAS VERY LITTLE DEEP LAYER MOISTURE AND WILL MISS
OUT TAPPING INTO THE RICH AIR OVER THE SWRN GULF. ANY QPF WITH THE
FRONT WILL STRUGGLE TO REACH ONE TENTH TO ONE QUARTER OF AN INCH AS
AXIS OF 0.8 INCH PWAT AIR MASS CROSSES THE AREA. INSTABILITY STILL
APPEARS MINIMAL WITH THIS SYSTEM AS DOES LOW LEVEL MOISTURE
CONVERGENCE.
CURRENTLY...VERY PERSISTENT BROKEN STRATUS DECK STILL TRAPPED UNDER
A SUBSIDENCE INVERSION OVER ERN MS WHILE MORE STRATUS STREAMING NWD
THROUGH TX INTO AR AND WRN LA ASSOCIATED WITH THE APPROACHING
FRONTAL BOUNDARY. TEMPERATURES HAVE HELD BETWEEN 48-54F AND WERE
WARMER THAN EXPECTED DUE TO THE CLOUDS REFUSING TO CLEAR. FOG HAS
BECOME A BIT DENSE ALONG THE HIGHWAY 84 CORRIDOR IN PLACES AND MAY
GO WITH AN ADVY UNTIL 15Z IN THOSE AREAS. OTHERWISE...WILL KEEP
MOSTLY CLOUDY CONDITIONS GOING UNTIL THE FRONT PASSES THROUGH WHEN
WE SHOULD FINALLY GET BETTER CLEARING FROM W TO E ON BETTER
DOWNGLIDE REGIME.
HIGH TEMPS THIS AFTERNOON IN PRE FRONTAL FLOW WILL BE WARMER THAN
MONDAY AS MOST AREAS REACH 64-69F...ENOUGH SUN COULD MEAN 70F IN SRN
MS. PLENTY OF LOW LEVEL MIXING TONIGHT AND WILL HELP KEEP LOWS MAINLY
IN THE MID 40S. MODEST CAA AND RETURN OF SUNSHINE HEADING THROUGH
WEDNESDAY SHOULD KEEP HIGHS ONLY 60-65F FOR MOST LOCALES. STRONGER
COOLING BEGINS TO ARRIVE WEDNESDAY NIGHT AS A SECONDARY UPPER TROUGH
RIDES SEWD THROUGH THE TN/OH VALLEYS. WE SHOULD MANAGE TO DROP TO
THE U30S TO AROUND 40F AS THE 850MB ZERO ISOTHERM MAKES A PLUNGE TO
TO AT LEAST THE HIGHWAY 82 CORRIDOR TO OPEN THANKSGIVING DAY./40/
.LONG TERM...THANKSGIVING DAY THROUGH TUESDAY...GFS/ECMWF/GEFS IN
GOOD AGREEMENT TO START OUT THIS PERIOD SHOWING A S/WV TRANSITING THE
GREAT LAKES REGION AND RIDGING OVER THE WESTERN PLAINS. THIS WILL
PLACE THE ARKLAMISS IN DRY NORTHWESTERLY FLOW ALOFT ALLOWING CLEAR
SKIES AND SEASONABLE TEMPS FOR THANKSGIVING DAY. THE DRY CONDITIONS
WILL CONTINUE THROUGH SATURDAY NIGHT AS COOL/DRY AIR ASSOCIATED WITH
SURFACE HIGH PRESSURE CONTINUES BUILDING OVER THE REGION.
UNSEASONABLY COOL TEMPS CAN BE EXPECTED FRI AND SAT MORNING DUE TO
EFFICIENT RADIATIONAL COOLING ASSOCIATED WITH THE CLEAR SKIES
EXPECTED...LIGHT WINDS AND THE COLD AIRMASS THAT WILL BE IN PLACE.
LOW 30S EAST OF I-55 LOOK VERY POSSIBLE BOTH MORNINGS. USUALLY THIS
TIME OF YEAR A FREEZE WILL HAVE OCCURRED MAKING MENTION OF FROST IN
THE FORECAST UNNECESSARY HOWEVER CONSIDERING WE HAVEN`T SEEN ONE YET
THIS YEAR WILL GO AHEAD AND INCLUDE FROST EAST OF I-55 FRI AND SAT
MORNINGS. WILL MENTION PATCHY FROST FRI MORNING AS THE HIGH BUILDS
IN AND GO WITH AREAS ON SAT AS WINDS DEFINITELY LOOK TO GO CALM WITH
THE RIDGE SITTING OVERHEAD.
THINGS WILL BEGIN TO CHANGE ON SATURDAY AFTERNOON AS THE HIGH
PRESSURE SHIFTS EAST OF MS DUE TO A DEVELOPING TROUGH OF LOW
PRESSURE OVER THE PLAINS. THE TROUGH LOOKS TO DROP DOWN AND
INTENSIFY THE SOUTHERN STREAM JET OVER TX WITH 200-300MB WIND
SPEEDS INCREASING TO NEAR 100KTS IN THE LEFT EXIT REGION OVER THE
ARKLAMISS LATE SUNDAY MORNING. THIS WILL PROVIDE ENHANCED LIFT TO
THE MOISTENING AIRMASS AND WILL INCREASE RAIN CHANCES FROM WEST TO
EAST SUNDAY. GFS HINTS AT PW VALUES INCREASING TO NEAR 1.25 IN BY
LATE SUNDAY AFTERNOON. THE COMBINATION OF DEEP LAYER LIFT AND
INCREASING MOISTURE WILL MEAN VERY WEAK THUNDERSTORM CHANCES
STARTING SUNDAY AFTERNOON. GFS SHOWS AN AREA OF 100-300J/KG MUCAPE
DEVELOPING OVER FAR SOUTHWESTERN ZONES SOUTH OF I-20 AT THIS TIME AND
HAVE MENTIONED A SLIGHT CHANCE OF THUNDER IN THESE AREAS ACCORDINGLY.
THIS WEAKLY UNSTABLE AREA WILL SLIDE ACROSS SOUTHERN ZONES SUNDAY
NIGHT INTO MONDAY AHEAD OF THE FRONT AND WILL MOVE THE THUNDER
CHANCES ACROSS THE CWA ACCORDINGLY...TAPERING OFF MONDAY AFTERNOON.
RAIN CHANCES WILL DECREASE FROM WEST TO EAST MONDAY NIGHT INTO
TUESDAY AS THE FRONT CLEARS THE AREA. GFS/ECMWF NOT IN THE BEST
AGREEMENT AS TO THE EVOLUTION OF THE UPPER LEVEL S/WV COME TUESDAY
MORNING WITH GFS MOVING IT INTO THE SOUTHERN GREAT LAKES REGION AND
ECMWF HANGING IT BACK IN THE CENTRAL PLAINS. WILL GO WITH THE FASTER
GFS SOLUTION ALTHOUGH THE GEFS DOES NOT SHOW THE WAVE CLEARING THE
AREA AS FAST AS THE GFS SUGGESTS. THIS COULD MEAN SOME HIGHER
POPS...PRIMARILY OVER NORTHERN ZONES...FOR TUES BUT CONSIDERING THE
UNCERTAINTY WILL KEEP LOW POPS GOING FOR NOW.
MEX TEMPS GENERALLY ACCEPTED ALTHOUGH SOME LOWERING TOWARD MEN
GUIDANCE WAS NEEDED...PRIMARILY WITH HIGH TEMPS OVER THE WEEKEND AND
LOW TEMPS EARLY NEXT WEEK. /BK/
&&
.AVIATION...IFR CONDITIONS WERE OBSERVED ACROSS MUCH OF THE AREA
WITH BROKEN CLOUDS 500-800FT AND/OR VISIBILITIES BELOW 3SM IN
MIST/FOG. LOWERING LIFR VISIBILITIES WERE BEGINNING TO DEVELOP ALONG
THE HIGHWAY 84 CORRIDOR AT TIMES AND THESE MAY PERSIST UNTIL AFTER
14Z OR SO. CLOUD BASES SHOULD GRADUALLY LIFT FROM THE SOUTH AND WEST
THIS MORNING AS SLY FLOW PICKS UP A LITTLE ACROSS THE REGION. CLOUD
DECKS SHOULD BECOME BROKEN 3-5K FEET WITH THE FRONT ARRIVING NEAR THE
MS RIVER BY 1-3PM...THE NATCHEZ TRACE PARKWAY 4-6PM...AND I-59
CORRIDOR BY 7-10PM.
SKIES SHOULD CLEAR FROM THE W 09-15Z WEDNESDAY MORNING AS DRIER AIR
SURGES INTO THE AREA FOLLOWED BY A LENGTHY PERIOD OF VFR CONDITIONS.
/40/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 66 43 63 40 / 13 22 2 4
MERIDIAN 66 42 65 38 / 5 21 4 4
VICKSBURG 65 44 63 40 / 19 22 1 3
HATTIESBURG 69 44 67 41 / 4 20 2 2
NATCHEZ 68 44 65 38 / 16 23 1 3
GREENVILLE 64 43 62 39 / 31 19 1 4
GREENWOOD 64 43 63 40 / 24 22 3 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ059>066-
072>074.
LA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR LAZ024-026.
AR...NONE.
&&
$$
40/BK
000
FXUS64 KJAN 240401
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1001 PM CDT MON NOV 23 2009
.DISCUSSION...CLOUDS ARE CONTINUING TO TRY AND BREAK UP FROM
SOUTHWEST TO NORTHEAST ACROSS THE FORECAST THIS EVENING...BUT IT`S
BEEN TO LITTLE OR NO AVAIL AS THEY`VE REDEVELOPED IN MOST PLACES.
WHERE THEY HAVEN`T REDEVELOPED THROUGH...THE COMBINATION OF THE
CLEARING SKIES...LIGHT WINDS...AND DAMP GROUND CONDITIONS HAS LEAD
TO THE DEVELOPMENT OF SOME PATCHY FOG OVER CENTRAL AND SOUTHERN
PORTIONS OF THE AREA. HOWEVER...THE FOG POTENTIAL IS EXPECTED TO
SHIFT FURTHER EAST OVER EAST AND SOUTHEAST MISSISSIPPI THROUGH THE
OVERNIGHT HOURS AS WINDS BEGIN TO PICK UP ACROSS WESTERN PORTIONS OF
THE AREA DUE TO A FRONTAL SYSTEM APPROACHING THAT AREA FROM THE WEST.
WITH CLOUDS REDEVELOPING ACROSS MUCH OF THE AREA...I`VE RAISED LOW
TEMPERATURES IN SEVERAL PLACES TONIGHT PARTICULARLY IN THE EAST.
OTHER THAN THIS...ALONG WITH SOME MINOR TWEAKS TO SKY COVER AND
HOURLY GRIDS AS A RESULT OF CURRENT TRENDS...THE REMAINDER OF THE
FORECAST LOOKS IN DECENT SHAPE. NO OTHER ADJUSTMENTS WILL BE MADE
TO THE FORECAST AT THIS TIME.
UPDATED PRODUCTS ARE SHIPPING.
&&
.AVIATION...LOOK FOR VFR CEILINGS TO PREVAIL AT MOST SITES THROUGH
MUCH OF THE NIGHT. HOWEVER...PATCHY GROUND FOG OVER PORTIONS OF
CENTRAL AND SOUTH MISSISSIPPI THIS EVENING COULD BRIEFLY REDUCE
VISIBILITIES TO MVFR STATUS. A COLD FRONT WILL PUSH CLOSER TO
WESTERN PORTIONS OF THE AREA OVERNIGHT. THIS WILL CAUSE WINDS TO
PICK UP A BIT IN THAT AREA WHICH WILL BEGIN TO HAMPER FOG
DEVELOPMENT THERE AFTER MIDNIGHT. WITH CLEAR AND LIGHTER WINDS
EXPECTED FURTHER EAST THOUGH...OFF AND ON MVFR VISIBILITIES WILL BE
POSSIBLE AFTER MIDNIGHT ACROSS MAINLY EAST AND SOUTHEAST
MISSISSIPPI...WITH IFR/LIFR VISIBILITIES POSSIBLE BY DAY BREAK
TUESDAY MORNING. ANY FOG THAT DEVELOPS TONIGHT SHOULD DISSIPATE IN
MOST LOCATIONS BETWEEN 14-15Z TUESDAY. AFTER THAT...LOOK FOR MORE
BROKEN STRATUS TO DEVELOP TUESDAY AHEAD OF THE BEFORE MENTIONED COLD
FRONT AS IT MOVES WEST TO EAST ACROSS THE AREA TUESDAY AFTERNOON
INTO TUESDAY NIGHT. A FEW SHOWERS...ESPECIALLY IN THE NORTH WILL BE
POSSIBLE WITH THE COLD FRONT AS IT PUSHES THROUGH TUESDAY.
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
19
000
FXUS64 KJAN 232108
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
301 PM CST MON NOV 23 2009
.DISCUSSION...
TONIGHT THROUGH WEDNESDAY NIGHT...
THE STRATUS DECK IS GRADUALLY ERODING FROM THE SOUTHWEST TODAY AND
EXPECT THIS TREND TO CONTINUE AS WE GO THROUGH THE NIGHTTIME HOURS.
OF COURSE IT IS ALWAYS BETTER TO PREDICT SLOWER CLEARING THIS TIME
OF THE YEAR AND WILL STAY PESSIMISTIC WITH THE OVERNIGHT CLOUD
FORECAST AT THIS TIME. WITH SOMEWHAT DAMP GROUND AND GENERALLY LIGHT
WINDS ANTICIPATED TONIGHT...WE WILL BE LOOKING OUT FOR AT LEAST
PATCHY FOG FORMATION LATER THIS EVENING AS CLEARING OCCURS. THE
POTENTIAL FOR DENSE FOG FORMATION IS HIGHEST LATE TONIGHT ACROSS
PORTIONS OF MS AWAY FROM THE UPPER DELTA AND WE WILL BE MONITORING.
A WEAK FRONTAL PASSAGE IS STILL EXPECTED LATE TUESDAY AFTERNOON AND
TUESDAY NIGHT. MODELS REMAIN CONSISTENT IN SHOWING THAT VERY LITTLE
MOISTURE IS FORECAST TO BE DRAWN NORTHWARD ALONG AND AHEAD OF THE
FRONT SO THE INHERITED LOW-END CHANCE POPS STILL LOOK GOOD FOR TUES
NIGHT. THERE COULD BE ENOUGH CONVERGENCE TO SQUEEZE OUT A BROKEN
LINE OF SHOWERS...BUT VERY LITTLE INSTABILITY WILL GREATLY LIMIT THE
POTENTIAL FOR TSTMS. THE AIRMASS FOLLOWING THE FRONT WILL BRING
SEASONABLE TEMPERATURES FOR WEDNESDAY/WED NIGHT. /EC/BB/
WEDNESDAY THROUGH NEXT MONDAY...QUIET WEATHER IS EXPECTED THROUGH
MOST OF THE EXTENDED FORECAST. AN UPPER TROUGH WILL MOVE ACROSS THE
REGION AND BRING A COLDER SHOT OF AIR TO THE ARKLAMISS WEDNESDAY
NIGHT INTO THURSDAY. THIS WILL MAKE FOR DRY AND SEASONABLY COOL
CONDITIONS FOR THANKSGIVING. CONDITIONS WILL BE CHILLIER FRIDAY AND
SATURDAY MORNINGS WITH LOWS LOOKING TO APPROACH THE FREEZING MARK IN
ERN MS. A 1026MB SURFACE HIGH OVER SOUTHEASTERN TEXAS FRIDAY WILL
MOVE EAST ALONG THE GULF COAST AND TAKE RESIDENCE GENERALLY OVER THE
ARKLAMISS FOR FRIDAY NIGHT INTO SATURDAY WITH RIDGING ALOFT MAKING
FOR GOOD TRAVEL CONDITIONS.
BY SATURDAY NIGHT...LIGHT RETURN FLOW RESUMES WITH SOME WEAK WAA.
DURING THIS TIME...THE SFC HIGH MOVES OFF TO THE EAST AND THE UPPER
FLOW BECOMES MORE ZONAL WITH A SLIGHT SOUTHWESTERLY TILT. THE NEXT
SYSTEM BEGINS TO TAKE SHAPE AS AN UPPER TROUGH OUT WEST OVER THE
ROCKIES STARTS TO DIG FURTHER SOUTH. IN RESPONSE TO THIS....A SFC
LOW/TROUGH STARTS TO DEVELOP ACROSS SOUTHERN PARTS OF TEXAS ON
SUNDAY. AS THIS SYSTEM MOVES CLOSER TO THE REGION SUNDAY NIGHT INTO
MONDAY...RAIN CHANCES BEGIN TO RETURN TO THE ARKLAMISS. AT THIS
POINT IN TIME...BOTH THE ECMWF AND THE GFS AGREE THAT IT COULD BE A
WET LAST DAY OF NOVEMBER...AND WILL HAVE TO KEEP AN EYE ON THE HEAVY
RAIN POTENTIAL. NO MAJOR ADJUSTMENTS MADE TO MEX MOS AS IT SEEMS
MODELS CONTINUE TO REMAIN RATHER CONSISTENT WITH EACH OTHER AND FROM
RUN TO RUN. /28/
&&
.AVIATION...THE BREAKS IN THE OVERCAST SO FAR THIS AFTERNOON WERE
LIMITED TO THE HIGHWAY 84 CORRIDOR AND SOUTH. CEILINGS ACROSS THE
CENTRAL PORTIONS HAVE RISEN ABOVE 3000FT WHILE MVFR CEILINGS BETWEEN
2-3KFT HAVE HUNG ON ALONG THE HIGHWAY 82 CORRIDOR. CLOUDS WILL
CONTINUE TO SLOWLY BREAKUP FROM THE SOUTHWEST THROUGH THIS EVENING.
WITH SOME CLEARING AND VERY LIGHT WINDS THIS EVENING AREAS OF FOG
WILL BE POSSIBLE BY MIDNIGHT. MODELS INDICATE POTENTIAL FOR LOCALLY
DENSE LIFR FOG OVER SOUTHERN AND EASTERN SECTIONS 09-13Z TUESDAY.
INCREASED FLOW OVER THE DELTA REGION AHEAD OF THE APPROACHING COLD
FRONT MAY LIMIT DENSE FOG DEVELOPMENT THERE. LOOK FOR MORE BROKEN
STRATUS TO DEVELOP TUESDAY AHEAD OF THE FRONTAL SYSTEM ARRIVING FOR
TUESDAY NIGHT. NO THUNDER BUT A FEW SHOWERS...ESPECIALLY NORTH WILL
BE POSSIBLE WITH THE COLD FRONT. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 45 65 45 63 / 0 15 22 3
MERIDIAN 41 67 40 65 / 0 8 21 5
VICKSBURG 46 66 43 63 / 1 19 22 2
HATTIESBURG 45 68 45 67 / 0 4 20 3
NATCHEZ 48 66 43 63 / 0 16 23 2
GREENVILLE 48 64 43 61 / 3 31 19 2
GREENWOOD 47 66 43 63 / 1 24 22 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/BB/28/22
000
FXUS64 KJAN 231550 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE JACKSON MS
950 AM CST MON NOV 23 2009
.DISCUSSION...
UPDATE: THE FORECAST IS IN GOOD SHAPE FOR TODAY AS STRATUS IS SLOWLY
ERODING FROM THE SOUTHWEST. MADE MINOR ADJUSTMENTS TO TODAY`S
TEMPERATURES BASED ON THE CURRENT TRENDS...BUT THE THINNING NATURE
OF THE STRATUS ON VISIBLE SATELLITE IMAGERY BRINGS A LOT OF
POTENTIAL FOR A BUSTED FORECAST. IF THE STRATUS BREAKS UP MORE THAN
DEPICTED...THEN SKIES WILL BECOME SUNNY AND TEMPERATURES WILL WARM
WELL INTO THE 60S AND PERHAPS APPROACH 70 IN SOME CASES...BUT IF IT
STAYS CLOUDY...TEMPERATURES WILL STRUGGLE TO REACH 60. HAVE STUCK
WITH A MORE PESSIMISTIC SOLUTION FOR NOW AND KEPT THE COOLER
TEMPERATURES IN THE NE WHERE IT IS MORE LIKELY THAT SKIES WILL
REMAIN CLOUDY UNDER THE FEEBLE LATE NOVEMBER SUN. THE UPDATED
AVIATION DISCUSSION IS BELOW. /EC/
PREVIOUS DISCUSSION...
SHORT TERM...TODAY THROUGH TUESDAY NIGHT...UPSTREAM TROUGH DIVING
INTO WY WILL CROSS KS TONIGHT AND SWING THROUGH MO ON TUESDAY. THE
ASSOCIATED SURFACE FRONTOGENESIS THIS AFTERNOON OVER THE CENTRAL
PLAINS SWEEPS SEWD TONIGHT AND THROUGH THE LOWER MS VALLEY TUESDAY
AFTERNOON/EVENING. THE BOUNDARY WILL HAVE ACCESS TO VERY LITTLE
MOISTURE AND SHOULD ONLY PRODUCE A MINIMAL BAND OF BROKEN SHRA/LIGHT
RAIN AS IT MOVES THROUGH OUR CWFA MAINLY BETWEEN NOON AND MIDNIGHT
TUESDAY.
CURRENTLY IN THE SHORT TERM...STUBBORN STRATUS DECK IS TRAPPED UNDER
A SUBSIDENCE INVERSION ACROSS THE GULF STATES FROM ABOUT THE SABINE
RIVER EWD. PATCHY DRIZZLE ALSO NOTED ALONG WITH SOME MOSTLY LIGHT
FOG. TEMPERATURES REMAIN STUCK BETWEEN 52-56F AND PROBABLY WILL BE
SLOW TO RISE AFTER DAYBREAK THIS MORNING. WILL KEEP NEARLY ALL
LOCATIONS CLOUDY THROUGH EARLY AFTERNOON BEFORE BREAKS BEGIN TO
SLOWLY ADVANCE FROM THE SW TO NE IN THE AFTERNOON IN WEAK DOWNGLIDE
REGIME. WE SHOULD MANAGE TO GET SOME BROKEN LAYERS BY EARLY TONIGHT
BUT NOT LOOKING FOR A COMPLETE CLEARING OUT OF THE LOW LEVEL
MOISTURE PROBABLY UNTIL THE FRONTAL PASSAGE TUESDAY NIGHT.
HIGH TEMPS THIS AFTERNOON WILL BE CONTROLLED BY THE AMOUNT OF
SUNBREAKS AT ANY ONE LOCATION. EXPECT MOST AREAS ONLY TO PEAK AT
58-66F WITH MOST OF THE M60S OVER SRN SECTIONS OF THE AREA. A LIGHT
SLY SURFACE BREEZE SETS UP FOR LATE AFTERNOON THROUGH TONIGHT AND
WILL HELP KEEP LOWS IN THE M-U40S EXCEPT OVER ERN MS WHERE LOWER 40S
ARE POSSIBLE. LOCATIONS IN THE HIGHWAY 84 CORRIDOR WILL ESPECIALLY
BE SUSCEPTIBLE TO PATCHY/AREAS OF FOG LATE TONIGHT IF PRIOR CLEARING
SKIES OCCUR.
THE PREFRONTAL AIR MASS ON TUESDAY WILL REMAIN QUITE STABLE AS A
WEAK AXIS OF NEAR 5.5C MID LEVEL LAPSE RATES...315K 850MB THETA E...
NEAR 20 K INDEXES...AND +2 SHOWALTER INDEXES PUSH ACROSS OUR CWFA
WITH MINIMAL MOISTURE CONVERGENCE. THAT AXIS EXITS SERN MS BY ABOUT
MIDNIGHT TUESDAY NIGHT FOLLOWED BY MODEST CAA HEADING INTO WEDNESDAY.
/40/
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...QUIET WEATHER THROUGH
MUCH OF THE EXTENDED FORECAST. FOLLOWING THE FRONT ON TUESDAY...THE
UPPER TROUGH MOVES ACROSS THE REGION AND BRINGS A REINFORCING SHOT OF
COLD AIR TO THE REGION WEDNESDAY NIGHT INTO THURSDAY. THIS WILL MAKE
FOR DRY BUT CHILLY CONDITIONS FOR THANKSGIVING WITH MODEST CAA IN
FULL FORCE. LOOK FOR LOWS IN THE UPPER 30S ON THANKSGIVING MORNING
AND HIGHS IN THE UPPER 50S NORTH AND WARMER INTO THE 60S FURTHER
SOUTH. CONDITIONS WILL BE CHILLIER FOR THOSE SHOPPERS WAITING OUTSIDE
THEIR FAVORITE STORE ON FRIDAY MORNING WITH LOWS LOOKING TO FLIRT
WITH THE FREEZING MARK IN THE EAST(BUT STAYING JUST ABOVE THAT) AND
INTO THE UPPER 30S ACROSS THE WEST.
A 1026MB SURFACE HIGH OVER SOUTHEASTERN TEXAS FRIDAY MOVES EAST
ALONG THE COAST AND TAKES RESIDENCE GENERALLY OVER THE REGION(1022MB
BY THIS TIME) FOR FRIDAY NIGHT INTO SATURDAY WITH RIDGING ALOFT.
THIS SHOULD MAKE FOR A NICE WEEKEND FOR FAMILY GATHERINGS/TRAVEL.
BY SATURDAY NIGHT...LIGHT RETURN FLOW RESUMES WITH SOME WEAK WAA.
DURING THIS TIME...THE SFC HIGH MOVES OFF TO THE EAST AND THE UPPER
FLOW BECOMES MORE ZONAL WITH A SLIGHT SOUTHWESTERLY TILT. THE NEXT
SYSTEM BEGINS TO TAKE SHAPE AS AN UPPER TROUGH OUT WEST OVER THE
ROCKIES STARTS TO DIG FURTHER SOUTH. IN RESPONSE TO THIS....A SFC
LOW/TROUGH STARTS TO DEVELOP ACROSS SOUTHERN PARTS OF TEXAS ON
SUNDAY. AS THIS SYSTEM MOVES CLOSER TO THE REGION SUNDAY NIGHT INTO
MONDAY...RAIN CHANCES BEGIN TO RETURN TO THE ARKLAMISS. AT THIS
POINT IN TIME...BOTH THE ECMWF AND THE GFS AGREE THAT IT COULD BE A
WET LAST DAY OF NOVEMBER.
NO MAJOR ADJUSTMENTS MADE TO MEX MOS AS IT SEEMS MODELS CONTINUE TO
REMAIN RATHER CONSISTENT WITH EACH OTHER AND FROM RUN TO RUN.
RESIDENTS WILL ENJOY A PLEASANT THANKSGIVING HOLIDAY WEEK FREE OF
SEVERE WEATHER(WHICH IS UNUSUAL FOR THIS REGION THIS TIME OF YEAR).
/28/
&&
.AVIATION...HBG WAS STILL REPORTING LIFR CONDITIONS AT 15Z WITH A
CEILING AT 400FT BUT IFR CLOUD DECKS CONTINUE ACROSS MOST OF THE
AREA WITH BASES 600-800FT. VISIBILITIES OF 3-5SM IN PATCHY LIGHT
DRIZZLE WAS ALSO BEING OBSERVED. VISIBILITIES AND CLOUD BASES SHOULD
GRADUALLY LIFT FROM THE SOUTHWEST AS WEAK HIGH PRESSURE STRENGTHENS
ACROSS THE REGION. VISIBLE SATELLITE IMAGERY WAS SHOWING A FEW
BREAKS DEVELOPING OVER SOUTHERN LOUISIANA ALREADY BUT ANY CLOUD
DECKS THAT PERSIST...PRIMARILY NRN/ERN ZONES...SHOULD BECOME BKN
AROUND 2K FEET 19-23Z AS MUCH OF THE CLOUD COVER THINS BY SUNSET.
AREAS OF LIGHT FOG WILL BE POSSIBLE LATER TONIGHT WITH LOCAL DENSE
IFR FOG OVER SRN SECTIONS 07-13Z TUESDAY. LOOK FOR MORE BROKEN
STRATUS TO DEVELOP TUESDAY AHEAD OF THE FRONTAL SYSTEM ARRIVING FOR
TUESDAY NIGHT. /22/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
000
FXUS64 KJAN 230935
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
335 AM CST MON NOV 23 2009
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...UPSTREAM TROUGH DIVING INTO
WY WILL CROSS KS TONIGHT AND SWING THROUGH MO ON TUESDAY. THE
ASSOCIATED SURFACE FRONTOGENESIS THIS AFTERNOON OVER THE CENTRAL
PLAINS SWEEPS SEWD TONIGHT AND THROUGH THE LOWER MS VALLEY TUESDAY
AFTERNOON/EVENING. THE BOUNDARY WILL HAVE ACCESS TO VERY LITTLE
MOISTURE AND SHOULD ONLY PRODUCE A MINIMAL BAND OF BROKEN SHRA/LIGHT
RAIN AS IT MOVES THROUGH OUR CWFA MAINLY BETWEEN NOON AND MIDNIGHT
TUESDAY.
CURRENTLY IN THE SHORT TERM...STUBBORN STRATUS DECK IS TRAPPED UNDER
A SUBSIDENCE INVERSION ACROSS THE GULF STATES FROM ABOUT THE SABINE
RIVER EWD. PATCHY DRIZZLE ALSO NOTED ALONG WITH SOME MOSTLY LIGHT
FOG. TEMPERATURES REMAIN STUCK BETWEEN 52-56F AND PROBABLY WILL BE
SLOW TO RISE AFTER DAYBREAK THIS MORNING. WILL KEEP NEARLY ALL
LOCATIONS CLOUDY THROUGH EARLY AFTERNOON BEFORE BREAKS BEGIN TO
SLOWLY ADVANCE FROM THE SW TO NE IN THE AFTERNOON IN WEAK DOWNGLIDE
REGIME. WE SHOULD MANAGE TO GET SOME BROKEN LAYERS BY EARLY TONIGHT
BUT NOT LOOKING FOR A COMPLETE CLEARING OUT OF THE LOW LEVEL
MOISTURE PROBABLY UNTIL THE FRONTAL PASSAGE TUESDAY NIGHT.
HIGH TEMPS THIS AFTERNOON WILL BE CONTROLLED BY THE AMOUNT OF
SUNBREAKS AT ANY ONE LOCATION. EXPECT MOST AREAS ONLY TO PEAK AT
58-66F WITH MOST OF THE M60S OVER SRN SECTIONS OF THE AREA. A LIGHT
SLY SURFACE BREEZE SETS UP FOR LATE AFTERNOON THROUGH TONIGHT AND
WILL HELP KEEP LOWS IN THE M-U40S EXCEPT OVER ERN MS WHERE LOWER 40S
ARE POSSIBLE. LOCATIONS IN THE HIGHWAY 84 CORRIDOR WILL ESPECIALLY
BE SUSCEPTIBLE TO PATCHY/AREAS OF FOG LATE TONIGHT IF PRIOR CLEARING
SKIES OCCUR.
THE PREFRONTAL AIR MASS ON TUESDAY WILL REMAIN QUITE STABLE AS A
WEAK AXIS OF NEAR 5.5C MID LEVEL LAPSE RATES...315K 850MB THETA E...
NEAR 20 K INDEXES...AND +2 SHOWALTER INDEXES PUSH ACROSS OUR CWFA
WITH MINIMAL MOISTURE CONVERGENCE. THAT AXIS EXITS SERN MS BY ABOUT
MIDNIGHT TUESDAY NIGHT FOLLOWED BY MODEST CAA HEADING INTO WEDNESDAY.
/40/
.LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...QUIET WEATHER THROUGH
MUCH OF THE EXTENDED FORECAST. FOLLOWING THE FRONT ON TUESDAY...THE
UPPER TROUGH MOVES ACROSS THE REGION AND BRINGS A REINFORCING SHOT OF
COLD AIR TO THE REGION WEDNESDAY NIGHT INTO THURSDAY. THIS WILL MAKE
FOR DRY BUT CHILLY CONDITIONS FOR THANKSGIVING WITH MODEST CAA IN
FULL FORCE. LOOK FOR LOWS IN THE UPPER 30S ON THANKSGIVING MORNING
AND HIGHS IN THE UPPER 50S NORTH AND WARMER INTO THE 60S FURTHER
SOUTH. CONDITIONS WILL BE CHILLIER FOR THOSE SHOPPERS WAITING OUTSIDE
THEIR FAVORITE STORE ON FRIDAY MORNING WITH LOWS LOOKING TO FLIRT
WITH THE FREEZING MARK IN THE EAST(BUT STAYING JUST ABOVE THAT) AND
INTO THE UPPER 30S ACROSS THE WEST.
A 1026MB SURFACE HIGH OVER SOUTHEASTERN TEXAS FRIDAY MOVES EAST
ALONG THE COAST AND TAKES RESIDENCE GENERALLY OVER THE REGION(1022MB
BY THIS TIME) FOR FRIDAY NIGHT INTO SATURDAY WITH RIDGING ALOFT.
THIS SHOULD MAKE FOR A NICE WEEKEND FOR FAMILY GATHERINGS/TRAVEL.
BY SATURDAY NIGHT...LIGHT RETURN FLOW RESUMES WITH SOME WEAK WAA.
DURING THIS TIME...THE SFC HIGH MOVES OFF TO THE EAST AND THE UPPER
FLOW BECOMES MORE ZONAL WITH A SLIGHT SOUTHWESTERLY TILT. THE NEXT
SYSTEM BEGINS TO TAKE SHAPE AS AN UPPER TROUGH OUT WEST OVER THE ROCKIES
STARTS TO DIG FURTHER SOUTH. IN RESPONSE TO THIS....A SFC LOW/TROUGH
STARTS TO DEVELOP ACROSS SOUTHERN PARTS OF TEXAS ON SUNDAY. AS THIS
SYSTEM MOVES CLOSER TO THE REGION SUNDAY NIGHT INTO MONDAY...RAIN
CHANCES BEGIN TO RETURN TO THE ARKLAMISS. AT THIS POINT IN
TIME...BOTH THE ECMWF AND THE GFS AGREE THAT IT COULD BE A WET LAST
DAY OF NOVEMBER.
NO MAJOR ADJUSTMENTS MADE TO MEX MOS AS IT SEEMS MODELS CONTINUE TO
REMAIN RATHER CONSISTENT WITH EACH OTHER AND FROM RUN TO RUN.
RESIDENTS WILL ENJOY A PLEASANT THANKSGIVING HOLIDAY WEEK FREE OF
SEVERE WEATHER(WHICH IS UNUSUAL FOR THIS REGION THIS TIME OF YEAR).
/28/
&&
.AVIATION...IFR CLOUD DECKS CONTINUE ACROSS MOST OF THE AREA WITH
BASES 400-800 FEET E OF THE MS RIVER AND ONLY 1-2K FEET W. LOWERING
MVFR VISIBILITIES OF 3-4SM IN PATCHY DRIZZLE ALSO OBSERVED WHICH MAY
DROP TO IFR AT TIMES UNTIL JUST AFTER SUNRISE. CLOUD BASES SHOULD
GRADUALLY LIFT FROM THE SOUTH AND WEST TODAY AS WEAK HIGH PRESSURE
DEVELOPS ACROSS THE REGION. CLOUD DECKS THAT PERSIST...PRIMARILY
NRN/ERN ZONES...SHOULD BECOME BKN AROUND 2K FEET 19-23Z AS MUCH OF
THE CLOUD COVER THINS BY SUNSET. AREAS OF LIGHT FOG WILL BE POSSIBLE
LATER TONIGHT WITH LOCAL DENSE IFR FOG OVER SRN SECTIONS 07-13Z
TUESDAY. LOOK FOR MORE BROKEN STRATUS TO DEVELOP TUESDAY AHEAD OF
THE FRONTAL SYSTEM ARRIVING FOR TUESDAY NIGHT./40/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 45 68 46 / 2 2 15 22
MERIDIAN 63 41 69 47 / 2 2 8 21
VICKSBURG 65 47 67 43 / 1 4 19 22
HATTIESBURG 65 45 72 48 / 2 2 4 20
NATCHEZ 66 47 70 43 / 2 2 16 23
GREENVILLE 63 48 64 43 / 1 5 31 19
GREENWOOD 62 46 68 44 / 2 3 24 22
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
40/28
| 
