Area Forecast Discussion
Issued by NWS Jackson, MS

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FXUS64 KJAN 161111
AFDJAN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
610 AM CDT WED APR 16 2014

.UPDATE...TEMPERATURES ACROSS THE REGION REMAIN A FEW DEGREES ABOVE
FREEZING. WITH WINDS AND MIXING EXPECTED TO CONTINUE AND SUNRISE
OCCURRING SOON...THE FREEZE WARNING HAS BEEN CANCELED. A FEW LOCATIONS WERE
AROUND 32 AND MAY FALL TO NEAR 30 BRIEFLY WITH SOME FROST...HOWEVER
WIDESPREAD FREEZING IS NOT EXPECTED AT THIS TIME.

THERE WAS ALSO SOME PATCHY FOG...EXPECTING TO SEE IT NEAR BODIES OF
WATER AND IN LOW LYING AREAS FOR THE NEXT FEW HOURS. WIDESPREAD DENSE
FOG WAS NOT EXPECTED.

./PREVIOUS DISCUSSION...417 AM CDT WED APR 16 2014

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT. TEMPERATURES WILL BE THE
BIGGEST CONCERN IN THE SHORT TERM...WITH HIGH PRESSURE IN PLACE FOR
THE NEXT DAY OR SO. POPS HAVE CHANGED IN THE NEWEST MODEL RUN...SO
BACKED OFF FOR THURSDAY NIGHT/FRIDAY. WENT WITH GUIDANCE TEMPS/DEWPOINTS
THROUGH THE PERIOD. OVERALL NO HUGE CHANGES...JUST A FEW TWEAKS TO
THE POPS.

WINDS AND MOISTURE HAVE REMAINED IN PLACE TONIGHT...SO TEMPERATURES
HAVE NOT FALLEN AS QUICKLY OR AS LOW AS EXPECTED SO FAR. WILL LIKELY
MAKE A LATE DECISION ON THE FREEZE WARNING TO AVOID FLIP FLOPPING AT
THIS POINT. THINKING TEMPERATURES WILL FALL QUICKLY IF THE WINDS
BECOME CALM. OTHERWISE...THERE WILL BE SOME FROST ACROSS THE
AREA...ESPECIALLY IN RURAL AREAS. ADJUSTED THE HOURLY VALUES TO
ACCOUNT FOR THE SLOW FALL. HOWEVER...IT SEEMS UNLIKELY THAT
WIDESPREAD FREEZING TEMPERATURES WILL OCCUR THIS MORNING.

WITH THE SURFACE RIDGE TO THE NORTHEAST AND COOL AIR DRAINING INTO
THE AREA...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THURSDAY.
SOUTHWESTERLY FLOW AND MOISTURE WILL RETURN BY THURSDAY AFTERNOON. AN
UPPER RIDGE IN THE WEST...WILL BRING A FEW UPPER WAVES THROUGH THE
MIDWEST...KEEPING THE AREA IN SOUTHWEST FLOW. A DISTURBANCE DEVELOPS
IN THE NORTHERN GULF ON THURSDAY...BRINGING A CHANCE OF RAIN
THURSDAY NIGHT INTO FRIDAY. THE GFS KEEPS THE DISTURBANCE SOUTH OF
THE AREA...BEFORE IT DEEPENS AND MOVES EAST. THE RAIN FOR THE
SOUTH/SOUTHEAST PORTIONS OF THE AREA WILL DEPEND ON THE TRACK...BUT
FOR NOW CHANCES SEEM LIMITED. THE GUIDANCE CAME IN WITH LOWER POPS
TODAY...SO WENT WITH THEM. A BOUNDARY...MAYBE AN INVERTED TROUGH
MOVES THROUGH THE PLAINS...BUT THE TAIL END OF THE BOUNDARY COULD
EXTEND INTO THE NORTHERN ZONES. AGAIN CHANCES SEEM LIMITED...SO LEFT
RAIN OUT OF THE NORTHWEST FRIDAY AND FRIDAY NIGHT.

.LONG TERM...SATURDAY THROUGH TUESDAY...WE WILL CONTINUE OUR
PROGRESSIVE COMPLICATED SPLIT FLOW PATTERN THROUGH THE PERIOD. THERE
IS SOME AMPLITUDE AND TIMING DIFFERENCES ON THE MOVEMENT OF THE
NORTHERN AND SOUTHERN STREAM SHORTWAVES. EVEN THE GFS ENSEMBLES HAD
SOME DIFFERENCES IN THE MOVING AND PHASING OF SHORTWAVES IN THE
NORTHERN AND SOUTHERN STREAMS. HOWEVER ALL MODELS HAD SOME FORM OF A
COMPLICATED SPLIT FLOW PATTERN. THE GFS AND EURO GENERALLY AGREED
WITH THE GENERAL PATTERN AND MOVEMENT OF SOUTHERN STREAM ENERGY.
..BUT NOT MUCH AGREEMENT IN THE  AMPLITUDE AND QPF WITH THE
SHORTWAVES. THIS ALSO THE CASE WITH THE NAVGEM MODEL WITH ITS OWN
SOLUTION WITH THIS UNSETTLED PATTERN. IT TRIED TO KEEP THE AREA DRY
FOR THE WEEKEND INTO EARLY NEXT WEEK. SO FORECAST CONFIDENCE IS NOT
REAL HIGH WITH THE TIMING OF THE MODELS ON THIS PROGRESSIVE PATTERN.

STARTING ON THE WEEKEND UPPER RIDGING WITH INCREASING HEIGHTS BUILDS
ACROSS THE REGION FROM THE WEST. A NEARLY PHASED SHORT WAVE WILL
APPROACH THE REGION FROM THE PLAINS FOR SUNDAY. SOUTHWEST FLOW AHEAD
OF THIS SYSTEM WILL BUILD IN MOISTURE IN FROM THE WEST FROM SATURDAY
NIGHT INTO SUNDAY. PWATS ON SUNDAY WILL INCREASE TO AROUND  1.5
INCHES. MODELS SOUNDINGS DON`T SHOW MUCH CAPPING WITH THIS SYSTEM.
AS MOISTURE TRANSPORT WILL HAVE ERODED THE DRY LAYER IN THE MIDLEVELS
FOR SUNDAY THROUGH MONDAY FOR DEEPER LAYER CONVECTION. MIDLEVEL
DRYING DOES COME BACK SOME ON TUESDAY AS WE GET SOME DRY INFLOW FROM
THE APPROACHING UPPER RIDGING FROM THE WEST. THERE WILL BE SOME
INSTABILITY WITH THIS SYSTEM AS A WARM FRONT PUSHES ACROSS THE
REGION.  THE SHORTWAVE WILL TAKE ITS TIME PUSHING THROUGH THE REGION
WHICH MEANS THAT THE WARM FRONT WILL BE STATIONARY NORTH OF THE
REGION FOR SUNDAY INTO TUESDAY. THERE WILL BE ENOUGH INSTABILITY FOR
CONVECTION FOR SUNDAY THROUGH TUESDAY. THE SHORTWAVE WILL FINALLY
EXIT THE REGION BY TUESDAY NIGHT ALONG WITH THE SHOWERS AS UPPER
RIDGING BUILDS IN FROM THE WEST.

AS FAR AS POPS AND TEMPS ARE CONCERN GENERALLY STUCK CLOSE TO A BLEND
OF MEX...GMOS AND HPC GUIDANCE./17/


&&

.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD.
WILL ADD SOUTHEASTERLY WINDS WITH THE NEXT PACKAGE. HIGH CLOUDS MAY
MOVE IN AT TH END OF THE FORECAST PERIOD...BUT WILL KEEP THING CLEAR.


&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       65  40  71  56 /   0   0   3  13
MERIDIAN      66  36  70  53 /   0   0   4  18
VICKSBURG     64  41  70  55 /   0   0   4  14
HATTIESBURG   67  41  71  57 /   0   0  11  18
NATCHEZ       63  42  68  54 /   0   0   9  11
GREENVILLE    64  42  70  54 /   0   0   4  14
GREENWOOD     64  40  71  53 /   0   0   4  13

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.

LA...NONE.

AR...NONE.

&&

$$

07/17/7








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