Area Forecast Discussion

FXUS64 KJAN 092157

AFDJAN

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE JACKSON MS

316 PM CST THU NOV 9 2006

.DISCUSSION...

WARM WEATHER ACROSS THE REGION LOOKS TO CONTINUE FOR AT LEAST ONE

MORE DAY...ALTHOUGH CLOUDS WILL GRADUALLY INCREASE OVER THE REGION

THROUGH THE NEXT 24 HOURS. LOWER CLOUDS EVIDENT ON SATELLITE IMAGERY

ALL DAY REMAINED JUST ALONG THE WESTERN BORDERS OF THE CWA. THESE

CLOUDS MARKED ZONE OF DEEPER MOISTURE AVAILABILITY AND THE GREATEST

PUSH OF SOUTHERLY GULF MOISTURE RETURN. THE AXIS OF RETURN FLOW WILL

SHIFT A LITTLE EAST OVERNIGHT...BRINGING AT LEAST WESTERN PORTIONS

OF AREA IN LINE WITH ZONE OF LOWER STRATUS PRODUCTION. MORE LIMITED

MOISTURE RETURN FURTHER EAST...COMBINED WITH LIGHTER WINDS...WILL

SPELL A TRICKY FOG/VERY LOW STRATUS RISK COMBINATION. REALLY FORESEE

TOO MUCH BL WIND TO WORRY MUCH ABOUT DENSE FOG ADVISORY AND NONE OF

THESE CLOUDS SHOULD BRING PRECIP. EXPECT LOWS TONIGHT MUCH WARMER

THAN LAST NIGHT AND I REMAINED NEAR MAV (WHICH FEATURES A RANGE FROM

LOWER 60S WEST TO LOWER 50S IN EASTERN MS).

SHORT WAVE UPPER LEVEL RIDGING THAT HAS BEEN IN PART RESPONSIBLE FOR

THE RECENT WARMTH WILL GET SHOVED ON TO THE EAST OF THE LOWER

MISSISSIPPI VALLEY THROUGH TOMORROW AS A TROUGH DIGS INTO THE PLAINS

STATES. UNDERNEATH THE TURMOIL ALOFT...A COLD FRONT OF DECENT

STRENGTH WILL APPROACH THE REGION FROM THE WEST BY LATE IN THE DAY.

CONVERGENCE ALONG THIS FRONT...AND/OR A WEAK SURFACE TROUGH JUST

AHEAD OF IT...SHOULD FORCE CONVECTION BY MID AFTERNOON OVER THE

ARKLATEX IN AN AREA OF MODERATE INSTABILITY AND SHEAR. THIS

ACTIVITY WILL PROGRESS EAST WITH THE WHOLE FRONTAL ZONE INTO WESTERN

ZONES BY EARLY EVENING AND THEN INTO A POSITION ROUGHLY PARALLEL

WITH THE NATCHEZ TRACE CORRIDOR BY LATE EVENING. GFS CONTINUES TO

FORECAST SIG SEVERE LEVELS OF 15 TO 20K OVER WESTERN ZONES AT

00Z...WHICH SHOULD LOWER TO ROUGHLY 10K BY LATE EVENING NEAR THE

NATCHEZ TRACE CORRIDOR. ALTHOUGH THE BRUNT OF UPPER FORCING

ASSOCIATED WITH THE INCOMING TROUGH SHOULD REMAIN TO OUR

NORTH...ATMOSPHERIC LAPSE RATES AND MOISTURE LEVELS ARE NOT TOO BAD

ALONG THE BOUNDARY SO KEEPING MENTION OF POSSIBILITY OF SEVERE

STORMS IN FOR WESTERN ZONES LATE TOMORROW DOES NOT SEEM LIKE A BAD

IDEA. STILL TRIED TO FOCUS ON JUST A MARGINAL RISK OF HAIL AND

DAMAGING WINDS SINCE SHEAR CHARACTERISTICS ARE NOT VERY SUPPORTIVE

OF SUPERCELLS OR TORNADOES. ALSO NOT LOOKING FOR A GREAT DEAL OF

RAINFALL WITH THIS FRONT AND I WOULD BE SURPRISED TO SEE ANYONE GET

AN INCH OF THE WET STUFF. COOL AIR WILL BEGIN TO FILTER INTO

NORTHWEST ZONES BY SATURDAY MORNING WITH RAIN STARTING TO TAPER OFF

FROM WEST TO EAST BY DAYBREAK. /BB/

THE COLD FRONT IS EXPECTED TO DROP INTO SERN ZONES BY SATURDAY

MORNING. NWLY FLOW DEVELOPS AT LOW LEVELS ACCOMPANIED BY COLD AIR

ADVECTION DURING THE DAY. THE AIR MASS DRIES AND RIDGING SHIFTS INTO

THE AREA SUNDAY BEFORE THE NEXT WEATHER SYSTEM BEGINS TO AFFECT

REGIONAL WEATHER. TIMING ON WEATHER FEATURES FOR THE NEXT WORK WEEK

HAVE BEEN IFFY AT BEST WITH MODELS FLIP-FLOPPING FROM RUN TO

RUN...PARTICULARLY ON THE DEPTH OF THE LOW PRESSURE SYSTEM THAT IS

EXPECTED AROUND TUESDAY.

A WARM FRONT IS FORECAST TO LIFT FROM THE GULF MONDAY...INCREASING

RAIN CHANCES MONDAY AND MONDAY NIGHT. DYNAMICS INCREASE

SIGNIFICANTLY LATE MONDAY NIGHT AND TUESDAY. THE GFS...WHICH HAS

MAINTAINED THE MOST INTENSE SOLUTION...DEVELOPS A STRONG LOW LEVEL

JET EARLY TUESDAY WITH HEALTHY DEEP LAYER SHEAR AND UPPER

DIVERGENCE. LATER MODEL RUNS HAVE TRENDED TOWARD HIGHER INSTABILITY

AND BETTER POOLING OF LOW LEVEL MOISTURE AHEAD OF THE COLD FRONT.

MODEL DISCREPANCIES NOTWITHSTANDING, THE MONDAY NIGHT TO TUESDAY

TIME FRAME SHOWS POTENTIAL FOR A SIGNIFICANT SEVERE WEATHER EVENT.

ALONG WITH THE QUESTION OF TIMING, THE MODELS HAVE YET TO SETTLE

QUESTIONS CONCERNING THE DEPTH OF THE SYSTEM AND ASSOCIATED DEGREE

OF LOW LEVEL MOISTURE RETURN. WILL ADD MENTION OF POTENTIAL FOR

SEVERE WEATHER TO THE HWO WITH EXPLANATION OF UNCERTAINTIES THAT

REMAIN.

THE DEPTH AND TIMING OF THE UPPER LOW WILL HAVE A MAJOR IMPACT ON

WEATHER BEHIND THE SYSTEM WEDNESDAY AND THURSDAY. AT THIS TIME WILL

LEAVE LOW END CHANCE POPS FOR WEDNESDAY AND DRY THINGS OUT FOR

THURSDAY. TEMPERATURES WILL BE COOLER BEHIND THE SYSTEM...ESPECIALLY

WEDNESDAY DUE TO POTENTIAL CLOUD COVER. /03/

&&

.AVIATION...

EXPECTING LOW CLOUDS TO FORM AT LEAST WEST OF INTERSTATE 55

OVERNIGHT AS MOISTURE RETURN AXIS SHIFTS A LITTLE EAST FROM THE

ARKLATEX. BIGGER QUESTION MARK IS LOW CLOUD AND FOG POTENTIAL ACROSS

EASTERN MISSISSIPPI. IN ANY CASE...ANY AREAS OF LOW CLOUDS COULD

BRING FLIGHT CATS DOWN TO AT LEAST IFR...ALTHOUGH STRONGER WINDS UP

AROUND GLH MAY KEEP CEILINGS FROM GOING BELOW MVFR LEVELS. FOG WILL

ALSO BE POSSIBLE IN SOUTHERN ZONES...BUT FLIGHT CAT REDUCTIONS

SHOULD NOT BE ANY WORSE THAN CORRESPONDING CEILING REDUCTIONS.

EXPECT FOG AND LOW CLOUDS TO LIFT BY 10 TO 11 AM TOMORROW MORNING

WITH CLOUDS AOA 3 KFT THE REST OF THE DAY. /BB/

&&

.PRELIMINARY POINT TEMPS/POPS...

JACKSON       57  81  54  62 /   2   6  72  14

MERIDIAN      52  80  56  64 /   2   4  61  18

VICKSBURG     58  82  53  60 /   2  12  72  11

HATTIESBURG   55  82  61  69 /   2   5  36  16

NATCHEZ       61  82  55  62 /   2  11  70  13

GREENVILLE    59  80  49  61 /   2  17  70   9

GREENWOOD     57  82  49  58 /   2  10  77  12

&&

.JAN WATCHES/WARNINGS/ADVISORIES...

MS...NONE.

LA...NONE.

AR...NONE.

&&

$$

SHORT TERM:50

LONG TERM: 03