037  
FXUS64 KJAN 270005  
AFDJAN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSON MS  
605 PM CST SUN FEB 26 2017  
   
..ACTIVE WEATHER EXPECTED THROUGH MID WEEK
 
 
   
UPDATE
 
 
UPDATED FOR 00Z AVIATION DISCUSSION  
 

 
   
AVIATION
 
 
00Z TAF DISCUSSION:  
THE WORST AVIATION CONDITIONS WILL BE ASSOCIATED WITH A COMPLEX OF  
SHRA/TSRA EXPECTED TO MOVE INTO THE GLH/GWO AREA AFTER 06Z AND  
EVENTUALLY DEVELOP SOUTHWARD THROUGH THE ENTIRE AREA AS WE GO PAST  
DAYBREAK AND INTO THE EARLY AFTERNOON. EXPECT IFR/MVFR CATEGORIES  
TO BE PROMINENT AT MOST SITES DURING THIS TIME WITH SOME  
IMPROVEMENT POSSIBLE DURING THE MID/LATE AFTERNOON. /EC/  
 

 
   
DISCUSSION
 
 
NOW THROUGH THE DAY TOMORROW:  
 
IT HAS BEEN ANOTHER VERY DRY (IN TERMS OF HUMIDITY) DAY ACROSS THE  
REGION WITH TEMPERATURES MORE PLEASANT THAN YESTERDAY AS THE  
OVERALL TREND TO ABOVE AVERAGE READINGS HAS KICKED BACK IN.  
DESPITE SOUTHEAST WINDS AT THE SURFACE, MOISTURE HAS YET TO RETURN  
TO THE BOUNDARY LAYER AND THE COMBINATION OF THE SOMEWHAT GUSTY  
WINDS AND LOW RELATIVE HUMIDITY IS AGAIN INCREASING FIRE WEATHER  
CONCERNS. MORE ON THE SPECIFICS OF THE FIRE CONCERNS IS MENTIONED  
IN THE DEDICATED SECTION BELOW. FORTUNATELY, FIRE DANGER WILL NOT  
BE A CONCERN ANYTIME IN THE NEAR FUTURE (AFTER THIS AFTERNOON)  
SINCE STARTING TONIGHT THE INCREASING SOUTHERLY FLOW ABOVE THE  
SURFACE WILL BE BRINGING BACK MOISTURE FROM THE GULF OF MEXICO  
QUICKLY.  
 
A FAST-MOVING UPPER LEVEL DISTURBANCE HEADED AT THE REGION TONIGHT  
WILL BE THE IMPETUS FOR THE RAPID MOISTURE RETURN AS THE  
DISTURBANCE EFFECTIVELY SHOVES THE NEARBY SURFACE HIGH QUICKLY OFF  
TO THE EAST AND STRENGTHENS RETURN FLOW UP THE LOWER MISSISSIPPI  
VALLEY. MODEL CONSENSUS SUGGESTS THE CURRENT RASH OF SHOWERS  
BREAKING OUT TO OUR WEST WILL CONSOLIDATE AND GROW THIS EVENING  
INTO A LARGER COMPLEX OF SHOWERS AND THUNDERSTORMS, WHICH WILL  
THEN TRANSLATE EAST INTO WESTERN ZONES BEFORE DAWN. AFTER DAYBREAK  
THIS CONVECTION SHOULD CONTINUE TO SHIFT EAST THROUGH THE HEART  
OF THE REGION, PROBABLY ANCHORED AT THE NOSE OF MAXIMUM WARMTH AND  
MOISTURE ADVECTION A FEW THOUSAND FEET ABOVE THE SURFACE (WHICH  
BASICALLY SHOULD BE ALONG THE I-20 CORRIDOR). INSTABILITY  
OVERNIGHT INTO MID MORNING TOMORROW SHOULD BE BASED ABOVE THE  
SURFACE, GREATLY LIMITING THE POTENTIAL FOR SEVERE WEATHER (ALTHOUGH  
SOME SMALL HAIL IS STILL POSSIBLE IN THIS TIME WINDOW OVER  
WESTERN ZONES). MORE WORRISOME WILL BE MID MORNING THROUGH EARLY  
AFTERNOON TOMORROW AS THERE WILL LIKELY BE AN OUTFLOW BOUNDARY  
LAID DOWN OVER SOUTHERN ZONES BY THE MAIN CONVECTION WHERE NON-  
NEGLIGIBLE SURFACE-BASED INSTABILITY COULD BUILD AND HELP TRIGGER  
SOME STORMS MORE CAPABLE OF SEVERE WEATHER. THE AVAILABLE SUITE OF  
HIGH RESOLUTION GUIDANCE IS NOT IN HIGH AGREEMENT CONCERNING  
CONVECTIVE EVOLUTION TOMORROW, BUT WE FEEL OVER CENTRAL AND ZONES  
IT IS STILL WORTH MENTIONING THE POTENTIAL FOR AT LEAST ONE OR TWO  
STORMS GETTING UP TO SEVERE POTENTIAL.  
 
BY LATE IN THE AFTERNOON TOMORROW THE MAIN UPPER LEVEL SHORT WAVE  
WILL BE SHIFTING TO THE EAST AND SUBSIDENCE IN ITS WAKE SHOULD BE  
SHUTTING DOWN THE THREAT FOR DEEP CONVECTION. MANY LOCATIONS,  
ESPECIALLY OVER EAST-CENTRAL MS, WILL HAVE STRUGGLED TO WARM MUCH  
BEFORE THIS TIME, BUT WILL LIKELY GET A CHANCE TO MAKE A RUN UP  
TOWARD 70 DEGREES BEFORE THE AFTERNOON IS TOTALLY DONE. /BB/  
 
MONDAY NIGHT THROUGH NEXT WEEK:  
 
WE WILL BE LOOKING AT AN ACTIVE PERIOD WITH RAIN CHANCES COMING FOR  
MONDAY NIGHT THROUGH WEDNESDAY NIGHT WITH MILD TEMPERATURES.  
THIS WILL BE FOLLOWED BY DRY AND COOL WEATHER FOR THURSDAY THROUGH  
SATURDAY BEFORE SOME RAIN COMES BACK IN THE SOUTH ON SATURDAY NIGHT.  
THE BEST SEVERE POTENTIAL LOOKS TO BE ON WEDNESDAY WITH THE COLD  
FRONT PASSAGE. THERE WILL BE SOME LIMITED SEVERE POTENTIAL FOR  
TUESDAY NIGHT IN THE NORTHWEST.  
 
ON MONDAY NIGHT CONVECTION WILL BE INCREASING OVER THE NORTHERN  
COUNTIES IN THE VICINITY OF THE WARM FRONT AND THE UPPER LEVEL JET.  
 
ON TUESDAY A MIDLEVEL TROUGH WILL BE PUSHING TOWARD THE PLAINS. THIS  
WILL PUSH A COLD FRONT TOWARD THE OZARKS FOR TUESDAY NIGHT. SURFACE  
BASED INSTABILITY WILL BE PREVALENT WITH LAPSE RATES 7-8C,  
INCREASING LOW LEVEL SHEAR 35 KNOTS AND DEEP LAYER SHEAR 60-70  
KNOTS IN THE DELTA REGION, SHOWALTER INDICES -2 TO -4, VERTICAL  
TOTALS 28-30, AND MOST UNSTABLE CAPE AROUND 1800 J/KG. THE MAIN  
AXIS OF THE UPPER JET WILL BE NORTH OF THE REGION. HOWEVER WE WILL  
HAVE A GOOD LOW LEVEL JET OF AROUND 40 TO 50 KNOTS. WITH WARM  
HEIGHTS OVER THE REGION WE WILL BE RATHER CAPPED WITH THE APPROACH  
OF THE MIDLEVEL TROUGH, WHICH WILL AFFECT THE CONVECTIVE COVERAGE  
IN THE SOUTH HALF. THE BEST CHANCE OF STORMS WILL BE IN THE  
NORTHWEST FOR TUESDAY NIGHT WITH THE APPROACH OF THE SYSTEM. SPC  
HAS A MARGINAL RISK FOR SEVERE STORMS OVER OUR NORTHWEST DELTA  
REGION WITH A SLIGHT RISK JUST TO OUR NORTHWEST. WITH THIS IN  
MIND WILL KEEP A LIMITED SEVERE THREAT GRAPHIC FOR THE NORTHWEST  
DELTA REGION WITH THE APPROACHING SYSTEM FOR TUESDAY NIGHT. THE  
PRIMARY RISKS WILL BE DAMAGING WINDS, AND HAIL.  
 
ON WEDNESDAY THE MIDLEVEL TROUGH WILL BE PUSHING TOWARD THE  
REGION FROM THE PLAINS. THIS WILL SEND A COLD FRONT INTO THE  
REGION. AHEAD OF THE COLD FRONT WE WILL HAVE LOW LEVEL SHEAR 30-40  
KNOTS, DEEP LAYER SHEAR 60-70 KNOTS, STORM RELATIVE HELICITY OF  
200-300, VT 28- 30, AND SHOWALTERS -2 TO -4. THIS WILL BE ENOUGH  
FOR SOME TORNADO POTENTIAL ACROSS THE REGION AHEAD OF THE COLD  
FRONT. SPC HAS PUT A 30 PERCENT RISK FOR OUR NORTHERN COUNTIES AND  
A 15 PERCENT RISK ELSEWHERE. SO WITH THIS IN MIND WILL KEEP THE  
ELEVATED RISK ACROSS THE NORTH AND LIMITED RISK ACROSS THE CENTRAL  
AND SOUTH. SO WILL KEEP THE PRIMARY RISK BEING DAMAGING WINDS,  
HAIL AND A TORNADO CAN NOT BE RULED OUT. CONDITIONS LOOK TO FAVOR  
A SQUALL LINE TO DEVELOP ALONG THE FRONTAL BOUNDARY AS IT SWEEP  
ACROSS THE REGION WITH SOME DAMAGING WINDS. THE FRONT WILL SWEEP  
ACROSS MOST OF THE REGION BY WEDNESDAY NIGHT. MODELS WERE STILL  
HAVING SOME TIMING ISSUES WITH THE FRONTAL PASSAGE. THE RAINS WILL  
END FROM THE NORTHWEST IN THE WAKE OF THE FRONT ON WEDNESDAY  
NIGHT. COOL HIGH PRESSURE WILL BUILD IN FROM THE PLAINS ON  
THURSDAY INTO FRIDAY. ON SATURDAY HIGH PRESSURE WILL TRACK EAST OF  
THE REGION WHICH WILL BRING BACK SOUTHERLY LOW LEVEL RETURN FLOW.  
PWATS WILL INCREASE FROM THE WEST TO AROUND ONE INCH, WHICH WILL  
HELP SOME ISOLATED SHOWERS TO DEVELOP ACROSS THE SOUTH ON SATURDAY  
NIGHT.  
 
AS FAR AS TEMPERATURES ARE CONCERNED WE WILL BE LOOKING AT A  
WARMING TREND AS WE PUSH THROUGH THE WORK WEEK WITH HIGHS PEAKING  
AT THE UPPER 70S TO THE LOWER 80S ON TUESDAY. LOWS WILL RISE TO  
THE 60S BY TUESDAY NIGHT. IN THE WAKE OF THE COLD FRONT HIGHS WILL  
BE IN THE 60S FOR THURSDAY THROUGH SATURDAY. LOWS WILL DIP INTO  
THE 40S FOR WEDNESDAY NIGHT THEN 30S AND 40S FOR THURSDAY NIGHT  
AND FRIDAY NIGHT. LOWS WILL RECOVER INTO THE 40S AND 50S FOR  
SATURDAY NIGHT.  
 
LOOKING INTO SUNDAY INTO EARLY NEXT WEEK IT LOOKS LIKE OUR RAIN  
CHANCES WILL SPREAD ACROSS THE REGION ON SUNDAY INTO MONDAY. THIS  
WILL BE ASSOCIATED WITH AN STRONG UPPER TROUGH TO THE NORTH WHICH  
WILL DRAG A COLD FRONT THROUGH FOR EARLY NEXT WEEK./17/  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
JACKSON 52 72 63 81 / 43 78 23 20  
MERIDIAN 47 70 61 79 / 13 73 23 20  
VICKSBURG 54 74 64 82 / 53 79 25 23  
HATTIESBURG 49 75 63 81 / 10 66 16 12  
NATCHEZ 57 77 66 82 / 47 74 18 20  
GREENVILLE 50 68 62 78 / 88 70 45 34  
GREENWOOD 49 67 61 80 / 75 83 44 33  
 

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

 
 

 
 
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