676  
FXUS64 KMEG 222337  
AFDMEG  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEMPHIS TN  
537 PM CST WED JAN 22 2020  
   
UPDATE
 
 
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.  
 

 
   
PREV DISCUSSION
 
/ISSUED 306 PM CST WED JAN 22 2020/  
 
DISCUSSION...  
LIGHT TO MODERATE RAIN CONTINUES ACROSS MUCH OF AR THIS AFTERNOON  
DOWNSTREAM OF A SHORTWAVE TROUGH CURRENTLY TRAVERSING THE SOUTHERN  
PLAINS. A WELL-DEFINED WARM CONVEYOR BELT IS CROSSING THE  
ARKLATEX AND WILL PUSH PRECIPITABLE WATER VALUES UP TOWARD 1.0" BY  
TOMORROW MORNING DESPITE TEMPERATURES IN THE 30S AND 40S. A  
DEEPENING SURFACE LOW OVER WESTERN NORTH TX WILL MOVE EAST ALONG  
THE I-20 CORRIDOR THROUGH TOMORROW BUT IS EXPECTED TO REMAIN WELL  
TO OUR SOUTH, KEEPING THE WARM SECTOR CUT-OFF AT THE SURFACE. AS  
THE LEAD SHORTWAVE TROUGH APPROACHES THE LOWER MS VALLEY TONIGHT,  
A TRAILING WAVE OVER THE NORTHERN ROCKIES WILL CLOSE OFF OVER THE  
CENTRAL PLAINS. THIS LOW WILL MOVE EAST INTO THE LOWER OH VALLEY  
TOMORROW NIGHT, EVENTUALLY MOVING INTO THE NORTHEAST THIS WEEKEND.  
 
AT THE SURFACE, TEMPERATURES ARE CURRENTLY IN THE 30S AND 40S.  
WARM ADVECTION HAS COMMENCED ACROSS THE CWA WITH SOUTHERLY WINDS  
OF 6-12 MPH. THIS SOUTHERLY FLOW, COMBINED WITH OVERCAST SKIES,  
WILL GENERALLY KEEP TEMPERATURES ABOVE FREEZING OVERNIGHT, BUT  
THERE IS A POTENTIAL FOR FURTHER COOLING VIA DIABATIC PROCESSES  
(WET-BULB EFFECTS) WITH DEWPOINTS STILL IN THE UPPER TEENS AND  
LOWER 20S. WITH RAIN MOVING INTO THE AREA THIS EVENING, A LIGHT  
WINTRY MIX IS POSSIBLE DURING THE OVERNIGHT PERIOD, BUT ANY  
POTENTIAL IMPACTS WILL BE LIMITED WITH TEMPERATURES GENERALLY  
ABOVE FREEZING. WE CONTINUE TO MONITOR THE PROBABILISTIC GUIDANCE,  
WHICH SUGGESTS ONLY A 10% CHANCE OF ANY ICE ACCUMULATIONS WITHIN  
THE CWA AND THAT REALLY ONLY AFFECTS PORTIONS OF CLAY AND POSSIBLY  
GREENE OR DUNKLIN COUNTIES. OTHERWISE, WE'RE LOOKING FOR A COLD  
RAIN TONIGHT MIXED WITH A FEW SNOWFLAKES OR SLEET PELLETS AT  
TIMES.  
 
RAIN WILL CONTINUE ACROSS THE MID-SOUTH TOMORROW, WITH MOST OF  
THE PRECIPITATION SHIFTING EAST TOMORROW NIGHT. TOTAL RAINFALL  
AMOUNTS FROM THIS SYSTEM WILL AVERAGE BETWEEN 1/2 AND 1 INCH  
ACROSS THE CWA WITH A FEW HIGHER AMOUNTS POSSIBLE. RAIN CHANCES  
COME TO AN END FRIDAY NIGHT AS THE DRY SLOT WRAPS AROUND THE LOW  
AND A WEAK PACIFIC COLD FRONT MOVES THROUGH THE REGION. WEST WINDS  
WILL INCREASE IN THE WAKE OF THIS FRONT BUT TEMPERATURES AREN'T  
EXPECTED TO TAKE MUCH OF A HIT.  
 
NORTHWEST FLOW ALOFT BEHIND THE DEPARTING TROUGH WILL GRADUALLY  
TRANSITION TO A QUASI-ZONAL PATTERN THIS WEEKEND. WE DO EXPECT DRY  
WEATHER ON SATURDAY WITH SLIGHTLY BELOW NORMAL TEMPERATURES.  
HOWEVER, A PROGRESSIVE OPEN WAVE IS FORECAST TO SWING ACROSS THE  
REGION SUNDAY. THERE IS ENOUGH OF A SIGNAL IN THE 12Z GLOBAL  
ENSEMBLES TO WARRANT THE ADDITION OF A SLIGHT CHANCE OF RAIN FOR  
SUNDAY, ALBEIT IT LIGHT RAIN.  
 
WE ENTER ANOTHER DRY PERIOD ON MONDAY AS A TRANSIENT SHORTWAVE  
RIDGE CROSSES THE MS VALLEY, BUT IT WILL BE SHORTWAVE LIVED AS THE  
NEXT SYNOPTIC TROUGH MOVES INTO THE AREA BY MIDWEEK. THERE ARE  
STILL SOME TIMING DIFFERENCES BETWEEN THE VARIOUS MODEL SOLUTIONS,  
BUT POPS WERE INTRODUCED WEST OF THE MS RIVER ON TUESDAY AND  
SPREAD ACROSS THE CWA FOR THE REMINDER OF THE FORECAST PERIOD.  
 
MJ  
 

 
   
AVIATION
 
 
/00Z TAFS/  
 
VFR CONDS TO BEGIN THE PERIOD. AN ARCTIC AIRMASS WILL SLOWLY  
SATURATE OVER THE NEXT SEVERAL HOURS AS AN AREA OF RAIN MOVES  
INTO MEM AND JBR. INITIAL ONSET OF PRECIPITATION MAY BE SLEET  
MIXED WITH RAIN AT BOTH MEM AND JBR. THERE IS SOME UNCERTAINTY AND  
CONCERN THAT RAIN MIXED WITH SLEET WILL PREVAIL AT JBR AND MEM  
FOR AN HOUR OR MORE, BUT THERE IS NOT ENOUGH CONFIDENCE TO INCLUDE  
IN MEM TAF AT THIS TIME. CIGS WILL LOWER AROUND SUNRISE AS SHRA  
OVERSPREAD THE AREA. EXPECT MVFR LOWERING TO IFR BY SUNRISE AND  
POSSIBLY LIFR BY 23/18Z. IFR CONDS WILL CARRY INTO THE NEXT TAF  
PERIOD AS WELL.  
 
AC3  
 

 
   
MEG WATCHES/WARNINGS/ADVISORIES
 
 
AR...NONE.  
MO...NONE.  
MS...NONE.  
TN...NONE.  

 
 

 
 
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