123 
FXUS63 KTOP 150839
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
339 AM CDT FRI MAR 15 2013

.DISCUSSION...

0Z DATA ANALYSIS SHOWED MODERATE UPPER LEVEL HEIGHT RISES AGAIN
OVER THE NORTHERN PLAINS WITH FAIRLY UNIFORM WEST-NORTHWEST FLOW
OVER THE NORTHERN AND CENTRAL STATES. 850MB TEMPS HAD REACHED
AROUND 10C AT NEARBY LOCATIONS...WITH HIGH PLAINS STATIONS AGAIN
SEVERAL DEGREES WARMER. 07Z OBJECTIVE SURFACE ANALYSIS SHOWED
BROAD LOW PRESSURE FROM SOUTHERN MONTANA TO SOUTHERN SOUTH DAKOTA.

THE WEAK LOW PRESSURE WILL WORK ITS WAY SOUTHEAST INTO LOCAL AREA 
TODAY WITH DEEP WESTERLY FLOW RESULTING. THE UPSTREAM 850MB TEMPS 
WILL BE USHERED EAST WITH 850-925MB LEVELS SOME 4-6C WARMER THAN 
THURSDAY. CLOUD COVER DOES LOOK A BIT MORE PREVALENT BUT BETTER 
MIXING IS LIKELY. HAVE GONE A BIT ABOVE MOS TEMPS FOR THE BULK OF 
THE AREA WHICH PUTS TOPEKA IN THE RECORD VICINITY. MODEL DEWPOINTS 
AGAIN APPEAR ON THE HIGH SIDE...AND WITH THE DEEP MIXING THE SETUP 
FOR THEM FALLING RATHER QUICKLY IS IN PLACE...INCREASING THE FIRE 
WEATHER CONCERN. RED FLAG LEVELS FOR BOTH WINDS AND HUMIDITIES LOOK 
TO BE JUST SHORT OF CRITERIA VALUES...BUT WILL NEED TO BE WATCHED. 

COLD AIR THEN SURGES SOUTH THROUGH KANSAS TONIGHT AS HIGH PRESSURE 
BUILDS SOUTHEAST OUT OF CENTRAL CANADA WITH THE ANOMALOUSLY WARM 
TEMPS ENDING. ISENTROPIC LIFT INCREASES THROUGHOUT SATURDAY IN THE 
MID AND UPPER LEVELS BUT SATURATION INTO THE LOWER LEVELS HOLDS OFF 
UNTIL SATURDAY NIGHT WITH THE APPROACH OF A SHORTWAVE. THE MODELS DO 
BECOME RATHER DIFFERENT IN THE HANDLING OF THE SHORTWAVES MOVING 
THROUGH THE FLOW BY THIS TIME...WITH THE NAM THE FARTHEST 
ASTRAY...THOUGH MINOR DIFFERENCES IN THE GLOBAL SOLUTIONS LEADING TO 
SIGNIFICANT DIFFERENCES WHERE PRECIPITATION WILL BE FAVORED. WITH 
MUCH OF THE STRONGER FORCING BEING USED TO SATURATE THE COLUMN 
SUFFICIENTLY...HEAVY AMOUNTS ARE VERY UNLIKELY...BUT SOME CONCERN 
FOR WINTRY PRECIP REMAINS FOR MAINLY NORTHERN AREAS WITH CONTINUED 
NORTH TO EAST LOW LEVEL FLOW AND SATURATION GETTING NEARLY DEEP 
ENOUGH FOR ICE TO BE INTRODUCED INTO THE CLOUD. THIS WAVE PASSES 
DURING THE DAY SUNDAY WITH A BRIEF BREAK LIKELY LATE SUNDAY UNTIL 
THE NEXT WAVE PASSES TO THE NORTH SUNDAY NIGHT AND MONDAY...WITH 
AGAIN MINOR AMOUNTS AND SOME MIXED PRECIP POSSIBLE IN THE NORTH. 
 
THE BULK OF THE REMAINDER OF THE FORECAST STILL LOOKS TO BE DRY WITH 
LOW LEVEL HIGH PRESSURE NOT FAR TO THE NORTHEAST BEHIND THE THE LATE 
WEEKEND WAVE CUTTING OFF OVER THE EASTERN GREAT LAKES. TEMPERATURES 
MAY MODIFY A BIT BUT SHOULD BE NEAR MID MARCH NORMALS. 

65

&&

.AVIATION...

EXPECT VFR CONDITIONS FOR THE NEXT 24 HOURS. A WEAK WIND SHIFT WILL
MOVE SOUTHWARD THROUGH THE TAFS SITES AFTER 00Z SAT.

GARGAN

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$