411
FXUS63 KTOP 222310
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
610 PM CDT WED MAY 22 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 354 PM CDT WED MAY 22 2013

THE UPPER LOW ASSOCIATED WITH THIS WEEKEND`S ACTIVE SEVERE WEATHER
WAS SITUATED OVER IOWA THIS AFTERNOON...WITH THE ASSOCIATED SURFACE
LOW PROGRESSING EASTWARD INTO WISCONSIN AND ILLINOIS. CLOUD COVER IN
ASSOCIATION WITH THIS SYSTEM STRETCHED WESTWARD INTO NORTHEAST AND
FAR EASTERN KANSAS THROUGH THE AFTERNOON HOURS...WHICH RESULTED IN
SOMEWHAT COOLER TEMPERATURES ACROSS THE REGION TODAY. WITH THE CLOUD
COVER...AFTERNOON HIGHS PEAKED IN THE MIDDLE TO UPPER 60S. SURFACE
HIGH PRESSURE OVER THE NORTHERN PLAINS WILL HELP TO PUSH THE LOW
PRESSURE SYSTEM EASTWARD TOWARD THE GREAT LAKES REGION AS THE HIGH
SPREADS SOUTHWARD INTO THE CENTRAL PLAINS TONIGHT INTO THURSDAY.
WITH THE EXITING SURFACE LOW...SHOULD START SEEING SOME BREAKS IN THE
CLOUD COVER TONIGHT INTO THE OVERNIGHT HOURS. THIS DIMINISHING CLOUD
COVER WILL ALLOW FOR MORE RADIATIONAL COOLING EARLY THURSDAY MORNING
WITH LOW TEMPERATURES EXPECTED TO BE A FEW DEGREES COOLER THAN
NORMAL...IN THE UPPER 40S TO LOWER 50S.

THE WEAK UPPER LEVEL RIDGE THAT WAS IN PLACE OVER THE CENTRAL
ROCKIES THIS AFTERNOON WILL CONTINUE TO BUILD AS IT PROGRESSES
EASTWARD INTO THE CENTRAL AND SOUTHERN PLAINS BY THURSDAY. MODELS
CONTINUE TO SHOW AN EMBEDDED SHORTWAVE DEVELOPING ALONG THE NORTHERN
EXTENT OF THE RIDGE OVER WESTERN KANSAS AND WESTERN OKLAHOMA...WHICH
MAY BRING SOME SCATTERED SHOWERS AND THUNDERSTORMS TO THAT REGION
THROUGH THE DAY. WHILE THIS ACTIVITY IS EXPECTED TO REMAIN SOUTHWEST
OF THE FORECAST AREA ON THURSDAY...SHOULD STILL HAVE SCATTERED CLOUD
COVER ACROSS MUCH OF THE AREA THROUGH THE DAY. THIS CLOUD COVER
COMBINED WITH NORTHEASTERLY WINDS AROUND THE SURFACE HIGH WILL KEEP
AFTERNOON HIGHS COOLER THAN NORMAL WITH READINGS LIKING PEAKING IN
THE UPPER 60S TO LOWER 70S.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 354 PM CDT WED MAY 22 2013

OVERALL PATTERN WILL FEATURE A FLAT RIDGE WITH INCREASING WAA AND
MOISTURE ADVECTION WHICH WILL SERVE TO PRODUCE SEVERAL BOUTS OF
THUNDERSTORM CHCS.  THE INITIAL FORCING IS WEAK THU NIGHT INTO FRI
AND SHOULD STAY FOCUSED ACROSS THE NORTHWEST PARTS OF THE CWA. WILL
KEEP RAIN CHCS LOW AND CONFINED TO AREAS TOPEKA NORTH AND WEST FOR
FRI BUT AGAIN WITHOUT A FOCUS AND GREATER FORCING NOT SURE HOW
WIDESPREAD ANY PRECIP WILL BE FRI.

BY FRI NIGHT INTO SAT THETA-E (MOISTURE AND TEMP ADVECTION) WILL
INCREASE ACROSS KS INTO NEBRASKA. NOSE OF THE 50KT LLJ WILL TARGET
NORTHEAST NEB SO IT WOULD APPEAR THAT THE MAIN COMPLEX OF ANY MCS
WOULD BE LOCATED NORTH OF THE AREA HOWEVER CANNOT RULE OUT SCT
CONVECTION WITHIN THE LLJ AXIS OVERNIGHT INTO EARLY SAT. ANOTHER
WEAK WAVE WILL MOVE ACROSS THE RIDGE SAT NIGHT INTO SUN AND THIS
SHOULD HELP ANOTHER CONVECTIVE COMPLEX DEVELOP ACROSS NE/NORTHERN KS
SO WILL KEEP 20 TO 40 POPS WITH THE HIGHEST ACROSS THE NORTHERN
COUNTIES.

SAME PATTERN WILL PERSIST INTO SUN NIGHT AND MON SO HAVE TO EXPECT
AT LEAST SOME CHCS FOR MAINLY NIGHTTIME THUNDERSTORMS ACROSS THE
AREA SUN NIGHT AND MON AS WEAK WAVES MOVE INTO THE FLATTENING RIDGE
AND COMBINE WITH THE NIGHTTIME LLJ TO FEED OVERNIGHT STORMS.

MON AND BEYOND...IT APPEARS THAT RIDGING SHOULD STRENGTHEN BY TUES
AHEAD OF A DEEPENING TROUGH ACROSS THE WEST. THIS SHOULD LEAD TO
GRADUALLY WARMER TEMPS AND PERHAPS A LULL IN PRECIP CHCS BY MID
WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 610 PM CDT WED MAY 22 2013

THINK THAT THE TERMINALS MAY SCATTER OUT THIS EVENING. HOWEVER THE
NAM AND RAP CONTINUE TO SHOW SOME MVFR CIGS AROUND 2500 FT MOVING
BACK IN FROM THE NORTH BY 12Z. THE CIGS ARE EXPECTED TO GRADUALLY
IMPROVE ABOVE 3 KFT BY NOON THURSDAY WITH A STRATOCU DECK HANGING
IN FOR A PORTION OF THE AFTERNOON. NO PRECIP IS ANTICIPATED DUE TO
A LACK OF FORCING AND SFC WINDS WILL GRADUALLY VEER THROUGH THE
DAY THURSDAY AS SFC RIDGING NOSES IN.

&&

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

$$

SHORT TERM...HENNECKE
LONG TERM...OMITT
AVIATION...WOLTERS