Area Forecast Discussion
Issued by NWS Topeka, KS

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000
FXUS63 KTOP 051730
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1230 PM CDT SUN JUL 5 2015

...UPDATE FOR CONVECTIVE TRENDS THROUGH THIS AFTERNOON...

.UPDATE...
ISSUED AT 1221 PM CDT SUN JUL 5 2015

WHILE EARLY CONVECTION WAS ELEVATED WITH ACCESS TO ONLY WEAK
INSTABILITY...BY LATE MORNING IT APPEARS THAT STORMS HAVE MADE AN
EFFORT TO BECOME SURFACE BASED...WITH APPROXIMATELY 2000-3000 J/KG
OF CAPE AVAILABLE AND 25 KTS OF EFFECTIVE SHEAR. THIS HAS RESULTED
IN FAIRLY ISOLATED DEVELOPMENT OF STORMS WITH MAINLY MULTI-CELL
STRUCTURES AND AN ATTENDANT HAIL/DOWNBURST THREAT. HAVE RECEIVED
REPORTS OF 40-50 MPH WINDS NEAR EMPORIA AND TOPEKA WITH THE
STRONGER STORMS AS WELL AS VERY SMALL HAIL. EXPECT OUTFLOW FROM
THE INITIAL STORMS TO WORK WITH A WEAK AREA OF FORCING TO CONTINUE
TO PRODUCE ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT THROUGH
THIS AFTERNOON. AS TEMPERATURES CLIMB COULD END UP SEEING AN
INCREASING POTENTIAL FOR ISOLATED STRONG TO SEVERE DOWNBURST WINDS
WITH STEEP LOW LEVEL LAPSE RATES AND INCREASING INSTABILITY. WHILE
THE MAIN FOCUS FOR THESE STORMS SHOULD BE OVER THE EASTERN HALF OF
THE FORECAST AREA...HAVE BECOME QUITE UNSTABLE FARTHER WEST AS
WELL AND ANY WEAK FORCING OR BOUNDARY MAY BE ABLE TO INITIATE
ADDITIONAL THUNDERSTORMS. CURRENTLY BELIEVE ANY SEVERE THREAT WILL
REMAIN RELATIVELY ISOLATED UNDER THE STRONGEST UPDRAFT CORES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 245 AM CDT SUN JUL 5 2015

THUNDERSTORMS CONTINUED OVER WESTERN KANSAS THIS MORNING AT 08Z
WITHIN THE LOW LEVEL JET AND MOISTURE AXIS. THE STORMS HAVE SHOWN
LITTLE MOVEMENT THROUGH THE NIGHT TO THE EAST AND GENERALLY WERE
NEARLY STATIONARY OR MOVING SLOWLY TO THE SOUTH. THE LOW LEVEL JET
HAS BEEN VEERING TO THE SOUTHWEST OVER THE LAST FEW HOURS. HIGH
RESOLUTION SHORT RANGE MODELS KEEP THE PRECIPITATION TO THE WEST AND
SOUTHWEST OF THE FORECAST AREA THIS MORNING TRACKING IT TO THE SOUTH
OR SOUTHEAST. HAVE MAINTAINED A SMALL CHANCE OF PRECIPITATION IN
NORTH CENTRAL KANSAS EARLY THIS MORNING THEN MAINLY ACROSS AREAS
SOUTH OF INTERSTATE 70 LATER THIS MORNING IN AREA OF ISENTROPIC
LIFT. MAY SEE SOME REDEVELOPMENT LATER THIS AFTERNOON ACROSS
NORTHEAST AND EAST CENTRAL KANSAS, BUT LACK OF FORCING IS A CONCERN
TO INITIATE CONVECTION. IF CONVECTION DOES DEVELOP LATER THIS
MORNING THERE COULD BE SOME LEFT OVER BOUNDARY TO FOCUS ON, SO WILL
LEAVE A SLIGHT CHANCE OF PRECIPITATION GOING. TEMPERATURES TODAY
SHOULD WARM INTO THE LOW TO MID 90S FOR MUCH OF THE AREA, WITH A FEW
LOCALS NEAR CENTRAL KANSAS REACHING THE UPPER 90S.

TONIGHT LOOKS TO BE DRY AND MILD FOR MUCH OF THE NIGHT. A COLD FRONT
WILL MOVE SOUTH ACROSS THE NORTHERN AND CENTRAL PLAINS OVERNIGHT AS
AN UPPER LEVEL WAVE MOVES ACROSS THE NORTHERN PLAINS. MODELS ARE
CONSISTENT WITH CONVECTION DEVELOPING ALONG THE FRONT. WILL INCLUDE
SLIGHT CHANCE POPS FOR AREAS NORTHWEST OF A MINNEAPOLIS TO
WASHINGTON LINE AFTER 09Z. LOWS TONIGHT WILL BE MILD IN THE LOWER TO
MIDDLE 70S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN JUL 5 2015

NEXT FRONT MAKING ITS WAY INTO THE FORECAST ARE BY MONDAY
MORNING...AS AN UPPER WAVE MAKES ITS WAY ACROSS THE NORTHERN
PLAINS. SOUTH TO SOUTHWEST WINDS AHEAD OF THE FRONT BRING MOISTURE
UP INTO THE CENTRAL PLAINS AND BOOST PW VALUES NEAR 2
INCHES...WHICH IS ABOVE THE 75TH PERCENTILE FOR THIS TIME OF YEAR.
ENOUGH INSTABILITY AVAILABLE FOR SOME STORMS TO BE STRONG AND
POSSIBLY SEVERE...AIDED BY MID DAY TIMING OF FRONTAL
PASSAGE.  WITH BULK SHEAR ONLY ABOUT 20KTS AM THINKING HAIL MORE
LIKELY THREAT FOLLOWED BY WIND. WOULD ANTICIPATE EFFICIENT
RAINFALL RATES FROM THESE STORMS AND COULD PRODUCE LOCALIZED
FLOODING...WITH AREAS SOUTH OF I70 SEEING RAIN FOR THE LONGER
PERIOD OF TIME.

POTENTIAL FOR MORE WIDESPREAD FLOODING WILL DEPEND ON HOW FAST
THE FRONT PROPAGATES TO THE SOUTH...AND WITH LACK OF A STRONG
UPPER PUSH WILL LIKELY NEED TO RELY ON STORM SCALE FEATURES TO
DRIVE THE PROCESS. THE ECMWF CLEARS THE CWA BY 0Z WED...BUT LIFTS
ANOTHER WAVE ACROSS THE SOUTHEAST THROUGH THE REMAINDER OF THE DAY
ON WEDNESDAY FOR ANOTHER CHANCE AT HEAVY RAINFALL. GFS BRINGS A
WAVE ACROSS THE FRONT FOR THE DAYTIME ON TUESDAY...WHILE THE NAM
DEVELOPS A MORE AMPLIFIED AND SLOWER MOVING WAVE ACROSS OKLAHOMA
EARLY TUESDAY AND KEEPS PRECIPITATION OVER THE AREA THROUGH AT
LEAST EARLY WEDNESDAY. AT THIS TIME...HAVE MOST CONFIDENCE IN RAIN
FOR MONDAY AND MONDAY NIGHT...WITH POSSIBLY ANOTHER ROUND IN THE
SOUTHEAST ON TUESDAY AND TUESDAY NIGHT. UNCERTAINTY GROWS FOR
WEDNESDAY AND THURSDAY...BUT WITH ENOUGH CONSENSUS TO AT LEAST
CARRY A LOW CHANCE POP THROUGH THE PERIOD. SENSIBLE WEATHER
ELEMENTS WILL ALSO BE DRIVEN BY RAIN CHANCES...WITH CURRENT
FORECAST CONTINUING TO BE COOLER THAN NORMAL.

FRI/SAT...SOME UNCERTAINTY CONTINUES INTO THESE LATTER
PERIODS...DEPENDING ON HOW MUCH THE WESTERN RIDGE IS IMPACTED BY
NEXT TROF MOVING ACROSS ITS NORTHERN PERIPHERY. CURRENT FORECAST
IS NEAR CLIMATOLOGY WITH HIGHS IN THE UPPER 80S NEAR 90.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 632 AM CDT SUN JUL 5 2015

ISOLATED TSRA EXPECTED THROUGH 18Z. CONFIDENCE IS NOT HIGH ENOUGH
TO PLACE IN TERMINALS. MVFR VSBYS AT TOP EXPECTED TO IMPROVE TO
VFR BY 14Z. SOUTH WINDS WILL INCREASE TO AROUND 12KTS BY 17Z WITH
GUSTS TO 23 KTS. THE WINDS WILL CONTINUE FROM THE SOUTH NEAR
10 KTS AFTER 00Z MON. VFR IS EXPECTED OUTSIDE OF CONVECTION.


&&

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

$$

UPDATE...BARJENBRUCH
SHORT TERM...53
LONG TERM...67
AVIATION...53


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