National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KLSX 151930
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
230 PM CDT WED MAY 15 2013

.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 222 PM CDT WED MAY 15 2013

FORECAST REASONING REALLY HAS NOT CHANGED WITH RESPECT TO
THUNDERSTORM CHANCES LATE THIS AFTERNOON AND TONIGHT. TWO AREAS WE
ARE MONITORING...

THE FIRST IS ASSOCIATED WITH A LOBE OF ENERGY ROTATING AROUND THE
UPPER LOW TO OUR SOUTHWEST. SOME CUMULUS STARTING TO DEVELOP FROM
NEAR THE LAKE OF THE OZARKS TO FARMINGTON. LATEST RUNS OF HRRR
CONTINUE TO INITIATE CONVECTION IN THIS AREA AND THEN LIFT IT
NORTHEAST TOWARD THE METRO DURING THE EVENING HOURS. CAN`T RULE
OUT THIS SOLUTION...BUT MODELS CONTINUE TO OVER FORECAST THE LOW
LEVEL MOISTURE WHICH LEADS TO HIGHER THAN OBSERVED INSTABILITY.

THE SECOND AREA IS ALONG THE FRONT WHICH CURRENTLY STRETCHES FROM
JUST NORTH OF ST. JOSEPH MISSOURI TO NEAR KIRKSVILLE AND THEN EAST
ACROSS NORTHERN KNOX AND LEWIS COUNTIES IN MISSOURI AND ADAMS
COUNTY IN ILLINOIS.

HAVE CONFINED CHANCE/LIKELY POPS TO THE SECOND AREA WHERE
FORCING/FOCUS WILL BE GREATER FOR INITIATION. ELSEWHERE...SLIGHT
CHANCE POPS/ISOLATED COVERAGE IS EXPECTED IF INITIATION OCCURS.

SHOULD BE ANOTHER WARM NIGHT AS DEWPOINTS HAVE INCREASED INTO THE
60S AREAWIDE.

CVKING

.LONG TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 322 AM CDT WED MAY 15 2013

THE HIGHEST PROBABILITY FOR SHOWERS AND STORMS SHOULD OCCUR ACROSS
NERN MO AND W CNTRL IL TGT ALONG AN E-W FRONT. MORE SCATTERED
ACTIVITY IS EXPECTED FURTHER S ACROSS PORTIONS OF SERN MO AHEAD OF
A SLOW MOVING UPPER LEVEL TROUGH/LOW. THIS FRONT SHOULD WEAKEN AND
BECOME MORE NW TO SE ORIENTED THU AS A SFC RIDGE MOVES EWD
THROUGH THE GREAT LAKES REGION WITH THE WRN PORTION OF THE FRONT
LIFTING NWD. THE UPPER LEVEL LOW/TROUGH WILL MOVE EWD THROUGH SRN
MO AND NRN AR. THERE SHOULD BE AT LEAST SCATTERED STORMS OVER MUCH
OF THE FORECAST AREA ON THU. HIGH TEMPERATURES ON THU WILL BE COOLER
...ALBEIT STILL ABOVE SEASONAL NORMALS. MAY GET A BREAK IN THE
CONVECTION THU NGT AS THE FRONT MOVES N-NE OF OUR FORECAST AREA
AND THE UPPER LEVEL TROUGH/LOW SHIFTS SE OF THE REGION. A MID LEVEL
VORT MAX MOVING E-SEWD THROUGH NRN MO MAY LEAD TO SCATTERED
CONVECTION ON FRI...ALTHOUGH IT APPEARS THAT THE GFS MODEL IS TOO
STRONG WITH THIS FEATURE AND OVERDONE WITH ITS QPF. THE UPPER
LEVEL RIDGE WILL BUILD BACK OVER THE CNTRL US FRI NGT INTO THE
WEEKEND. THIS ALONG WITH CONTINUED SLY SFC/LOW LEVEL FLOW WILL
LEAD TO WARMER HIGH TEMPERATURES WELL INTO THE 80S FOR THE
WEEKEND. THE GFS MODEL STILL APPEARS OVERDONE WITH ITS QPF...
ALTHOUGH THERE MAY BE ISOLATED TO WIDELY SCATTERED SHOWERS AND
STORMS MAINLY DURING THE AFTN INTO THE EARLY EVNG ON SAT. THE
POPS SHOULD BEGIN TO RAMP UP BEGINNING SUN AFTN...MAINLY ACROSS
NERN AND CNTRL MO AS SW FLOW SHORTWAVES AHEAD OF AN APPROACHING
UPPER LEVEL TROUGH MOVE NEWD THROUGH THIS REGION. THE MODELS
CONTINUE TO SLOW THE PROGRESSION OF THE UPPER LEVEL TROUGH/LOW
MOVING EWD THROUGH THE NRN PLAINS AND ITS ASSOCIATED COLD FRONT.
WE SHOULD SEE MORE WIDESPREAD AND ORGANIZED CONVECTION MON AND
MON NGT AHEAD OF THIS UPPER LEVEL TROUGH AND ASSOCIATED COLD
FRONT. THE COLD FRONT SHOULD FINALLY MOVE SEWD THROUGH OUR
FORECAST AREA TUE AND TUE EVNG WITH TEMPERATURES DROPPING BACK
DOWN TO SEASONAL NORMALS FOR TUE AND TUE NGT.

GKS

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1112 AM CDT WED MAY 15 2013

VFR CONDTIONS EXPECTED OUTSIDE OF CONVECTION. COLD FRONT CONTINUES
TO SLOWLY SINK SOUTH THIS MORNING AND WILL BECOME NEARLY
STATIONARY BY THIS AFTERNOON ACROSS FAR NORTHERN MISSOURI AND WEST
CENTRAL ILLINOIS. THIS IS THE MOST LIKELY AREAD FOR THUNDERSTORMS
TO DEVELOP LATE THIS AFTERNOON AND THIS EVENING. THIS WOULD HAVE
THE HIGHEST IMPACT ON KUIN TERMINAL. OTHERWISE AND
ELSEWHERE...ISOLATED CONVECTION COULD DEVELOP THIS AFTERNOON AND
EARLY THIS EVENING DUE TO DIURNAL HEATING. SOUTHWEST WIND TO
CONTINUE...WITH BRIEF WIND SHIFT AT KUIN POSSIBLE IF FRONT SINKS
THAT FAR SOUTH.

SPECIFICS FOR KSTL...
VFR CONDITIONS TO CONTINUE. CHANCES OF THUNDERSTORMS AFFECTING
TERMINAL TOO SMALL TO INCLUDE ANYTHING MORE THAN A VCTS IN
FORECAST AT THIS TIME. WEST/SOUTHWEST WIND TO CONTINUE THROUGH
FORECAST.

CVKING

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX