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000
FXUS63 KDMX 222341
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
641 PM CDT FRI AUG 22 2014

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

THROUGH EARLY EVENING...STORMS HAVE FIRED IN TWO AREAS ACROSS
CENTRAL IOWA.  THE NORTHERN MOST LINE OF STORMS IS ASSOCIATED WITH A
FRONTAL BOUNDARY THAT IS EVER SO SLOWLY MEANDERING SOUTH.  FLOW IS
WEAK AND THERE IS LITTLE CONVERGENCE AND NO SHEAR TO SPEAK OF SO THE
STORMS WILL BECOME OUTFLOW DOMINANT AND SHOULD FALL APART BY 00-01Z.
FURTHER SOUTH STORMS HAVE FIRED ALONG A MOISTURE AXIS.  THIS AXIS
WAS EVIDENT ON RADAR FOR MUCH OF THE DAY AND STORMS FIRED AFTER
SUFFICIENT HEATING DESTABILIZED THE ATMOSPHERE.  THESE STORMS WILL
BE A BIT MORE ROBUST AND PRODUCE LOCALLY HEAVY RAINFALL...SOME
STRONGER WIND GUSTS AND POSSIBLY SOME SMALL HAIL.  AGAIN...THESE
STORMS SHOULD MOVE EAST SOUTHEAST AND DIMINISH SHORTLY AFTER 00Z.

THE REST OF EARLY TO MID EVENING SHOULD BE RELATIVELY QUIET THOUGH
THINGS WILL FESTER THROUGH THE EVENING SO ISOLATED STORMS WILL STILL
BE POSSIBLE.

FOR THE REST OF TONIGHT...UPPER RIDGE OVER IOWA WILL GET PUSHED TO
THE EAST WITH THE AXIS BY 12Z SAT INTO WESTERN IL BY A DEEPENING
TROUGH OVER THE ROCKIES.  SEVERAL WEAKER SHORTWAVES WILL EJECT OUT
OF THE BASE OF THE TROUGH PUSHING ACROSS NORTHERN/WESTERN IOWA.  IN
ADDITION...THE FRONTAL BOUNDARY FROM A SURFACE LOW IN WESTERN KS
WILL LIFT NORTHWARD AS THE SURFACE LOW SHIFT TO THE NORTHEAST.  TO
THE WEST OF IOWA THERE IS PRETTY IMPRESSIVE SHEAR AND STRONG THETA-E
ADVECTION THAT WILL WORK INTO THE WEST AND NORTH AND GRADUALLY SHIFT
MORE NORTH AND EAST.  ONE AGAIN THE 4KM WRF HAD A DECENT HANDLE ON
ALL OF THE CONVECTION OF THIS AFTERNOON AND TONIGHT SO I DID PUT
SOME WEIGHT ON ITS SOLUTION FOR TONIGHT.  STORMS SHOULD FIRE OUT
WEST OF IOWA THIS AFTERNOON AND EVENING AND WILL PROBABLY MERGE INTO
A CLUSTER OF STORMS THAT WILL THEN SHIFT INTO THE SOUTHWEST THIRD OF
SO OF IOWA DURING THE OVERNIGHT.  THERE MAY BE ISOLATED STORMS
THROUGHOUT THE EVENING BUT THE MAIN PRECIP EVENT WILL OCCUR OVER THE
SOUTHWEST BETWEEN 08Z-12Z BEFORE LIFTING NORTH.  SOME STORMS WILL
PRODUCE HEAVY RAINFALL BUT THERE MAY ALSO BE A COUPLE SEVERE STORMS
AS WELL...MAINLY OVER THE FAR WESTERN PORTION OF THE CWA.  IT WILL
BE A MUGGY NIGHT WITH LOWS IN THE UPPER 60S OVER FAR NORTHERN IOWA
AND 70S ELSEWHERE.  DEWPOINTS WILL STAY IN THE UPPER 60S AND LOW TO
MID 70S SO FOG WILL ONCE AGAIN DEVELOP...ESPECIALLY ACROSS THE
NORTH.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

ACTIVE WX PATTERN EXPECTED AT LEAST THROUGH THE MIDDLE OF NEXT
WEEK...WITH HOT AND HUMID SUMMERTIME WEATHER GIVING WAY TO FALL-LIKE
WEATHER.

MID/UPPER-LEVEL WIND SPEED MAX PLUNGING SOUTHWARD ALONG THE PAC
COAST...ON THE WEST SIDE OF THE WESTERN U.S. TROF...WILL HELP
FACILIATE ITS INTENSIFICATION BEFORE IT LIFTS OUT. IN RESPONSE...THE
EASTERN U.S. RIDGE WILL AMPLIFY INTO THIS WEEKEND. A VORT MAX OVER
THE SW U.S. WILL CONTINUE LIFTING NORTHEASTWARD. BY THE BEGINNING OF
THE LONG TERM FCST PERIOD...LINGERING CONVECTION FROM OVERNIGHT WILL
CONTINUE LIFTING NORTHWARD AHEAD OF A NORTHWARD-ADVANCING FRONTAL
BOUNDARY. THE BOUNDARY IS EXPECTED TO BE IN THE VICINITY OF THE IA-
MN BORDER...LIKELY JUST NORTH OF IT...BY LATE AFTERNOON SATURDAY.
SOUTH OF THE BOUNDARY...TEMPERATURES WILL WARM MORE THAN WHAT WAS
SEEN TODAY. PREVIOUS FCST DISCUSSION ACKNOWLEDGED MIXING ISSUES OVER
THE PAST FEW DAYS AND ON SATURDAY...AND AGREE WITH THAT THINKING
HOWEVER EXPECT IT TO BE MORE THAN WAS SEEN TODAY AS EVIDENCED BY
STRONGER SURFACE WINDS THAN WAS SEEN TODAY. THUS HAVE NUDGED TEMPS
UP A DEGREE OR TWO FROM THE GOING FORECAST FOR SATURDAY AFTERNOON.

ADDITIONAL CONVECTION IS POSSIBLE SATURDAY NIGHT AS ANOTHER
MID/UPPER-LEVEL DISTURBANCE MOVES THROUGH THE CENTRAL/NORTHERN
PLAINS. BEST FORCING WILL REMAIN WEST AND NORTH OF THE CWA...AND
HAVE PAINTED POPS AS SUCH.

SUNDAY IS EXPECTED TO BE THE WARMEST DAY OF THE FCST PD WITH IA
SOLIDLY WITHIN THE WARM SECTOR. NAM HAS CONTINUED TREND FROM
PREVIOUS FCST OF BEING THE WARMEST WITH FCST HIGHS WELL INTO THE
90S. NAM IS SUGGESTING MORE MIXING ON SUNDAY THAN ON SATURDAY AS
EVIDENCED BY LOWER DEWPOINTS AND STRONGER SURFACE WINDS. FOR NOW
HAVE NOT CHANGED SUNDAY/S MAX TEMPS MUCH FROM PREVIOUS FCST. HEAT
INDEX VALUES WILL BE AS HIGH AS AROUND 100F.

HIGHER CHANCES OF SHRA/TSRA OCCUR SUNDAY NIGHT AS UPPER-LEVEL TROF
TO OUR WEST EJECTS NORTHEASTWARD AND PUSHES A BOUNDARY INTO IA.
MODELS SUGGEST THE BOUNDARY WILL HANG UP IN THE STATE...LIKELY
MAKING IT AS FAR SOUTHEAST AS CENTRAL IA. INSTABILITY AND FORCING
WILL BE PLENTIFUL ENOUGH TO RESULT IN AT LEAST SCATTERED SHRA/TSRA
DURING THE NIGHT. AS THE UPPER LEVEL TROF EJECTS...ADDITIONAL
UPSTREAM ENERGY WILL HELP ANOTHER TROF TO DEVELOP IN ITS PLACE OVER
THE NORTHERN U.S. ROCKIES.

WITH BOUNDARY REMAINING IN THE REGION...HAVE KEPT SLIGHT CHANCE POPS
GOING INTO MONDAY. AFTER THIS POINT...THE MODEL SOLUTIONS DIVERGE
LEADING TO INCREASING FORECAST UNCERTAINTY. GFS BRINGS THE SECOND
TROF THROUGH FASTER THAN THE EURO. EXPECT THE BOUNDARY TO MOVE
THROUGH THE CWA BY WEDNESDAY. HAVE INCREASED POPS BEGINNING TUESDAY
AND KEPT THEM IN PLACE THROUGH LATE IN THE DAY ON WEDNESDAY.

AFTER THE FRONTAL PASSAGE...A FEW DAYS OF FALL-LIKE WEATHER WILL
PREVAIL WITH HIGH TEMPS ACROSS THE NORTHERN CWA POSSIBLY NOT LEAVING
THE LOWER 70S ON WEDNESDAY.

&&

.AVIATION...23/00Z
ISSUED AT 635 PM CDT FRI AUG 22 2014

BOUNDARY LAID UP B/T HWY 30 AND HWY 20 WILL CONTINUE TO BE THE
FOCUS FOR CONVECTION THROUGH THE EVENING HOURS. WILL LITTLE
FORWARD MOVEMENT AND LOW CONFIDENCE WITH TIMING STORMS TO AFFECT
ANY OF THE TAF SITES...ONLY HAVE VCTS MENTIONED AT FOD/OTM/DSM FOR
LATER TONIGHT AS BOUNDARY EXPECTED TO SURGE BACK NORTH. HOWEVER IF
NO CONVECTION OCCURS...FOG IS LIKELY TO DEVELOP OVER MUCH OF THE
AREA. SO WAS CONFIDENT ENOUGH TO MENTION MVFR TO IFR VIS AT
MCW/ALO AND MVFR ELSEWHERE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...ZOGG
AVIATION...PODRAZIK




000
FXUS63 KDMX 222341
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
641 PM CDT FRI AUG 22 2014

...UPDATED AVIATION DISCUSSION...

.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

THROUGH EARLY EVENING...STORMS HAVE FIRED IN TWO AREAS ACROSS
CENTRAL IOWA.  THE NORTHERN MOST LINE OF STORMS IS ASSOCIATED WITH A
FRONTAL BOUNDARY THAT IS EVER SO SLOWLY MEANDERING SOUTH.  FLOW IS
WEAK AND THERE IS LITTLE CONVERGENCE AND NO SHEAR TO SPEAK OF SO THE
STORMS WILL BECOME OUTFLOW DOMINANT AND SHOULD FALL APART BY 00-01Z.
FURTHER SOUTH STORMS HAVE FIRED ALONG A MOISTURE AXIS.  THIS AXIS
WAS EVIDENT ON RADAR FOR MUCH OF THE DAY AND STORMS FIRED AFTER
SUFFICIENT HEATING DESTABILIZED THE ATMOSPHERE.  THESE STORMS WILL
BE A BIT MORE ROBUST AND PRODUCE LOCALLY HEAVY RAINFALL...SOME
STRONGER WIND GUSTS AND POSSIBLY SOME SMALL HAIL.  AGAIN...THESE
STORMS SHOULD MOVE EAST SOUTHEAST AND DIMINISH SHORTLY AFTER 00Z.

THE REST OF EARLY TO MID EVENING SHOULD BE RELATIVELY QUIET THOUGH
THINGS WILL FESTER THROUGH THE EVENING SO ISOLATED STORMS WILL STILL
BE POSSIBLE.

FOR THE REST OF TONIGHT...UPPER RIDGE OVER IOWA WILL GET PUSHED TO
THE EAST WITH THE AXIS BY 12Z SAT INTO WESTERN IL BY A DEEPENING
TROUGH OVER THE ROCKIES.  SEVERAL WEAKER SHORTWAVES WILL EJECT OUT
OF THE BASE OF THE TROUGH PUSHING ACROSS NORTHERN/WESTERN IOWA.  IN
ADDITION...THE FRONTAL BOUNDARY FROM A SURFACE LOW IN WESTERN KS
WILL LIFT NORTHWARD AS THE SURFACE LOW SHIFT TO THE NORTHEAST.  TO
THE WEST OF IOWA THERE IS PRETTY IMPRESSIVE SHEAR AND STRONG THETA-E
ADVECTION THAT WILL WORK INTO THE WEST AND NORTH AND GRADUALLY SHIFT
MORE NORTH AND EAST.  ONE AGAIN THE 4KM WRF HAD A DECENT HANDLE ON
ALL OF THE CONVECTION OF THIS AFTERNOON AND TONIGHT SO I DID PUT
SOME WEIGHT ON ITS SOLUTION FOR TONIGHT.  STORMS SHOULD FIRE OUT
WEST OF IOWA THIS AFTERNOON AND EVENING AND WILL PROBABLY MERGE INTO
A CLUSTER OF STORMS THAT WILL THEN SHIFT INTO THE SOUTHWEST THIRD OF
SO OF IOWA DURING THE OVERNIGHT.  THERE MAY BE ISOLATED STORMS
THROUGHOUT THE EVENING BUT THE MAIN PRECIP EVENT WILL OCCUR OVER THE
SOUTHWEST BETWEEN 08Z-12Z BEFORE LIFTING NORTH.  SOME STORMS WILL
PRODUCE HEAVY RAINFALL BUT THERE MAY ALSO BE A COUPLE SEVERE STORMS
AS WELL...MAINLY OVER THE FAR WESTERN PORTION OF THE CWA.  IT WILL
BE A MUGGY NIGHT WITH LOWS IN THE UPPER 60S OVER FAR NORTHERN IOWA
AND 70S ELSEWHERE.  DEWPOINTS WILL STAY IN THE UPPER 60S AND LOW TO
MID 70S SO FOG WILL ONCE AGAIN DEVELOP...ESPECIALLY ACROSS THE
NORTH.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

ACTIVE WX PATTERN EXPECTED AT LEAST THROUGH THE MIDDLE OF NEXT
WEEK...WITH HOT AND HUMID SUMMERTIME WEATHER GIVING WAY TO FALL-LIKE
WEATHER.

MID/UPPER-LEVEL WIND SPEED MAX PLUNGING SOUTHWARD ALONG THE PAC
COAST...ON THE WEST SIDE OF THE WESTERN U.S. TROF...WILL HELP
FACILIATE ITS INTENSIFICATION BEFORE IT LIFTS OUT. IN RESPONSE...THE
EASTERN U.S. RIDGE WILL AMPLIFY INTO THIS WEEKEND. A VORT MAX OVER
THE SW U.S. WILL CONTINUE LIFTING NORTHEASTWARD. BY THE BEGINNING OF
THE LONG TERM FCST PERIOD...LINGERING CONVECTION FROM OVERNIGHT WILL
CONTINUE LIFTING NORTHWARD AHEAD OF A NORTHWARD-ADVANCING FRONTAL
BOUNDARY. THE BOUNDARY IS EXPECTED TO BE IN THE VICINITY OF THE IA-
MN BORDER...LIKELY JUST NORTH OF IT...BY LATE AFTERNOON SATURDAY.
SOUTH OF THE BOUNDARY...TEMPERATURES WILL WARM MORE THAN WHAT WAS
SEEN TODAY. PREVIOUS FCST DISCUSSION ACKNOWLEDGED MIXING ISSUES OVER
THE PAST FEW DAYS AND ON SATURDAY...AND AGREE WITH THAT THINKING
HOWEVER EXPECT IT TO BE MORE THAN WAS SEEN TODAY AS EVIDENCED BY
STRONGER SURFACE WINDS THAN WAS SEEN TODAY. THUS HAVE NUDGED TEMPS
UP A DEGREE OR TWO FROM THE GOING FORECAST FOR SATURDAY AFTERNOON.

ADDITIONAL CONVECTION IS POSSIBLE SATURDAY NIGHT AS ANOTHER
MID/UPPER-LEVEL DISTURBANCE MOVES THROUGH THE CENTRAL/NORTHERN
PLAINS. BEST FORCING WILL REMAIN WEST AND NORTH OF THE CWA...AND
HAVE PAINTED POPS AS SUCH.

SUNDAY IS EXPECTED TO BE THE WARMEST DAY OF THE FCST PD WITH IA
SOLIDLY WITHIN THE WARM SECTOR. NAM HAS CONTINUED TREND FROM
PREVIOUS FCST OF BEING THE WARMEST WITH FCST HIGHS WELL INTO THE
90S. NAM IS SUGGESTING MORE MIXING ON SUNDAY THAN ON SATURDAY AS
EVIDENCED BY LOWER DEWPOINTS AND STRONGER SURFACE WINDS. FOR NOW
HAVE NOT CHANGED SUNDAY/S MAX TEMPS MUCH FROM PREVIOUS FCST. HEAT
INDEX VALUES WILL BE AS HIGH AS AROUND 100F.

HIGHER CHANCES OF SHRA/TSRA OCCUR SUNDAY NIGHT AS UPPER-LEVEL TROF
TO OUR WEST EJECTS NORTHEASTWARD AND PUSHES A BOUNDARY INTO IA.
MODELS SUGGEST THE BOUNDARY WILL HANG UP IN THE STATE...LIKELY
MAKING IT AS FAR SOUTHEAST AS CENTRAL IA. INSTABILITY AND FORCING
WILL BE PLENTIFUL ENOUGH TO RESULT IN AT LEAST SCATTERED SHRA/TSRA
DURING THE NIGHT. AS THE UPPER LEVEL TROF EJECTS...ADDITIONAL
UPSTREAM ENERGY WILL HELP ANOTHER TROF TO DEVELOP IN ITS PLACE OVER
THE NORTHERN U.S. ROCKIES.

WITH BOUNDARY REMAINING IN THE REGION...HAVE KEPT SLIGHT CHANCE POPS
GOING INTO MONDAY. AFTER THIS POINT...THE MODEL SOLUTIONS DIVERGE
LEADING TO INCREASING FORECAST UNCERTAINTY. GFS BRINGS THE SECOND
TROF THROUGH FASTER THAN THE EURO. EXPECT THE BOUNDARY TO MOVE
THROUGH THE CWA BY WEDNESDAY. HAVE INCREASED POPS BEGINNING TUESDAY
AND KEPT THEM IN PLACE THROUGH LATE IN THE DAY ON WEDNESDAY.

AFTER THE FRONTAL PASSAGE...A FEW DAYS OF FALL-LIKE WEATHER WILL
PREVAIL WITH HIGH TEMPS ACROSS THE NORTHERN CWA POSSIBLY NOT LEAVING
THE LOWER 70S ON WEDNESDAY.

&&

.AVIATION...23/00Z
ISSUED AT 635 PM CDT FRI AUG 22 2014

BOUNDARY LAID UP B/T HWY 30 AND HWY 20 WILL CONTINUE TO BE THE
FOCUS FOR CONVECTION THROUGH THE EVENING HOURS. WILL LITTLE
FORWARD MOVEMENT AND LOW CONFIDENCE WITH TIMING STORMS TO AFFECT
ANY OF THE TAF SITES...ONLY HAVE VCTS MENTIONED AT FOD/OTM/DSM FOR
LATER TONIGHT AS BOUNDARY EXPECTED TO SURGE BACK NORTH. HOWEVER IF
NO CONVECTION OCCURS...FOG IS LIKELY TO DEVELOP OVER MUCH OF THE
AREA. SO WAS CONFIDENT ENOUGH TO MENTION MVFR TO IFR VIS AT
MCW/ALO AND MVFR ELSEWHERE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...ZOGG
AVIATION...PODRAZIK





000
FXUS63 KDMX 222029
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
329 PM CDT FRI AUG 22 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

THROUGH EARLY EVENING...STORMS HAVE FIRED IN TWO AREAS ACROSS
CENTRAL IOWA.  THE NORTHERN MOST LINE OF STORMS IS ASSOCIATED WITH A
FRONTAL BOUNDARY THAT IS EVER SO SLOWLY MEANDERING SOUTH.  FLOW IS
WEAK AND THERE IS LITTLE CONVERGENCE AND NO SHEAR TO SPEAK OF SO THE
STORMS WILL BECOME OUTFLOW DOMINANT AND SHOULD FALL APART BY 00-01Z.
FURTHER SOUTH STORMS HAVE FIRED ALONG A MOISTURE AXIS.  THIS AXIS
WAS EVIDENT ON RADAR FOR MUCH OF THE DAY AND STORMS FIRED AFTER
SUFFICIENT HEATING DESTABILIZED THE ATMOSPHERE.  THESE STORMS WILL
BE A BIT MORE ROBUST AND PRODUCE LOCALLY HEAVY RAINFALL...SOME
STRONGER WIND GUSTS AND POSSIBLY SOME SMALL HAIL.  AGAIN...THESE
STORMS SHOULD MOVE EAST SOUTHEAST AND DIMINISH SHORTLY AFTER 00Z.

THE REST OF EARLY TO MID EVENING SHOULD BE RELATIVELY QUIET THOUGH
THINGS WILL FESTER THROUGH THE EVENING SO ISOLATED STORMS WILL STILL
BE POSSIBLE.

FOR THE REST OF TONIGHT...UPPER RIDGE OVER IOWA WILL GET PUSHED TO
THE EAST WITH THE AXIS BY 12Z SAT INTO WESTERN IL BY A DEEPENING
TROUGH OVER THE ROCKIES.  SEVERAL WEAKER SHORTWAVES WILL EJECT OUT
OF THE BASE OF THE TROUGH PUSHING ACROSS NORTHERN/WESTERN IOWA.  IN
ADDITION...THE FRONTAL BOUNDARY FROM A SURFACE LOW IN WESTERN KS
WILL LIFT NORTHWARD AS THE SURFACE LOW SHIFT TO THE NORTHEAST.  TO
THE WEST OF IOWA THERE IS PRETTY IMPRESSIVE SHEAR AND STRONG THETA-E
ADVECTION THAT WILL WORK INTO THE WEST AND NORTH AND GRADUALLY SHIFT
MORE NORTH AND EAST.  ONE AGAIN THE 4KM WRF HAD A DECENT HANDLE ON
ALL OF THE CONVECTION OF THIS AFTERNOON AND TONIGHT SO I DID PUT
SOME WEIGHT ON ITS SOLUTION FOR TONIGHT.  STORMS SHOULD FIRE OUT
WEST OF IOWA THIS AFTERNOON AND EVENING AND WILL PROBABLY MERGE INTO
A CLUSTER OF STORMS THAT WILL THEN SHIFT INTO THE SOUTHWEST THIRD OF
SO OF IOWA DURING THE OVERNIGHT.  THERE MAY BE ISOLATED STORMS
THROUGHOUT THE EVENING BUT THE MAIN PRECIP EVENT WILL OCCUR OVER THE
SOUTHWEST BETWEEN 08Z-12Z BEFORE LIFTING NORTH.  SOME STORMS WILL
PRODUCE HEAVY RAINFALL BUT THERE MAY ALSO BE A COUPLE SEVERE STORMS
AS WELL...MAINLY OVER THE FAR WESTERN PORTION OF THE CWA.  IT WILL
BE A MUGGY NIGHT WITH LOWS IN THE UPPER 60S OVER FAR NORTHERN IOWA
AND 70S ELSEWHERE.  DEWPOINTS WILL STAY IN THE UPPER 60S AND LOW TO
MID 70S SO FOG WILL ONCE AGAIN DEVELOP...ESPECIALLY ACROSS THE
NORTH.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

ACTIVE WX PATTERN EXPECTED AT LEAST THROUGH THE MIDDLE OF NEXT
WEEK...WITH HOT AND HUMID SUMMERTIME WEATHER GIVING WAY TO FALL-LIKE
WEATHER.

MID/UPPER-LEVEL WIND SPEED MAX PLUNGING SOUTHWARD ALONG THE PAC
COAST...ON THE WEST SIDE OF THE WESTERN U.S. TROF...WILL HELP
FACILIATE ITS INTENSIFICATION BEFORE IT LIFTS OUT. IN RESPONSE...THE
EASTERN U.S. RIDGE WILL AMPLIFY INTO THIS WEEKEND. A VORT MAX OVER
THE SW U.S. WILL CONTINUE LIFTING NORTHEASTWARD. BY THE BEGINNING OF
THE LONG TERM FCST PERIOD...LINGERING CONVECTION FROM OVERNIGHT WILL
CONTINUE LIFTING NORTHWARD AHEAD OF A NORTHWARD-ADVANCING FRONTAL
BOUNDARY. THE BOUNDARY IS EXPECTED TO BE IN THE VICINITY OF THE IA-
MN BORDER...LIKELY JUST NORTH OF IT...BY LATE AFTERNOON SATURDAY.
SOUTH OF THE BOUNDARY...TEMPERATURES WILL WARM MORE THAN WHAT WAS
SEEN TODAY. PREVIOUS FCST DISCUSSION ACKNOWLEDGED MIXING ISSUES OVER
THE PAST FEW DAYS AND ON SATURDAY...AND AGREE WITH THAT THINKING
HOWEVER EXPECT IT TO BE MORE THAN WAS SEEN TODAY AS EVIDENCED BY
STRONGER SURFACE WINDS THAN WAS SEEN TODAY. THUS HAVE NUDGED TEMPS
UP A DEGREE OR TWO FROM THE GOING FORECAST FOR SATURDAY AFTERNOON.

ADDITIONAL CONVECTION IS POSSIBLE SATURDAY NIGHT AS ANOTHER
MID/UPPER-LEVEL DISTURBANCE MOVES THROUGH THE CENTRAL/NORTHERN
PLAINS. BEST FORCING WILL REMAIN WEST AND NORTH OF THE CWA...AND
HAVE PAINTED POPS AS SUCH.

SUNDAY IS EXPECTED TO BE THE WARMEST DAY OF THE FCST PD WITH IA
SOLIDLY WITHIN THE WARM SECTOR. NAM HAS CONTINUED TREND FROM
PREVIOUS FCST OF BEING THE WARMEST WITH FCST HIGHS WELL INTO THE
90S. NAM IS SUGGESTING MORE MIXING ON SUNDAY THAN ON SATURDAY AS
EVIDENCED BY LOWER DEWPOINTS AND STRONGER SURFACE WINDS. FOR NOW
HAVE NOT CHANGED SUNDAY/S MAX TEMPS MUCH FROM PREVIOUS FCST. HEAT
INDEX VALUES WILL BE AS HIGH AS AROUND 100F.

HIGHER CHANCES OF SHRA/TSRA OCCUR SUNDAY NIGHT AS UPPER-LEVEL TROF
TO OUR WEST EJECTS NORTHEASTWARD AND PUSHES A BOUNDARY INTO IA.
MODELS SUGGEST THE BOUNDARY WILL HANG UP IN THE STATE...LIKELY
MAKING IT AS FAR SOUTHEAST AS CENTRAL IA. INSTABILITY AND FORCING
WILL BE PLENTIFUL ENOUGH TO RESULT IN AT LEAST SCATTERED SHRA/TSRA
DURING THE NIGHT. AS THE UPPER LEVEL TROF EJECTS...ADDITIONAL
UPSTREAM ENERGY WILL HELP ANOTHER TROF TO DEVELOP IN ITS PLACE OVER
THE NORTHERN U.S. ROCKIES.

WITH BOUNDARY REMAINING IN THE REGION...HAVE KEPT SLIGHT CHANCE POPS
GOING INTO MONDAY. AFTER THIS POINT...THE MODEL SOLUTIONS DIVERGE
LEADING TO INCREASING FORECAST UNCERTAINTY. GFS BRINGS THE SECOND
TROF THROUGH FASTER THAN THE EURO. EXPECT THE BOUNDARY TO MOVE
THROUGH THE CWA BY WEDNESDAY. HAVE INCREASED POPS BEGINNING TUESDAY
AND KEPT THEM IN PLACE THROUGH LATE IN THE DAY ON WEDNESDAY.

AFTER THE FRONTAL PASSAGE...A FEW DAYS OF FALL-LIKE WEATHER WILL
PREVAIL WITH HIGH TEMPS ACROSS THE NORTHERN CWA POSSIBLY NOT LEAVING
THE LOWER 70S ON WEDNESDAY.

&&

.AVIATION...22/18Z
ISSUED AT 1242 PM CDT FRI AUG 22 2014

PATCHY STRATUS WILL PLAGUE NORTHERN TAF LOCATIONS FOR A COUPLE MORE
HOURS BUT THE FOG HAS FINALLY LIFTED/DISSIPATED.  IN GENERAL THERE
WILL BE VFR CIGS BUT BRIEF PERIODS WHERE STRATUS MAY DRIFT OVER TAF
LOCATIONS WILL YIELD IFR CIGS.  SOME OF THE HI-RES MODELS SUGGEST
STORMS TO DEVELOP ALONG/SOUTH OF I-80 AROUND 21Z.  SAT ALREADY
SHOWING CU BUBBLING AND WITH THE BOUNDARY APPROACHING I COULD NOT
LEAVE KDSM AND KOTM DRY 21Z-00Z.  STORMS WILL BE ISOLD AT BEST
THOUGH SO JUST A MENTION OF VCTS IN THOSE TAFS.  LATE TONIGHT A
BETTER CHANCE FOR STORMS SW OF A LINE FROM KFOD TO KOTM WITH FOG
AND MVFR/LOCAL IFR COND ONCE AGAIN NORTH OF THAT LINE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...FAB
LONG TERM...ZOGG
AVIATION...FAB





000
FXUS63 KDMX 222029
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
329 PM CDT FRI AUG 22 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

THROUGH EARLY EVENING...STORMS HAVE FIRED IN TWO AREAS ACROSS
CENTRAL IOWA.  THE NORTHERN MOST LINE OF STORMS IS ASSOCIATED WITH A
FRONTAL BOUNDARY THAT IS EVER SO SLOWLY MEANDERING SOUTH.  FLOW IS
WEAK AND THERE IS LITTLE CONVERGENCE AND NO SHEAR TO SPEAK OF SO THE
STORMS WILL BECOME OUTFLOW DOMINANT AND SHOULD FALL APART BY 00-01Z.
FURTHER SOUTH STORMS HAVE FIRED ALONG A MOISTURE AXIS.  THIS AXIS
WAS EVIDENT ON RADAR FOR MUCH OF THE DAY AND STORMS FIRED AFTER
SUFFICIENT HEATING DESTABILIZED THE ATMOSPHERE.  THESE STORMS WILL
BE A BIT MORE ROBUST AND PRODUCE LOCALLY HEAVY RAINFALL...SOME
STRONGER WIND GUSTS AND POSSIBLY SOME SMALL HAIL.  AGAIN...THESE
STORMS SHOULD MOVE EAST SOUTHEAST AND DIMINISH SHORTLY AFTER 00Z.

THE REST OF EARLY TO MID EVENING SHOULD BE RELATIVELY QUIET THOUGH
THINGS WILL FESTER THROUGH THE EVENING SO ISOLATED STORMS WILL STILL
BE POSSIBLE.

FOR THE REST OF TONIGHT...UPPER RIDGE OVER IOWA WILL GET PUSHED TO
THE EAST WITH THE AXIS BY 12Z SAT INTO WESTERN IL BY A DEEPENING
TROUGH OVER THE ROCKIES.  SEVERAL WEAKER SHORTWAVES WILL EJECT OUT
OF THE BASE OF THE TROUGH PUSHING ACROSS NORTHERN/WESTERN IOWA.  IN
ADDITION...THE FRONTAL BOUNDARY FROM A SURFACE LOW IN WESTERN KS
WILL LIFT NORTHWARD AS THE SURFACE LOW SHIFT TO THE NORTHEAST.  TO
THE WEST OF IOWA THERE IS PRETTY IMPRESSIVE SHEAR AND STRONG THETA-E
ADVECTION THAT WILL WORK INTO THE WEST AND NORTH AND GRADUALLY SHIFT
MORE NORTH AND EAST.  ONE AGAIN THE 4KM WRF HAD A DECENT HANDLE ON
ALL OF THE CONVECTION OF THIS AFTERNOON AND TONIGHT SO I DID PUT
SOME WEIGHT ON ITS SOLUTION FOR TONIGHT.  STORMS SHOULD FIRE OUT
WEST OF IOWA THIS AFTERNOON AND EVENING AND WILL PROBABLY MERGE INTO
A CLUSTER OF STORMS THAT WILL THEN SHIFT INTO THE SOUTHWEST THIRD OF
SO OF IOWA DURING THE OVERNIGHT.  THERE MAY BE ISOLATED STORMS
THROUGHOUT THE EVENING BUT THE MAIN PRECIP EVENT WILL OCCUR OVER THE
SOUTHWEST BETWEEN 08Z-12Z BEFORE LIFTING NORTH.  SOME STORMS WILL
PRODUCE HEAVY RAINFALL BUT THERE MAY ALSO BE A COUPLE SEVERE STORMS
AS WELL...MAINLY OVER THE FAR WESTERN PORTION OF THE CWA.  IT WILL
BE A MUGGY NIGHT WITH LOWS IN THE UPPER 60S OVER FAR NORTHERN IOWA
AND 70S ELSEWHERE.  DEWPOINTS WILL STAY IN THE UPPER 60S AND LOW TO
MID 70S SO FOG WILL ONCE AGAIN DEVELOP...ESPECIALLY ACROSS THE
NORTH.

.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 327 PM CDT FRI AUG 22 2014

ACTIVE WX PATTERN EXPECTED AT LEAST THROUGH THE MIDDLE OF NEXT
WEEK...WITH HOT AND HUMID SUMMERTIME WEATHER GIVING WAY TO FALL-LIKE
WEATHER.

MID/UPPER-LEVEL WIND SPEED MAX PLUNGING SOUTHWARD ALONG THE PAC
COAST...ON THE WEST SIDE OF THE WESTERN U.S. TROF...WILL HELP
FACILIATE ITS INTENSIFICATION BEFORE IT LIFTS OUT. IN RESPONSE...THE
EASTERN U.S. RIDGE WILL AMPLIFY INTO THIS WEEKEND. A VORT MAX OVER
THE SW U.S. WILL CONTINUE LIFTING NORTHEASTWARD. BY THE BEGINNING OF
THE LONG TERM FCST PERIOD...LINGERING CONVECTION FROM OVERNIGHT WILL
CONTINUE LIFTING NORTHWARD AHEAD OF A NORTHWARD-ADVANCING FRONTAL
BOUNDARY. THE BOUNDARY IS EXPECTED TO BE IN THE VICINITY OF THE IA-
MN BORDER...LIKELY JUST NORTH OF IT...BY LATE AFTERNOON SATURDAY.
SOUTH OF THE BOUNDARY...TEMPERATURES WILL WARM MORE THAN WHAT WAS
SEEN TODAY. PREVIOUS FCST DISCUSSION ACKNOWLEDGED MIXING ISSUES OVER
THE PAST FEW DAYS AND ON SATURDAY...AND AGREE WITH THAT THINKING
HOWEVER EXPECT IT TO BE MORE THAN WAS SEEN TODAY AS EVIDENCED BY
STRONGER SURFACE WINDS THAN WAS SEEN TODAY. THUS HAVE NUDGED TEMPS
UP A DEGREE OR TWO FROM THE GOING FORECAST FOR SATURDAY AFTERNOON.

ADDITIONAL CONVECTION IS POSSIBLE SATURDAY NIGHT AS ANOTHER
MID/UPPER-LEVEL DISTURBANCE MOVES THROUGH THE CENTRAL/NORTHERN
PLAINS. BEST FORCING WILL REMAIN WEST AND NORTH OF THE CWA...AND
HAVE PAINTED POPS AS SUCH.

SUNDAY IS EXPECTED TO BE THE WARMEST DAY OF THE FCST PD WITH IA
SOLIDLY WITHIN THE WARM SECTOR. NAM HAS CONTINUED TREND FROM
PREVIOUS FCST OF BEING THE WARMEST WITH FCST HIGHS WELL INTO THE
90S. NAM IS SUGGESTING MORE MIXING ON SUNDAY THAN ON SATURDAY AS
EVIDENCED BY LOWER DEWPOINTS AND STRONGER SURFACE WINDS. FOR NOW
HAVE NOT CHANGED SUNDAY/S MAX TEMPS MUCH FROM PREVIOUS FCST. HEAT
INDEX VALUES WILL BE AS HIGH AS AROUND 100F.

HIGHER CHANCES OF SHRA/TSRA OCCUR SUNDAY NIGHT AS UPPER-LEVEL TROF
TO OUR WEST EJECTS NORTHEASTWARD AND PUSHES A BOUNDARY INTO IA.
MODELS SUGGEST THE BOUNDARY WILL HANG UP IN THE STATE...LIKELY
MAKING IT AS FAR SOUTHEAST AS CENTRAL IA. INSTABILITY AND FORCING
WILL BE PLENTIFUL ENOUGH TO RESULT IN AT LEAST SCATTERED SHRA/TSRA
DURING THE NIGHT. AS THE UPPER LEVEL TROF EJECTS...ADDITIONAL
UPSTREAM ENERGY WILL HELP ANOTHER TROF TO DEVELOP IN ITS PLACE OVER
THE NORTHERN U.S. ROCKIES.

WITH BOUNDARY REMAINING IN THE REGION...HAVE KEPT SLIGHT CHANCE POPS
GOING INTO MONDAY. AFTER THIS POINT...THE MODEL SOLUTIONS DIVERGE
LEADING TO INCREASING FORECAST UNCERTAINTY. GFS BRINGS THE SECOND
TROF THROUGH FASTER THAN THE EURO. EXPECT THE BOUNDARY TO MOVE
THROUGH THE CWA BY WEDNESDAY. HAVE INCREASED POPS BEGINNING TUESDAY
AND KEPT THEM IN PLACE THROUGH LATE IN THE DAY ON WEDNESDAY.

AFTER THE FRONTAL PASSAGE...A FEW DAYS OF FALL-LIKE WEATHER WILL
PREVAIL WITH HIGH TEMPS ACROSS THE NORTHERN CWA POSSIBLY NOT LEAVING
THE LOWER 70S ON WEDNESDAY.

&&

.AVIATION...22/18Z
ISSUED AT 1242 PM CDT FRI AUG 22 2014

PATCHY STRATUS WILL PLAGUE NORTHERN TAF LOCATIONS FOR A COUPLE MORE
HOURS BUT THE FOG HAS FINALLY LIFTED/DISSIPATED.  IN GENERAL THERE
WILL BE VFR CIGS BUT BRIEF PERIODS WHERE STRATUS MAY DRIFT OVER TAF
LOCATIONS WILL YIELD IFR CIGS.  SOME OF THE HI-RES MODELS SUGGEST
STORMS TO DEVELOP ALONG/SOUTH OF I-80 AROUND 21Z.  SAT ALREADY
SHOWING CU BUBBLING AND WITH THE BOUNDARY APPROACHING I COULD NOT
LEAVE KDSM AND KOTM DRY 21Z-00Z.  STORMS WILL BE ISOLD AT BEST
THOUGH SO JUST A MENTION OF VCTS IN THOSE TAFS.  LATE TONIGHT A
BETTER CHANCE FOR STORMS SW OF A LINE FROM KFOD TO KOTM WITH FOG
AND MVFR/LOCAL IFR COND ONCE AGAIN NORTH OF THAT LINE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...FAB
LONG TERM...ZOGG
AVIATION...FAB




000
FXUS63 KDMX 221743
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1242 PM CDT FRI AUG 22 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

A CLUSTER OF THUNDERSTORMS DEVELOPED ACROSS SOUTHWEST IOWA OVERNIGHT
AND IS CURRENTLY WEAKENING AS IT PROGRESSES EASTWARD ACROSS ABOUT
THE SOUTHERN HALF OF THE FORECAST AREA. OVERALL INTENSITY TREND
SHOULD CONTINUE DOWNWARD WITH THIS ACTIVITY EARLY THIS MORNING.
MEANWHILE FOG AND PATCHY STRATUS HAVE DEVELOPED ACROSS THE NORTH IN
AN AIRMASS CHARACTERIZED BY NEARLY CALM WINDS AND DEWPOINTS IN THE
LOWER 70S...HOWEVER VSBYS HAVE SO FAR NOT DROPPED BELOW A MILE AND
BELIEVE ANY DENSE FOG WILL BE ISOLATED THUS NO ADVISORY IS BEING
ISSUED WITH THE MORNING PACKAGE BUT THE SITUATION WILL BE CLOSELY
MONITORED.

THE AFOREMENTIONED THUNDERSTORMS AND FOG SHOULD BOTH DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNRISE. THEREAFTER...IT WILL BE ANOTHER
VERY HUMID DAY WITH LIGHT WINDS AND GENERALLY VERY SWEATY
CONDITIONS. THERE IS A HIGH DEGREE OF UNCERTAINTY REGARDING
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TODAY. MOST OF THE LARGE
SCALE AND EVEN SOME OF THE HI RES MODELS ARE PAINTING LIGHT QPF
ACROSS CENTRAL IOWA THROUGH MIDDAY AND THE
AFTERNOON...HOWEVER...UPSTREAM RADAR BELIES THIS WITH NO DEVELOPMENT
OF ANY KIND AND FORECAST SOUNDINGS SHOW A MODEST BUT EFFECTIVE
CAPPING INVERSION FOR MOST OF THE DAY...PARTICULARLY GIVEN THE
LIKELIHOOD OF CONVECTIVE DEBRIS CLOUDS EARLY IN THE DAY LIMITING
INSOLATION. THERE IS ALSO NO REAL FOCUS MECHANISM IN TERMS OF
FORCING FOR MOST OF THE DAY. CONVECTION SEEMS SOMEWHAT MORE PROBABLE
LATE IN THE DAY TOWARD THIS EVENING AS SURFACE HEATING ALLOWS THE
CAP TO BREAK AND WE WILL LIKELY SEE TYPICAL LATE SUMMER POPCORN
STORMS TOWARD SUNSET...WHICH IS COVERED BY 30 TO 40 POPS AND
SCATTERED WORDING IN THE FORECAST. TIED INTO THE DIFFICULT PRECIP
FORECAST FOR TODAY IS YET ANOTHER LOW CONFIDENCE TEMPERATURE
FORECAST. THE DEGREE OF SUNSHINE VERSUS CLOUDS IS PARTICULARLY
PROBLEMATIC...BUT EVEN ON THURSDAY WHEN THERE WAS AMPLE SUNSHINE
TEMPERATURES HAD A DIFFICULT TIME WARMING GIVEN THE VERY HUMID
AIRMASS IN PLACE. WILL CONTINUE THE TREND OF THE LAST COUPLE OF DAYS
IN LIMITING HIGH TEMPERATURES IN THE UPPER 80S AS IT APPEARS THE
REAL WARM UP WILL WAIT FOR THIS WEEKEND.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

ALTHOUGH THERE WILL CERTAINLY BE SOME BREAKS...THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK BEFORE CALMING DOWN TO END THE PERIOD.
EXPECT MORE CONVECTION AGAIN TONIGHT BUT FROM A DIFFERENT SCENARIO
THAN RECENTLY. ATTENTION WILL TURN UPSTREAM LOOKING AT EVOLUTION OF
AZ SHORT WAVE. REMNANTS SHOULD REACH THE PLAINS TONIGHT WITH LARGE
SCALE FORCING INCREASING INTO THE UPPER/MID MO VALLEY. THIS WILL
ALSO MATURE THERMODYNAMIC FORCING WITH THETA-E ADVECTION AND
BAROCLINIC ZONE STRENGTHENING AS IT LIFTS NORTHWARD. ALTHOUGH BEST
SUPPORT LOOKS TO REMAIN NORTH AND WEST OF IA...THIS SHOULD STILL BE
SUFFICIENT FOR MCS WITH AIRMASS STILL VERY FAVORABLE FOR CONVECTION.
CONVECTIVE POTENTIAL SHOULD DIMINISH SOUTH TO NORTH SAT WITH
BAROCLINIC ZONE EXITING IA TO THE NORTH...AND WARM FRONT LIFTING
FROM SRN IA TO OR BEYOND THE MN BORDER BY 00Z.  TEMPERATURES HAVE
BEEN PROBLEMATIC RECENTLY...OVER FORECAST...WITH MIXING DIFFICULT TO
GRASP DUE TO LINGERING CONVECTION AND LIGHTER WINDS. MOS HAS NOT
DONE TOO POORLY CAPTURING THIS HOWEVER SO STAYED CLOSE TO THOSE
NUMBERS FOR MAXES SAT.

FORCING ASSOCIATED WITH NRN ROCKIES/NRN PLAINS LONG WAVE TROUGH WILL
CONTINUE TO BRUSH WRN IA THROUGH THE WEEKEND...AND ALTHOUGH
THERMODYNAMIC FORCING WILL BE WEAKER...IT MAY STILL BE SUFFICIENT FOR
A FEW SURGES OF CONVECTION KEEPING LOW POPS GOING NORTH AND WEST SAT
NIGHT.  IA SHOULD BE THOROUGHLY INTO WARM SECTOR SUN WITH MORE
QUESTIONS ON THE DEGREE OF MIXING.  NAM IS VERY STRONG IN THIS
REGARD WITH RAW TEMPS SUGGESTING HIGHS FURTHER INTO THE 90S.
DEWPOINTS WILL BE A TAD LOWER...BUT STILL 70 PLUS...SO HAVE
FINALLY NUDGED HIGHS JUST OVER SATURDAYS /ONLY LOW 90S/ WITH
LITTLE PRECIP EXPECTED. DEGREE OF MIXING WILL NEED TO BE WATCHED
HOWEVER TO SEE IF NAM SUGGESTIONS CAN OVERCOME HIGH LOW LEVEL
MOISTURE CONTENT.

SURFACE FRONT MAY JUST REACH WRN SECTIONS LATE SUN WITH SURFACE
BASED POTENTIAL TOWARD THE MO RIVER. THERE SHOULD BE SUFFICIENT
FORCING FOR AT LEAST WEAK SCATTERED CONVECTION INTO THE NIGHT.
MODELS BEGIN TO DIVERGE INTO THE MIDDLE OF NEXT WEEK WITH
DIFFERENCES IN STRENGTH OF NRN STREAM SHORT WAVE AND LINGERING
ROCKIES SHORT WAVE ENERGY...BUT MOST SOLUTIONS SUGGEST MORE
CONVECTION REGARDLESS OF THE SOLUTION. HAVE GONE DRY BY WED NIGHT
AND THU HOWEVER AS EVEN THE SLOWER ECMWF SUGGESTS NO PRECIP.

PERSISTENCE OF HEAT WILL BE A PROBLEM OVER THE WEEKEND...BUT BETTER
MIXING POTENTIAL MAY JUST LOWER DEWPOINTS ENOUGH TO KEEP HEAT
INDICES OUT OF ADVISORY RANGE.  IN FACT...HEAT INDICES SAT AND SUN
MAY BE A TOUCH LOWER THAN TODAY.

&&

.AVIATION...22/18Z
ISSUED AT 1242 PM CDT FRI AUG 22 2014

PATCHY STRATUS WILL PLAGUE NORTHERN TAF LOCATIONS FOR A COUPLE MORE
HOURS BUT THE FOG HAS FINALLY LIFTED/DISSIPATED.  IN GENERAL THERE
WILL BE VFR CIGS BUT BRIEF PERIODS WHERE STRATUS MAY DRIFT OVER TAF
LOCATIONS WILL YIELD IFR CIGS.  SOME OF THE HI-RES MODELS SUGGEST
STORMS TO DEVELOP ALONG/SOUTH OF I-80 AROUND 21Z.  SAT ALREADY
SHOWING CU BUBBLING AND WITH THE BOUNDARY APPROACHING I COULD NOT
LEAVE KDSM AND KOTM DRY 21Z-00Z.  STORMS WILL BE ISOLD AT BEST
THOUGH SO JUST A MENTION OF VCTS IN THOSE TAFS.  LATE TONIGHT A
BETTER CHANCE FOR STORMS SW OF A LINE FROM KFOD TO KOTM WITH FOG
AND MVFR/LOCAL IFR COND ONCE AGAIN NORTH OF THAT LINE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...FAB




000
FXUS63 KDMX 221743
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1242 PM CDT FRI AUG 22 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

A CLUSTER OF THUNDERSTORMS DEVELOPED ACROSS SOUTHWEST IOWA OVERNIGHT
AND IS CURRENTLY WEAKENING AS IT PROGRESSES EASTWARD ACROSS ABOUT
THE SOUTHERN HALF OF THE FORECAST AREA. OVERALL INTENSITY TREND
SHOULD CONTINUE DOWNWARD WITH THIS ACTIVITY EARLY THIS MORNING.
MEANWHILE FOG AND PATCHY STRATUS HAVE DEVELOPED ACROSS THE NORTH IN
AN AIRMASS CHARACTERIZED BY NEARLY CALM WINDS AND DEWPOINTS IN THE
LOWER 70S...HOWEVER VSBYS HAVE SO FAR NOT DROPPED BELOW A MILE AND
BELIEVE ANY DENSE FOG WILL BE ISOLATED THUS NO ADVISORY IS BEING
ISSUED WITH THE MORNING PACKAGE BUT THE SITUATION WILL BE CLOSELY
MONITORED.

THE AFOREMENTIONED THUNDERSTORMS AND FOG SHOULD BOTH DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNRISE. THEREAFTER...IT WILL BE ANOTHER
VERY HUMID DAY WITH LIGHT WINDS AND GENERALLY VERY SWEATY
CONDITIONS. THERE IS A HIGH DEGREE OF UNCERTAINTY REGARDING
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TODAY. MOST OF THE LARGE
SCALE AND EVEN SOME OF THE HI RES MODELS ARE PAINTING LIGHT QPF
ACROSS CENTRAL IOWA THROUGH MIDDAY AND THE
AFTERNOON...HOWEVER...UPSTREAM RADAR BELIES THIS WITH NO DEVELOPMENT
OF ANY KIND AND FORECAST SOUNDINGS SHOW A MODEST BUT EFFECTIVE
CAPPING INVERSION FOR MOST OF THE DAY...PARTICULARLY GIVEN THE
LIKELIHOOD OF CONVECTIVE DEBRIS CLOUDS EARLY IN THE DAY LIMITING
INSOLATION. THERE IS ALSO NO REAL FOCUS MECHANISM IN TERMS OF
FORCING FOR MOST OF THE DAY. CONVECTION SEEMS SOMEWHAT MORE PROBABLE
LATE IN THE DAY TOWARD THIS EVENING AS SURFACE HEATING ALLOWS THE
CAP TO BREAK AND WE WILL LIKELY SEE TYPICAL LATE SUMMER POPCORN
STORMS TOWARD SUNSET...WHICH IS COVERED BY 30 TO 40 POPS AND
SCATTERED WORDING IN THE FORECAST. TIED INTO THE DIFFICULT PRECIP
FORECAST FOR TODAY IS YET ANOTHER LOW CONFIDENCE TEMPERATURE
FORECAST. THE DEGREE OF SUNSHINE VERSUS CLOUDS IS PARTICULARLY
PROBLEMATIC...BUT EVEN ON THURSDAY WHEN THERE WAS AMPLE SUNSHINE
TEMPERATURES HAD A DIFFICULT TIME WARMING GIVEN THE VERY HUMID
AIRMASS IN PLACE. WILL CONTINUE THE TREND OF THE LAST COUPLE OF DAYS
IN LIMITING HIGH TEMPERATURES IN THE UPPER 80S AS IT APPEARS THE
REAL WARM UP WILL WAIT FOR THIS WEEKEND.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

ALTHOUGH THERE WILL CERTAINLY BE SOME BREAKS...THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK BEFORE CALMING DOWN TO END THE PERIOD.
EXPECT MORE CONVECTION AGAIN TONIGHT BUT FROM A DIFFERENT SCENARIO
THAN RECENTLY. ATTENTION WILL TURN UPSTREAM LOOKING AT EVOLUTION OF
AZ SHORT WAVE. REMNANTS SHOULD REACH THE PLAINS TONIGHT WITH LARGE
SCALE FORCING INCREASING INTO THE UPPER/MID MO VALLEY. THIS WILL
ALSO MATURE THERMODYNAMIC FORCING WITH THETA-E ADVECTION AND
BAROCLINIC ZONE STRENGTHENING AS IT LIFTS NORTHWARD. ALTHOUGH BEST
SUPPORT LOOKS TO REMAIN NORTH AND WEST OF IA...THIS SHOULD STILL BE
SUFFICIENT FOR MCS WITH AIRMASS STILL VERY FAVORABLE FOR CONVECTION.
CONVECTIVE POTENTIAL SHOULD DIMINISH SOUTH TO NORTH SAT WITH
BAROCLINIC ZONE EXITING IA TO THE NORTH...AND WARM FRONT LIFTING
FROM SRN IA TO OR BEYOND THE MN BORDER BY 00Z.  TEMPERATURES HAVE
BEEN PROBLEMATIC RECENTLY...OVER FORECAST...WITH MIXING DIFFICULT TO
GRASP DUE TO LINGERING CONVECTION AND LIGHTER WINDS. MOS HAS NOT
DONE TOO POORLY CAPTURING THIS HOWEVER SO STAYED CLOSE TO THOSE
NUMBERS FOR MAXES SAT.

FORCING ASSOCIATED WITH NRN ROCKIES/NRN PLAINS LONG WAVE TROUGH WILL
CONTINUE TO BRUSH WRN IA THROUGH THE WEEKEND...AND ALTHOUGH
THERMODYNAMIC FORCING WILL BE WEAKER...IT MAY STILL BE SUFFICIENT FOR
A FEW SURGES OF CONVECTION KEEPING LOW POPS GOING NORTH AND WEST SAT
NIGHT.  IA SHOULD BE THOROUGHLY INTO WARM SECTOR SUN WITH MORE
QUESTIONS ON THE DEGREE OF MIXING.  NAM IS VERY STRONG IN THIS
REGARD WITH RAW TEMPS SUGGESTING HIGHS FURTHER INTO THE 90S.
DEWPOINTS WILL BE A TAD LOWER...BUT STILL 70 PLUS...SO HAVE
FINALLY NUDGED HIGHS JUST OVER SATURDAYS /ONLY LOW 90S/ WITH
LITTLE PRECIP EXPECTED. DEGREE OF MIXING WILL NEED TO BE WATCHED
HOWEVER TO SEE IF NAM SUGGESTIONS CAN OVERCOME HIGH LOW LEVEL
MOISTURE CONTENT.

SURFACE FRONT MAY JUST REACH WRN SECTIONS LATE SUN WITH SURFACE
BASED POTENTIAL TOWARD THE MO RIVER. THERE SHOULD BE SUFFICIENT
FORCING FOR AT LEAST WEAK SCATTERED CONVECTION INTO THE NIGHT.
MODELS BEGIN TO DIVERGE INTO THE MIDDLE OF NEXT WEEK WITH
DIFFERENCES IN STRENGTH OF NRN STREAM SHORT WAVE AND LINGERING
ROCKIES SHORT WAVE ENERGY...BUT MOST SOLUTIONS SUGGEST MORE
CONVECTION REGARDLESS OF THE SOLUTION. HAVE GONE DRY BY WED NIGHT
AND THU HOWEVER AS EVEN THE SLOWER ECMWF SUGGESTS NO PRECIP.

PERSISTENCE OF HEAT WILL BE A PROBLEM OVER THE WEEKEND...BUT BETTER
MIXING POTENTIAL MAY JUST LOWER DEWPOINTS ENOUGH TO KEEP HEAT
INDICES OUT OF ADVISORY RANGE.  IN FACT...HEAT INDICES SAT AND SUN
MAY BE A TOUCH LOWER THAN TODAY.

&&

.AVIATION...22/18Z
ISSUED AT 1242 PM CDT FRI AUG 22 2014

PATCHY STRATUS WILL PLAGUE NORTHERN TAF LOCATIONS FOR A COUPLE MORE
HOURS BUT THE FOG HAS FINALLY LIFTED/DISSIPATED.  IN GENERAL THERE
WILL BE VFR CIGS BUT BRIEF PERIODS WHERE STRATUS MAY DRIFT OVER TAF
LOCATIONS WILL YIELD IFR CIGS.  SOME OF THE HI-RES MODELS SUGGEST
STORMS TO DEVELOP ALONG/SOUTH OF I-80 AROUND 21Z.  SAT ALREADY
SHOWING CU BUBBLING AND WITH THE BOUNDARY APPROACHING I COULD NOT
LEAVE KDSM AND KOTM DRY 21Z-00Z.  STORMS WILL BE ISOLD AT BEST
THOUGH SO JUST A MENTION OF VCTS IN THOSE TAFS.  LATE TONIGHT A
BETTER CHANCE FOR STORMS SW OF A LINE FROM KFOD TO KOTM WITH FOG
AND MVFR/LOCAL IFR COND ONCE AGAIN NORTH OF THAT LINE.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...FAB





000
FXUS63 KDMX 221135
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
635 AM CDT FRI AUG 22 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

A CLUSTER OF THUNDERSTORMS DEVELOPED ACROSS SOUTHWEST IOWA OVERNIGHT
AND IS CURRENTLY WEAKENING AS IT PROGRESSES EASTWARD ACROSS ABOUT
THE SOUTHERN HALF OF THE FORECAST AREA. OVERALL INTENSITY TREND
SHOULD CONTINUE DOWNWARD WITH THIS ACTIVITY EARLY THIS MORNING.
MEANWHILE FOG AND PATCHY STRATUS HAVE DEVELOPED ACROSS THE NORTH IN
AN AIRMASS CHARACTERIZED BY NEARLY CALM WINDS AND DEWPOINTS IN THE
LOWER 70S...HOWEVER VSBYS HAVE SO FAR NOT DROPPED BELOW A MILE AND
BELIEVE ANY DENSE FOG WILL BE ISOLATED THUS NO ADVISORY IS BEING
ISSUED WITH THE MORNING PACKAGE BUT THE SITUATION WILL BE CLOSELY
MONITORED.

THE AFOREMENTIONED THUNDERSTORMS AND FOG SHOULD BOTH DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNRISE. THEREAFTER...IT WILL BE ANOTHER
VERY HUMID DAY WITH LIGHT WINDS AND GENERALLY VERY SWEATY
CONDITIONS. THERE IS A HIGH DEGREE OF UNCERTAINTY REGARDING
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TODAY. MOST OF THE LARGE
SCALE AND EVEN SOME OF THE HI RES MODELS ARE PAINTING LIGHT QPFS
ACROSS CENTRAL IOWA THROUGH MIDDAY AND THE
AFTERNOON...HOWEVER...UPSTREAM RADAR BELIES THIS WITH NO DEVELOPMENT
OF ANY KIND AND FORECAST SOUNDINGS SHOW A MODEST BUT EFFECTIVE
CAPPING INVERSION FOR MOST OF THE DAY...PARTICULARLY GIVEN THE
LIKELIHOOD OF CONVECTIVE DEBRIS CLOUDS EARLY IN THE DAY LIMITING
INSOLATION. THERE IS ALSO NO REAL FOCUS MECHANISM IN TERMS OF
FORCING FOR MOST OF THE DAY. CONVECTION SEEMS SOMEWHAT MORE PROBABLE
LATE IN THE DAY TOWARD THIS EVENING AS SURFACE HEATING ALLOWS THE
CAP TO BREAK AND WE WILL LIKELY SEE TYPICAL LATE SUMMER POPCORN
STORMS TOWARD SUNSET...WHICH IS COVERED BY 30 TO 40 POPS AND
SCATTERED WORDING IN THE FORECAST. TIED INTO THE DIFFICULT PRECIP
FORECAST FOR TODAY IS YET ANOTHER LOW CONFIDENCE TEMPERATURE
FORECAST. THE DEGREE OF SUNSHINE VERSUS CLOUDS IS PARTICULARLY
PROBLEMATIC...BUT EVEN ON THURSDAY WHEN THERE WAS AMPLE SUNSHINE
TEMPERATURES HAD A DIFFICULT TIME WARMING GIVEN THE VERY HUMID
AIRMASS IN PLACE. WILL CONTINUE THE TREND OF THE LAST COUPLE OF DAYS
IN LIMITING HIGH TEMPERATURES IN THE UPPER 80S AS IT APPEARS THE
REAL WARM UP WILL WAIT FOR THIS WEEKEND.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

ALTHOUGH THERE WILL CERTAINLY BE SOME BREAKS...THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK BEFORE CALMING DOWN TO END THE PERIOD.
EXPECT MORE CONVECTION AGAIN TONIGHT BUT FROM A DIFFERENT SCENARIO
THAN RECENTLY. ATTENTION WILL TURN UPSTREAM LOOKING AT EVOLUTION OF
AZ SHORT WAVE. REMNANTS SHOULD REACH THE PLAINS TONIGHT WITH LARGE
SCALE FORCING INCREASING INTO THE UPPER/MID MO VALLEY. THIS WILL
ALSO MATURE THERMODYNAMIC FORCING WITH THETA-E ADVECTION AND
BAROCLINIC ZONE STRENGTHENING AS IT LIFTS NORTHWARD. ALTHOUGH BEST
SUPPORT LOOKS TO REMAIN NORTH AND WEST OF IA...THIS SHOULD STILL BE
SUFFICIENT FOR MCS WITH AIRMASS STILL VERY FAVORABLE FOR CONVECTION.
CONVECTIVE POTENTIAL SHOULD DIMINISH SOUTH TO NORTH SAT WITH
BAROCLINIC ZONE EXITING IA TO THE NORTH...AND WARM FRONT LIFTING
FROM SRN IA TO OR BEYOND THE MN BORDER BY 00Z.  TEMPERATURES HAVE
BEEN PROBLEMATIC RECENTLY...OVER FORECAST...WITH MIXING DIFFICULT TO
GRASP DUE TO LINGERING CONVECTION AND LIGHTER WINDS. MOS HAS NOT
DONE TOO POORLY CAPTURING THIS HOWEVER SO STAYED CLOSE TO THOSE
NUMBERS FOR MAXES SAT.

FORCING ASSOCIATED WITH NRN ROCKIES/NRN PLAINS LONG WAVE TROUGH WILL
CONTINUE TO BRUSH WRN IA THROUGH THE WEEKEND...AND ALTHOUGH
THERMODYNAMIC FORCING WILL BE WEAKER...IT MAY STILL BE SUFFICIENT FOR
A FEW SURGES OF CONVECTION KEEPING LOW POPS GOING NORTH AND WEST SAT
NIGHT.  IA SHOULD BE THOROUGHLY INTO WARM SECTOR SUN WITH MORE
QUESTIONS ON THE DEGREE OF MIXING.  NAM IS VERY STRONG IN THIS
REGARD WITH RAW TEMPS SUGGESTING HIGHS FURTHER INTO THE 90S.
DEWPOINTS WILL BE A TAD LOWER...BUT STILL 70 PLUS...SO HAVE
FINALLY NUDGED HIGHS JUST OVER SATURDAYS /ONLY LOW 90S/ WITH
LITTLE PRECIP EXPECTED. DEGREE OF MIXING WILL NEED TO BE WATCHED
HOWEVER TO SEE IF NAM SUGGESTIONS CAN OVERCOME HIGH LOW LEVEL
MOISTURE CONTENT.

SURFACE FRONT MAY JUST REACH WRN SECTIONS LATE SUN WITH SURFACE
BASED POTENTIAL TOWARD THE MO RIVER. THERE SHOULD BE SUFFICIENT
FORCING FOR AT LEAST WEAK SCATTERED CONVECTION INTO THE NIGHT.
MODELS BEGIN TO DIVERGE INTO THE MIDDLE OF NEXT WEEK WITH
DIFFERENCES IN STRENGTH OF NRN STREAM SHORT WAVE AND LINGERING
ROCKIES SHORT WAVE ENERGY...BUT MOST SOLUTIONS SUGGEST MORE
CONVECTION REGARDLESS OF THE SOLUTION. HAVE GONE DRY BY WED NIGHT
AND THU HOWEVER AS EVEN THE SLOWER ECMWF SUGGESTS NO PRECIP.

PERSISTENCE OF HEAT WILL BE A PROBLEM OVER THE WEEKEND...BUT BETTER
MIXING POTENTIAL MAY JUST LOWER DEWPOINTS ENOUGH TO KEEP HEAT
INDICES OUT OF ADVISORY RANGE.  IN FACT...HEAT INDICES SAT AND SUN
MAY BE A TOUCH LOWER THAN TODAY.

&&

.AVIATION...22/12Z
ISSUED AT 635 AM CDT FRI AUG 22 2014

ISOLD TSRA WILL AFFECT SOUTHERN IA THIS MORNING...BUT ANY EFFECTS
AT DSM/OTM ARE UNLIKELY AND WOULD BE BRIEF THUS LITTLE MENTION IN
12Z TAFS. MEANWHILE LARGE FOG/STRATUS BANK THAT DEVELOPED OVER MN
EARLY THIS AM IS IMPACTING MCW AND NEARING FOD/ALO AT SUNRISE.
EXPECT THE FOG TO BURN OFF BY 14Z WITH THE STRATUS GRADUALLY
LIFTING/BREAKING UP AS WELL. IFR CONDITIONS AT TIMES AT MCW NEXT
COUPLE HOURS...BUT THEREAFTER VFR SHOULD BE THE NORM THROUGH THE
REST OF TODAY. ADDITIONAL TSRA/BR POSSIBLE AGAIN TONIGHT MAINLY
AFTER DARK THOUGH SOME UNCERTAINTY REGARDING COVERAGE AND ONSET
TIME...SO HAVE HANDLED WITH SOME VCTS AND MVFR VSBY BR MENTIONS
IN THE TAFS FOR NOW.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...LEE




000
FXUS63 KDMX 221135
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
635 AM CDT FRI AUG 22 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

A CLUSTER OF THUNDERSTORMS DEVELOPED ACROSS SOUTHWEST IOWA OVERNIGHT
AND IS CURRENTLY WEAKENING AS IT PROGRESSES EASTWARD ACROSS ABOUT
THE SOUTHERN HALF OF THE FORECAST AREA. OVERALL INTENSITY TREND
SHOULD CONTINUE DOWNWARD WITH THIS ACTIVITY EARLY THIS MORNING.
MEANWHILE FOG AND PATCHY STRATUS HAVE DEVELOPED ACROSS THE NORTH IN
AN AIRMASS CHARACTERIZED BY NEARLY CALM WINDS AND DEWPOINTS IN THE
LOWER 70S...HOWEVER VSBYS HAVE SO FAR NOT DROPPED BELOW A MILE AND
BELIEVE ANY DENSE FOG WILL BE ISOLATED THUS NO ADVISORY IS BEING
ISSUED WITH THE MORNING PACKAGE BUT THE SITUATION WILL BE CLOSELY
MONITORED.

THE AFOREMENTIONED THUNDERSTORMS AND FOG SHOULD BOTH DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNRISE. THEREAFTER...IT WILL BE ANOTHER
VERY HUMID DAY WITH LIGHT WINDS AND GENERALLY VERY SWEATY
CONDITIONS. THERE IS A HIGH DEGREE OF UNCERTAINTY REGARDING
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TODAY. MOST OF THE LARGE
SCALE AND EVEN SOME OF THE HI RES MODELS ARE PAINTING LIGHT QPFS
ACROSS CENTRAL IOWA THROUGH MIDDAY AND THE
AFTERNOON...HOWEVER...UPSTREAM RADAR BELIES THIS WITH NO DEVELOPMENT
OF ANY KIND AND FORECAST SOUNDINGS SHOW A MODEST BUT EFFECTIVE
CAPPING INVERSION FOR MOST OF THE DAY...PARTICULARLY GIVEN THE
LIKELIHOOD OF CONVECTIVE DEBRIS CLOUDS EARLY IN THE DAY LIMITING
INSOLATION. THERE IS ALSO NO REAL FOCUS MECHANISM IN TERMS OF
FORCING FOR MOST OF THE DAY. CONVECTION SEEMS SOMEWHAT MORE PROBABLE
LATE IN THE DAY TOWARD THIS EVENING AS SURFACE HEATING ALLOWS THE
CAP TO BREAK AND WE WILL LIKELY SEE TYPICAL LATE SUMMER POPCORN
STORMS TOWARD SUNSET...WHICH IS COVERED BY 30 TO 40 POPS AND
SCATTERED WORDING IN THE FORECAST. TIED INTO THE DIFFICULT PRECIP
FORECAST FOR TODAY IS YET ANOTHER LOW CONFIDENCE TEMPERATURE
FORECAST. THE DEGREE OF SUNSHINE VERSUS CLOUDS IS PARTICULARLY
PROBLEMATIC...BUT EVEN ON THURSDAY WHEN THERE WAS AMPLE SUNSHINE
TEMPERATURES HAD A DIFFICULT TIME WARMING GIVEN THE VERY HUMID
AIRMASS IN PLACE. WILL CONTINUE THE TREND OF THE LAST COUPLE OF DAYS
IN LIMITING HIGH TEMPERATURES IN THE UPPER 80S AS IT APPEARS THE
REAL WARM UP WILL WAIT FOR THIS WEEKEND.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

ALTHOUGH THERE WILL CERTAINLY BE SOME BREAKS...THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK BEFORE CALMING DOWN TO END THE PERIOD.
EXPECT MORE CONVECTION AGAIN TONIGHT BUT FROM A DIFFERENT SCENARIO
THAN RECENTLY. ATTENTION WILL TURN UPSTREAM LOOKING AT EVOLUTION OF
AZ SHORT WAVE. REMNANTS SHOULD REACH THE PLAINS TONIGHT WITH LARGE
SCALE FORCING INCREASING INTO THE UPPER/MID MO VALLEY. THIS WILL
ALSO MATURE THERMODYNAMIC FORCING WITH THETA-E ADVECTION AND
BAROCLINIC ZONE STRENGTHENING AS IT LIFTS NORTHWARD. ALTHOUGH BEST
SUPPORT LOOKS TO REMAIN NORTH AND WEST OF IA...THIS SHOULD STILL BE
SUFFICIENT FOR MCS WITH AIRMASS STILL VERY FAVORABLE FOR CONVECTION.
CONVECTIVE POTENTIAL SHOULD DIMINISH SOUTH TO NORTH SAT WITH
BAROCLINIC ZONE EXITING IA TO THE NORTH...AND WARM FRONT LIFTING
FROM SRN IA TO OR BEYOND THE MN BORDER BY 00Z.  TEMPERATURES HAVE
BEEN PROBLEMATIC RECENTLY...OVER FORECAST...WITH MIXING DIFFICULT TO
GRASP DUE TO LINGERING CONVECTION AND LIGHTER WINDS. MOS HAS NOT
DONE TOO POORLY CAPTURING THIS HOWEVER SO STAYED CLOSE TO THOSE
NUMBERS FOR MAXES SAT.

FORCING ASSOCIATED WITH NRN ROCKIES/NRN PLAINS LONG WAVE TROUGH WILL
CONTINUE TO BRUSH WRN IA THROUGH THE WEEKEND...AND ALTHOUGH
THERMODYNAMIC FORCING WILL BE WEAKER...IT MAY STILL BE SUFFICIENT FOR
A FEW SURGES OF CONVECTION KEEPING LOW POPS GOING NORTH AND WEST SAT
NIGHT.  IA SHOULD BE THOROUGHLY INTO WARM SECTOR SUN WITH MORE
QUESTIONS ON THE DEGREE OF MIXING.  NAM IS VERY STRONG IN THIS
REGARD WITH RAW TEMPS SUGGESTING HIGHS FURTHER INTO THE 90S.
DEWPOINTS WILL BE A TAD LOWER...BUT STILL 70 PLUS...SO HAVE
FINALLY NUDGED HIGHS JUST OVER SATURDAYS /ONLY LOW 90S/ WITH
LITTLE PRECIP EXPECTED. DEGREE OF MIXING WILL NEED TO BE WATCHED
HOWEVER TO SEE IF NAM SUGGESTIONS CAN OVERCOME HIGH LOW LEVEL
MOISTURE CONTENT.

SURFACE FRONT MAY JUST REACH WRN SECTIONS LATE SUN WITH SURFACE
BASED POTENTIAL TOWARD THE MO RIVER. THERE SHOULD BE SUFFICIENT
FORCING FOR AT LEAST WEAK SCATTERED CONVECTION INTO THE NIGHT.
MODELS BEGIN TO DIVERGE INTO THE MIDDLE OF NEXT WEEK WITH
DIFFERENCES IN STRENGTH OF NRN STREAM SHORT WAVE AND LINGERING
ROCKIES SHORT WAVE ENERGY...BUT MOST SOLUTIONS SUGGEST MORE
CONVECTION REGARDLESS OF THE SOLUTION. HAVE GONE DRY BY WED NIGHT
AND THU HOWEVER AS EVEN THE SLOWER ECMWF SUGGESTS NO PRECIP.

PERSISTENCE OF HEAT WILL BE A PROBLEM OVER THE WEEKEND...BUT BETTER
MIXING POTENTIAL MAY JUST LOWER DEWPOINTS ENOUGH TO KEEP HEAT
INDICES OUT OF ADVISORY RANGE.  IN FACT...HEAT INDICES SAT AND SUN
MAY BE A TOUCH LOWER THAN TODAY.

&&

.AVIATION...22/12Z
ISSUED AT 635 AM CDT FRI AUG 22 2014

ISOLD TSRA WILL AFFECT SOUTHERN IA THIS MORNING...BUT ANY EFFECTS
AT DSM/OTM ARE UNLIKELY AND WOULD BE BRIEF THUS LITTLE MENTION IN
12Z TAFS. MEANWHILE LARGE FOG/STRATUS BANK THAT DEVELOPED OVER MN
EARLY THIS AM IS IMPACTING MCW AND NEARING FOD/ALO AT SUNRISE.
EXPECT THE FOG TO BURN OFF BY 14Z WITH THE STRATUS GRADUALLY
LIFTING/BREAKING UP AS WELL. IFR CONDITIONS AT TIMES AT MCW NEXT
COUPLE HOURS...BUT THEREAFTER VFR SHOULD BE THE NORM THROUGH THE
REST OF TODAY. ADDITIONAL TSRA/BR POSSIBLE AGAIN TONIGHT MAINLY
AFTER DARK THOUGH SOME UNCERTAINTY REGARDING COVERAGE AND ONSET
TIME...SO HAVE HANDLED WITH SOME VCTS AND MVFR VSBY BR MENTIONS
IN THE TAFS FOR NOW.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...LEE





000
FXUS63 KDMX 220914
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
414 AM CDT FRI AUG 22 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

A CLUSTER OF THUNDERSTORMS DEVELOPED ACROSS SOUTHWEST IOWA OVERNIGHT
AND IS CURRENTLY WEAKENING AS IT PROGRESSES EASTWARD ACROSS ABOUT
THE SOUTHERN HALF OF THE FORECAST AREA. OVERALL INTENSITY TREND
SHOULD CONTINUE DOWNWARD WITH THIS ACTIVITY EARLY THIS MORNING.
MEANWHILE FOG AND PATCHY STRATUS HAVE DEVELOPED ACROSS THE NORTH IN
AN AIRMASS CHARACTERIZED BY NEARLY CALM WINDS AND DEWPOINTS IN THE
LOWER 70S...HOWEVER VSBYS HAVE SO FAR NOT DROPPED BELOW A MILE AND
BELIEVE ANY DENSE FOG WILL BE ISOLATED THUS NO ADVISORY IS BEING
ISSUED WITH THE MORNING PACKAGE BUT THE SITUATION WILL BE CLOSELY
MONITORED.

THE AFOREMENTIONED THUNDERSTORMS AND FOG SHOULD BOTH DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNRISE. THEREAFTER...IT WILL BE ANOTHER
VERY HUMID DAY WITH LIGHT WINDS AND GENERALLY VERY SWEATY
CONDITIONS. THERE IS A HIGH DEGREE OF UNCERTAINTY REGARDING
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TODAY. MOST OF THE LARGE
SCALE AND EVEN SOME OF THE HI RES MODELS ARE PAINTING LIGHT QPFS
ACROSS CENTRAL IOWA THROUGH MIDDAY AND THE
AFTERNOON...HOWEVER...UPSTREAM RADAR BELIES THIS WITH NO DEVELOPMENT
OF ANY KIND AND FORECAST SOUNDINGS SHOW A MODEST BUT EFFECTIVE
CAPPING INVERSION FOR MOST OF THE DAY...PARTICULARLY GIVEN THE
LIKELIHOOD OF CONVECTIVE DEBRIS CLOUDS EARLY IN THE DAY LIMITING
INSOLATION. THERE IS ALSO NO REAL FOCUS MECHANISM IN TERMS OF
FORCING FOR MOST OF THE DAY. CONVECTION SEEMS SOMEWHAT MORE PROBABLE
LATE IN THE DAY TOWARD THIS EVENING AS SURFACE HEATING ALLOWS THE
CAP TO BREAK AND WE WILL LIKELY SEE TYPICAL LATE SUMMER POPCORN
STORMS TOWARD SUNSET...WHICH IS COVERED BY 30 TO 40 POPS AND
SCATTERED WORDING IN THE FORECAST. TIED INTO THE DIFFICULT PRECIP
FORECAST FOR TODAY IS YET ANOTHER LOW CONFIDENCE TEMPERATURE
FORECAST. THE DEGREE OF SUNSHINE VERSUS CLOUDS IS PARTICULARLY
PROBLEMATIC...BUT EVEN ON THURSDAY WHEN THERE WAS AMPLE SUNSHINE
TEMPERATURES HAD A DIFFICULT TIME WARMING GIVEN THE VERY HUMID
AIRMASS IN PLACE. WILL CONTINUE THE TREND OF THE LAST COUPLE OF DAYS
IN LIMITING HIGH TEMPERATURES IN THE UPPER 80S AS IT APPEARS THE
REAL WARM UP WILL WAIT FOR THIS WEEKEND.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

ALTHOUGH THERE WILL CERTAINLY BE SOME BREAKS...THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK BEFORE CALMING DOWN TO END THE PERIOD.
EXPECT MORE CONVECTION AGAIN TONIGHT BUT FROM A DIFFERENT SCENARIO
THAN RECENTLY. ATTENTION WILL TURN UPSTREAM LOOKING AT EVOLUTION OF
AZ SHORT WAVE. REMNANTS SHOULD REACH THE PLAINS TONIGHT WITH LARGE
SCALE FORCING INCREASING INTO THE UPPER/MID MO VALLEY. THIS WILL
ALSO MATURE THERMODYNAMIC FORCING WITH THETA-E ADVECTION AND
BAROCLINIC ZONE STRENGTHENING AS IT LIFTS NORTHWARD. ALTHOUGH BEST
SUPPORT LOOKS TO REMAIN NORTH AND WEST OF IA...THIS SHOULD STILL BE
SUFFICIENT FOR MCS WITH AIRMASS STILL VERY FAVORABLE FOR CONVECTION.
CONVECTIVE POTENTIAL SHOULD DIMINISH SOUTH TO NORTH SAT WITH
BAROCLINIC ZONE EXITING IA TO THE NORTH...AND WARM FRONT LIFTING
FROM SRN IA TO OR BEYOND THE MN BORDER BY 00Z.  TEMPERATURES HAVE
BEEN PROBLEMATIC RECENTLY...OVER FORECAST...WITH MIXING DIFFICULT TO
GRASP DUE TO LINGERING CONVECTION AND LIGHTER WINDS. MOS HAS NOT
DONE TOO POORLY CAPTURING THIS HOWEVER SO STAYED CLOSE TO THOSE
NUMBERS FOR MAXES SAT.

FORCING ASSOCIATED WITH NRN ROCKIES/NRN PLAINS LONG WAVE TROUGH WILL
CONTINUE TO BRUSH WRN IA THROUGH THE WEEKEND...AND ALTHOUGH
THERMODYNAMIC FORCING WILL BE WEAKER...IT MAY STILL BE SUFFICIENT FOR
A FEW SURGES OF CONVECTION KEEPING LOW POPS GOING NORTH AND WEST SAT
NIGHT.  IA SHOULD BE THOROUGHLY INTO WARM SECTOR SUN WITH MORE
QUESTIONS ON THE DEGREE OF MIXING.  NAM IS VERY STRONG IN THIS
REGARD WITH RAW TEMPS SUGGESTING HIGHS FURTHER INTO THE 90S.
DEWPOINTS WILL BE A TAD LOWER...BUT STILL 70 PLUS...SO HAVE
FINALLY NUDGED HIGHS JUST OVER SATURDAYS /ONLY LOW 90S/ WITH
LITTLE PRECIP EXPECTED. DEGREE OF MIXING WILL NEED TO BE WATCHED
HOWEVER TO SEE IF NAM SUGGESTIONS CAN OVERCOME HIGH LOW LEVEL
MOISTURE CONTENT.

SURFACE FRONT MAY JUST REACH WRN SECTIONS LATE SUN WITH SURFACE
BASED POTENTIAL TOWARD THE MO RIVER. THERE SHOULD BE SUFFICIENT
FORCING FOR AT LEAST WEAK SCATTERED CONVECTION INTO THE NIGHT.
MODELS BEGIN TO DIVERGE INTO THE MIDDLE OF NEXT WEEK WITH
DIFFERENCES IN STRENGTH OF NRN STREAM SHORT WAVE AND LINGERING
ROCKIES SHORT WAVE ENERGY...BUT MOST SOLUTIONS SUGGEST MORE
CONVECTION REGARDLESS OF THE SOLUTION. HAVE GONE DRY BY WED NIGHT
AND THU HOWEVER AS EVEN THE SLOWER ECMWF SUGGESTS NO PRECIP.

PERSISTENCE OF HEAT WILL BE A PROBLEM OVER THE WEEKEND...BUT BETTER
MIXING POTENTIAL MAY JUST LOWER DEWPOINTS ENOUGH TO KEEP HEAT
INDICES OUT OF ADVISORY RANGE.  IN FACT...HEAT INDICES SAT AND SUN
MAY BE A TOUCH LOWER THAN TODAY.

&&

.AVIATION...22/06Z
ISSUED AT 1205 AM CDT FRI AUG 22 2014

SYSTEM PUSHING ACROSS SOUTHERN IOWA WILL BRING TSRA TO SOUTHERN
SITES KDSM/KOTM FOR BEGINNING OF PERIOD WITH MVFR AND IFR
CONDITIONS EXPECTED WITH TSRA. BR/FG WILL DEVELOP AT REMAINING
SITES NEAR 12Z WITH MVFR OR IFR CONDITIONS EXPECTED. CONDITIONS
WILL IMPROVE QUICKLY AFTER 12Z...WITH WINDS REMAINING LIGHT AND
CONDITIONS REMAINING VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...AWB




000
FXUS63 KDMX 220914
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
414 AM CDT FRI AUG 22 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

A CLUSTER OF THUNDERSTORMS DEVELOPED ACROSS SOUTHWEST IOWA OVERNIGHT
AND IS CURRENTLY WEAKENING AS IT PROGRESSES EASTWARD ACROSS ABOUT
THE SOUTHERN HALF OF THE FORECAST AREA. OVERALL INTENSITY TREND
SHOULD CONTINUE DOWNWARD WITH THIS ACTIVITY EARLY THIS MORNING.
MEANWHILE FOG AND PATCHY STRATUS HAVE DEVELOPED ACROSS THE NORTH IN
AN AIRMASS CHARACTERIZED BY NEARLY CALM WINDS AND DEWPOINTS IN THE
LOWER 70S...HOWEVER VSBYS HAVE SO FAR NOT DROPPED BELOW A MILE AND
BELIEVE ANY DENSE FOG WILL BE ISOLATED THUS NO ADVISORY IS BEING
ISSUED WITH THE MORNING PACKAGE BUT THE SITUATION WILL BE CLOSELY
MONITORED.

THE AFOREMENTIONED THUNDERSTORMS AND FOG SHOULD BOTH DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNRISE. THEREAFTER...IT WILL BE ANOTHER
VERY HUMID DAY WITH LIGHT WINDS AND GENERALLY VERY SWEATY
CONDITIONS. THERE IS A HIGH DEGREE OF UNCERTAINTY REGARDING
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT TODAY. MOST OF THE LARGE
SCALE AND EVEN SOME OF THE HI RES MODELS ARE PAINTING LIGHT QPFS
ACROSS CENTRAL IOWA THROUGH MIDDAY AND THE
AFTERNOON...HOWEVER...UPSTREAM RADAR BELIES THIS WITH NO DEVELOPMENT
OF ANY KIND AND FORECAST SOUNDINGS SHOW A MODEST BUT EFFECTIVE
CAPPING INVERSION FOR MOST OF THE DAY...PARTICULARLY GIVEN THE
LIKELIHOOD OF CONVECTIVE DEBRIS CLOUDS EARLY IN THE DAY LIMITING
INSOLATION. THERE IS ALSO NO REAL FOCUS MECHANISM IN TERMS OF
FORCING FOR MOST OF THE DAY. CONVECTION SEEMS SOMEWHAT MORE PROBABLE
LATE IN THE DAY TOWARD THIS EVENING AS SURFACE HEATING ALLOWS THE
CAP TO BREAK AND WE WILL LIKELY SEE TYPICAL LATE SUMMER POPCORN
STORMS TOWARD SUNSET...WHICH IS COVERED BY 30 TO 40 POPS AND
SCATTERED WORDING IN THE FORECAST. TIED INTO THE DIFFICULT PRECIP
FORECAST FOR TODAY IS YET ANOTHER LOW CONFIDENCE TEMPERATURE
FORECAST. THE DEGREE OF SUNSHINE VERSUS CLOUDS IS PARTICULARLY
PROBLEMATIC...BUT EVEN ON THURSDAY WHEN THERE WAS AMPLE SUNSHINE
TEMPERATURES HAD A DIFFICULT TIME WARMING GIVEN THE VERY HUMID
AIRMASS IN PLACE. WILL CONTINUE THE TREND OF THE LAST COUPLE OF DAYS
IN LIMITING HIGH TEMPERATURES IN THE UPPER 80S AS IT APPEARS THE
REAL WARM UP WILL WAIT FOR THIS WEEKEND.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 409 AM CDT FRI AUG 22 2014

ALTHOUGH THERE WILL CERTAINLY BE SOME BREAKS...THE PATTERN WILL
REMAIN ACTIVE INTO NEXT WEEK BEFORE CALMING DOWN TO END THE PERIOD.
EXPECT MORE CONVECTION AGAIN TONIGHT BUT FROM A DIFFERENT SCENARIO
THAN RECENTLY. ATTENTION WILL TURN UPSTREAM LOOKING AT EVOLUTION OF
AZ SHORT WAVE. REMNANTS SHOULD REACH THE PLAINS TONIGHT WITH LARGE
SCALE FORCING INCREASING INTO THE UPPER/MID MO VALLEY. THIS WILL
ALSO MATURE THERMODYNAMIC FORCING WITH THETA-E ADVECTION AND
BAROCLINIC ZONE STRENGTHENING AS IT LIFTS NORTHWARD. ALTHOUGH BEST
SUPPORT LOOKS TO REMAIN NORTH AND WEST OF IA...THIS SHOULD STILL BE
SUFFICIENT FOR MCS WITH AIRMASS STILL VERY FAVORABLE FOR CONVECTION.
CONVECTIVE POTENTIAL SHOULD DIMINISH SOUTH TO NORTH SAT WITH
BAROCLINIC ZONE EXITING IA TO THE NORTH...AND WARM FRONT LIFTING
FROM SRN IA TO OR BEYOND THE MN BORDER BY 00Z.  TEMPERATURES HAVE
BEEN PROBLEMATIC RECENTLY...OVER FORECAST...WITH MIXING DIFFICULT TO
GRASP DUE TO LINGERING CONVECTION AND LIGHTER WINDS. MOS HAS NOT
DONE TOO POORLY CAPTURING THIS HOWEVER SO STAYED CLOSE TO THOSE
NUMBERS FOR MAXES SAT.

FORCING ASSOCIATED WITH NRN ROCKIES/NRN PLAINS LONG WAVE TROUGH WILL
CONTINUE TO BRUSH WRN IA THROUGH THE WEEKEND...AND ALTHOUGH
THERMODYNAMIC FORCING WILL BE WEAKER...IT MAY STILL BE SUFFICIENT FOR
A FEW SURGES OF CONVECTION KEEPING LOW POPS GOING NORTH AND WEST SAT
NIGHT.  IA SHOULD BE THOROUGHLY INTO WARM SECTOR SUN WITH MORE
QUESTIONS ON THE DEGREE OF MIXING.  NAM IS VERY STRONG IN THIS
REGARD WITH RAW TEMPS SUGGESTING HIGHS FURTHER INTO THE 90S.
DEWPOINTS WILL BE A TAD LOWER...BUT STILL 70 PLUS...SO HAVE
FINALLY NUDGED HIGHS JUST OVER SATURDAYS /ONLY LOW 90S/ WITH
LITTLE PRECIP EXPECTED. DEGREE OF MIXING WILL NEED TO BE WATCHED
HOWEVER TO SEE IF NAM SUGGESTIONS CAN OVERCOME HIGH LOW LEVEL
MOISTURE CONTENT.

SURFACE FRONT MAY JUST REACH WRN SECTIONS LATE SUN WITH SURFACE
BASED POTENTIAL TOWARD THE MO RIVER. THERE SHOULD BE SUFFICIENT
FORCING FOR AT LEAST WEAK SCATTERED CONVECTION INTO THE NIGHT.
MODELS BEGIN TO DIVERGE INTO THE MIDDLE OF NEXT WEEK WITH
DIFFERENCES IN STRENGTH OF NRN STREAM SHORT WAVE AND LINGERING
ROCKIES SHORT WAVE ENERGY...BUT MOST SOLUTIONS SUGGEST MORE
CONVECTION REGARDLESS OF THE SOLUTION. HAVE GONE DRY BY WED NIGHT
AND THU HOWEVER AS EVEN THE SLOWER ECMWF SUGGESTS NO PRECIP.

PERSISTENCE OF HEAT WILL BE A PROBLEM OVER THE WEEKEND...BUT BETTER
MIXING POTENTIAL MAY JUST LOWER DEWPOINTS ENOUGH TO KEEP HEAT
INDICES OUT OF ADVISORY RANGE.  IN FACT...HEAT INDICES SAT AND SUN
MAY BE A TOUCH LOWER THAN TODAY.

&&

.AVIATION...22/06Z
ISSUED AT 1205 AM CDT FRI AUG 22 2014

SYSTEM PUSHING ACROSS SOUTHERN IOWA WILL BRING TSRA TO SOUTHERN
SITES KDSM/KOTM FOR BEGINNING OF PERIOD WITH MVFR AND IFR
CONDITIONS EXPECTED WITH TSRA. BR/FG WILL DEVELOP AT REMAINING
SITES NEAR 12Z WITH MVFR OR IFR CONDITIONS EXPECTED. CONDITIONS
WILL IMPROVE QUICKLY AFTER 12Z...WITH WINDS REMAINING LIGHT AND
CONDITIONS REMAINING VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...AWB





000
FXUS63 KDMX 220506
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1206 AM CDT FRI AUG 22 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 351 PM CDT THU AUG 21 2014

YET ANOTHER MESSY FORECAST FOR TONIGHT. CURRENTLY A SHORTWAVE IS
EXITING IOWA AND THE ASSOCIATED FORCING WITH IT HAS PUSHED INTO
ILLINOIS. ANY CONVECTION IS WANING AND WILL BE ALL BUT GONE IN AN
HOUR OR TWO. CLOUDS ARE CLEARING FAST AND THE SUNNY SKIES ARE
ALLOWING FOR CLOUDS TO CLEAR OR AT LEAST LIFT AND WE ARE HEATING
UP...HOWEVER IT MAY BE LATE ENOUGH THAT HIGHS WILL REMAIN CLOSE TO
THE GOING FORECAST. NOT REALLY LOOKING FOR ANY STORMS THIS EARLY
EVENING AS THERE WILL BE LITTLE TO FOCUS ON...UNTIL THE LOW LEVEL
JET INCREASES. HOWEVER...THE LATEST SPC SWODY1 STILL KEEPS A
SLIGHT RISK ACROSS MOST OF THE CWA. CANNOT SAY I AGREE TOTALLY
WITH IT BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY EITHER.
THEIR THOUGHT IS THAT WITH CLEARING WILL COME DESTABILIZATION AND
ADDITIONAL STORM DEVELOPMENT WHICH WILL SINK INTO FAR NORTHERN
IOWA THIS EVENING/TONIGHT. THE 4KM NSSL DOES IN FACT SHOW THIS
SCENARIO BUT THE HOPWRF...HRRR...AND NAM 12 FAIL TO MATERIALIZE
ANY REAL CONVECTION UNTIL LATER TONIGHT WHEN A SHORTWAVE DRIVES A
FRONTAL BOUNDARY INTO US AS A LOW LEVEL JET FOCUSES ACROSS
SOUTHEAST IOWA.

MY ASSESSMENT IS THAT LATER THIS EVENING/TONIGHT ANOTHER SHORTWAVE
WILL CROSS IOWA FLATTENING THE UPPER RIDGE A BIT COINCIDENT WITH
THE LOW LEVEL JET WHICH WILL FOCUS INTO SOUTHERN/SOUTHEAST IOWA.
THERE IS ABUNDANT MOISTURE IN PLACE AND SOME WEAK THETA-E
ADVECTION AND FORCING MOVES INTO SOUTHERN IOWA AS WELL SO IF ALL
THIS COMES TOGETHER...LATER THIS EVENING THROUGH A FAIR PORTION OF
THE OVERNIGHT WE SHOULD SEE REDEVELOPMENT OF THUNDERSTORMS ACROSS
THE SOUTHERN/SOUTHEAST THIRD OR SO OF THE FORECAST AREA.

ADDING TO THIS WILL BE A SURFACE LOW OVER WESTERN MINNESOTA THAT
WILL MOVE EAST SOUTHEAST TONIGHT AS THE SHORTWAVE PUSHES ACROSS...
DRAGGING A FRONTAL BOUNDARY ALONG WITH IT.  BY 12Z THE FRONTAL
BOUNDARY WILL LIE SOMEWHERE NEAR A LINE FROM WATERLOO TO OMAHA.
PRETTY MUCH KEPT POPS CONFINED TO ALONG AND SOUTH OF THIS BOUNDARY
WITH THE BEST POPS FURTHER SOUTH ALONG THE MO BORDER. NORTH OF
THIS BOUNDARY THE LOW LEVEL MOISTURE WILL STILL RESIDE AND
PATCHY FOG WILL DEVELOP. VISIBILITIES COULD BE AS LOW AS A MILE OR
SO AND IT WILL BE POSSIBLE ACROSS A FAIRLY EXPANSIVE AREA...ENOUGH
TO WARRANT MENTION IN THE ZONES. PATCHY FOG IS POSSIBLE
ELSEWHERE...SOUTH OF THE BOUNDARY AS WELL BUT IT ISN`T AS CLEAR
CUT AS NORTH OF THE BOUNDARY. GIVEN THE POSSIBILITY OF
REDEVELOPMENT ACROSS THE NORTH I DID CARRY VERY LOW POPS ACROSS
FAR FAR NORTH FOR A COUPLE OF HOURS MID TO LATE EVENING BUT KEPT
HIGHER POPS SOUTH/SOUTHEAST.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 351 PM CDT THU AUG 21 2014

FORECAST REMAINED FOCUSED ON CONTINUED HOT AND HUMID CONDITIONS
AND THUNDERSTORM CHANCES OVER THE WEEKEND. LEANED TOWARD THE
DRIER...AND THUS WARMER NAM/ECMWF THROUGH THE WEEKEND.

FRIDAY THROUGH SUNDAY...OVERNIGHT CONVECTION WILL LINGER ACROSS
THE SOUTH PAST 12Z FRIDAY BEFORE PEAK HEATING IN CONJUNCTION WITH
A WEAK SHORTWAVE RIDING ALONG THE UPPER RIDGE BY THE LATE
AFTERNOON AND EVENING HOURS FRIDAY. MUCH OF THE FORECAST AREA
REMAINS CAPPED THROUGH 20Z FRIDAY AND PULLED BACK THE RE-DEVELOP
UNTIL THEN. MAINLY EXPECTING ISOLATED CONVECTION LATE TOMORROW
AFTERNOON INTO THE EVENING BEFORE THE MAIN SURFACE LOW AND
ASSOCIATED WARM FRONT TRANSITION ACROSS THE STATE. A LITTLE BETTER
ORGANIZED FOCUS BY SATURDAY MORNING AS THE WARM FRONT BULGES INTO
NORTHERN IOWA BY 12Z SATURDAY AND COINCIDES WITH A DECENT SLUG OF
THETA-E ADVECTION AND QG FORCING IN THIS AREA. HAVE LIKELY POPS
12-18Z SATURDAY BEFORE CONVECTION SHOULD MOVE INTO MINNESOTA BY
THE AFTERNOON. SEVERE POTENTIAL TOMORROW INTO SATURDAY ARE LIKELY
LIMITED WITH LACK OF SIGNIFICANT SHEAR PRESENT.

TWEAKED UP MAX TEMPS ON SATURDAY AND SUNDAY WITH THE WAA AND GOOD
MIXING BOTH DAYS. HEAT INDEX VALUES ACROSS THE CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA LOOK TO TOP 100 EACH
AFTERNOON BUT STILL BELOW ADVISORY CRITERIA ATTM. ON
FRIDAY...ALTHOUGH SOUTHERN IOWA HEAT INDEX VALUES NEAR
CRITERIA...WITH THE MORNING CONVECTION AND LINGERING CLOUD COVER
MAY INHIBIT THE MAX TEMPS AND THUS LOW CONFIDENCE WITH ANY
HEADLINES ATTM.

MONDAY THROUGH THURSDAY...LARGE UPPER LEVEL RIDGE HOLDS IN PLACE
OVER THE SOUTHEAST PORTION OF THE COUNTRY AND KEEPS WESTERN TO
NORTHERN IOWA IN THE RING OF FIRE. A FEW ADDITIONAL SHORTWAVES
RIDE ATOP THE RIDGE SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A
DECENT COLD FRONT PUSHES ACROSS THE REGION WEDNESDAY. TWEAKED UP
MAX TEMPS ON WEDNESDAY WITH GOOD WAA AHEAD OF THE FRONT.
OTHERWISE...DRY AND COOLER LATE NEXT WEEK.

&&

.AVIATION...22/06Z
ISSUED AT 1205 AM CDT FRI AUG 22 2014

SYSTEM PUSHING ACROSS SOUTHERN IOWA WILL BRING TSRA TO SOUTHERN
SITES KDSM/KOTM FOR BEGINNING OF PERIOD WITH MVFR AND IFR
CONDITIONS EXPECTED WITH TSRA. BR/FG WILL DEVELOP AT REMAINING
SITES NEAR 12Z WITH MVFR OR IFR CONDITIONS EXPECTED. CONDITIONS
WILL IMPROVE QUICKLY AFTER 12Z...WITH WINDS REMAINING LIGHT AND
CONDITIONS REMAINING VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...PODRAZIK
AVIATION...AWB




000
FXUS63 KDMX 220506
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1206 AM CDT FRI AUG 22 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 351 PM CDT THU AUG 21 2014

YET ANOTHER MESSY FORECAST FOR TONIGHT. CURRENTLY A SHORTWAVE IS
EXITING IOWA AND THE ASSOCIATED FORCING WITH IT HAS PUSHED INTO
ILLINOIS. ANY CONVECTION IS WANING AND WILL BE ALL BUT GONE IN AN
HOUR OR TWO. CLOUDS ARE CLEARING FAST AND THE SUNNY SKIES ARE
ALLOWING FOR CLOUDS TO CLEAR OR AT LEAST LIFT AND WE ARE HEATING
UP...HOWEVER IT MAY BE LATE ENOUGH THAT HIGHS WILL REMAIN CLOSE TO
THE GOING FORECAST. NOT REALLY LOOKING FOR ANY STORMS THIS EARLY
EVENING AS THERE WILL BE LITTLE TO FOCUS ON...UNTIL THE LOW LEVEL
JET INCREASES. HOWEVER...THE LATEST SPC SWODY1 STILL KEEPS A
SLIGHT RISK ACROSS MOST OF THE CWA. CANNOT SAY I AGREE TOTALLY
WITH IT BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY EITHER.
THEIR THOUGHT IS THAT WITH CLEARING WILL COME DESTABILIZATION AND
ADDITIONAL STORM DEVELOPMENT WHICH WILL SINK INTO FAR NORTHERN
IOWA THIS EVENING/TONIGHT. THE 4KM NSSL DOES IN FACT SHOW THIS
SCENARIO BUT THE HOPWRF...HRRR...AND NAM 12 FAIL TO MATERIALIZE
ANY REAL CONVECTION UNTIL LATER TONIGHT WHEN A SHORTWAVE DRIVES A
FRONTAL BOUNDARY INTO US AS A LOW LEVEL JET FOCUSES ACROSS
SOUTHEAST IOWA.

MY ASSESSMENT IS THAT LATER THIS EVENING/TONIGHT ANOTHER SHORTWAVE
WILL CROSS IOWA FLATTENING THE UPPER RIDGE A BIT COINCIDENT WITH
THE LOW LEVEL JET WHICH WILL FOCUS INTO SOUTHERN/SOUTHEAST IOWA.
THERE IS ABUNDANT MOISTURE IN PLACE AND SOME WEAK THETA-E
ADVECTION AND FORCING MOVES INTO SOUTHERN IOWA AS WELL SO IF ALL
THIS COMES TOGETHER...LATER THIS EVENING THROUGH A FAIR PORTION OF
THE OVERNIGHT WE SHOULD SEE REDEVELOPMENT OF THUNDERSTORMS ACROSS
THE SOUTHERN/SOUTHEAST THIRD OR SO OF THE FORECAST AREA.

ADDING TO THIS WILL BE A SURFACE LOW OVER WESTERN MINNESOTA THAT
WILL MOVE EAST SOUTHEAST TONIGHT AS THE SHORTWAVE PUSHES ACROSS...
DRAGGING A FRONTAL BOUNDARY ALONG WITH IT.  BY 12Z THE FRONTAL
BOUNDARY WILL LIE SOMEWHERE NEAR A LINE FROM WATERLOO TO OMAHA.
PRETTY MUCH KEPT POPS CONFINED TO ALONG AND SOUTH OF THIS BOUNDARY
WITH THE BEST POPS FURTHER SOUTH ALONG THE MO BORDER. NORTH OF
THIS BOUNDARY THE LOW LEVEL MOISTURE WILL STILL RESIDE AND
PATCHY FOG WILL DEVELOP. VISIBILITIES COULD BE AS LOW AS A MILE OR
SO AND IT WILL BE POSSIBLE ACROSS A FAIRLY EXPANSIVE AREA...ENOUGH
TO WARRANT MENTION IN THE ZONES. PATCHY FOG IS POSSIBLE
ELSEWHERE...SOUTH OF THE BOUNDARY AS WELL BUT IT ISN`T AS CLEAR
CUT AS NORTH OF THE BOUNDARY. GIVEN THE POSSIBILITY OF
REDEVELOPMENT ACROSS THE NORTH I DID CARRY VERY LOW POPS ACROSS
FAR FAR NORTH FOR A COUPLE OF HOURS MID TO LATE EVENING BUT KEPT
HIGHER POPS SOUTH/SOUTHEAST.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 351 PM CDT THU AUG 21 2014

FORECAST REMAINED FOCUSED ON CONTINUED HOT AND HUMID CONDITIONS
AND THUNDERSTORM CHANCES OVER THE WEEKEND. LEANED TOWARD THE
DRIER...AND THUS WARMER NAM/ECMWF THROUGH THE WEEKEND.

FRIDAY THROUGH SUNDAY...OVERNIGHT CONVECTION WILL LINGER ACROSS
THE SOUTH PAST 12Z FRIDAY BEFORE PEAK HEATING IN CONJUNCTION WITH
A WEAK SHORTWAVE RIDING ALONG THE UPPER RIDGE BY THE LATE
AFTERNOON AND EVENING HOURS FRIDAY. MUCH OF THE FORECAST AREA
REMAINS CAPPED THROUGH 20Z FRIDAY AND PULLED BACK THE RE-DEVELOP
UNTIL THEN. MAINLY EXPECTING ISOLATED CONVECTION LATE TOMORROW
AFTERNOON INTO THE EVENING BEFORE THE MAIN SURFACE LOW AND
ASSOCIATED WARM FRONT TRANSITION ACROSS THE STATE. A LITTLE BETTER
ORGANIZED FOCUS BY SATURDAY MORNING AS THE WARM FRONT BULGES INTO
NORTHERN IOWA BY 12Z SATURDAY AND COINCIDES WITH A DECENT SLUG OF
THETA-E ADVECTION AND QG FORCING IN THIS AREA. HAVE LIKELY POPS
12-18Z SATURDAY BEFORE CONVECTION SHOULD MOVE INTO MINNESOTA BY
THE AFTERNOON. SEVERE POTENTIAL TOMORROW INTO SATURDAY ARE LIKELY
LIMITED WITH LACK OF SIGNIFICANT SHEAR PRESENT.

TWEAKED UP MAX TEMPS ON SATURDAY AND SUNDAY WITH THE WAA AND GOOD
MIXING BOTH DAYS. HEAT INDEX VALUES ACROSS THE CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA LOOK TO TOP 100 EACH
AFTERNOON BUT STILL BELOW ADVISORY CRITERIA ATTM. ON
FRIDAY...ALTHOUGH SOUTHERN IOWA HEAT INDEX VALUES NEAR
CRITERIA...WITH THE MORNING CONVECTION AND LINGERING CLOUD COVER
MAY INHIBIT THE MAX TEMPS AND THUS LOW CONFIDENCE WITH ANY
HEADLINES ATTM.

MONDAY THROUGH THURSDAY...LARGE UPPER LEVEL RIDGE HOLDS IN PLACE
OVER THE SOUTHEAST PORTION OF THE COUNTRY AND KEEPS WESTERN TO
NORTHERN IOWA IN THE RING OF FIRE. A FEW ADDITIONAL SHORTWAVES
RIDE ATOP THE RIDGE SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A
DECENT COLD FRONT PUSHES ACROSS THE REGION WEDNESDAY. TWEAKED UP
MAX TEMPS ON WEDNESDAY WITH GOOD WAA AHEAD OF THE FRONT.
OTHERWISE...DRY AND COOLER LATE NEXT WEEK.

&&

.AVIATION...22/06Z
ISSUED AT 1205 AM CDT FRI AUG 22 2014

SYSTEM PUSHING ACROSS SOUTHERN IOWA WILL BRING TSRA TO SOUTHERN
SITES KDSM/KOTM FOR BEGINNING OF PERIOD WITH MVFR AND IFR
CONDITIONS EXPECTED WITH TSRA. BR/FG WILL DEVELOP AT REMAINING
SITES NEAR 12Z WITH MVFR OR IFR CONDITIONS EXPECTED. CONDITIONS
WILL IMPROVE QUICKLY AFTER 12Z...WITH WINDS REMAINING LIGHT AND
CONDITIONS REMAINING VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...PODRAZIK
AVIATION...AWB





000
FXUS63 KDMX 212346
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
646 PM CDT THU AUG 21 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 351 PM CDT THU AUG 21 2014

YET ANOTHER MESSY FORECAST FOR TONIGHT. CURRENTLY A SHORTWAVE IS
EXITING IOWA AND THE ASSOCIATED FORCING WITH IT HAS PUSHED INTO
ILLINOIS. ANY CONVECTION IS WANING AND WILL BE ALL BUT GONE IN AN
HOUR OR TWO. CLOUDS ARE CLEARING FAST AND THE SUNNY SKIES ARE
ALLOWING FOR CLOUDS TO CLEAR OR AT LEAST LIFT AND WE ARE HEATING
UP...HOWEVER IT MAY BE LATE ENOUGH THAT HIGHS WILL REMAIN CLOSE TO
THE GOING FORECAST. NOT REALLY LOOKING FOR ANY STORMS THIS EARLY
EVENING AS THERE WILL BE LITTLE TO FOCUS ON...UNTIL THE LOW LEVEL
JET INCREASES. HOWEVER...THE LATEST SPC SWODY1 STILL KEEPS A
SLIGHT RISK ACROSS MOST OF THE CWA. CANNOT SAY I AGREE TOTALLY
WITH IT BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY EITHER.
THEIR THOUGHT IS THAT WITH CLEARING WILL COME DESTABILIZATION AND
ADDITIONAL STORM DEVELOPMENT WHICH WILL SINK INTO FAR NORTHERN
IOWA THIS EVENING/TONIGHT. THE 4KM NSSL DOES IN FACT SHOW THIS
SCENARIO BUT THE HOPWRF...HRRR...AND NAM 12 FAIL TO MATERIALIZE
ANY REAL CONVECTION UNTIL LATER TONIGHT WHEN A SHORTWAVE DRIVES A
FRONTAL BOUNDARY INTO US AS A LOW LEVEL JET FOCUSES ACROSS
SOUTHEAST IOWA.

MY ASSESSMENT IS THAT LATER THIS EVENING/TONIGHT ANOTHER SHORTWAVE
WILL CROSS IOWA FLATTENING THE UPPER RIDGE A BIT COINCIDENT WITH
THE LOW LEVEL JET WHICH WILL FOCUS INTO SOUTHERN/SOUTHEAST IOWA.
THERE IS ABUNDANT MOISTURE IN PLACE AND SOME WEAK THETA-E
ADVECTION AND FORCING MOVES INTO SOUTHERN IOWA AS WELL SO IF ALL
THIS COMES TOGETHER...LATER THIS EVENING THROUGH A FAIR PORTION OF
THE OVERNIGHT WE SHOULD SEE REDEVELOPMENT OF THUNDERSTORMS ACROSS
THE SOUTHERN/SOUTHEAST THIRD OR SO OF THE FORECAST AREA.

ADDING TO THIS WILL BE A SURFACE LOW OVER WESTERN MINNESOTA THAT
WILL MOVE EAST SOUTHEAST TONIGHT AS THE SHORTWAVE PUSHES ACROSS...
DRAGGING A FRONTAL BOUNDARY ALONG WITH IT.  BY 12Z THE FRONTAL
BOUNDARY WILL LIE SOMEWHERE NEAR A LINE FROM WATERLOO TO OMAHA.
PRETTY MUCH KEPT POPS CONFINED TO ALONG AND SOUTH OF THIS BOUNDARY
WITH THE BEST POPS FURTHER SOUTH ALONG THE MO BORDER. NORTH OF
THIS BOUNDARY THE LOW LEVEL MOISTURE WILL STILL RESIDE AND
PATCHY FOG WILL DEVELOP. VISIBILITIES COULD BE AS LOW AS A MILE OR
SO AND IT WILL BE POSSIBLE ACROSS A FAIRLY EXPANSIVE AREA...ENOUGH
TO WARRANT MENTION IN THE ZONES. PATCHY FOG IS POSSIBLE
ELSEWHERE...SOUTH OF THE BOUNDARY AS WELL BUT IT ISN`T AS CLEAR
CUT AS NORTH OF THE BOUNDARY. GIVEN THE POSSIBILITY OF
REDEVELOPMENT ACROSS THE NORTH I DID CARRY VERY LOW POPS ACROSS
FAR FAR NORTH FOR A COUPLE OF HOURS MID TO LATE EVENING BUT KEPT
HIGHER POPS SOUTH/SOUTHEAST.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 351 PM CDT THU AUG 21 2014

FORECAST REMAINED FOCUSED ON CONTINUED HOT AND HUMID CONDITIONS
AND THUNDERSTORM CHANCES OVER THE WEEKEND. LEANED TOWARD THE
DRIER...AND THUS WARMER NAM/ECMWF THROUGH THE WEEKEND.

FRIDAY THROUGH SUNDAY...OVERNIGHT CONVECTION WILL LINGER ACROSS
THE SOUTH PAST 12Z FRIDAY BEFORE PEAK HEATING IN CONJUNCTION WITH
A WEAK SHORTWAVE RIDING ALONG THE UPPER RIDGE BY THE LATE
AFTERNOON AND EVENING HOURS FRIDAY. MUCH OF THE FORECAST AREA
REMAINS CAPPED THROUGH 20Z FRIDAY AND PULLED BACK THE RE-DEVELOP
UNTIL THEN. MAINLY EXPECTING ISOLATED CONVECTION LATE TOMORROW
AFTERNOON INTO THE EVENING BEFORE THE MAIN SURFACE LOW AND
ASSOCIATED WARM FRONT TRANSITION ACROSS THE STATE. A LITTLE BETTER
ORGANIZED FOCUS BY SATURDAY MORNING AS THE WARM FRONT BULGES INTO
NORTHERN IOWA BY 12Z SATURDAY AND COINCIDES WITH A DECENT SLUG OF
THETA-E ADVECTION AND QG FORCING IN THIS AREA. HAVE LIKELY POPS
12-18Z SATURDAY BEFORE CONVECTION SHOULD MOVE INTO MINNESOTA BY
THE AFTERNOON. SEVERE POTENTIAL TOMORROW INTO SATURDAY ARE LIKELY
LIMITED WITH LACK OF SIGNIFICANT SHEAR PRESENT.

TWEAKED UP MAX TEMPS ON SATURDAY AND SUNDAY WITH THE WAA AND GOOD
MIXING BOTH DAYS. HEAT INDEX VALUES ACROSS THE CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA LOOK TO TOP 100 EACH
AFTERNOON BUT STILL BELOW ADVISORY CRITERIA ATTM. ON
FRIDAY...ALTHOUGH SOUTHERN IOWA HEAT INDEX VALUES NEAR
CRITERIA...WITH THE MORNING CONVECTION AND LINGERING CLOUD COVER
MAY INHIBIT THE MAX TEMPS AND THUS LOW CONFIDENCE WITH ANY
HEADLINES ATTM.

MONDAY THROUGH THURSDAY...LARGE UPPER LEVEL RIDGE HOLDS IN PLACE
OVER THE SOUTHEAST PORTION OF THE COUNTRY AND KEEPS WESTERN TO
NORTHERN IOWA IN THE RING OF FIRE. A FEW ADDITIONAL SHORTWAVES
RIDE ATOP THE RIDGE SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A
DECENT COLD FRONT PUSHES ACROSS THE REGION WEDNESDAY. TWEAKED UP
MAX TEMPS ON WEDNESDAY WITH GOOD WAA AHEAD OF THE FRONT.
OTHERWISE...DRY AND COOLER LATE NEXT WEEK.

&&

.AVIATION...22/00Z
ISSUED AT 637 PM CDT THU AUG 21 2014

WINDS WILL LESSEN OVERNIGHT...WITH LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE WILL SEE BR/FG AT SITES NEAR 12Z...AND HAVE TRENDED
VISIBILITIES AND CEILINGS DOWN TO MVFR AND IFR...THOUGH MAY DROP
LOWER AT TIMES. IN ADDITION...ADDITIONAL ROUNDS OF TSRA/SHRA MAY
AFFECT SOUTHERN SITES NEAR 12Z...KDSM/KOTM...WITH CEILINGS AND
VISIBILITIES REDUCING TO MVFR OR LOWER WITH TSRA. WINDS WILL
REMAIN LIGHT THROUGH REMAINDER OF PERIOD WITH CONDITIONS RETURNING
TO VFR BEYOND 12Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...PODRAZIK
AVIATION...AWB





000
FXUS63 KDMX 212346
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
646 PM CDT THU AUG 21 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 351 PM CDT THU AUG 21 2014

YET ANOTHER MESSY FORECAST FOR TONIGHT. CURRENTLY A SHORTWAVE IS
EXITING IOWA AND THE ASSOCIATED FORCING WITH IT HAS PUSHED INTO
ILLINOIS. ANY CONVECTION IS WANING AND WILL BE ALL BUT GONE IN AN
HOUR OR TWO. CLOUDS ARE CLEARING FAST AND THE SUNNY SKIES ARE
ALLOWING FOR CLOUDS TO CLEAR OR AT LEAST LIFT AND WE ARE HEATING
UP...HOWEVER IT MAY BE LATE ENOUGH THAT HIGHS WILL REMAIN CLOSE TO
THE GOING FORECAST. NOT REALLY LOOKING FOR ANY STORMS THIS EARLY
EVENING AS THERE WILL BE LITTLE TO FOCUS ON...UNTIL THE LOW LEVEL
JET INCREASES. HOWEVER...THE LATEST SPC SWODY1 STILL KEEPS A
SLIGHT RISK ACROSS MOST OF THE CWA. CANNOT SAY I AGREE TOTALLY
WITH IT BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY EITHER.
THEIR THOUGHT IS THAT WITH CLEARING WILL COME DESTABILIZATION AND
ADDITIONAL STORM DEVELOPMENT WHICH WILL SINK INTO FAR NORTHERN
IOWA THIS EVENING/TONIGHT. THE 4KM NSSL DOES IN FACT SHOW THIS
SCENARIO BUT THE HOPWRF...HRRR...AND NAM 12 FAIL TO MATERIALIZE
ANY REAL CONVECTION UNTIL LATER TONIGHT WHEN A SHORTWAVE DRIVES A
FRONTAL BOUNDARY INTO US AS A LOW LEVEL JET FOCUSES ACROSS
SOUTHEAST IOWA.

MY ASSESSMENT IS THAT LATER THIS EVENING/TONIGHT ANOTHER SHORTWAVE
WILL CROSS IOWA FLATTENING THE UPPER RIDGE A BIT COINCIDENT WITH
THE LOW LEVEL JET WHICH WILL FOCUS INTO SOUTHERN/SOUTHEAST IOWA.
THERE IS ABUNDANT MOISTURE IN PLACE AND SOME WEAK THETA-E
ADVECTION AND FORCING MOVES INTO SOUTHERN IOWA AS WELL SO IF ALL
THIS COMES TOGETHER...LATER THIS EVENING THROUGH A FAIR PORTION OF
THE OVERNIGHT WE SHOULD SEE REDEVELOPMENT OF THUNDERSTORMS ACROSS
THE SOUTHERN/SOUTHEAST THIRD OR SO OF THE FORECAST AREA.

ADDING TO THIS WILL BE A SURFACE LOW OVER WESTERN MINNESOTA THAT
WILL MOVE EAST SOUTHEAST TONIGHT AS THE SHORTWAVE PUSHES ACROSS...
DRAGGING A FRONTAL BOUNDARY ALONG WITH IT.  BY 12Z THE FRONTAL
BOUNDARY WILL LIE SOMEWHERE NEAR A LINE FROM WATERLOO TO OMAHA.
PRETTY MUCH KEPT POPS CONFINED TO ALONG AND SOUTH OF THIS BOUNDARY
WITH THE BEST POPS FURTHER SOUTH ALONG THE MO BORDER. NORTH OF
THIS BOUNDARY THE LOW LEVEL MOISTURE WILL STILL RESIDE AND
PATCHY FOG WILL DEVELOP. VISIBILITIES COULD BE AS LOW AS A MILE OR
SO AND IT WILL BE POSSIBLE ACROSS A FAIRLY EXPANSIVE AREA...ENOUGH
TO WARRANT MENTION IN THE ZONES. PATCHY FOG IS POSSIBLE
ELSEWHERE...SOUTH OF THE BOUNDARY AS WELL BUT IT ISN`T AS CLEAR
CUT AS NORTH OF THE BOUNDARY. GIVEN THE POSSIBILITY OF
REDEVELOPMENT ACROSS THE NORTH I DID CARRY VERY LOW POPS ACROSS
FAR FAR NORTH FOR A COUPLE OF HOURS MID TO LATE EVENING BUT KEPT
HIGHER POPS SOUTH/SOUTHEAST.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 351 PM CDT THU AUG 21 2014

FORECAST REMAINED FOCUSED ON CONTINUED HOT AND HUMID CONDITIONS
AND THUNDERSTORM CHANCES OVER THE WEEKEND. LEANED TOWARD THE
DRIER...AND THUS WARMER NAM/ECMWF THROUGH THE WEEKEND.

FRIDAY THROUGH SUNDAY...OVERNIGHT CONVECTION WILL LINGER ACROSS
THE SOUTH PAST 12Z FRIDAY BEFORE PEAK HEATING IN CONJUNCTION WITH
A WEAK SHORTWAVE RIDING ALONG THE UPPER RIDGE BY THE LATE
AFTERNOON AND EVENING HOURS FRIDAY. MUCH OF THE FORECAST AREA
REMAINS CAPPED THROUGH 20Z FRIDAY AND PULLED BACK THE RE-DEVELOP
UNTIL THEN. MAINLY EXPECTING ISOLATED CONVECTION LATE TOMORROW
AFTERNOON INTO THE EVENING BEFORE THE MAIN SURFACE LOW AND
ASSOCIATED WARM FRONT TRANSITION ACROSS THE STATE. A LITTLE BETTER
ORGANIZED FOCUS BY SATURDAY MORNING AS THE WARM FRONT BULGES INTO
NORTHERN IOWA BY 12Z SATURDAY AND COINCIDES WITH A DECENT SLUG OF
THETA-E ADVECTION AND QG FORCING IN THIS AREA. HAVE LIKELY POPS
12-18Z SATURDAY BEFORE CONVECTION SHOULD MOVE INTO MINNESOTA BY
THE AFTERNOON. SEVERE POTENTIAL TOMORROW INTO SATURDAY ARE LIKELY
LIMITED WITH LACK OF SIGNIFICANT SHEAR PRESENT.

TWEAKED UP MAX TEMPS ON SATURDAY AND SUNDAY WITH THE WAA AND GOOD
MIXING BOTH DAYS. HEAT INDEX VALUES ACROSS THE CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA LOOK TO TOP 100 EACH
AFTERNOON BUT STILL BELOW ADVISORY CRITERIA ATTM. ON
FRIDAY...ALTHOUGH SOUTHERN IOWA HEAT INDEX VALUES NEAR
CRITERIA...WITH THE MORNING CONVECTION AND LINGERING CLOUD COVER
MAY INHIBIT THE MAX TEMPS AND THUS LOW CONFIDENCE WITH ANY
HEADLINES ATTM.

MONDAY THROUGH THURSDAY...LARGE UPPER LEVEL RIDGE HOLDS IN PLACE
OVER THE SOUTHEAST PORTION OF THE COUNTRY AND KEEPS WESTERN TO
NORTHERN IOWA IN THE RING OF FIRE. A FEW ADDITIONAL SHORTWAVES
RIDE ATOP THE RIDGE SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A
DECENT COLD FRONT PUSHES ACROSS THE REGION WEDNESDAY. TWEAKED UP
MAX TEMPS ON WEDNESDAY WITH GOOD WAA AHEAD OF THE FRONT.
OTHERWISE...DRY AND COOLER LATE NEXT WEEK.

&&

.AVIATION...22/00Z
ISSUED AT 637 PM CDT THU AUG 21 2014

WINDS WILL LESSEN OVERNIGHT...WITH LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE WILL SEE BR/FG AT SITES NEAR 12Z...AND HAVE TRENDED
VISIBILITIES AND CEILINGS DOWN TO MVFR AND IFR...THOUGH MAY DROP
LOWER AT TIMES. IN ADDITION...ADDITIONAL ROUNDS OF TSRA/SHRA MAY
AFFECT SOUTHERN SITES NEAR 12Z...KDSM/KOTM...WITH CEILINGS AND
VISIBILITIES REDUCING TO MVFR OR LOWER WITH TSRA. WINDS WILL
REMAIN LIGHT THROUGH REMAINDER OF PERIOD WITH CONDITIONS RETURNING
TO VFR BEYOND 12Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...PODRAZIK
AVIATION...AWB




000
FXUS63 KDMX 212056
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
356 PM CDT THU AUG 21 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 351 PM CDT THU AUG 21 2014

YET ANOTHER MESSY FORECAST FOR TONIGHT. CURRENTLY A SHORTWAVE IS
EXITING IOWA AND THE ASSOCIATED FORCING WITH IT HAS PUSHED INTO
ILLINOIS. ANY CONVECTION IS WANING AND WILL BE ALL BUT GONE IN AN
HOUR OR TWO. CLOUDS ARE CLEARING FAST AND THE SUNNY SKIES ARE
ALLOWING FOR CLOUDS TO CLEAR OR AT LEAST LIFT AND WE ARE HEATING
UP...HOWEVER IT MAY BE LATE ENOUGH THAT HIGHS WILL REMAIN CLOSE TO
THE GOING FORECAST. NOT REALLY LOOKING FOR ANY STORMS THIS EARLY
EVENING AS THERE WILL BE LITTLE TO FOCUS ON...UNTIL THE LOW LEVEL
JET INCREASES. HOWEVER...THE LATEST SPC SWODY1 STILL KEEPS A
SLIGHT RISK ACROSS MOST OF THE CWA. CANNOT SAY I AGREE TOTALLY
WITH IT BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY EITHER.
THEIR THOUGHT IS THAT WITH CLEARING WILL COME DESTABILIZATION AND
ADDITIONAL STORM DEVELOPMENT WHICH WILL SINK INTO FAR NORTHERN
IOWA THIS EVENING/TONIGHT. THE 4KM NSSL DOES IN FACT SHOW THIS
SCENARIO BUT THE HOPWRF...HRRR...AND NAM 12 FAIL TO MATERIALIZE
ANY REAL CONVECTION UNTIL LATER TONIGHT WHEN A SHORTWAVE DRIVES A
FRONTAL BOUNDARY INTO US AS A LOW LEVEL JET FOCUSES ACROSS
SOUTHEAST IOWA.

MY ASSESSMENT IS THAT LATER THIS EVENING/TONIGHT ANOTHER SHORTWAVE
WILL CROSS IOWA FLATTENING THE UPPER RIDGE A BIT COINCIDENT WITH
THE LOW LEVEL JET WHICH WILL FOCUS INTO SOUTHERN/SOUTHEAST IOWA.
THERE IS ABUNDANT MOISTURE IN PLACE AND SOME WEAK THETA-E
ADVECTION AND FORCING MOVES INTO SOUTHERN IOWA AS WELL SO IF ALL
THIS COMES TOGETHER...LATER THIS EVENING THROUGH A FAIR PORTION OF
THE OVERNIGHT WE SHOULD SEE REDEVELOPMENT OF THUNDERSTORMS ACROSS
THE SOUTHERN/SOUTHEAST THIRD OR SO OF THE FORECAST AREA.

ADDING TO THIS WILL BE A SURFACE LOW OVER WESTERN MINNESOTA THAT
WILL MOVE EAST SOUTHEAST TONIGHT AS THE SHORTWAVE PUSHES ACROSS...
DRAGGING A FRONTAL BOUNDARY ALONG WITH IT.  BY 12Z THE FRONTAL
BOUNDARY WILL LIE SOMEWHERE NEAR A LINE FROM WATERLOO TO OMAHA.
PRETTY MUCH KEPT POPS CONFINED TO ALONG AND SOUTH OF THIS BOUNDARY
WITH THE BEST POPS FURTHER SOUTH ALONG THE MO BORDER. NORTH OF
THIS BOUNDARY THE LOW LEVEL MOISTURE WILL STILL RESIDE AND
PATCHY FOG WILL DEVELOP. VISIBILITIES COULD BE AS LOW AS A MILE OR
SO AND IT WILL BE POSSIBLE ACROSS A FAIRLY EXPANSIVE AREA...ENOUGH
TO WARRANT MENTION IN THE ZONES. PATCHY FOG IS POSSIBLE
ELSEWHERE...SOUTH OF THE BOUNDARY AS WELL BUT IT ISN`T AS CLEAR
CUT AS NORTH OF THE BOUNDARY. GIVEN THE POSSIBILITY OF
REDEVELOPMENT ACROSS THE NORTH I DID CARRY VERY LOW POPS ACROSS
FAR FAR NORTH FOR A COUPLE OF HOURS MID TO LATE EVENING BUT KEPT
HIGHER POPS SOUTH/SOUTHEAST.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 351 PM CDT THU AUG 21 2014

FORECAST REMAINED FOCUSED ON CONTINUED HOT AND HUMID CONDITIONS
AND THUNDERSTORM CHANCES OVER THE WEEKEND. LEANED TOWARD THE
DRIER...AND THUS WARMER NAM/ECMWF THROUGH THE WEEKEND.

FRIDAY THROUGH SUNDAY...OVERNIGHT CONVECTION WILL LINGER ACROSS
THE SOUTH PAST 12Z FRIDAY BEFORE PEAK HEATING IN CONJUNCTION WITH
A WEAK SHORTWAVE RIDING ALONG THE UPPER RIDGE BY THE LATE
AFTERNOON AND EVENING HOURS FRIDAY. MUCH OF THE FORECAST AREA
REMAINS CAPPED THROUGH 20Z FRIDAY AND PULLED BACK THE RE-DEVELOP
UNTIL THEN. MAINLY EXPECTING ISOLATED CONVECTION LATE TOMORROW
AFTERNOON INTO THE EVENING BEFORE THE MAIN SURFACE LOW AND
ASSOCIATED WARM FRONT TRANSITION ACROSS THE STATE. A LITTLE BETTER
ORGANIZED FOCUS BY SATURDAY MORNING AS THE WARM FRONT BULGES INTO
NORTHERN IOWA BY 12Z SATURDAY AND COINCIDES WITH A DECENT SLUG OF
THETA-E ADVECTION AND QG FORCING IN THIS AREA. HAVE LIKELY POPS
12-18Z SATURDAY BEFORE CONVECTION SHOULD MOVE INTO MINNESOTA BY
THE AFTERNOON. SEVERE POTENTIAL TOMORROW INTO SATURDAY ARE LIKELY
LIMITED WITH LACK OF SIGNIFICANT SHEAR PRESENT.

TWEAKED UP MAX TEMPS ON SATURDAY AND SUNDAY WITH THE WAA AND GOOD
MIXING BOTH DAYS. HEAT INDEX VALUES ACROSS THE CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA LOOK TO TOP 100 EACH
AFTERNOON BUT STILL BELOW ADVISORY CRITERIA ATTM. ON
FRIDAY...ALTHOUGH SOUTHERN IOWA HEAT INDEX VALUES NEAR
CRITERIA...WITH THE MORNING CONVECTION AND LINGERING CLOUD COVER
MAY INHIBIT THE MAX TEMPS AND THUS LOW CONFIDENCE WITH ANY
HEADLINES ATTM.

MONDAY THROUGH THURSDAY...LARGE UPPER LEVEL RIDGE HOLDS IN PLACE
OVER THE SOUTHEAST PORTION OF THE COUNTRY AND KEEPS WESTERN TO
NORTHERN IOWA IN THE RING OF FIRE. A FEW ADDITIONAL SHORTWAVES
RIDE ATOP THE RIDGE SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A
DECENT COLD FRONT PUSHES ACROSS THE REGION WEDNESDAY. TWEAKED UP
MAX TEMPS ON WEDNESDAY WITH GOOD WAA AHEAD OF THE FRONT.
OTHERWISE...DRY AND COOLER LATE NEXT WEEK.

&&

.AVIATION...21/18Z
ISSUED AT 112 PM CDT THU AUG 21 2014

TSRA WANING/MOVING OUT OF THE FORECAST AREA.  SHOULD MAINLY BE VFR
COND WITH PATCHY MVFR CIGS FAR W AND FAR E.  ABUNDANT LOW LEVEL
MOISTURE MAY ALSO PROVIDE FOR SOME SCT CLOUDS BLO 1000KFT.  WITH
ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...EXPECT TO SEE SO FOG
TONIGHT...MAINLY AFT06Z.  AN UPPER LEVEL DISTURBANCE MAY BRING SOME
POTENTIAL FOR ISOLD THUNDER ACROSS THE EAST.  UNCERTAINTY ON STORMS
TONIGHT THOUGH IS STILL HIGH.  WILL MAINTAIN VCTS FOR THE MOST
PART...EXCEPT FOR KOTM AREA WHERE POTENTIAL LOOKS BEST.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...FAB
LONG TERM...PODRAZIK
AVIATION...FAB




000
FXUS63 KDMX 212056
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
356 PM CDT THU AUG 21 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 351 PM CDT THU AUG 21 2014

YET ANOTHER MESSY FORECAST FOR TONIGHT. CURRENTLY A SHORTWAVE IS
EXITING IOWA AND THE ASSOCIATED FORCING WITH IT HAS PUSHED INTO
ILLINOIS. ANY CONVECTION IS WANING AND WILL BE ALL BUT GONE IN AN
HOUR OR TWO. CLOUDS ARE CLEARING FAST AND THE SUNNY SKIES ARE
ALLOWING FOR CLOUDS TO CLEAR OR AT LEAST LIFT AND WE ARE HEATING
UP...HOWEVER IT MAY BE LATE ENOUGH THAT HIGHS WILL REMAIN CLOSE TO
THE GOING FORECAST. NOT REALLY LOOKING FOR ANY STORMS THIS EARLY
EVENING AS THERE WILL BE LITTLE TO FOCUS ON...UNTIL THE LOW LEVEL
JET INCREASES. HOWEVER...THE LATEST SPC SWODY1 STILL KEEPS A
SLIGHT RISK ACROSS MOST OF THE CWA. CANNOT SAY I AGREE TOTALLY
WITH IT BUT IT IS NOT OUT OF THE REALM OF POSSIBILITY EITHER.
THEIR THOUGHT IS THAT WITH CLEARING WILL COME DESTABILIZATION AND
ADDITIONAL STORM DEVELOPMENT WHICH WILL SINK INTO FAR NORTHERN
IOWA THIS EVENING/TONIGHT. THE 4KM NSSL DOES IN FACT SHOW THIS
SCENARIO BUT THE HOPWRF...HRRR...AND NAM 12 FAIL TO MATERIALIZE
ANY REAL CONVECTION UNTIL LATER TONIGHT WHEN A SHORTWAVE DRIVES A
FRONTAL BOUNDARY INTO US AS A LOW LEVEL JET FOCUSES ACROSS
SOUTHEAST IOWA.

MY ASSESSMENT IS THAT LATER THIS EVENING/TONIGHT ANOTHER SHORTWAVE
WILL CROSS IOWA FLATTENING THE UPPER RIDGE A BIT COINCIDENT WITH
THE LOW LEVEL JET WHICH WILL FOCUS INTO SOUTHERN/SOUTHEAST IOWA.
THERE IS ABUNDANT MOISTURE IN PLACE AND SOME WEAK THETA-E
ADVECTION AND FORCING MOVES INTO SOUTHERN IOWA AS WELL SO IF ALL
THIS COMES TOGETHER...LATER THIS EVENING THROUGH A FAIR PORTION OF
THE OVERNIGHT WE SHOULD SEE REDEVELOPMENT OF THUNDERSTORMS ACROSS
THE SOUTHERN/SOUTHEAST THIRD OR SO OF THE FORECAST AREA.

ADDING TO THIS WILL BE A SURFACE LOW OVER WESTERN MINNESOTA THAT
WILL MOVE EAST SOUTHEAST TONIGHT AS THE SHORTWAVE PUSHES ACROSS...
DRAGGING A FRONTAL BOUNDARY ALONG WITH IT.  BY 12Z THE FRONTAL
BOUNDARY WILL LIE SOMEWHERE NEAR A LINE FROM WATERLOO TO OMAHA.
PRETTY MUCH KEPT POPS CONFINED TO ALONG AND SOUTH OF THIS BOUNDARY
WITH THE BEST POPS FURTHER SOUTH ALONG THE MO BORDER. NORTH OF
THIS BOUNDARY THE LOW LEVEL MOISTURE WILL STILL RESIDE AND
PATCHY FOG WILL DEVELOP. VISIBILITIES COULD BE AS LOW AS A MILE OR
SO AND IT WILL BE POSSIBLE ACROSS A FAIRLY EXPANSIVE AREA...ENOUGH
TO WARRANT MENTION IN THE ZONES. PATCHY FOG IS POSSIBLE
ELSEWHERE...SOUTH OF THE BOUNDARY AS WELL BUT IT ISN`T AS CLEAR
CUT AS NORTH OF THE BOUNDARY. GIVEN THE POSSIBILITY OF
REDEVELOPMENT ACROSS THE NORTH I DID CARRY VERY LOW POPS ACROSS
FAR FAR NORTH FOR A COUPLE OF HOURS MID TO LATE EVENING BUT KEPT
HIGHER POPS SOUTH/SOUTHEAST.

.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 351 PM CDT THU AUG 21 2014

FORECAST REMAINED FOCUSED ON CONTINUED HOT AND HUMID CONDITIONS
AND THUNDERSTORM CHANCES OVER THE WEEKEND. LEANED TOWARD THE
DRIER...AND THUS WARMER NAM/ECMWF THROUGH THE WEEKEND.

FRIDAY THROUGH SUNDAY...OVERNIGHT CONVECTION WILL LINGER ACROSS
THE SOUTH PAST 12Z FRIDAY BEFORE PEAK HEATING IN CONJUNCTION WITH
A WEAK SHORTWAVE RIDING ALONG THE UPPER RIDGE BY THE LATE
AFTERNOON AND EVENING HOURS FRIDAY. MUCH OF THE FORECAST AREA
REMAINS CAPPED THROUGH 20Z FRIDAY AND PULLED BACK THE RE-DEVELOP
UNTIL THEN. MAINLY EXPECTING ISOLATED CONVECTION LATE TOMORROW
AFTERNOON INTO THE EVENING BEFORE THE MAIN SURFACE LOW AND
ASSOCIATED WARM FRONT TRANSITION ACROSS THE STATE. A LITTLE BETTER
ORGANIZED FOCUS BY SATURDAY MORNING AS THE WARM FRONT BULGES INTO
NORTHERN IOWA BY 12Z SATURDAY AND COINCIDES WITH A DECENT SLUG OF
THETA-E ADVECTION AND QG FORCING IN THIS AREA. HAVE LIKELY POPS
12-18Z SATURDAY BEFORE CONVECTION SHOULD MOVE INTO MINNESOTA BY
THE AFTERNOON. SEVERE POTENTIAL TOMORROW INTO SATURDAY ARE LIKELY
LIMITED WITH LACK OF SIGNIFICANT SHEAR PRESENT.

TWEAKED UP MAX TEMPS ON SATURDAY AND SUNDAY WITH THE WAA AND GOOD
MIXING BOTH DAYS. HEAT INDEX VALUES ACROSS THE CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA LOOK TO TOP 100 EACH
AFTERNOON BUT STILL BELOW ADVISORY CRITERIA ATTM. ON
FRIDAY...ALTHOUGH SOUTHERN IOWA HEAT INDEX VALUES NEAR
CRITERIA...WITH THE MORNING CONVECTION AND LINGERING CLOUD COVER
MAY INHIBIT THE MAX TEMPS AND THUS LOW CONFIDENCE WITH ANY
HEADLINES ATTM.

MONDAY THROUGH THURSDAY...LARGE UPPER LEVEL RIDGE HOLDS IN PLACE
OVER THE SOUTHEAST PORTION OF THE COUNTRY AND KEEPS WESTERN TO
NORTHERN IOWA IN THE RING OF FIRE. A FEW ADDITIONAL SHORTWAVES
RIDE ATOP THE RIDGE SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A
DECENT COLD FRONT PUSHES ACROSS THE REGION WEDNESDAY. TWEAKED UP
MAX TEMPS ON WEDNESDAY WITH GOOD WAA AHEAD OF THE FRONT.
OTHERWISE...DRY AND COOLER LATE NEXT WEEK.

&&

.AVIATION...21/18Z
ISSUED AT 112 PM CDT THU AUG 21 2014

TSRA WANING/MOVING OUT OF THE FORECAST AREA.  SHOULD MAINLY BE VFR
COND WITH PATCHY MVFR CIGS FAR W AND FAR E.  ABUNDANT LOW LEVEL
MOISTURE MAY ALSO PROVIDE FOR SOME SCT CLOUDS BLO 1000KFT.  WITH
ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...EXPECT TO SEE SO FOG
TONIGHT...MAINLY AFT06Z.  AN UPPER LEVEL DISTURBANCE MAY BRING SOME
POTENTIAL FOR ISOLD THUNDER ACROSS THE EAST.  UNCERTAINTY ON STORMS
TONIGHT THOUGH IS STILL HIGH.  WILL MAINTAIN VCTS FOR THE MOST
PART...EXCEPT FOR KOTM AREA WHERE POTENTIAL LOOKS BEST.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...FAB
LONG TERM...PODRAZIK
AVIATION...FAB





000
FXUS63 KDMX 211815
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
112 PM CDT THU AUG 21 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

THUNDERSTORMS DEVELOPING ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA WILL AFFECT OUR FAR NORTHERN COUNTIES EARLY THIS MORNING
WITH A LOW RISK OF SEVERE WEATHER AND LOCALIZED FLOODING...BUT WILL
EXIT THE FORECAST AREA AROUND OR SHORTLY AFTER 12Z. OTHERWISE
ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS CENTRAL IOWA BOTH
FROM EARLY MORNING DEVELOPMENT OVERHEAD AND FROM THE CLUSTER OF
STORMS MOVING IN FROM CENTRAL NEBRASKA...WHICH SHOULD FADE AS THEY
ENTER IOWA LATER IN THE MORNING. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING THE DEGREE TO WHICH STORMS WILL OR WILL NOT BE
ABLE TO SURVIVE IN THE LATE MORNING AND AFTERNOON...WHICH WILL HAVE
A SIGNIFICANT EFFECT ON OUR TEMPERATURES LATER IN THE DAY. WE SAW
YESTERDAY WHAT CAN HAPPEN IF THE PRECIP/CLOUDS LINGER INTO THE
AFTERNOON AS TEMPERATURES WERE NEARLY 10 DEGREES COOLER THAN
ANTICIPATED IN SOME AREAS. FOR NOW HAVE LINGERED ISOLATED
THUNDERSTORM WORDING THROUGH AROUND MIDDAY ACROSS CENTRAL
IOWA...LOWERED HIGH TEMPERATURES A BIT AS IT APPEARS RESIDUAL
CONVECTIVE DEBRIS CLOUDS WILL ONCE AGAIN BE AN ISSUE AT LEAST TO
SOME EXTENT...AND DO NOT FEEL THAT HEAT HEADLINES ARE WARRANTED IN
THIS SCENARIO. TOWARD THIS EVENING STORMS WILL AGAIN BE
POSSIBLE...BUT BELIEVE WE WILL REMAIN CAPPED OFF WITH PRECIP
LIKELIER AFTER DARK AND INTO THE OVERNIGHT PERIOD ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS THROUGH THE
ENTIRE PERIOD WITH PATTERN REMAINING QUITE ACTIVE.  MODELS REMAIN IN
DECENT AGREEMENT ON THE LARGER SCALE INTO EARLY NEXT WEEK WITH
FAIRLY HIGH AMPLITUDE WRN TROUGH TO OH VALLEY/ERN GREAT LAKES RIDGE.
SHORT WAVE CURRENTLY PUSHING THROUGH DAKOTAS/MN AND DRIVING MCS FROM
NRN IA INTO MN WILL ALSO EVENTUALLY SAG SURFACE REFLECTION AND
BOUNDARY INTO IA BY TONIGHT. THERE IS SOME POTENTIAL FOR SURFACE
BASED CONVECTION TO FIRE ALONG THE LOW LEVEL CONVERGENCE AND
CONTINUE INTO THE EVENING AS THETA-E ADVECTION AND MOISTURE
TRANSPORT INTERSECTS THE BOUNDARY. IT QUICKLY VEERS TOWARD
DAYBREAK HOWEVER...SO IT SHOULD BEGIN TO WANE AND DISSIPATE INTO
FRI MORNING. LOOKING FOR THINGS TO TURN MORE ACTIVE TOWARD 00Z
AND INTO THE NIGHT HOWEVER. SURFACE BASED CONVECTION MAY RE-FIRE
NEAR THE WARM FRONT FROM NE INTO IA. WRN TROUGH IS EXPECTED TO BE
JUST PROGRESSIVE ENOUGH TO INCREASE SYNOPTIC SCALE LIFT AND
THERMODYNAMIC FORCING TO FUEL MCS INTO THE NIGHT AS WARM FRONT
AGAIN LIFTS NORTHWARD. PRECIP CHANCES MAY STILL LINGER THROUGH THE
DAY...BUT GRADUALLY LIFT SOUTH TO NORTH. CHANCES WILL REMAIN IN
THE FORECAST...MAINLY NW THIRD ATTENDANT TO NE/SD SURFACE
FRONT...THEN INCREASE INTO SUN NIGHT WEST TO EAST AS SURFACE BASED
CONVECTION OOZES INTO IA LATER IN THE NIGHT FUELED BY AN UPTICK IN
KINEMATIC FORCING ASSOCIATED WITH SHORT WAVE LIFTING THROUGH THE
NRN PLAINS.

FORECAST CONFIDENCE DECREASES INTO NEXT WEEK HOWEVER AS GFS/GEM ARE
STILL MORE PROGRESSIVE LIFTING LONG WAVE TROUGH FROM THE NRN
ROCKIES INTO THE NRN PLAINS WHILE THE ECMWF HAS CHANGED SOMEWHAT
LEAVING CUTOFF REMNANTS OVER THE ROCKIES. HAVE NOT CHANGED
FORECAST TOO MUCH DUE TO THIS UNCERTAINTY. MODELS SUGGEST POPS TO
SOME DEGREE THROUGH WED FOR DIFFERENT REASONS...ECMWF WARM
ADVECTION VS GFS LINGERING WEAKER PRECIP BEHIND THE TROUGH.

THE AIRMASS THROUGH EARLY NEXT WEEK WILL NOT CHANGE MUCH AND REMAIN
FAVORABLE FOR LOCALLY HEAVY RAIN WITH ELEVATED PWS AND WARM CLOUD
DEPTHS.  AS MENTIONED IN PREVIOUS DISCUSSIONS...FLASH FLOOD WATCHES
MAY EVENTUALLY BE NEEDED BUT NOT UNTIL CONFIDENCE IN CONVECTIVE
TRENDS OVER FAVORABLE HIGH SOIL MOISTURE AREAS INCREASES.  SEVERE
POTENTIAL WILL REMAIN THERE AS WELL BUT WITH NO PARTICULAR TIME OR
LOCATION TO FOCUS ON AS OF YET...ALTHOUGH SURFACE BASED DEVELOPMENT
LATE SUN SEEMS SOMEWHAT MORE FAVORABLE WITH BETTER PHASED
INSTABILITY...SHEAR AND FORCING.

HEAT INDICES WILL APPROACH ADVISORY CRITERIA THROUGH THE
WEEKEND...AND HEADLINES COULD EVENTUALLY BE NEEDED IF THIS OCCURS
REPETITIVELY FOR SEVERAL DAYS...BUT CONVECTION AND ASSOCIATED DEBRIS
COULD CERTAINLY AFFECT THINGS AND KEEPS CONFIDENCE LOW ENOUGH TO
PRECLUDE ANY HEADLINES AT THE MOMENT.

&&

.AVIATION...21/18Z
ISSUED AT 112 PM CDT THU AUG 21 2014

TSRA WANING/MOVING OUT OF THE FORECAST AREA.  SHOULD MAINLY BE VFR
COND WITH PATCHY MVFR CIGS FAR W AND FAR E.  ABUNDANT LOW LEVEL
MOISTURE MAY ALSO PROVIDE FOR SOME SCT CLOUDS BLO 1000KFT.  WITH
ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...EXPECT TO SEE SO FOG
TONIGHT...MAINLY AFT06Z.  AN UPPER LEVEL DISTURBANCE MAY BRING SOME
POTENTIAL FOR ISOLD THUNDER ACROSS THE EAST.  UNCERTAINTY ON STORMS
TONIGHT THOUGH IS STILL HIGH.  WILL MAINTAIN VCTS FOR THE MOST
PART...EXCEPT FOR KOTM AREA WHERE POTENTIAL LOOKS BEST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...FAB




000
FXUS63 KDMX 211815
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
112 PM CDT THU AUG 21 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

THUNDERSTORMS DEVELOPING ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA WILL AFFECT OUR FAR NORTHERN COUNTIES EARLY THIS MORNING
WITH A LOW RISK OF SEVERE WEATHER AND LOCALIZED FLOODING...BUT WILL
EXIT THE FORECAST AREA AROUND OR SHORTLY AFTER 12Z. OTHERWISE
ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS CENTRAL IOWA BOTH
FROM EARLY MORNING DEVELOPMENT OVERHEAD AND FROM THE CLUSTER OF
STORMS MOVING IN FROM CENTRAL NEBRASKA...WHICH SHOULD FADE AS THEY
ENTER IOWA LATER IN THE MORNING. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING THE DEGREE TO WHICH STORMS WILL OR WILL NOT BE
ABLE TO SURVIVE IN THE LATE MORNING AND AFTERNOON...WHICH WILL HAVE
A SIGNIFICANT EFFECT ON OUR TEMPERATURES LATER IN THE DAY. WE SAW
YESTERDAY WHAT CAN HAPPEN IF THE PRECIP/CLOUDS LINGER INTO THE
AFTERNOON AS TEMPERATURES WERE NEARLY 10 DEGREES COOLER THAN
ANTICIPATED IN SOME AREAS. FOR NOW HAVE LINGERED ISOLATED
THUNDERSTORM WORDING THROUGH AROUND MIDDAY ACROSS CENTRAL
IOWA...LOWERED HIGH TEMPERATURES A BIT AS IT APPEARS RESIDUAL
CONVECTIVE DEBRIS CLOUDS WILL ONCE AGAIN BE AN ISSUE AT LEAST TO
SOME EXTENT...AND DO NOT FEEL THAT HEAT HEADLINES ARE WARRANTED IN
THIS SCENARIO. TOWARD THIS EVENING STORMS WILL AGAIN BE
POSSIBLE...BUT BELIEVE WE WILL REMAIN CAPPED OFF WITH PRECIP
LIKELIER AFTER DARK AND INTO THE OVERNIGHT PERIOD ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS THROUGH THE
ENTIRE PERIOD WITH PATTERN REMAINING QUITE ACTIVE.  MODELS REMAIN IN
DECENT AGREEMENT ON THE LARGER SCALE INTO EARLY NEXT WEEK WITH
FAIRLY HIGH AMPLITUDE WRN TROUGH TO OH VALLEY/ERN GREAT LAKES RIDGE.
SHORT WAVE CURRENTLY PUSHING THROUGH DAKOTAS/MN AND DRIVING MCS FROM
NRN IA INTO MN WILL ALSO EVENTUALLY SAG SURFACE REFLECTION AND
BOUNDARY INTO IA BY TONIGHT. THERE IS SOME POTENTIAL FOR SURFACE
BASED CONVECTION TO FIRE ALONG THE LOW LEVEL CONVERGENCE AND
CONTINUE INTO THE EVENING AS THETA-E ADVECTION AND MOISTURE
TRANSPORT INTERSECTS THE BOUNDARY. IT QUICKLY VEERS TOWARD
DAYBREAK HOWEVER...SO IT SHOULD BEGIN TO WANE AND DISSIPATE INTO
FRI MORNING. LOOKING FOR THINGS TO TURN MORE ACTIVE TOWARD 00Z
AND INTO THE NIGHT HOWEVER. SURFACE BASED CONVECTION MAY RE-FIRE
NEAR THE WARM FRONT FROM NE INTO IA. WRN TROUGH IS EXPECTED TO BE
JUST PROGRESSIVE ENOUGH TO INCREASE SYNOPTIC SCALE LIFT AND
THERMODYNAMIC FORCING TO FUEL MCS INTO THE NIGHT AS WARM FRONT
AGAIN LIFTS NORTHWARD. PRECIP CHANCES MAY STILL LINGER THROUGH THE
DAY...BUT GRADUALLY LIFT SOUTH TO NORTH. CHANCES WILL REMAIN IN
THE FORECAST...MAINLY NW THIRD ATTENDANT TO NE/SD SURFACE
FRONT...THEN INCREASE INTO SUN NIGHT WEST TO EAST AS SURFACE BASED
CONVECTION OOZES INTO IA LATER IN THE NIGHT FUELED BY AN UPTICK IN
KINEMATIC FORCING ASSOCIATED WITH SHORT WAVE LIFTING THROUGH THE
NRN PLAINS.

FORECAST CONFIDENCE DECREASES INTO NEXT WEEK HOWEVER AS GFS/GEM ARE
STILL MORE PROGRESSIVE LIFTING LONG WAVE TROUGH FROM THE NRN
ROCKIES INTO THE NRN PLAINS WHILE THE ECMWF HAS CHANGED SOMEWHAT
LEAVING CUTOFF REMNANTS OVER THE ROCKIES. HAVE NOT CHANGED
FORECAST TOO MUCH DUE TO THIS UNCERTAINTY. MODELS SUGGEST POPS TO
SOME DEGREE THROUGH WED FOR DIFFERENT REASONS...ECMWF WARM
ADVECTION VS GFS LINGERING WEAKER PRECIP BEHIND THE TROUGH.

THE AIRMASS THROUGH EARLY NEXT WEEK WILL NOT CHANGE MUCH AND REMAIN
FAVORABLE FOR LOCALLY HEAVY RAIN WITH ELEVATED PWS AND WARM CLOUD
DEPTHS.  AS MENTIONED IN PREVIOUS DISCUSSIONS...FLASH FLOOD WATCHES
MAY EVENTUALLY BE NEEDED BUT NOT UNTIL CONFIDENCE IN CONVECTIVE
TRENDS OVER FAVORABLE HIGH SOIL MOISTURE AREAS INCREASES.  SEVERE
POTENTIAL WILL REMAIN THERE AS WELL BUT WITH NO PARTICULAR TIME OR
LOCATION TO FOCUS ON AS OF YET...ALTHOUGH SURFACE BASED DEVELOPMENT
LATE SUN SEEMS SOMEWHAT MORE FAVORABLE WITH BETTER PHASED
INSTABILITY...SHEAR AND FORCING.

HEAT INDICES WILL APPROACH ADVISORY CRITERIA THROUGH THE
WEEKEND...AND HEADLINES COULD EVENTUALLY BE NEEDED IF THIS OCCURS
REPETITIVELY FOR SEVERAL DAYS...BUT CONVECTION AND ASSOCIATED DEBRIS
COULD CERTAINLY AFFECT THINGS AND KEEPS CONFIDENCE LOW ENOUGH TO
PRECLUDE ANY HEADLINES AT THE MOMENT.

&&

.AVIATION...21/18Z
ISSUED AT 112 PM CDT THU AUG 21 2014

TSRA WANING/MOVING OUT OF THE FORECAST AREA.  SHOULD MAINLY BE VFR
COND WITH PATCHY MVFR CIGS FAR W AND FAR E.  ABUNDANT LOW LEVEL
MOISTURE MAY ALSO PROVIDE FOR SOME SCT CLOUDS BLO 1000KFT.  WITH
ABUNDANT LOW LEVEL MOISTURE REMAINING IN PLACE...EXPECT TO SEE SO FOG
TONIGHT...MAINLY AFT06Z.  AN UPPER LEVEL DISTURBANCE MAY BRING SOME
POTENTIAL FOR ISOLD THUNDER ACROSS THE EAST.  UNCERTAINTY ON STORMS
TONIGHT THOUGH IS STILL HIGH.  WILL MAINTAIN VCTS FOR THE MOST
PART...EXCEPT FOR KOTM AREA WHERE POTENTIAL LOOKS BEST.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...FAB





000
FXUS63 KDMX 211130
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
630 AM CDT THU AUG 21 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

THUNDERSTORMS DEVELOPING ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA WILL AFFECT OUR FAR NORTHERN COUNTIES EARLY THIS MORNING
WITH A LOW RISK OF SEVERE WEATHER AND LOCALIZED FLOODING...BUT WILL
EXIT THE FORECAST AREA AROUND OR SHORTLY AFTER 12Z. OTHERWISE
ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS CENTRAL IOWA BOTH
FROM EARLY MORNING DEVELOPMENT OVERHEAD AND FROM THE CLUSTER OF
STORMS MOVING IN FROM CENTRAL NEBRASKA...WHICH SHOULD FADE AS THEY
ENTER IOWA LATER IN THE MORNING. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING THE DEGREE TO WHICH STORMS WILL OR WILL NOT BE
ABLE TO SURVIVE IN THE LATE MORNING AND AFTERNOON...WHICH WILL HAVE
A SIGNIFICANT EFFECT ON OUR TEMPERATURES LATER IN THE DAY. WE SAW
YESTERDAY WHAT CAN HAPPEN IF THE PRECIP/CLOUDS LINGER INTO THE
AFTERNOON AS TEMPERATURES WERE NEARLY 10 DEGREES COOLER THAN
ANTICIPATED IN SOME AREAS. FOR NOW HAVE LINGERED ISOLATED
THUNDERSTORM WORDING THROUGH AROUND MIDDAY ACROSS CENTRAL
IOWA...LOWERED HIGH TEMPERATURES A BIT AS IT APPEARS RESIDUAL
CONVECTIVE DEBRIS CLOUDS WILL ONCE AGAIN BE AN ISSUE AT LEAST TO
SOME EXTENT...AND DO NOT FEEL THAT HEAT HEADLINES ARE WARRANTED IN
THIS SCENARIO. TOWARD THIS EVENING STORMS WILL AGAIN BE
POSSIBLE...BUT BELIEVE WE WILL REMAIN CAPPED OFF WITH PRECIP
LIKELIER AFTER DARK AND INTO THE OVERNIGHT PERIOD ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS THROUGH THE
ENTIRE PERIOD WITH PATTERN REMAINING QUITE ACTIVE.  MODELS REMAIN IN
DECENT AGREEMENT ON THE LARGER SCALE INTO EARLY NEXT WEEK WITH
FAIRLY HIGH AMPLITUDE WRN TROUGH TO OH VALLEY/ERN GREAT LAKES RIDGE.
SHORT WAVE CURRENTLY PUSHING THROUGH DAKOTAS/MN AND DRIVING MCS FROM
NRN IA INTO MN WILL ALSO EVENTUALLY SAG SURFACE REFLECTION AND
BOUNDARY INTO IA BY TONIGHT. THERE IS SOME POTENTIAL FOR SURFACE
BASED CONVECTION TO FIRE ALONG THE LOW LEVEL CONVERGENCE AND
CONTINUE INTO THE EVENING AS THETA-E ADVECTION AND MOISTURE
TRANSPORT INTERSECTS THE BOUNDARY. IT QUICKLY VEERS TOWARD
DAYBREAK HOWEVER...SO IT SHOULD BEGIN TO WANE AND DISSIPATE INTO
FRI MORNING. LOOKING FOR THINGS TO TURN MORE ACTIVE TOWARD 00Z
AND INTO THE NIGHT HOWEVER. SURFACE BASED CONVECTION MAY RE-FIRE
NEAR THE WARM FRONT FROM NE INTO IA. WRN TROUGH IS EXPECTED TO BE
JUST PROGRESSIVE ENOUGH TO INCREASE SYNOPTIC SCALE LIFT AND
THERMODYNAMIC FORCING TO FUEL MCS INTO THE NIGHT AS WARM FRONT
AGAIN LIFTS NORTHWARD. PRECIP CHANCES MAY STILL LINGER THROUGH THE
DAY...BUT GRADUALLY LIFT SOUTH TO NORTH. CHANCES WILL REMAIN IN
THE FORECAST...MAINLY NW THIRD ATTENDANT TO NE/SD SURFACE
FRONT...THEN INCREASE INTO SUN NIGHT WEST TO EAST AS SURFACE BASED
CONVECTION OOZES INTO IA LATER IN THE NIGHT FUELED BY AN UPTICK IN
KINEMATIC FORCING ASSOCIATED WITH SHORT WAVE LIFTING THROUGH THE
NRN PLAINS.

FORECAST CONFIDENCE DECREASES INTO NEXT WEEK HOWEVER AS GFS/GEM ARE
STILL MORE PROGRESSIVE LIFTING LONG WAVE TROUGH FROM THE NRN
ROCKIES INTO THE NRN PLAINS WHILE THE ECMWF HAS CHANGED SOMEWHAT
LEAVING CUTOFF REMNANTS OVER THE ROCKIES. HAVE NOT CHANGED
FORECAST TOO MUCH DUE TO THIS UNCERTAINTY. MODELS SUGGEST POPS TO
SOME DEGREE THROUGH WED FOR DIFFERENT REASONS...ECMWF WARM
ADVECTION VS GFS LINGERING WEAKER PRECIP BEHIND THE TROUGH.

THE AIRMASS THROUGH EARLY NEXT WEEK WILL NOT CHANGE MUCH AND REMAIN
FAVORABLE FOR LOCALLY HEAVY RAIN WITH ELEVATED PWS AND WARM CLOUD
DEPTHS.  AS MENTIONED IN PREVIOUS DISCUSSIONS...FLASH FLOOD WATCHES
MAY EVENTUALLY BE NEEDED BUT NOT UNTIL CONFIDENCE IN CONVECTIVE
TRENDS OVER FAVORABLE HIGH SOIL MOISTURE AREAS INCREASES.  SEVERE
POTENTIAL WILL REMAIN THERE AS WELL BUT WITH NO PARTICULAR TIME OR
LOCATION TO FOCUS ON AS OF YET...ALTHOUGH SURFACE BASED DEVELOPMENT
LATE SUN SEEMS SOMEWHAT MORE FAVORABLE WITH BETTER PHASED
INSTABILITY...SHEAR AND FORCING.

HEAT INDICES WILL APPROACH ADVISORY CRITERIA THROUGH THE
WEEKEND...AND HEADLINES COULD EVENTUALLY BE NEEDED IF THIS OCCURS
REPETITIVELY FOR SEVERAL DAYS...BUT CONVECTION AND ASSOCIATED DEBRIS
COULD CERTAINLY AFFECT THINGS AND KEEPS CONFIDENCE LOW ENOUGH TO
PRECLUDE ANY HEADLINES AT THE MOMENT.

&&

.AVIATION...21/12Z
ISSUED AT 630 AM CDT THU AUG 21 2014

WDLY SCT TSRA WILL PERSIST FOR THE NEXT SEVERAL HOURS...PRIMARILY
AFFECTING MCW...THEN DIMINISH BY MIDDAY WITH VERY LOW PROBS
THEREAFTER PRECLUDING TAF MENTION. EXPECT VFR CONDITIONS TO
PREVAIL FOR MOST OF THE DAY...THEN TONIGHT AFTER DARK STRATUS/FOG
SHOULD DEVELOP ESPECIALLY AT MCW/ALO. AT THIS RANGE CONFIDENCE IN
MAGNITUDE AND TIMING IS LOW BUT HAVE ADVERTISED IFR VSBYS AT THOSE
TERMINALS. ADDITIONAL TSTORMS ARE ALSO POSSIBLE OVERNIGHT...BUT
UNCERTAINTY IS HIGH IN THAT REGARD SO NO MENTION HAS BEEN MADE IN
THE 12Z TAFS. THIS WILL BE CLOSELY MONITORED TODAY AND TONIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...LEE




000
FXUS63 KDMX 211130
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
630 AM CDT THU AUG 21 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

THUNDERSTORMS DEVELOPING ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA WILL AFFECT OUR FAR NORTHERN COUNTIES EARLY THIS MORNING
WITH A LOW RISK OF SEVERE WEATHER AND LOCALIZED FLOODING...BUT WILL
EXIT THE FORECAST AREA AROUND OR SHORTLY AFTER 12Z. OTHERWISE
ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS CENTRAL IOWA BOTH
FROM EARLY MORNING DEVELOPMENT OVERHEAD AND FROM THE CLUSTER OF
STORMS MOVING IN FROM CENTRAL NEBRASKA...WHICH SHOULD FADE AS THEY
ENTER IOWA LATER IN THE MORNING. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING THE DEGREE TO WHICH STORMS WILL OR WILL NOT BE
ABLE TO SURVIVE IN THE LATE MORNING AND AFTERNOON...WHICH WILL HAVE
A SIGNIFICANT EFFECT ON OUR TEMPERATURES LATER IN THE DAY. WE SAW
YESTERDAY WHAT CAN HAPPEN IF THE PRECIP/CLOUDS LINGER INTO THE
AFTERNOON AS TEMPERATURES WERE NEARLY 10 DEGREES COOLER THAN
ANTICIPATED IN SOME AREAS. FOR NOW HAVE LINGERED ISOLATED
THUNDERSTORM WORDING THROUGH AROUND MIDDAY ACROSS CENTRAL
IOWA...LOWERED HIGH TEMPERATURES A BIT AS IT APPEARS RESIDUAL
CONVECTIVE DEBRIS CLOUDS WILL ONCE AGAIN BE AN ISSUE AT LEAST TO
SOME EXTENT...AND DO NOT FEEL THAT HEAT HEADLINES ARE WARRANTED IN
THIS SCENARIO. TOWARD THIS EVENING STORMS WILL AGAIN BE
POSSIBLE...BUT BELIEVE WE WILL REMAIN CAPPED OFF WITH PRECIP
LIKELIER AFTER DARK AND INTO THE OVERNIGHT PERIOD ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS THROUGH THE
ENTIRE PERIOD WITH PATTERN REMAINING QUITE ACTIVE.  MODELS REMAIN IN
DECENT AGREEMENT ON THE LARGER SCALE INTO EARLY NEXT WEEK WITH
FAIRLY HIGH AMPLITUDE WRN TROUGH TO OH VALLEY/ERN GREAT LAKES RIDGE.
SHORT WAVE CURRENTLY PUSHING THROUGH DAKOTAS/MN AND DRIVING MCS FROM
NRN IA INTO MN WILL ALSO EVENTUALLY SAG SURFACE REFLECTION AND
BOUNDARY INTO IA BY TONIGHT. THERE IS SOME POTENTIAL FOR SURFACE
BASED CONVECTION TO FIRE ALONG THE LOW LEVEL CONVERGENCE AND
CONTINUE INTO THE EVENING AS THETA-E ADVECTION AND MOISTURE
TRANSPORT INTERSECTS THE BOUNDARY. IT QUICKLY VEERS TOWARD
DAYBREAK HOWEVER...SO IT SHOULD BEGIN TO WANE AND DISSIPATE INTO
FRI MORNING. LOOKING FOR THINGS TO TURN MORE ACTIVE TOWARD 00Z
AND INTO THE NIGHT HOWEVER. SURFACE BASED CONVECTION MAY RE-FIRE
NEAR THE WARM FRONT FROM NE INTO IA. WRN TROUGH IS EXPECTED TO BE
JUST PROGRESSIVE ENOUGH TO INCREASE SYNOPTIC SCALE LIFT AND
THERMODYNAMIC FORCING TO FUEL MCS INTO THE NIGHT AS WARM FRONT
AGAIN LIFTS NORTHWARD. PRECIP CHANCES MAY STILL LINGER THROUGH THE
DAY...BUT GRADUALLY LIFT SOUTH TO NORTH. CHANCES WILL REMAIN IN
THE FORECAST...MAINLY NW THIRD ATTENDANT TO NE/SD SURFACE
FRONT...THEN INCREASE INTO SUN NIGHT WEST TO EAST AS SURFACE BASED
CONVECTION OOZES INTO IA LATER IN THE NIGHT FUELED BY AN UPTICK IN
KINEMATIC FORCING ASSOCIATED WITH SHORT WAVE LIFTING THROUGH THE
NRN PLAINS.

FORECAST CONFIDENCE DECREASES INTO NEXT WEEK HOWEVER AS GFS/GEM ARE
STILL MORE PROGRESSIVE LIFTING LONG WAVE TROUGH FROM THE NRN
ROCKIES INTO THE NRN PLAINS WHILE THE ECMWF HAS CHANGED SOMEWHAT
LEAVING CUTOFF REMNANTS OVER THE ROCKIES. HAVE NOT CHANGED
FORECAST TOO MUCH DUE TO THIS UNCERTAINTY. MODELS SUGGEST POPS TO
SOME DEGREE THROUGH WED FOR DIFFERENT REASONS...ECMWF WARM
ADVECTION VS GFS LINGERING WEAKER PRECIP BEHIND THE TROUGH.

THE AIRMASS THROUGH EARLY NEXT WEEK WILL NOT CHANGE MUCH AND REMAIN
FAVORABLE FOR LOCALLY HEAVY RAIN WITH ELEVATED PWS AND WARM CLOUD
DEPTHS.  AS MENTIONED IN PREVIOUS DISCUSSIONS...FLASH FLOOD WATCHES
MAY EVENTUALLY BE NEEDED BUT NOT UNTIL CONFIDENCE IN CONVECTIVE
TRENDS OVER FAVORABLE HIGH SOIL MOISTURE AREAS INCREASES.  SEVERE
POTENTIAL WILL REMAIN THERE AS WELL BUT WITH NO PARTICULAR TIME OR
LOCATION TO FOCUS ON AS OF YET...ALTHOUGH SURFACE BASED DEVELOPMENT
LATE SUN SEEMS SOMEWHAT MORE FAVORABLE WITH BETTER PHASED
INSTABILITY...SHEAR AND FORCING.

HEAT INDICES WILL APPROACH ADVISORY CRITERIA THROUGH THE
WEEKEND...AND HEADLINES COULD EVENTUALLY BE NEEDED IF THIS OCCURS
REPETITIVELY FOR SEVERAL DAYS...BUT CONVECTION AND ASSOCIATED DEBRIS
COULD CERTAINLY AFFECT THINGS AND KEEPS CONFIDENCE LOW ENOUGH TO
PRECLUDE ANY HEADLINES AT THE MOMENT.

&&

.AVIATION...21/12Z
ISSUED AT 630 AM CDT THU AUG 21 2014

WDLY SCT TSRA WILL PERSIST FOR THE NEXT SEVERAL HOURS...PRIMARILY
AFFECTING MCW...THEN DIMINISH BY MIDDAY WITH VERY LOW PROBS
THEREAFTER PRECLUDING TAF MENTION. EXPECT VFR CONDITIONS TO
PREVAIL FOR MOST OF THE DAY...THEN TONIGHT AFTER DARK STRATUS/FOG
SHOULD DEVELOP ESPECIALLY AT MCW/ALO. AT THIS RANGE CONFIDENCE IN
MAGNITUDE AND TIMING IS LOW BUT HAVE ADVERTISED IFR VSBYS AT THOSE
TERMINALS. ADDITIONAL TSTORMS ARE ALSO POSSIBLE OVERNIGHT...BUT
UNCERTAINTY IS HIGH IN THAT REGARD SO NO MENTION HAS BEEN MADE IN
THE 12Z TAFS. THIS WILL BE CLOSELY MONITORED TODAY AND TONIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...LEE





000
FXUS63 KDMX 210912
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
412 AM CDT THU AUG 21 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

THUNDERSTORMS DEVELOPING ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA WILL AFFECT OUR FAR NORTHERN COUNTIES EARLY THIS MORNING
WITH A LOW RISK OF SEVERE WEATHER AND LOCALIZED FLOODING...BUT WILL
EXIT THE FORECAST AREA AROUND OR SHORTLY AFTER 12Z. OTHERWISE
ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS CENTRAL IOWA BOTH
FROM EARLY MORNING DEVELOPMENT OVERHEAD AND FROM THE CLUSTER OF
STORMS MOVING IN FROM CENTRAL NEBRASKA...WHICH SHOULD FADE AS THEY
ENTER IOWA LATER IN THE MORNING. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING THE DEGREE TO WHICH STORMS WILL OR WILL NOT BE
ABLE TO SURVIVE IN THE LATE MORNING AND AFTERNOON...WHICH WILL HAVE
A SIGNIFICANT EFFECT ON OUR TEMPERATURES LATER IN THE DAY. WE SAW
YESTERDAY WHAT CAN HAPPEN IF THE PRECIP/CLOUDS LINGER INTO THE
AFTERNOON AS TEMPERATURES WERE NEARLY 10 DEGREES COOLER THAN
ANTICIPATED IN SOME AREAS. FOR NOW HAVE LINGERED ISOLATED
THUNDERSTORM WORDING THROUGH AROUND MIDDAY ACROSS CENTRAL
IOWA...LOWERED HIGH TEMPERATURES A BIT AS IT APPEARS RESIDUAL
CONVECTIVE DEBRIS CLOUDS WILL ONCE AGAIN BE AN ISSUE AT LEAST TO
SOME EXTENT...AND DO NOT FEEL THAT HEAT HEADLINES ARE WARRANTED IN
THIS SCENARIO. TOWARD THIS EVENING STORMS WILL AGAIN BE
POSSIBLE...BUT BELIEVE WE WILL REMAIN CAPPED OFF WITH PRECIP
LIKELIER AFTER DARK AND INTO THE OVERNIGHT PERIOD ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS THROUGH THE
ENTIRE PERIOD WITH PATTERN REMAINING QUITE ACTIVE.  MODELS REMAIN IN
DECENT AGREEMENT ON THE LARGER SCALE INTO EARLY NEXT WEEK WITH
FAIRLY HIGH AMPLITUDE WRN TROUGH TO OH VALLEY/ERN GREAT LAKES RIDGE.
SHORT WAVE CURRENTLY PUSHING THROUGH DAKOTAS/MN AND DRIVING MCS FROM
NRN IA INTO MN WILL ALSO EVENTUALLY SAG SURFACE REFLECTION AND
BOUNDARY INTO IA BY TONIGHT. THERE IS SOME POTENTIAL FOR SURFACE
BASED CONVECTION TO FIRE ALONG THE LOW LEVEL CONVERGENCE AND
CONTINUE INTO THE EVENING AS THETA-E ADVECTION AND MOISTURE
TRANSPORT INTERSECTS THE BOUNDARY. IT QUICKLY VEERS TOWARD
DAYBREAK HOWEVER...SO IT SHOULD BEGIN TO WANE AND DISSIPATE INTO
FRI MORNING. LOOKING FOR THINGS TO TURN MORE ACTIVE TOWARD 00Z
AND INTO THE NIGHT HOWEVER. SURFACE BASED CONVECTION MAY RE-FIRE
NEAR THE WARM FRONT FROM NE INTO IA. WRN TROUGH IS EXPECTED TO BE
JUST PROGRESSIVE ENOUGH TO INCREASE SYNOPTIC SCALE LIFT AND
THERMODYNAMIC FORCING TO FUEL MCS INTO THE NIGHT AS WARM FRONT
AGAIN LIFTS NORTHWARD. PRECIP CHANCES MAY STILL LINGER THROUGH THE
DAY...BUT GRADUALLY LIFT SOUTH TO NORTH. CHANCES WILL REMAIN IN
THE FORECAST...MAINLY NW THIRD ATTENDANT TO NE/SD SURFACE
FRONT...THEN INCREASE INTO SUN NIGHT WEST TO EAST AS SURFACE BASED
CONVECTION OOZES INTO IA LATER IN THE NIGHT FUELED BY AN UPTICK IN
KINEMATIC FORCING ASSOCIATED WITH SHORT WAVE LIFTING THROUGH THE
NRN PLAINS.

FORECAST CONFIDENCE DECREASES INTO NEXT WEEK HOWEVER AS GFS/GEM ARE
STILL MORE PROGRESSIVE LIFTING LONG WAVE TROUGH FROM THE NRN
ROCKIES INTO THE NRN PLAINS WHILE THE ECMWF HAS CHANGED SOMEWHAT
LEAVING CUTOFF REMNANTS OVER THE ROCKIES. HAVE NOT CHANGED
FORECAST TOO MUCH DUE TO THIS UNCERTAINTY. MODELS SUGGEST POPS TO
SOME DEGREE THROUGH WED FOR DIFFERENT REASONS...ECMWF WARM
ADVECTION VS GFS LINGERING WEAKER PRECIP BEHIND THE TROUGH.

THE AIRMASS THROUGH EARLY NEXT WEEK WILL NOT CHANGE MUCH AND REMAIN
FAVORABLE FOR LOCALLY HEAVY RAIN WITH ELEVATED PWS AND WARM CLOUD
DEPTHS.  AS MENTIONED IN PREVIOUS DISCUSSIONS...FLASH FLOOD WATCHES
MAY EVENTUALLY BE NEEDED BUT NOT UNTIL CONFIDENCE IN CONVECTIVE
TRENDS OVER FAVORABLE HIGH SOIL MOISTURE AREAS INCREASES.  SEVERE
POTENTIAL WILL REMAIN THERE AS WELL BUT WITH NO PARTICULAR TIME OR
LOCATION TO FOCUS ON AS OF YET...ALTHOUGH SURFACE BASED DEVELOPMENT
LATE SUN SEEMS SOMEWHAT MORE FAVORABLE WITH BETTER PHASED
INSTABILITY...SHEAR AND FORCING.

HEAT INDICES WILL APPROACH ADVISORY CRITERIA THROUGH THE
WEEKEND...AND HEADLINES COULD EVENTUALLY BE NEEDED IF THIS OCCURS
REPETITIVELY FOR SEVERAL DAYS...BUT CONVECTION AND ASSOCIATED DEBRIS
COULD CERTAINLY AFFECT THINGS AND KEEPS CONFIDENCE LOW ENOUGH TO
PRECLUDE ANY HEADLINES AT THE MOMENT.

&&

.AVIATION...21/06Z
ISSUED AT 1150 PM CDT WED AUG 20 2014

BOUNDARY NEAR NORTHERN IOWA WILL ALLOW FOR TSRA CHANCES AT SITES.
HAVE INCLUDED MENTION AT NORTHERN SITES KMCW/KALO...WITH
CONDITIONS DROPPING TO MVFR OR IFR...POSSIBLY LOWER IF HEAVY RAIN
REDUCES VISIBILITIES NEAR 12Z. SYSTEM WILL PUSH EAST...WITH A
RETURN TO VFR CONDITIONS AT SITES. WINDS WILL BE FROM THE SOUTH
AND MAY BE GUSTY IN THE AFTERNOON. ADDITIONAL CHANCES FOR
SHRA/TSRA WILL BE POSSIBLE AT SITES LATE IN THE PERIOD...THOUGH
HAVE LEFT OUT MENTION ATTM DUE TO UNCERTAINTIES IN TIMING AND
PLACEMENT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...AWB





000
FXUS63 KDMX 210912
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
412 AM CDT THU AUG 21 2014

.SHORT TERM /TODAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

THUNDERSTORMS DEVELOPING ACROSS NORTHWEST IOWA AND SOUTHERN
MINNESOTA WILL AFFECT OUR FAR NORTHERN COUNTIES EARLY THIS MORNING
WITH A LOW RISK OF SEVERE WEATHER AND LOCALIZED FLOODING...BUT WILL
EXIT THE FORECAST AREA AROUND OR SHORTLY AFTER 12Z. OTHERWISE
ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE ACROSS CENTRAL IOWA BOTH
FROM EARLY MORNING DEVELOPMENT OVERHEAD AND FROM THE CLUSTER OF
STORMS MOVING IN FROM CENTRAL NEBRASKA...WHICH SHOULD FADE AS THEY
ENTER IOWA LATER IN THE MORNING. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING THE DEGREE TO WHICH STORMS WILL OR WILL NOT BE
ABLE TO SURVIVE IN THE LATE MORNING AND AFTERNOON...WHICH WILL HAVE
A SIGNIFICANT EFFECT ON OUR TEMPERATURES LATER IN THE DAY. WE SAW
YESTERDAY WHAT CAN HAPPEN IF THE PRECIP/CLOUDS LINGER INTO THE
AFTERNOON AS TEMPERATURES WERE NEARLY 10 DEGREES COOLER THAN
ANTICIPATED IN SOME AREAS. FOR NOW HAVE LINGERED ISOLATED
THUNDERSTORM WORDING THROUGH AROUND MIDDAY ACROSS CENTRAL
IOWA...LOWERED HIGH TEMPERATURES A BIT AS IT APPEARS RESIDUAL
CONVECTIVE DEBRIS CLOUDS WILL ONCE AGAIN BE AN ISSUE AT LEAST TO
SOME EXTENT...AND DO NOT FEEL THAT HEAT HEADLINES ARE WARRANTED IN
THIS SCENARIO. TOWARD THIS EVENING STORMS WILL AGAIN BE
POSSIBLE...BUT BELIEVE WE WILL REMAIN CAPPED OFF WITH PRECIP
LIKELIER AFTER DARK AND INTO THE OVERNIGHT PERIOD ONCE AGAIN.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 409 AM CDT THU AUG 21 2014

PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS THROUGH THE
ENTIRE PERIOD WITH PATTERN REMAINING QUITE ACTIVE.  MODELS REMAIN IN
DECENT AGREEMENT ON THE LARGER SCALE INTO EARLY NEXT WEEK WITH
FAIRLY HIGH AMPLITUDE WRN TROUGH TO OH VALLEY/ERN GREAT LAKES RIDGE.
SHORT WAVE CURRENTLY PUSHING THROUGH DAKOTAS/MN AND DRIVING MCS FROM
NRN IA INTO MN WILL ALSO EVENTUALLY SAG SURFACE REFLECTION AND
BOUNDARY INTO IA BY TONIGHT. THERE IS SOME POTENTIAL FOR SURFACE
BASED CONVECTION TO FIRE ALONG THE LOW LEVEL CONVERGENCE AND
CONTINUE INTO THE EVENING AS THETA-E ADVECTION AND MOISTURE
TRANSPORT INTERSECTS THE BOUNDARY. IT QUICKLY VEERS TOWARD
DAYBREAK HOWEVER...SO IT SHOULD BEGIN TO WANE AND DISSIPATE INTO
FRI MORNING. LOOKING FOR THINGS TO TURN MORE ACTIVE TOWARD 00Z
AND INTO THE NIGHT HOWEVER. SURFACE BASED CONVECTION MAY RE-FIRE
NEAR THE WARM FRONT FROM NE INTO IA. WRN TROUGH IS EXPECTED TO BE
JUST PROGRESSIVE ENOUGH TO INCREASE SYNOPTIC SCALE LIFT AND
THERMODYNAMIC FORCING TO FUEL MCS INTO THE NIGHT AS WARM FRONT
AGAIN LIFTS NORTHWARD. PRECIP CHANCES MAY STILL LINGER THROUGH THE
DAY...BUT GRADUALLY LIFT SOUTH TO NORTH. CHANCES WILL REMAIN IN
THE FORECAST...MAINLY NW THIRD ATTENDANT TO NE/SD SURFACE
FRONT...THEN INCREASE INTO SUN NIGHT WEST TO EAST AS SURFACE BASED
CONVECTION OOZES INTO IA LATER IN THE NIGHT FUELED BY AN UPTICK IN
KINEMATIC FORCING ASSOCIATED WITH SHORT WAVE LIFTING THROUGH THE
NRN PLAINS.

FORECAST CONFIDENCE DECREASES INTO NEXT WEEK HOWEVER AS GFS/GEM ARE
STILL MORE PROGRESSIVE LIFTING LONG WAVE TROUGH FROM THE NRN
ROCKIES INTO THE NRN PLAINS WHILE THE ECMWF HAS CHANGED SOMEWHAT
LEAVING CUTOFF REMNANTS OVER THE ROCKIES. HAVE NOT CHANGED
FORECAST TOO MUCH DUE TO THIS UNCERTAINTY. MODELS SUGGEST POPS TO
SOME DEGREE THROUGH WED FOR DIFFERENT REASONS...ECMWF WARM
ADVECTION VS GFS LINGERING WEAKER PRECIP BEHIND THE TROUGH.

THE AIRMASS THROUGH EARLY NEXT WEEK WILL NOT CHANGE MUCH AND REMAIN
FAVORABLE FOR LOCALLY HEAVY RAIN WITH ELEVATED PWS AND WARM CLOUD
DEPTHS.  AS MENTIONED IN PREVIOUS DISCUSSIONS...FLASH FLOOD WATCHES
MAY EVENTUALLY BE NEEDED BUT NOT UNTIL CONFIDENCE IN CONVECTIVE
TRENDS OVER FAVORABLE HIGH SOIL MOISTURE AREAS INCREASES.  SEVERE
POTENTIAL WILL REMAIN THERE AS WELL BUT WITH NO PARTICULAR TIME OR
LOCATION TO FOCUS ON AS OF YET...ALTHOUGH SURFACE BASED DEVELOPMENT
LATE SUN SEEMS SOMEWHAT MORE FAVORABLE WITH BETTER PHASED
INSTABILITY...SHEAR AND FORCING.

HEAT INDICES WILL APPROACH ADVISORY CRITERIA THROUGH THE
WEEKEND...AND HEADLINES COULD EVENTUALLY BE NEEDED IF THIS OCCURS
REPETITIVELY FOR SEVERAL DAYS...BUT CONVECTION AND ASSOCIATED DEBRIS
COULD CERTAINLY AFFECT THINGS AND KEEPS CONFIDENCE LOW ENOUGH TO
PRECLUDE ANY HEADLINES AT THE MOMENT.

&&

.AVIATION...21/06Z
ISSUED AT 1150 PM CDT WED AUG 20 2014

BOUNDARY NEAR NORTHERN IOWA WILL ALLOW FOR TSRA CHANCES AT SITES.
HAVE INCLUDED MENTION AT NORTHERN SITES KMCW/KALO...WITH
CONDITIONS DROPPING TO MVFR OR IFR...POSSIBLY LOWER IF HEAVY RAIN
REDUCES VISIBILITIES NEAR 12Z. SYSTEM WILL PUSH EAST...WITH A
RETURN TO VFR CONDITIONS AT SITES. WINDS WILL BE FROM THE SOUTH
AND MAY BE GUSTY IN THE AFTERNOON. ADDITIONAL CHANCES FOR
SHRA/TSRA WILL BE POSSIBLE AT SITES LATE IN THE PERIOD...THOUGH
HAVE LEFT OUT MENTION ATTM DUE TO UNCERTAINTIES IN TIMING AND
PLACEMENT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...AWB




000
FXUS63 KDMX 210454
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1154 PM CDT WED AUG 20 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CDT WED AUG 20 2014

TONIGHTS FORECAST IS QUITE DIFFICULT AND THE MODELS ARE NOT MUCH
HELP.  A WARM FRONT ACROSS IOWA STRETCHES FROM A LOW OVER WEST
CENTRAL SOUTH DAKOTA.  THETA-E ADVECTION AND SOME MODEST INSTABILITY
KEPT THUNDERSTORMS FESTERING AHEAD OF THE FRONTAL BOUNDARY ALL DAY
LONG AND SHEAR ACTUALLY INCREASED THROUGH THE AFTERNOON HOURS.  THE
MODELS CONTINUE THE SHOWERS/STORMS ALONG AND AHEAD OF THE FRONTAL
BOUNDARY IN A ZONE OF WARM ADVECTION THROUGH THE AFTERNOON HOURS
INTO EARLY EVENING.  THE HRRR AND HOPWRF THEN SQUELCH THE PRECIP IN
IOWA OVERNIGHT WHILE THE NAM CONTINUES TO DEVELOP STORMS ACROSS
NORTH CENTRAL/NORTHEAST IOWA...ESPECIALLY WITH A LOW LEVEL JET THAT
INTENSIFIES LATER THIS EVENING.  IT IS VERY HARD TO SAY WHERE THAT
BOUNDARY WILL LIFT TO THIS EVENING...OR WILL IT REMAIN FAIRLY
STATIONARY.  I AM REASONABLY CERTAIN THAT WE WILL NOT BE DRY ACROSS
THE NORTH BUT I AM SKEPTICAL ABOUT KEEPING 60-70 POPS IN THAT AREA
GIVEN THE TRENDS FOR THE PRECIP TO SLOWLY LIFT NORTH.

THE MAIN ADJUSTMENTS TO THE GOING FORECAST WERE TO LOWER POPS SOME
ACROSS THE NORTH AND MENTION HEAVY RAIN ACROSS A PART OF THE NORTH
CENTRAL AND NORTHEAST.  HOWEVER...IF THE NAM12 IS CORRECT MY
FORECAST WILL NEED TO BE ADJUSTED ONCE THE LLJ COMES INTO PLAY AFTER
03Z OR SO AS HIGHER POPS WILL BE NEEDED FURTHER SOUTH.  HEAVY
RAINFALL WILL ALSO BE MORE OF A CONCERN ACROSS AREAS NORTH OF
HIGHWAY 20.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 340 PM CDT WED AUG 20 2014

RELATIVELY ACTIVE CONDITIONS TO PERSIST FOR MUCH OF THE LONG TERM
WITH BROAD WSW FLOW ALOFT AND SURFACE BOUNDARY NEARBY. ANY ONGOING
CONVECTION ON THURSDAY MORNING SHOULD DISSIPATE WITH FORCING
WEAKENING. WARM SECTOR WILL BE IN PLACE WITH TEMPERATURES CLIMBING
NICELY THROUGH THE DAY. STILL MAY SEE SOME MID TO HIGH CLOUDS
OVERHEAD AND THIS MAY LIMIT DAYTIME HIGHS...HOWEVER STILL A VERY
WARM AND HUMID DAY EXPECTED FOR MOST LOCATIONS. SURFACE BOUNDARY
WILL EASE INTO NORTHERN IOWA ON THURSDAY NIGHT WITH SOME SCATTERED
CONVECTION EXPECTED ALONG THE FRONT OVERNIGHT. THESE STORMS ARE
EXPECTED TO WEAKEN OVERNIGHT TOWARD DAYBREAK AS INFLOW WEAKENS AND
COL REGION PUSHES INTO THE STATE. FRIDAY WILL SEE THE COL PASS
THROUGH IOWA WITH LIMITED CONVECTION CHANCES FOR MUCH OF THE DAY.
HOWEVER...A MORE VIGOROUS SHORTWAVE WILL EJECT INTO THE PLAINS
LATER FRIDAY WITH INCREASING FLOW INTO THE FRONT LATE FRIDAY INTO
FRIDAY NIGHT. MODELS HAVE ALL BEEN INDICATING RATHER ROBUST
CONVECTION BY LATE FRIDAY ACROSS THE PLAINS PUSHING INTO IOWA
OVERNIGHT. HAVE CONTINUED THE HIGHER POPS ON FRIDAY
NIGHT...ESPECIALLY ACROSS THE NORTHWEST WHERE THE BEST FORCING AND
INFLOW INTO SYSTEM IS ANTICIPATED. THE THREAT FOR CONVECTION WILL
PERSIST INTO THE WEEKEND AND EARLY NEXT WEEK AS THE FRONTAL
BOUNDARY REMAINS NEAR THE STATE. AT THIS POINT...IT APPEARS MUCH
OF THE CONVECTION THIS WEEKEND WILL BE NEAR NORTHERN IOWA WITH HOT
AND HUMID CONDITIONS IN THE SOUTH. THE BULK OF THE SYSTEM IS NOT
EXPECTED TO PASS THROUGH THE REGION UNTIL THE MIDDLE OF NEXT WEEK
WHEN GOOD COVERAGE OF STORMS IS ANTICIPATED TUESDAY NIGHT INTO
WEDNESDAY. TEMPERATURES WILL REMAIN VERY WARM TO HOT SOUTH OF THE
BOUNDARY DURING THIS TIME.

THE THREAT FOR HEAVY RAINFALL WILL BE EVER PRESENT WITH THIS
CONVECTION FOR MUCH OF THE FORECAST. PWAT VALUES WILL IN GENERAL
BE AT OR ABOVE 1.50" WITH CONVECTION EAST OR SOUTHEAST AND
TRAINING A POSSIBILITY FROM TIME TO TIME. WHILE WIDESPREAD
FLOODING IS NOT EXPECTED GIVEN MATURE VEGETATIVE
GROWTH...LOCALIZED FLOODING MAY OCCUR. THE PRIMARY FLASH FLOOD
THREAT WILL REMAIN IN URBAN AREAS. HOWEVER...IF SEVERAL NIGHTS OF
RAIN DO OCCUR IN THE SAME AREA...A MORE GENERALIZED FLASH FLOOD
THREAT MAY MATERIALIZE.

THE OTHER CONCERN WILL BE WITH HOT AND HUMID CONDITIONS SOUTH OF
THE BOUNDARY. HEAT INDEX VALUES ARE EXPECTED TO CLIMB ABOVE 100
DEGREES FROM TIME TO TIME AND MAY BECOME PROBLEMATIC...ESPECIALLY
IN SOUTHERN IOWA SHOULD SEVERAL DAY STRING TOGETHER OF HOT AND
STICKY CONDITIONS. MUCH WILL DEPEND ON THE EXTEND OF CONVECTION
AND WHERE OUTFLOW BOUNDARYS AND SUBSEQUENT CONVECTION END UP. AT
THIS POINT...GIVEN THE UNCERTAINTY...NO HEADLINES FOR HEAT WILL BE
ISSUED.

&&

.AVIATION...21/06Z
ISSUED AT 1150 PM CDT WED AUG 20 2014

BOUNDARY NEAR NORTHERN IOWA WILL ALLOW FOR TSRA CHANCES AT SITES.
HAVE INCLUDED MENTION AT NORTHERN SITES KMCW/KALO...WITH
CONDITIONS DROPPING TO MVFR OR IFR...POSSIBLY LOWER IF HEAVY RAIN
REDUCES VISIBILITIES NEAR 12Z. SYSTEM WILL PUSH EAST...WITH A
RETURN TO VFR CONDITIONS AT SITES. WINDS WILL BE FROM THE SOUTH
AND MAY BE GUSTY IN THE AFTERNOON. ADDITIONAL CHANCES FOR
SHRA/TSRA WILL BE POSSIBLE AT SITES LATE IN THE PERIOD...THOUGH
HAVE LEFT OUT MENTION ATTM DUE TO UNCERTAINTIES IN TIMING AND
PLACEMENT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...COGIL
AVIATION...AWB




000
FXUS63 KDMX 210454
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1154 PM CDT WED AUG 20 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CDT WED AUG 20 2014

TONIGHTS FORECAST IS QUITE DIFFICULT AND THE MODELS ARE NOT MUCH
HELP.  A WARM FRONT ACROSS IOWA STRETCHES FROM A LOW OVER WEST
CENTRAL SOUTH DAKOTA.  THETA-E ADVECTION AND SOME MODEST INSTABILITY
KEPT THUNDERSTORMS FESTERING AHEAD OF THE FRONTAL BOUNDARY ALL DAY
LONG AND SHEAR ACTUALLY INCREASED THROUGH THE AFTERNOON HOURS.  THE
MODELS CONTINUE THE SHOWERS/STORMS ALONG AND AHEAD OF THE FRONTAL
BOUNDARY IN A ZONE OF WARM ADVECTION THROUGH THE AFTERNOON HOURS
INTO EARLY EVENING.  THE HRRR AND HOPWRF THEN SQUELCH THE PRECIP IN
IOWA OVERNIGHT WHILE THE NAM CONTINUES TO DEVELOP STORMS ACROSS
NORTH CENTRAL/NORTHEAST IOWA...ESPECIALLY WITH A LOW LEVEL JET THAT
INTENSIFIES LATER THIS EVENING.  IT IS VERY HARD TO SAY WHERE THAT
BOUNDARY WILL LIFT TO THIS EVENING...OR WILL IT REMAIN FAIRLY
STATIONARY.  I AM REASONABLY CERTAIN THAT WE WILL NOT BE DRY ACROSS
THE NORTH BUT I AM SKEPTICAL ABOUT KEEPING 60-70 POPS IN THAT AREA
GIVEN THE TRENDS FOR THE PRECIP TO SLOWLY LIFT NORTH.

THE MAIN ADJUSTMENTS TO THE GOING FORECAST WERE TO LOWER POPS SOME
ACROSS THE NORTH AND MENTION HEAVY RAIN ACROSS A PART OF THE NORTH
CENTRAL AND NORTHEAST.  HOWEVER...IF THE NAM12 IS CORRECT MY
FORECAST WILL NEED TO BE ADJUSTED ONCE THE LLJ COMES INTO PLAY AFTER
03Z OR SO AS HIGHER POPS WILL BE NEEDED FURTHER SOUTH.  HEAVY
RAINFALL WILL ALSO BE MORE OF A CONCERN ACROSS AREAS NORTH OF
HIGHWAY 20.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 340 PM CDT WED AUG 20 2014

RELATIVELY ACTIVE CONDITIONS TO PERSIST FOR MUCH OF THE LONG TERM
WITH BROAD WSW FLOW ALOFT AND SURFACE BOUNDARY NEARBY. ANY ONGOING
CONVECTION ON THURSDAY MORNING SHOULD DISSIPATE WITH FORCING
WEAKENING. WARM SECTOR WILL BE IN PLACE WITH TEMPERATURES CLIMBING
NICELY THROUGH THE DAY. STILL MAY SEE SOME MID TO HIGH CLOUDS
OVERHEAD AND THIS MAY LIMIT DAYTIME HIGHS...HOWEVER STILL A VERY
WARM AND HUMID DAY EXPECTED FOR MOST LOCATIONS. SURFACE BOUNDARY
WILL EASE INTO NORTHERN IOWA ON THURSDAY NIGHT WITH SOME SCATTERED
CONVECTION EXPECTED ALONG THE FRONT OVERNIGHT. THESE STORMS ARE
EXPECTED TO WEAKEN OVERNIGHT TOWARD DAYBREAK AS INFLOW WEAKENS AND
COL REGION PUSHES INTO THE STATE. FRIDAY WILL SEE THE COL PASS
THROUGH IOWA WITH LIMITED CONVECTION CHANCES FOR MUCH OF THE DAY.
HOWEVER...A MORE VIGOROUS SHORTWAVE WILL EJECT INTO THE PLAINS
LATER FRIDAY WITH INCREASING FLOW INTO THE FRONT LATE FRIDAY INTO
FRIDAY NIGHT. MODELS HAVE ALL BEEN INDICATING RATHER ROBUST
CONVECTION BY LATE FRIDAY ACROSS THE PLAINS PUSHING INTO IOWA
OVERNIGHT. HAVE CONTINUED THE HIGHER POPS ON FRIDAY
NIGHT...ESPECIALLY ACROSS THE NORTHWEST WHERE THE BEST FORCING AND
INFLOW INTO SYSTEM IS ANTICIPATED. THE THREAT FOR CONVECTION WILL
PERSIST INTO THE WEEKEND AND EARLY NEXT WEEK AS THE FRONTAL
BOUNDARY REMAINS NEAR THE STATE. AT THIS POINT...IT APPEARS MUCH
OF THE CONVECTION THIS WEEKEND WILL BE NEAR NORTHERN IOWA WITH HOT
AND HUMID CONDITIONS IN THE SOUTH. THE BULK OF THE SYSTEM IS NOT
EXPECTED TO PASS THROUGH THE REGION UNTIL THE MIDDLE OF NEXT WEEK
WHEN GOOD COVERAGE OF STORMS IS ANTICIPATED TUESDAY NIGHT INTO
WEDNESDAY. TEMPERATURES WILL REMAIN VERY WARM TO HOT SOUTH OF THE
BOUNDARY DURING THIS TIME.

THE THREAT FOR HEAVY RAINFALL WILL BE EVER PRESENT WITH THIS
CONVECTION FOR MUCH OF THE FORECAST. PWAT VALUES WILL IN GENERAL
BE AT OR ABOVE 1.50" WITH CONVECTION EAST OR SOUTHEAST AND
TRAINING A POSSIBILITY FROM TIME TO TIME. WHILE WIDESPREAD
FLOODING IS NOT EXPECTED GIVEN MATURE VEGETATIVE
GROWTH...LOCALIZED FLOODING MAY OCCUR. THE PRIMARY FLASH FLOOD
THREAT WILL REMAIN IN URBAN AREAS. HOWEVER...IF SEVERAL NIGHTS OF
RAIN DO OCCUR IN THE SAME AREA...A MORE GENERALIZED FLASH FLOOD
THREAT MAY MATERIALIZE.

THE OTHER CONCERN WILL BE WITH HOT AND HUMID CONDITIONS SOUTH OF
THE BOUNDARY. HEAT INDEX VALUES ARE EXPECTED TO CLIMB ABOVE 100
DEGREES FROM TIME TO TIME AND MAY BECOME PROBLEMATIC...ESPECIALLY
IN SOUTHERN IOWA SHOULD SEVERAL DAY STRING TOGETHER OF HOT AND
STICKY CONDITIONS. MUCH WILL DEPEND ON THE EXTEND OF CONVECTION
AND WHERE OUTFLOW BOUNDARYS AND SUBSEQUENT CONVECTION END UP. AT
THIS POINT...GIVEN THE UNCERTAINTY...NO HEADLINES FOR HEAT WILL BE
ISSUED.

&&

.AVIATION...21/06Z
ISSUED AT 1150 PM CDT WED AUG 20 2014

BOUNDARY NEAR NORTHERN IOWA WILL ALLOW FOR TSRA CHANCES AT SITES.
HAVE INCLUDED MENTION AT NORTHERN SITES KMCW/KALO...WITH
CONDITIONS DROPPING TO MVFR OR IFR...POSSIBLY LOWER IF HEAVY RAIN
REDUCES VISIBILITIES NEAR 12Z. SYSTEM WILL PUSH EAST...WITH A
RETURN TO VFR CONDITIONS AT SITES. WINDS WILL BE FROM THE SOUTH
AND MAY BE GUSTY IN THE AFTERNOON. ADDITIONAL CHANCES FOR
SHRA/TSRA WILL BE POSSIBLE AT SITES LATE IN THE PERIOD...THOUGH
HAVE LEFT OUT MENTION ATTM DUE TO UNCERTAINTIES IN TIMING AND
PLACEMENT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...COGIL
AVIATION...AWB





000
FXUS63 KDMX 202320
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
620 PM CDT WED AUG 20 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CDT WED AUG 20 2014

TONIGHTS FORECAST IS QUITE DIFFICULT AND THE MODELS ARE NOT MUCH
HELP.  A WARM FRONT ACROSS IOWA STRETCHES FROM A LOW OVER WEST
CENTRAL SOUTH DAKOTA.  THETA-E ADVECTION AND SOME MODEST INSTABILITY
KEPT THUNDERSTORMS FESTERING AHEAD OF THE FRONTAL BOUNDARY ALL DAY
LONG AND SHEAR ACTUALLY INCREASED THROUGH THE AFTERNOON HOURS.  THE
MODELS CONTINUE THE SHOWERS/STORMS ALONG AND AHEAD OF THE FRONTAL
BOUNDARY IN A ZONE OF WARM ADVECTION THROUGH THE AFTERNOON HOURS
INTO EARLY EVENING.  THE HRRR AND HOPWRF THEN SQUELCH THE PRECIP IN
IOWA OVERNIGHT WHILE THE NAM CONTINUES TO DEVELOP STORMS ACROSS
NORTH CENTRAL/NORTHEAST IOWA...ESPECIALLY WITH A LOW LEVEL JET THAT
INTENSIFIES LATER THIS EVENING.  IT IS VERY HARD TO SAY WHERE THAT
BOUNDARY WILL LIFT TO THIS EVENING...OR WILL IT REMAIN FAIRLY
STATIONARY.  I AM REASONABLY CERTAIN THAT WE WILL NOT BE DRY ACROSS
THE NORTH BUT I AM SKEPTICAL ABOUT KEEPING 60-70 POPS IN THAT AREA
GIVEN THE TRENDS FOR THE PRECIP TO SLOWLY LIFT NORTH.

THE MAIN ADJUSTMENTS TO THE GOING FORECAST WERE TO LOWER POPS SOME
ACROSS THE NORTH AND MENTION HEAVY RAIN ACROSS A PART OF THE NORTH
CENTRAL AND NORTHEAST.  HOWEVER...IF THE NAM12 IS CORRECT MY
FORECAST WILL NEED TO BE ADJUSTED ONCE THE LLJ COMES INTO PLAY AFTER
03Z OR SO AS HIGHER POPS WILL BE NEEDED FURTHER SOUTH.  HEAVY
RAINFALL WILL ALSO BE MORE OF A CONCERN ACROSS AREAS NORTH OF
HIGHWAY 20.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 340 PM CDT WED AUG 20 2014

RELATIVELY ACTIVE CONDITIONS TO PERSIST FOR MUCH OF THE LONG TERM
WITH BROAD WSW FLOW ALOFT AND SURFACE BOUNDARY NEARBY. ANY ONGOING
CONVECTION ON THURSDAY MORNING SHOULD DISSIPATE WITH FORCING
WEAKENING. WARM SECTOR WILL BE IN PLACE WITH TEMPERATURES CLIMBING
NICELY THROUGH THE DAY. STILL MAY SEE SOME MID TO HIGH CLOUDS
OVERHEAD AND THIS MAY LIMIT DAYTIME HIGHS...HOWEVER STILL A VERY
WARM AND HUMID DAY EXPECTED FOR MOST LOCATIONS. SURFACE BOUNDARY
WILL EASE INTO NORTHERN IOWA ON THURSDAY NIGHT WITH SOME SCATTERED
CONVECTION EXPECTED ALONG THE FRONT OVERNIGHT. THESE STORMS ARE
EXPECTED TO WEAKEN OVERNIGHT TOWARD DAYBREAK AS INFLOW WEAKENS AND
COL REGION PUSHES INTO THE STATE. FRIDAY WILL SEE THE COL PASS
THROUGH IOWA WITH LIMITED CONVECTION CHANCES FOR MUCH OF THE DAY.
HOWEVER...A MORE VIGOROUS SHORTWAVE WILL EJECT INTO THE PLAINS
LATER FRIDAY WITH INCREASING FLOW INTO THE FRONT LATE FRIDAY INTO
FRIDAY NIGHT. MODELS HAVE ALL BEEN INDICATING RATHER ROBUST
CONVECTION BY LATE FRIDAY ACROSS THE PLAINS PUSHING INTO IOWA
OVERNIGHT. HAVE CONTINUED THE HIGHER POPS ON FRIDAY
NIGHT...ESPECIALLY ACROSS THE NORTHWEST WHERE THE BEST FORCING AND
INFLOW INTO SYSTEM IS ANTICIPATED. THE THREAT FOR CONVECTION WILL
PERSIST INTO THE WEEKEND AND EARLY NEXT WEEK AS THE FRONTAL
BOUNDARY REMAINS NEAR THE STATE. AT THIS POINT...IT APPEARS MUCH
OF THE CONVECTION THIS WEEKEND WILL BE NEAR NORTHERN IOWA WITH HOT
AND HUMID CONDITIONS IN THE SOUTH. THE BULK OF THE SYSTEM IS NOT
EXPECTED TO PASS THROUGH THE REGION UNTIL THE MIDDLE OF NEXT WEEK
WHEN GOOD COVERAGE OF STORMS IS ANTICIPATED TUESDAY NIGHT INTO
WEDNESDAY. TEMPERATURES WILL REMAIN VERY WARM TO HOT SOUTH OF THE
BOUNDARY DURING THIS TIME.

THE THREAT FOR HEAVY RAINFALL WILL BE EVER PRESENT WITH THIS
CONVECTION FOR MUCH OF THE FORECAST. PWAT VALUES WILL IN GENERAL
BE AT OR ABOVE 1.50" WITH CONVECTION EAST OR SOUTHEAST AND
TRAINING A POSSIBILITY FROM TIME TO TIME. WHILE WIDESPREAD
FLOODING IS NOT EXPECTED GIVEN MATURE VEGETATIVE
GROWTH...LOCALIZED FLOODING MAY OCCUR. THE PRIMARY FLASH FLOOD
THREAT WILL REMAIN IN URBAN AREAS. HOWEVER...IF SEVERAL NIGHTS OF
RAIN DO OCCUR IN THE SAME AREA...A MORE GENERALIZED FLASH FLOOD
THREAT MAY MATERIALIZE.

THE OTHER CONCERN WILL BE WITH HOT AND HUMID CONDITIONS SOUTH OF
THE BOUNDARY. HEAT INDEX VALUES ARE EXPECTED TO CLIMB ABOVE 100
DEGREES FROM TIME TO TIME AND MAY BECOME PROBLEMATIC...ESPECIALLY
IN SOUTHERN IOWA SHOULD SEVERAL DAY STRING TOGETHER OF HOT AND
STICKY CONDITIONS. MUCH WILL DEPEND ON THE EXTEND OF CONVECTION
AND WHERE OUTFLOW BOUNDARYS AND SUBSEQUENT CONVECTION END UP. AT
THIS POINT...GIVEN THE UNCERTAINTY...NO HEADLINES FOR HEAT WILL BE
ISSUED.

&&

.AVIATION...21/00Z
ISSUED AT 614 PM CDT WED AUG 20 2014

DISTURBANCE PUSHING EASTWARD WILL BRING CHANCES FOR SHRA/TSRA TO
NORTHERN SITES THROUGH 12Z. HAVE INCLUDED MENTION AT
KDSM/KFOD/KMCW/KALO. CONDITIONS WILL DROP TO MVFR OR IFR AT TIMES
WITH TSRA. IN ADDITION...BR/FG MAY REDUCE VISIBILITIES FURTHER
NEAR 12Z. WINDS WILL REMAIN STRONGER...AND HAVE ONLY BROUGHT
VISIBILITIES DOWN TO IFR ATTM. HAVE LEFT KOTM OUT WITH
PRECIPITATION FURTHER NORTH. WINDS WILL REMAIN SOUTHERLY THROUGH
THURSDAY AND MAY BE GUSTY AFTER 18Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...COGIL
AVIATION...AWB




000
FXUS63 KDMX 202320
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
620 PM CDT WED AUG 20 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CDT WED AUG 20 2014

TONIGHTS FORECAST IS QUITE DIFFICULT AND THE MODELS ARE NOT MUCH
HELP.  A WARM FRONT ACROSS IOWA STRETCHES FROM A LOW OVER WEST
CENTRAL SOUTH DAKOTA.  THETA-E ADVECTION AND SOME MODEST INSTABILITY
KEPT THUNDERSTORMS FESTERING AHEAD OF THE FRONTAL BOUNDARY ALL DAY
LONG AND SHEAR ACTUALLY INCREASED THROUGH THE AFTERNOON HOURS.  THE
MODELS CONTINUE THE SHOWERS/STORMS ALONG AND AHEAD OF THE FRONTAL
BOUNDARY IN A ZONE OF WARM ADVECTION THROUGH THE AFTERNOON HOURS
INTO EARLY EVENING.  THE HRRR AND HOPWRF THEN SQUELCH THE PRECIP IN
IOWA OVERNIGHT WHILE THE NAM CONTINUES TO DEVELOP STORMS ACROSS
NORTH CENTRAL/NORTHEAST IOWA...ESPECIALLY WITH A LOW LEVEL JET THAT
INTENSIFIES LATER THIS EVENING.  IT IS VERY HARD TO SAY WHERE THAT
BOUNDARY WILL LIFT TO THIS EVENING...OR WILL IT REMAIN FAIRLY
STATIONARY.  I AM REASONABLY CERTAIN THAT WE WILL NOT BE DRY ACROSS
THE NORTH BUT I AM SKEPTICAL ABOUT KEEPING 60-70 POPS IN THAT AREA
GIVEN THE TRENDS FOR THE PRECIP TO SLOWLY LIFT NORTH.

THE MAIN ADJUSTMENTS TO THE GOING FORECAST WERE TO LOWER POPS SOME
ACROSS THE NORTH AND MENTION HEAVY RAIN ACROSS A PART OF THE NORTH
CENTRAL AND NORTHEAST.  HOWEVER...IF THE NAM12 IS CORRECT MY
FORECAST WILL NEED TO BE ADJUSTED ONCE THE LLJ COMES INTO PLAY AFTER
03Z OR SO AS HIGHER POPS WILL BE NEEDED FURTHER SOUTH.  HEAVY
RAINFALL WILL ALSO BE MORE OF A CONCERN ACROSS AREAS NORTH OF
HIGHWAY 20.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 340 PM CDT WED AUG 20 2014

RELATIVELY ACTIVE CONDITIONS TO PERSIST FOR MUCH OF THE LONG TERM
WITH BROAD WSW FLOW ALOFT AND SURFACE BOUNDARY NEARBY. ANY ONGOING
CONVECTION ON THURSDAY MORNING SHOULD DISSIPATE WITH FORCING
WEAKENING. WARM SECTOR WILL BE IN PLACE WITH TEMPERATURES CLIMBING
NICELY THROUGH THE DAY. STILL MAY SEE SOME MID TO HIGH CLOUDS
OVERHEAD AND THIS MAY LIMIT DAYTIME HIGHS...HOWEVER STILL A VERY
WARM AND HUMID DAY EXPECTED FOR MOST LOCATIONS. SURFACE BOUNDARY
WILL EASE INTO NORTHERN IOWA ON THURSDAY NIGHT WITH SOME SCATTERED
CONVECTION EXPECTED ALONG THE FRONT OVERNIGHT. THESE STORMS ARE
EXPECTED TO WEAKEN OVERNIGHT TOWARD DAYBREAK AS INFLOW WEAKENS AND
COL REGION PUSHES INTO THE STATE. FRIDAY WILL SEE THE COL PASS
THROUGH IOWA WITH LIMITED CONVECTION CHANCES FOR MUCH OF THE DAY.
HOWEVER...A MORE VIGOROUS SHORTWAVE WILL EJECT INTO THE PLAINS
LATER FRIDAY WITH INCREASING FLOW INTO THE FRONT LATE FRIDAY INTO
FRIDAY NIGHT. MODELS HAVE ALL BEEN INDICATING RATHER ROBUST
CONVECTION BY LATE FRIDAY ACROSS THE PLAINS PUSHING INTO IOWA
OVERNIGHT. HAVE CONTINUED THE HIGHER POPS ON FRIDAY
NIGHT...ESPECIALLY ACROSS THE NORTHWEST WHERE THE BEST FORCING AND
INFLOW INTO SYSTEM IS ANTICIPATED. THE THREAT FOR CONVECTION WILL
PERSIST INTO THE WEEKEND AND EARLY NEXT WEEK AS THE FRONTAL
BOUNDARY REMAINS NEAR THE STATE. AT THIS POINT...IT APPEARS MUCH
OF THE CONVECTION THIS WEEKEND WILL BE NEAR NORTHERN IOWA WITH HOT
AND HUMID CONDITIONS IN THE SOUTH. THE BULK OF THE SYSTEM IS NOT
EXPECTED TO PASS THROUGH THE REGION UNTIL THE MIDDLE OF NEXT WEEK
WHEN GOOD COVERAGE OF STORMS IS ANTICIPATED TUESDAY NIGHT INTO
WEDNESDAY. TEMPERATURES WILL REMAIN VERY WARM TO HOT SOUTH OF THE
BOUNDARY DURING THIS TIME.

THE THREAT FOR HEAVY RAINFALL WILL BE EVER PRESENT WITH THIS
CONVECTION FOR MUCH OF THE FORECAST. PWAT VALUES WILL IN GENERAL
BE AT OR ABOVE 1.50" WITH CONVECTION EAST OR SOUTHEAST AND
TRAINING A POSSIBILITY FROM TIME TO TIME. WHILE WIDESPREAD
FLOODING IS NOT EXPECTED GIVEN MATURE VEGETATIVE
GROWTH...LOCALIZED FLOODING MAY OCCUR. THE PRIMARY FLASH FLOOD
THREAT WILL REMAIN IN URBAN AREAS. HOWEVER...IF SEVERAL NIGHTS OF
RAIN DO OCCUR IN THE SAME AREA...A MORE GENERALIZED FLASH FLOOD
THREAT MAY MATERIALIZE.

THE OTHER CONCERN WILL BE WITH HOT AND HUMID CONDITIONS SOUTH OF
THE BOUNDARY. HEAT INDEX VALUES ARE EXPECTED TO CLIMB ABOVE 100
DEGREES FROM TIME TO TIME AND MAY BECOME PROBLEMATIC...ESPECIALLY
IN SOUTHERN IOWA SHOULD SEVERAL DAY STRING TOGETHER OF HOT AND
STICKY CONDITIONS. MUCH WILL DEPEND ON THE EXTEND OF CONVECTION
AND WHERE OUTFLOW BOUNDARYS AND SUBSEQUENT CONVECTION END UP. AT
THIS POINT...GIVEN THE UNCERTAINTY...NO HEADLINES FOR HEAT WILL BE
ISSUED.

&&

.AVIATION...21/00Z
ISSUED AT 614 PM CDT WED AUG 20 2014

DISTURBANCE PUSHING EASTWARD WILL BRING CHANCES FOR SHRA/TSRA TO
NORTHERN SITES THROUGH 12Z. HAVE INCLUDED MENTION AT
KDSM/KFOD/KMCW/KALO. CONDITIONS WILL DROP TO MVFR OR IFR AT TIMES
WITH TSRA. IN ADDITION...BR/FG MAY REDUCE VISIBILITIES FURTHER
NEAR 12Z. WINDS WILL REMAIN STRONGER...AND HAVE ONLY BROUGHT
VISIBILITIES DOWN TO IFR ATTM. HAVE LEFT KOTM OUT WITH
PRECIPITATION FURTHER NORTH. WINDS WILL REMAIN SOUTHERLY THROUGH
THURSDAY AND MAY BE GUSTY AFTER 18Z.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...COGIL
AVIATION...AWB





000
FXUS63 KDMX 202039
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
339 PM CDT WED AUG 20 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 340 PM CDT WED AUG 20 2014

TONIGHTS FORECAST IS QUITE DIFFICULT AND THE MODELS ARE NOT MUCH
HELP.  A WARM FRONT ACROSS IOWA STRETCHES FROM A LOW OVER WEST
CENTRAL SOUTH DAKOTA.  THETA-E ADVECTION AND SOME MODEST INSTABILITY
KEPT THUNDERSTORMS FESTERING AHEAD OF THE FRONTAL BOUNDARY ALL DAY
LONG AND SHEAR ACTUALLY INCREASED THROUGH THE AFTERNOON HOURS.  THE
MODELS CONTINUE THE SHOWERS/STORMS ALONG AND AHEAD OF THE FRONTAL
BOUNDARY IN A ZONE OF WARM ADVECTION THROUGH THE AFTERNOON HOURS
INTO EARLY EVENING.  THE HRRR AND HOPWRF THEN SQUELCH THE PRECIP IN
IOWA OVERNIGHT WHILE THE NAM CONTINUES TO DEVELOP STORMS ACROSS
NORTH CENTRAL/NORTHEAST IOWA...ESPECIALLY WITH A LOW LEVEL JET THAT
INTENSIFIES LATER THIS EVENING.  IT IS VERY HARD TO SAY WHERE THAT
BOUNDARY WILL LIFT TO THIS EVENING...OR WILL IT REMAIN FAIRLY
STATIONARY.  I AM REASONABLY CERTAIN THAT WE WILL NOT BE DRY ACROSS
THE NORTH BUT I AM SKEPTICAL ABOUT KEEPING 60-70 POPS IN THAT AREA
GIVEN THE TRENDS FOR THE PRECIP TO SLOWLY LIFT NORTH.

THE MAIN ADJUSTMENTS TO THE GOING FORECAST WERE TO LOWER POPS SOME
ACROSS THE NORTH AND MENTION HEAVY RAIN ACROSS A PART OF THE NORTH
CENTRAL AND NORTHEAST.  HOWEVER...IF THE NAM12 IS CORRECT MY
FORECAST WILL NEED TO BE ADJUSTED ONCE THE LLJ COMES INTO PLAY AFTER
03Z OR SO AS HIGHER POPS WILL BE NEEDED FURTHER SOUTH.  HEAVY
RAINFALL WILL ALSO BE MORE OF A CONCERN ACROSS AREAS NORTH OF
HIGHWAY 20.

.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 340 PM CDT WED AUG 20 2014

RELATIVELY ACTIVE CONDITIONS TO PERSIST FOR MUCH OF THE LONG TERM
WITH BROAD WSW FLOW ALOFT AND SURFACE BOUNDARY NEARBY. ANY ONGOING
CONVECTION ON THURSDAY MORNING SHOULD DISSIPATE WITH FORCING
WEAKENING. WARM SECTOR WILL BE IN PLACE WITH TEMPERATURES CLIMBING
NICELY THROUGH THE DAY. STILL MAY SEE SOME MID TO HIGH CLOUDS
OVERHEAD AND THIS MAY LIMIT DAYTIME HIGHS...HOWEVER STILL A VERY
WARM AND HUMID DAY EXPECTED FOR MOST LOCATIONS. SURFACE BOUNDARY
WILL EASE INTO NORTHERN IOWA ON THURSDAY NIGHT WITH SOME SCATTERED
CONVECTION EXPECTED ALONG THE FRONT OVERNIGHT. THESE STORMS ARE
EXPECTED TO WEAKEN OVERNIGHT TOWARD DAYBREAK AS INFLOW WEAKENS AND
COL REGION PUSHES INTO THE STATE. FRIDAY WILL SEE THE COL PASS
THROUGH IOWA WITH LIMITED CONVECTION CHANCES FOR MUCH OF THE DAY.
HOWEVER...A MORE VIGOROUS SHORTWAVE WILL EJECT INTO THE PLAINS
LATER FRIDAY WITH INCREASING FLOW INTO THE FRONT LATE FRIDAY INTO
FRIDAY NIGHT. MODELS HAVE ALL BEEN INDICATING RATHER ROBUST
CONVECTION BY LATE FRIDAY ACROSS THE PLAINS PUSHING INTO IOWA
OVERNIGHT. HAVE CONTINUED THE HIGHER POPS ON FRIDAY
NIGHT...ESPECIALLY ACROSS THE NORTHWEST WHERE THE BEST FORCING AND
INFLOW INTO SYSTEM IS ANTICIPATED. THE THREAT FOR CONVECTION WILL
PERSIST INTO THE WEEKEND AND EARLY NEXT WEEK AS THE FRONTAL
BOUNDARY REMAINS NEAR THE STATE. AT THIS POINT...IT APPEARS MUCH
OF THE CONVECTION THIS WEEKEND WILL BE NEAR NORTHERN IOWA WITH HOT
AND HUMID CONDITIONS IN THE SOUTH. THE BULK OF THE SYSTEM IS NOT
EXPECTED TO PASS THROUGH THE REGION UNTIL THE MIDDLE OF NEXT WEEK
WHEN GOOD COVERAGE OF STORMS IS ANTICIPATED TUESDAY NIGHT INTO
WEDNESDAY. TEMPERATURES WILL REMAIN VERY WARM TO HOT SOUTH OF THE
BOUNDARY DURING THIS TIME.

THE THREAT FOR HEAVY RAINFALL WILL BE EVER PRESENT WITH THIS
CONVECTION FOR MUCH OF THE FORECAST. PWAT VALUES WILL IN GENERAL
BE AT OR ABOVE 1.50" WITH CONVECTION EAST OR SOUTHEAST AND
TRAINING A POSSIBILITY FROM TIME TO TIME. WHILE WIDESPREAD
FLOODING IS NOT EXPECTED GIVEN MATURE VEGETATIVE
GROWTH...LOCALIZED FLOODING MAY OCCUR. THE PRIMARY FLASH FLOOD
THREAT WILL REMAIN IN URBAN AREAS. HOWEVER...IF SEVERAL NIGHTS OF
RAIN DO OCCUR IN THE SAME AREA...A MORE GENERALIZED FLASH FLOOD
THREAT MAY MATERIALIZE.

THE OTHER CONCERN WILL BE WITH HOT AND HUMID CONDITIONS SOUTH OF
THE BOUNDARY. HEAT INDEX VALUES ARE EXPECTED TO CLIMB ABOVE 100
DEGREES FROM TIME TO TIME AND MAY BECOME PROBLEMATIC...ESPECIALLY
IN SOUTHERN IOWA SHOULD SEVERAL DAY STRING TOGETHER OF HOT AND
STICKY CONDITIONS. MUCH WILL DEPEND ON THE EXTEND OF CONVECTION
AND WHERE OUTFLOW BOUNDARYS AND SUBSEQUENT CONVECTION END UP. AT
THIS POINT...GIVEN THE UNCERTAINTY...NO HEADLINES FOR HEAT WILL BE
ISSUED.

&&

.AVIATION...20/18Z
ISSUED AT 1248 PM CDT WED AUG 20 2014

SHOWERS AND THUNDERSTORMS PERSIST IN A ZONE OF INSTABILITY AHEAD OF
A WARM FRONT OVER SOUTHERN IOWA THAT  EXTENDS BACK INTO SOUTH DAKOTA.
SHOWERS AND STORMS KEEP REDEVELOPING IN THIS ZONE EVEN BACK INTO
NEBRASKA AND WILL CONTINUE TO FESTER OVER TAF LOCATIONS FROM FOD TO
ALO AND MCW THROUGH 02Z.  THERE MAY BE A SHORT BREAK THIS EVENING
BEFORE A STRONG PUSH OF MOISTURE SURGES INTO IOWA ON A STRONG LOW
LEVEL JET.  ALONG AND NORTH OF THE FRONTAL BOUNDARY STORMS MAY
INTENSIFY PRODUCING HEAVY RAINFALL AND A FEW OF THE MORE ROBUST
STORMS MAY PRODUCE STRONG WIND AND HAIL.  MVFR VSBYS WILL LARGELY
PREVAIL EITHER DUE TO FOG AND/OR HEAVY RAIN.  CIGS WILL ALSO LOWER
IN THUNDERSTORMS.


&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...FAB
LONG TERM...COGIL
AVIATION...FAB





000
FXUS63 KDMX 201754
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1248 PM CDT WED AUG 20 2014

.SHORT TERM /TODAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

AS ANTICIPATED ELEVATED THUNDERSTORMS HAVE FORMED IN A BROKEN BAND
ACROSS SOUTHERN/SOUTHWESTERN IOWA EARLY THIS MORNING...ALONG THE
NOSE OF THE VEERING LOW LEVEL JET AND WITHIN A REGION OF THETA E
ADVECTION ALOFT. A FEW STORMS WILL LIKELY PRODUCE SOME HAIL BUT NO
ORGANIZED SEVERE WEATHER IS EXPECTED. THIS ACTIVITY WILL PERSIST FOR
THE NEXT SEVERAL HOURS AS IT SLOWLY DRIFTS NORTHEAST TOWARD CENTRAL
IOWA...THEN GRADUALLY FADE LATER THIS MORNING WITH MOSTLY DRY
CONDITIONS ANTICIPATED BY THE AFTERNOON. CONCURRENTLY...AN EFFECTIVE
WARM FRONT IN THE FORM OF A SURGE OF WARMER AND MORE MOIST AIR WILL
MOVE IN FROM THE SOUTHWEST TODAY...RESULTING IN SULTRY CONDITIONS
ACROSS MUCH OF OUR AREA BY LATER TODAY. HEAT INDEX VALUES WILL TOP
OUT NEAR 100 DEGREES FROM AROUND THE I-80 CORRIDOR SOUTHWARD THUS NO
ADVISORY IS WARRANTED AT THIS TIME.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

PRECIP TRENDS WILL BE THE PRIMARY FORECAST CONCERN RIGHT ON INTO
NEXT WEEK...BUT UNFORTUNATELY DETAILS WILL BE HARD TO COME BY.
GENERAL PATTERN CHANGES LITTLE WITH PERSISTENT WRN CONUS TROUGH/ERN
RIDGE SCENARIO AS PNA INDEX CONTINUES TO LOWER. THIS LEAVES IA IN
PROLONGED SW FLOW ALOFT WITH SURFACE FEATURES REACHING THE STATE
LATER THIS WEEK AND MOVING LITTLE INTO NEXT WEEK.  CONVECTION FOR
THE NEXT FEW DAYS WILL MAINLY BE NOCTURNAL WITH LITTLE CONVERGENCE
OR LARGER SCALE FORCING.  WARM/THETA-E ADVECTION SURGE WILL PUSH
THROUGH TONIGHT WITH WEAKER THERMODYNAMIC FORCING THU NIGHT. WITH
BAROCLINIC ZONE ADVANCING NE...THIS WILL LEAVE IA IN A VERY WARM AND
HUMID AIRMASS WITH HIGHS IN THE UPPER 80S/LOWER 90S. PEAK HEAT
INDICES WILL BE PUSHING ADVISORY CRITERIA...JUST OVER 100F...BUT NOT
QUITE THERE SO WILL CONTINUE MENTION IN THE HWO.

BY THE WEEKEND AND EARLY NEXT WEEK SURFACE BOUNDARY SHOULD ADVANCE
MORE SOUTH AND EAST INCREASING THE POTENTIAL FOR PEAK
HEATING/SURFACE BASED CONVECTION. SURFACE FEATURES SHOULD LINGER
THROUGH THE END OF THE VALID PERIOD WITH A PROLONGED MENTION OF
POPS. BETTER SYNOPTIC FORCING WITH WRN TROUGH FINALLY ADVANCES FAR
ENOUGH EAST TO INCREASE POPS AND PRECIP COVERAGE BY TUE...BUT BEST
SENSIBLE WEATHER REFLECTION SEEMS JUST BEYOND THE CURRENT VALID
PERIOD TUE NIGHT INTO WED.

THE AIRMASS WILL BE FAVORABLE FOR LOCALLY HEAVY RAINS THROUGH THE
ENTIRE PERIOD WITH QUITE FAVORABLE ELEVATED K INDICES...WARM CLOUD
DEPTHS AND PWS.  HAVE STARTED WITH HEAVY RAIN MENTION NORTH
TONIGHT...BUT ADDITIONAL WORDING MAY NEED TO BE ADDED WITH LATER
PACKAGES. NE HALF OF THE FORECAST AREA REMAINS QUITE DRY...SO NO
HEADLINES FOR NOW UNTIL CONFIDENCE OF HEAVY RAIN LOCATIONS AND
MORE FAVORABLE ANTECEDENT MOISTURE CONDITIONS BECOME BETTER
PHASED. SEVERE POTENTIAL WILL REMAIN ELEVATED AS WELL DUE TO THE
DEGREE OF INSTABILITY AND AT LEAST MARGINAL EFFECT SHEAR...BUT
THERE DOES NOT APPEAR TO BE ANY PARTICULAR PERIOD TO FOCUS ON
BESIDE MARGINAL INCREASE FROM THE WEEKEND ON DUE TO BOUNDARY
INTERACTIONS. WILL KEEP BROAD MENTION OF BOTH THREATS GOING IN
THE HWO.

&&

.AVIATION...20/18Z
ISSUED AT 1248 PM CDT WED AUG 20 2014

SHOWERS AND THUNDERSTORMS PERSIST IN A ZONE OF INSTABILITY AHEAD OF
A WARM FRONT OVER SOUTHERN IOWA THAT  EXTENDS BACK INTO SOUTH DAKOTA.
SHOWERS AND STORMS KEEP REDEVELOPING IN THIS ZONE EVEN BACK INTO
NEBRASKA AND WILL CONTINUE TO FESTER OVER TAF LOCATIONS FROM FOD TO
ALO AND MCW THROUGH 02Z.  THERE MAY BE A SHORT BREAK THIS EVENING
BEFORE A STRONG PUSH OF MOISTURE SURGES INTO IOWA ON A STRONG LOW
LEVEL JET.  ALONG AND NORTH OF THE FRONTAL BOUNDARY STORMS MAY
INTENSIFY PRODUCING HEAVY RAINFALL AND A FEW OF THE MORE ROBUST
STORMS MAY PRODUCE STRONG WIND AND HAIL.  MVFR VSBYS WILL LARGELY
PREVAIL EITHER DUE TO FOG AND/OR HEAVY RAIN.  CIGS WILL ALSO LOWER
IN THUNDERSTORMS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...FAB





000
FXUS63 KDMX 201754
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1248 PM CDT WED AUG 20 2014

.SHORT TERM /TODAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

AS ANTICIPATED ELEVATED THUNDERSTORMS HAVE FORMED IN A BROKEN BAND
ACROSS SOUTHERN/SOUTHWESTERN IOWA EARLY THIS MORNING...ALONG THE
NOSE OF THE VEERING LOW LEVEL JET AND WITHIN A REGION OF THETA E
ADVECTION ALOFT. A FEW STORMS WILL LIKELY PRODUCE SOME HAIL BUT NO
ORGANIZED SEVERE WEATHER IS EXPECTED. THIS ACTIVITY WILL PERSIST FOR
THE NEXT SEVERAL HOURS AS IT SLOWLY DRIFTS NORTHEAST TOWARD CENTRAL
IOWA...THEN GRADUALLY FADE LATER THIS MORNING WITH MOSTLY DRY
CONDITIONS ANTICIPATED BY THE AFTERNOON. CONCURRENTLY...AN EFFECTIVE
WARM FRONT IN THE FORM OF A SURGE OF WARMER AND MORE MOIST AIR WILL
MOVE IN FROM THE SOUTHWEST TODAY...RESULTING IN SULTRY CONDITIONS
ACROSS MUCH OF OUR AREA BY LATER TODAY. HEAT INDEX VALUES WILL TOP
OUT NEAR 100 DEGREES FROM AROUND THE I-80 CORRIDOR SOUTHWARD THUS NO
ADVISORY IS WARRANTED AT THIS TIME.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

PRECIP TRENDS WILL BE THE PRIMARY FORECAST CONCERN RIGHT ON INTO
NEXT WEEK...BUT UNFORTUNATELY DETAILS WILL BE HARD TO COME BY.
GENERAL PATTERN CHANGES LITTLE WITH PERSISTENT WRN CONUS TROUGH/ERN
RIDGE SCENARIO AS PNA INDEX CONTINUES TO LOWER. THIS LEAVES IA IN
PROLONGED SW FLOW ALOFT WITH SURFACE FEATURES REACHING THE STATE
LATER THIS WEEK AND MOVING LITTLE INTO NEXT WEEK.  CONVECTION FOR
THE NEXT FEW DAYS WILL MAINLY BE NOCTURNAL WITH LITTLE CONVERGENCE
OR LARGER SCALE FORCING.  WARM/THETA-E ADVECTION SURGE WILL PUSH
THROUGH TONIGHT WITH WEAKER THERMODYNAMIC FORCING THU NIGHT. WITH
BAROCLINIC ZONE ADVANCING NE...THIS WILL LEAVE IA IN A VERY WARM AND
HUMID AIRMASS WITH HIGHS IN THE UPPER 80S/LOWER 90S. PEAK HEAT
INDICES WILL BE PUSHING ADVISORY CRITERIA...JUST OVER 100F...BUT NOT
QUITE THERE SO WILL CONTINUE MENTION IN THE HWO.

BY THE WEEKEND AND EARLY NEXT WEEK SURFACE BOUNDARY SHOULD ADVANCE
MORE SOUTH AND EAST INCREASING THE POTENTIAL FOR PEAK
HEATING/SURFACE BASED CONVECTION. SURFACE FEATURES SHOULD LINGER
THROUGH THE END OF THE VALID PERIOD WITH A PROLONGED MENTION OF
POPS. BETTER SYNOPTIC FORCING WITH WRN TROUGH FINALLY ADVANCES FAR
ENOUGH EAST TO INCREASE POPS AND PRECIP COVERAGE BY TUE...BUT BEST
SENSIBLE WEATHER REFLECTION SEEMS JUST BEYOND THE CURRENT VALID
PERIOD TUE NIGHT INTO WED.

THE AIRMASS WILL BE FAVORABLE FOR LOCALLY HEAVY RAINS THROUGH THE
ENTIRE PERIOD WITH QUITE FAVORABLE ELEVATED K INDICES...WARM CLOUD
DEPTHS AND PWS.  HAVE STARTED WITH HEAVY RAIN MENTION NORTH
TONIGHT...BUT ADDITIONAL WORDING MAY NEED TO BE ADDED WITH LATER
PACKAGES. NE HALF OF THE FORECAST AREA REMAINS QUITE DRY...SO NO
HEADLINES FOR NOW UNTIL CONFIDENCE OF HEAVY RAIN LOCATIONS AND
MORE FAVORABLE ANTECEDENT MOISTURE CONDITIONS BECOME BETTER
PHASED. SEVERE POTENTIAL WILL REMAIN ELEVATED AS WELL DUE TO THE
DEGREE OF INSTABILITY AND AT LEAST MARGINAL EFFECT SHEAR...BUT
THERE DOES NOT APPEAR TO BE ANY PARTICULAR PERIOD TO FOCUS ON
BESIDE MARGINAL INCREASE FROM THE WEEKEND ON DUE TO BOUNDARY
INTERACTIONS. WILL KEEP BROAD MENTION OF BOTH THREATS GOING IN
THE HWO.

&&

.AVIATION...20/18Z
ISSUED AT 1248 PM CDT WED AUG 20 2014

SHOWERS AND THUNDERSTORMS PERSIST IN A ZONE OF INSTABILITY AHEAD OF
A WARM FRONT OVER SOUTHERN IOWA THAT  EXTENDS BACK INTO SOUTH DAKOTA.
SHOWERS AND STORMS KEEP REDEVELOPING IN THIS ZONE EVEN BACK INTO
NEBRASKA AND WILL CONTINUE TO FESTER OVER TAF LOCATIONS FROM FOD TO
ALO AND MCW THROUGH 02Z.  THERE MAY BE A SHORT BREAK THIS EVENING
BEFORE A STRONG PUSH OF MOISTURE SURGES INTO IOWA ON A STRONG LOW
LEVEL JET.  ALONG AND NORTH OF THE FRONTAL BOUNDARY STORMS MAY
INTENSIFY PRODUCING HEAVY RAINFALL AND A FEW OF THE MORE ROBUST
STORMS MAY PRODUCE STRONG WIND AND HAIL.  MVFR VSBYS WILL LARGELY
PREVAIL EITHER DUE TO FOG AND/OR HEAVY RAIN.  CIGS WILL ALSO LOWER
IN THUNDERSTORMS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...FAB




000
FXUS63 KDMX 201127
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
627 AM CDT WED AUG 20 2014

.SHORT TERM /TODAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

AS ANTICIPATED ELEVATED THUNDERSTORMS HAVE FORMED IN A BROKEN BAND
ACROSS SOUTHERN/SOUTHWESTERN IOWA EARLY THIS MORNING...ALONG THE
NOSE OF THE VEERING LOW LEVEL JET AND WITHIN A REGION OF THETA E
ADVECTION ALOFT. A FEW STORMS WILL LIKELY PRODUCE SOME HAIL BUT NO
ORGANIZED SEVERE WEATHER IS EXPECTED. THIS ACTIVITY WILL PERSIST FOR
THE NEXT SEVERAL HOURS AS IT SLOWLY DRIFTS NORTHEAST TOWARD CENTRAL
IOWA...THEN GRADUALLY FADE LATER THIS MORNING WITH MOSTLY DRY
CONDITIONS ANTICIPATED BY THE AFTERNOON. CONCURRENTLY...AN EFFECTIVE
WARM FRONT IN THE FORM OF A SURGE OF WARMER AND MORE MOIST AIR WILL
MOVE IN FROM THE SOUTHWEST TODAY...RESULTING IN SULTRY CONDITIONS
ACROSS MUCH OF OUR AREA BY LATER TODAY. HEAT INDEX VALUES WILL TOP
OUT NEAR 100 DEGREES FROM AROUND THE I-80 CORRIDOR SOUTHWARD THUS NO
ADVISORY IS WARRANTED AT THIS TIME.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

PRECIP TRENDS WILL BE THE PRIMARY FORECAST CONCERN RIGHT ON INTO
NEXT WEEK...BUT UNFORTUNATELY DETAILS WILL BE HARD TO COME BY.
GENERAL PATTERN CHANGES LITTLE WITH PERSISTENT WRN CONUS TROUGH/ERN
RIDGE SCENARIO AS PNA INDEX CONTINUES TO LOWER. THIS LEAVES IA IN
PROLONGED SW FLOW ALOFT WITH SURFACE FEATURES REACHING THE STATE
LATER THIS WEEK AND MOVING LITTLE INTO NEXT WEEK.  CONVECTION FOR
THE NEXT FEW DAYS WILL MAINLY BE NOCTURNAL WITH LITTLE CONVERGENCE
OR LARGER SCALE FORCING.  WARM/THETA-E ADVECTION SURGE WILL PUSH
THROUGH TONIGHT WITH WEAKER THERMODYNAMIC FORCING THU NIGHT. WITH
BAROCLINIC ZONE ADVANCING NE...THIS WILL LEAVE IA IN A VERY WARM AND
HUMID AIRMASS WITH HIGHS IN THE UPPER 80S/LOWER 90S. PEAK HEAT
INDICES WILL BE PUSHING ADVISORY CRITERIA...JUST OVER 100F...BUT NOT
QUITE THERE SO WILL CONTINUE MENTION IN THE HWO.

BY THE WEEKEND AND EARLY NEXT WEEK SURFACE BOUNDARY SHOULD ADVANCE
MORE SOUTH AND EAST INCREASING THE POTENTIAL FOR PEAK
HEATING/SURFACE BASED CONVECTION. SURFACE FEATURES SHOULD LINGER
THROUGH THE END OF THE VALID PERIOD WITH A PROLONGED MENTION OF
POPS. BETTER SYNOPTIC FORCING WITH WRN TROUGH FINALLY ADVANCES FAR
ENOUGH EAST TO INCREASE POPS AND PRECIP COVERAGE BY TUE...BUT BEST
SENSIBLE WEATHER REFLECTION SEEMS JUST BEYOND THE CURRENT VALID
PERIOD TUE NIGHT INTO WED.

THE AIRMASS WILL BE FAVORABLE FOR LOCALLY HEAVY RAINS THROUGH THE
ENTIRE PERIOD WITH QUITE FAVORABLE ELEVATED K INDICES...WARM CLOUD
DEPTHS AND PWS.  HAVE STARTED WITH HEAVY RAIN MENTION NORTH
TONIGHT...BUT ADDITIONAL WORDING MAY NEED TO BE ADDED WITH LATER
PACKAGES. NE HALF OF THE FORECAST AREA REMAINS QUITE DRY...SO NO
HEADLINES FOR NOW UNTIL CONFIDENCE OF HEAVY RAIN LOCATIONS AND
MORE FAVORABLE ANTECEDENT MOISTURE CONDITIONS BECOME BETTER
PHASED. SEVERE POTENTIAL WILL REMAIN ELEVATED AS WELL DUE TO THE
DEGREE OF INSTABILITY AND AT LEAST MARGINAL EFFECT SHEAR...BUT
THERE DOES NOT APPEAR TO BE ANY PARTICULAR PERIOD TO FOCUS ON
BESIDE MARGINAL INCREASE FROM THE WEEKEND ON DUE TO BOUNDARY
INTERACTIONS. WILL KEEP BROAD MENTION OF BOTH THREATS GOING IN
THE HWO.

&&

.AVIATION...20/12Z
ISSUED AT 627 AM CDT WED AUG 20 2014

SCATTERED THUNDERSTORMS WILL AFFECT THE AREA THIS
MORNING...ESPECIALLY FOD/DSM/OTM...THEN DISSIPATE BEFORE MIDDAY.
SOME FOG IS ALSO POSSIBLE AT MCW/ALO EARLY THIS MORNING BUT WILL
END BY 14Z OR SO. THIS AFTERNOON AND EVENING VFR CONDITIONS ARE
FORECAST WITH VERY LITTLE THREAT OF RAIN/TSRA. AFTER MIDNIGHT
TONIGHT BR AND LOWER CIGS WILL BE POSSIBLE ALONG WITH ISOLD/WDLY
SCT TSRA...BUT CONFIDENCE IS LOW AT THIS RANGE AND HAVE JUST
ADVERTISED 5SM BR AT THE NORTHERN TERMINALS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...LEE




000
FXUS63 KDMX 201127
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
627 AM CDT WED AUG 20 2014

.SHORT TERM /TODAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

AS ANTICIPATED ELEVATED THUNDERSTORMS HAVE FORMED IN A BROKEN BAND
ACROSS SOUTHERN/SOUTHWESTERN IOWA EARLY THIS MORNING...ALONG THE
NOSE OF THE VEERING LOW LEVEL JET AND WITHIN A REGION OF THETA E
ADVECTION ALOFT. A FEW STORMS WILL LIKELY PRODUCE SOME HAIL BUT NO
ORGANIZED SEVERE WEATHER IS EXPECTED. THIS ACTIVITY WILL PERSIST FOR
THE NEXT SEVERAL HOURS AS IT SLOWLY DRIFTS NORTHEAST TOWARD CENTRAL
IOWA...THEN GRADUALLY FADE LATER THIS MORNING WITH MOSTLY DRY
CONDITIONS ANTICIPATED BY THE AFTERNOON. CONCURRENTLY...AN EFFECTIVE
WARM FRONT IN THE FORM OF A SURGE OF WARMER AND MORE MOIST AIR WILL
MOVE IN FROM THE SOUTHWEST TODAY...RESULTING IN SULTRY CONDITIONS
ACROSS MUCH OF OUR AREA BY LATER TODAY. HEAT INDEX VALUES WILL TOP
OUT NEAR 100 DEGREES FROM AROUND THE I-80 CORRIDOR SOUTHWARD THUS NO
ADVISORY IS WARRANTED AT THIS TIME.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

PRECIP TRENDS WILL BE THE PRIMARY FORECAST CONCERN RIGHT ON INTO
NEXT WEEK...BUT UNFORTUNATELY DETAILS WILL BE HARD TO COME BY.
GENERAL PATTERN CHANGES LITTLE WITH PERSISTENT WRN CONUS TROUGH/ERN
RIDGE SCENARIO AS PNA INDEX CONTINUES TO LOWER. THIS LEAVES IA IN
PROLONGED SW FLOW ALOFT WITH SURFACE FEATURES REACHING THE STATE
LATER THIS WEEK AND MOVING LITTLE INTO NEXT WEEK.  CONVECTION FOR
THE NEXT FEW DAYS WILL MAINLY BE NOCTURNAL WITH LITTLE CONVERGENCE
OR LARGER SCALE FORCING.  WARM/THETA-E ADVECTION SURGE WILL PUSH
THROUGH TONIGHT WITH WEAKER THERMODYNAMIC FORCING THU NIGHT. WITH
BAROCLINIC ZONE ADVANCING NE...THIS WILL LEAVE IA IN A VERY WARM AND
HUMID AIRMASS WITH HIGHS IN THE UPPER 80S/LOWER 90S. PEAK HEAT
INDICES WILL BE PUSHING ADVISORY CRITERIA...JUST OVER 100F...BUT NOT
QUITE THERE SO WILL CONTINUE MENTION IN THE HWO.

BY THE WEEKEND AND EARLY NEXT WEEK SURFACE BOUNDARY SHOULD ADVANCE
MORE SOUTH AND EAST INCREASING THE POTENTIAL FOR PEAK
HEATING/SURFACE BASED CONVECTION. SURFACE FEATURES SHOULD LINGER
THROUGH THE END OF THE VALID PERIOD WITH A PROLONGED MENTION OF
POPS. BETTER SYNOPTIC FORCING WITH WRN TROUGH FINALLY ADVANCES FAR
ENOUGH EAST TO INCREASE POPS AND PRECIP COVERAGE BY TUE...BUT BEST
SENSIBLE WEATHER REFLECTION SEEMS JUST BEYOND THE CURRENT VALID
PERIOD TUE NIGHT INTO WED.

THE AIRMASS WILL BE FAVORABLE FOR LOCALLY HEAVY RAINS THROUGH THE
ENTIRE PERIOD WITH QUITE FAVORABLE ELEVATED K INDICES...WARM CLOUD
DEPTHS AND PWS.  HAVE STARTED WITH HEAVY RAIN MENTION NORTH
TONIGHT...BUT ADDITIONAL WORDING MAY NEED TO BE ADDED WITH LATER
PACKAGES. NE HALF OF THE FORECAST AREA REMAINS QUITE DRY...SO NO
HEADLINES FOR NOW UNTIL CONFIDENCE OF HEAVY RAIN LOCATIONS AND
MORE FAVORABLE ANTECEDENT MOISTURE CONDITIONS BECOME BETTER
PHASED. SEVERE POTENTIAL WILL REMAIN ELEVATED AS WELL DUE TO THE
DEGREE OF INSTABILITY AND AT LEAST MARGINAL EFFECT SHEAR...BUT
THERE DOES NOT APPEAR TO BE ANY PARTICULAR PERIOD TO FOCUS ON
BESIDE MARGINAL INCREASE FROM THE WEEKEND ON DUE TO BOUNDARY
INTERACTIONS. WILL KEEP BROAD MENTION OF BOTH THREATS GOING IN
THE HWO.

&&

.AVIATION...20/12Z
ISSUED AT 627 AM CDT WED AUG 20 2014

SCATTERED THUNDERSTORMS WILL AFFECT THE AREA THIS
MORNING...ESPECIALLY FOD/DSM/OTM...THEN DISSIPATE BEFORE MIDDAY.
SOME FOG IS ALSO POSSIBLE AT MCW/ALO EARLY THIS MORNING BUT WILL
END BY 14Z OR SO. THIS AFTERNOON AND EVENING VFR CONDITIONS ARE
FORECAST WITH VERY LITTLE THREAT OF RAIN/TSRA. AFTER MIDNIGHT
TONIGHT BR AND LOWER CIGS WILL BE POSSIBLE ALONG WITH ISOLD/WDLY
SCT TSRA...BUT CONFIDENCE IS LOW AT THIS RANGE AND HAVE JUST
ADVERTISED 5SM BR AT THE NORTHERN TERMINALS.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...LEE





000
FXUS63 KDMX 200909
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
409 AM CDT WED AUG 20 2014

.SHORT TERM /TODAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

AS ANTICIPATED ELEVATED THUNDERSTORMS HAVE FORMED IN A BROKEN BAND
ACROSS SOUTHERN/SOUTHWESTERN IOWA EARLY THIS MORNING...ALONG THE
NOSE OF THE VEERING LOW LEVEL JET AND WITHIN A REGION OF THETA E
ADVECTION ALOFT. A FEW STORMS WILL LIKELY PRODUCE SOME HAIL BUT NO
ORGANIZED SEVERE WEATHER IS EXPECTED. THIS ACTIVITY WILL PERSIST FOR
THE NEXT SEVERAL HOURS AS IT SLOWLY DRIFTS NORTHEAST TOWARD CENTRAL
IOWA...THEN GRADUALLY FADE LATER THIS MORNING WITH MOSTLY DRY
CONDITIONS ANTICIPATED BY THE AFTERNOON. CONCURRENTLY...AN EFFECTIVE
WARM FRONT IN THE FORM OF A SURGE OF WARMER AND MORE MOIST AIR WILL
MOVE IN FROM THE SOUTHWEST TODAY...RESULTING IN SULTRY CONDITIONS
ACROSS MUCH OF OUR AREA BY LATER TODAY. HEAT INDEX VALUES WILL TOP
OUT NEAR 100 DEGREES FROM AROUND THE I-80 CORRIDOR SOUTHWARD THUS NO
ADVISORY IS WARRANTED AT THIS TIME.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

PRECIP TRENDS WILL BE THE PRIMARY FORECAST CONCERN RIGHT ON INTO
NEXT WEEK...BUT UNFORTUNATELY DETAILS WILL BE HARD TO COME BY.
GENERAL PATTERN CHANGES LITTLE WITH PERSISTENT WRN CONUS TROUGH/ERN
RIDGE SCENARIO AS PNA INDEX CONTINUES TO LOWER. THIS LEAVES IA IN
PROLONGED SW FLOW ALOFT WITH SURFACE FEATURES REACHING THE STATE
LATER THIS WEEK AND MOVING LITTLE INTO NEXT WEEK.  CONVECTION FOR
THE NEXT FEW DAYS WILL MAINLY BE NOCTURNAL WITH LITTLE CONVERGENCE
OR LARGER SCALE FORCING.  WARM/THETA-E ADVECTION SURGE WILL PUSH
THROUGH TONIGHT WITH WEAKER THERMODYNAMIC FORCING THU NIGHT. WITH
BAROCLINIC ZONE ADVANCING NE...THIS WILL LEAVE IA IN A VERY WARM AND
HUMID AIRMASS WITH HIGHS IN THE UPPER 80S/LOWER 90S. PEAK HEAT
INDICES WILL BE PUSHING ADVISORY CRITERIA...JUST OVER 100F...BUT NOT
QUITE THERE SO WILL CONTINUE MENTION IN THE HWO.

BY THE WEEKEND AND EARLY NEXT WEEK SURFACE BOUNDARY SHOULD ADVANCE
MORE SOUTH AND EAST INCREASING THE POTENTIAL FOR PEAK
HEATING/SURFACE BASED CONVECTION. SURFACE FEATURES SHOULD LINGER
THROUGH THE END OF THE VALID PERIOD WITH A PROLONGED MENTION OF
POPS. BETTER SYNOPTIC FORCING WITH WRN TROUGH FINALLY ADVANCES FAR
ENOUGH EAST TO INCREASE POPS AND PRECIP COVERAGE BY TUE...BUT BEST
SENSIBLE WEATHER REFLECTION SEEMS JUST BEYOND THE CURRENT VALID
PERIOD TUE NIGHT INTO WED.

THE AIRMASS WILL BE FAVORABLE FOR LOCALLY HEAVY RAINS THROUGH THE
ENTIRE PERIOD WITH QUITE FAVORABLE ELEVATED K INDICES...WARM CLOUD
DEPTHS AND PWS.  HAVE STARTED WITH HEAVY RAIN MENTION NORTH
TONIGHT...BUT ADDITIONAL WORDING MAY NEED TO BE ADDED WITH LATER
PACKAGES. NE HALF OF THE FORECAST AREA REMAINS QUITE DRY...SO NO
HEADLINES FOR NOW UNTIL CONFIDENCE OF HEAVY RAIN LOCATIONS AND
MORE FAVORABLE ANTECEDENT MOISTURE CONDITIONS BECOME BETTER
PHASED. SEVERE POTENTIAL WILL REMAIN ELEVATED AS WELL DUE TO THE
DEGREE OF INSTABILITY AND AT LEAST MARGINAL EFFECT SHEAR...BUT
THERE DOES NOT APPEAR TO BE ANY PARTICULAR PERIOD TO FOCUS ON
BESIDE MARGINAL INCREASE FROM THE WEEKEND ON DUE TO BOUNDARY
INTERACTIONS. WILL KEEP BROAD MENTION OF BOTH THREATS GOING IN
THE HWO.

&&

.AVIATION...20/06Z
ISSUED AT 1134 PM CDT TUE AUG 19 2014

BOUNDARY WILL LIFT ACROSS IOWA THROUGH WEDNESDAY...THIS WILL BRING
CHANCES FOR SHRA/TSRA TO SITES...PRIMARILY SOUTHERN SITES
THROUGHOUT THE PERIOD. BEST CHANCES WILL COME BEFORE 12Z...BEFORE
DECREASING. HAVE INCLUDED VC MENTION AT KFOD/KDSM/KOTM. NORTHERN
SITES WILL LIKELY SEE BR/FG NEAR 12Z GIVEN AMPLE LOW LEVEL
MOISTURE. MVFR...IFR OR LOWER CEILINGS AND VISIBILITIES WILL BE
POSSIBLE AT TIMES AT SITES THROUGH 12Z BEFORE IMPROVING QUICKLY
AFTER 12Z. WINDS WILL BECOME SOUTHERLY AND CONDITIONS WILL REMAIN
VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...AWB




000
FXUS63 KDMX 200909
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
409 AM CDT WED AUG 20 2014

.SHORT TERM /TODAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

AS ANTICIPATED ELEVATED THUNDERSTORMS HAVE FORMED IN A BROKEN BAND
ACROSS SOUTHERN/SOUTHWESTERN IOWA EARLY THIS MORNING...ALONG THE
NOSE OF THE VEERING LOW LEVEL JET AND WITHIN A REGION OF THETA E
ADVECTION ALOFT. A FEW STORMS WILL LIKELY PRODUCE SOME HAIL BUT NO
ORGANIZED SEVERE WEATHER IS EXPECTED. THIS ACTIVITY WILL PERSIST FOR
THE NEXT SEVERAL HOURS AS IT SLOWLY DRIFTS NORTHEAST TOWARD CENTRAL
IOWA...THEN GRADUALLY FADE LATER THIS MORNING WITH MOSTLY DRY
CONDITIONS ANTICIPATED BY THE AFTERNOON. CONCURRENTLY...AN EFFECTIVE
WARM FRONT IN THE FORM OF A SURGE OF WARMER AND MORE MOIST AIR WILL
MOVE IN FROM THE SOUTHWEST TODAY...RESULTING IN SULTRY CONDITIONS
ACROSS MUCH OF OUR AREA BY LATER TODAY. HEAT INDEX VALUES WILL TOP
OUT NEAR 100 DEGREES FROM AROUND THE I-80 CORRIDOR SOUTHWARD THUS NO
ADVISORY IS WARRANTED AT THIS TIME.

.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 405 AM CDT WED AUG 20 2014

PRECIP TRENDS WILL BE THE PRIMARY FORECAST CONCERN RIGHT ON INTO
NEXT WEEK...BUT UNFORTUNATELY DETAILS WILL BE HARD TO COME BY.
GENERAL PATTERN CHANGES LITTLE WITH PERSISTENT WRN CONUS TROUGH/ERN
RIDGE SCENARIO AS PNA INDEX CONTINUES TO LOWER. THIS LEAVES IA IN
PROLONGED SW FLOW ALOFT WITH SURFACE FEATURES REACHING THE STATE
LATER THIS WEEK AND MOVING LITTLE INTO NEXT WEEK.  CONVECTION FOR
THE NEXT FEW DAYS WILL MAINLY BE NOCTURNAL WITH LITTLE CONVERGENCE
OR LARGER SCALE FORCING.  WARM/THETA-E ADVECTION SURGE WILL PUSH
THROUGH TONIGHT WITH WEAKER THERMODYNAMIC FORCING THU NIGHT. WITH
BAROCLINIC ZONE ADVANCING NE...THIS WILL LEAVE IA IN A VERY WARM AND
HUMID AIRMASS WITH HIGHS IN THE UPPER 80S/LOWER 90S. PEAK HEAT
INDICES WILL BE PUSHING ADVISORY CRITERIA...JUST OVER 100F...BUT NOT
QUITE THERE SO WILL CONTINUE MENTION IN THE HWO.

BY THE WEEKEND AND EARLY NEXT WEEK SURFACE BOUNDARY SHOULD ADVANCE
MORE SOUTH AND EAST INCREASING THE POTENTIAL FOR PEAK
HEATING/SURFACE BASED CONVECTION. SURFACE FEATURES SHOULD LINGER
THROUGH THE END OF THE VALID PERIOD WITH A PROLONGED MENTION OF
POPS. BETTER SYNOPTIC FORCING WITH WRN TROUGH FINALLY ADVANCES FAR
ENOUGH EAST TO INCREASE POPS AND PRECIP COVERAGE BY TUE...BUT BEST
SENSIBLE WEATHER REFLECTION SEEMS JUST BEYOND THE CURRENT VALID
PERIOD TUE NIGHT INTO WED.

THE AIRMASS WILL BE FAVORABLE FOR LOCALLY HEAVY RAINS THROUGH THE
ENTIRE PERIOD WITH QUITE FAVORABLE ELEVATED K INDICES...WARM CLOUD
DEPTHS AND PWS.  HAVE STARTED WITH HEAVY RAIN MENTION NORTH
TONIGHT...BUT ADDITIONAL WORDING MAY NEED TO BE ADDED WITH LATER
PACKAGES. NE HALF OF THE FORECAST AREA REMAINS QUITE DRY...SO NO
HEADLINES FOR NOW UNTIL CONFIDENCE OF HEAVY RAIN LOCATIONS AND
MORE FAVORABLE ANTECEDENT MOISTURE CONDITIONS BECOME BETTER
PHASED. SEVERE POTENTIAL WILL REMAIN ELEVATED AS WELL DUE TO THE
DEGREE OF INSTABILITY AND AT LEAST MARGINAL EFFECT SHEAR...BUT
THERE DOES NOT APPEAR TO BE ANY PARTICULAR PERIOD TO FOCUS ON
BESIDE MARGINAL INCREASE FROM THE WEEKEND ON DUE TO BOUNDARY
INTERACTIONS. WILL KEEP BROAD MENTION OF BOTH THREATS GOING IN
THE HWO.

&&

.AVIATION...20/06Z
ISSUED AT 1134 PM CDT TUE AUG 19 2014

BOUNDARY WILL LIFT ACROSS IOWA THROUGH WEDNESDAY...THIS WILL BRING
CHANCES FOR SHRA/TSRA TO SITES...PRIMARILY SOUTHERN SITES
THROUGHOUT THE PERIOD. BEST CHANCES WILL COME BEFORE 12Z...BEFORE
DECREASING. HAVE INCLUDED VC MENTION AT KFOD/KDSM/KOTM. NORTHERN
SITES WILL LIKELY SEE BR/FG NEAR 12Z GIVEN AMPLE LOW LEVEL
MOISTURE. MVFR...IFR OR LOWER CEILINGS AND VISIBILITIES WILL BE
POSSIBLE AT TIMES AT SITES THROUGH 12Z BEFORE IMPROVING QUICKLY
AFTER 12Z. WINDS WILL BECOME SOUTHERLY AND CONDITIONS WILL REMAIN
VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...LEE
LONG TERM...SMALL
AVIATION...AWB





000
FXUS63 KDMX 200438
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1138 PM CDT TUE AUG 19 2014

.SYNOPSIS...
ISSUED AT 305 PM CDT TUE AUG 19 2014

WEAK HIGH PRESSURE OVER IOWA WILL MOVE EAST AS A WARM FRONT
DEVELOPS TO THE SOUTH AND BEGINS TO LIFT NORTH TONIGHT. THE FRONT
WILL LIFT NORTH OF THE STATE ON WEDNESDAY NIGHT. STRONG S/WV WILL
MOVE UP THE BACK SIDE OF THE UPPER LEVEL RIDGE AND PUSH A COLD
FRONT ACROSS THE STATE THIS WEEKEND.

&&

.SHORT TERM /TONIGHT/...
ISSUED AT 305 PM CDT TUE AUG 19 2014

A SURFACE LOW DEVELOPING OVER NORTHEAST COLORADO WILL SHIFT INTO
NORTHWEST NEBRASKA OVERNIGHT.  AN ASSOCIATED WARM FRONT WILL EXTEND
FROM THE LOW THROUGH EASTERN NEBRASKA AND INTO SOUTHWEST IOWA AND
NORTHERN MISSOURI BY 12Z WEDNESDAY BEFORE SURGING NORTH THROUGH THE
DAY WEDNESDAY.  STRONG THETA-E ADVECTION IS FORECAST TO LIFT ACROSS
CENTRAL IOWA DURING THE OVERNIGHT HOURS...ESPECIALLY AFTER 06Z.
FORCING IS WEAK BUT DOES IMPROVE OVERNIGHT AS A LOW LEVEL JET
FOCUSES INTO SOUTHWEST IOWA.  ALOFT A WEAK SHORTWAVE IS PROGGED TO
MOVE ACROSS EASTERN NEBRASKA/SOUTHWEST IOWA.  THIS SHOULD BE ENOUGH
TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS SOUTHWEST INTO CENTRAL
IOWA.  STORMS SHOULD MAINLY BE ELEVATED AS LOW LEVEL CONVERGENCE IS
WEAK TO NON EXISTENT.  THERE IS ALSO SOME WEAK SHEAR...PERHAPS
ENOUGH FOR AN ISOLATED STORM TO BRIEFLY PRODUCE SOME MARGINALLY
SEVERE TO SEVERE HAIL. THE HIGH RES AND NAM12 MODELS ARE NOT AS
IMPRESSIVE WITH DEVELOPING STORMS ACROSS THE AREA BUT THE SREF DOES
AS DOES PREVIOUS RUN OF THE HI-RES MODELS.  THE HRRR IN PARTICULAR
IS FAIRLY BULLISH ON BRINING PRECIP INTO THE SW WHILE THE MEMBERS OF
THE HOPWRF ARE A LITTLE MORE RESERVED...AT LEAST THROUGH 09Z.

SOME POTENTIAL FOR FOG ACROSS THE NORTHEAST OVERNIGHT AS REMAINING
CLOUDS ACROSS THE AREA DISSIPATE WITH SUNSET AND SURFACE RIDGING
MOVES OVERHEAD PRODUCING LIGHT WIND.  NOT LOOKING AT DENSE FOG AT
THIS POINT GIVEN THE VERY SHALLOW NATURE OF THE MOISTURE MOVING IN.
GENERALLY WENT WITH PATCHY FOG WORDING HOWEVER ALO/MCW WILL BE EAST
OF THE RIDGE AXIS AND MOISTURE COULD BE ENOUGH FOR A LITTLE MORE
WIDESPREAD FOG SO I MENTION AREAS OF FOG OVER THESE LOCATIONS.

.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 305 PM CDT TUE AUG 19 2014

A BREAK IN THE CONVECTION IS EXPECTED ON WED AS THE FIRST ROUND OF
THETA-E ADVECTON LIFTS OUT OF THE STATE. A RENEWED THREAT OF
THUNDERSTORMS WILL COME AS THE WARM FRONT LIFTS NORTH AND STRONG
THETA-E ADVECTION TAKES PLACE WED NIGHT. THE H8 SHOWS GOOD SPEED
CONVERGENCE AND THERE IS DIVERGENCE ALOFT...THE FLY IN THE
OINTMENT WILL BE IF THE ATMOSPHERE CAPS OFF OR NOT. AN EML IS IN
PLACE...BUT IT IS NOT ALL THAT STRONG.

WARM AND HUMID WEATHER WILL HOLD INTO THE WEEKEND WITH AFTERNOON
HEAT INDICES IN THE LOW TO MID 90S NORTH...AND 95 TO 105 SOUTH
TUE-THU AFTERNOON. BELOW CRITERIA...BUT WILL MENTION IN THE HWO
WITH ALL THE SCHOOL ACTIVITIES GOING ON.

COOLER WEATHER WILL MOVE IN OVER THE WEEKEND...FIRST DUE TO THE
INCREASED CLOUD COVER...THEN DUE TO THE FRONTAL PASSAGE SAT. COOL
AIR WILL SETTLE IN SLOWLY WITH TEMPS FALLING BELOW NORMAL; FOR MON
AND TUE.

&&

.AVIATION...20/06Z
ISSUED AT 1134 PM CDT TUE AUG 19 2014

BOUNDARY WILL LIFT ACROSS IOWA THROUGH WEDNESDAY...THIS WILL BRING
CHANCES FOR SHRA/TSRA TO SITES...PRIMARILY SOUTHERN SITES
THROUGHOUT THE PERIOD. BEST CHANCES WILL COME BEFORE 12Z...BEFORE
DECREASING. HAVE INCLUDED VC MENTION AT KFOD/KDSM/KOTM. NORTHERN
SITES WILL LIKELY SEE BR/FG NEAR 12Z GIVEN AMPLE LOW LEVEL
MOISTURE. MVFR...IFR OR LOWER CEILINGS AND VISIBILITIES WILL BE
POSSIBLE AT TIMES AT SITES THROUGH 12Z BEFORE IMPROVING QUICKLY
AFTER 12Z. WINDS WILL BECOME SOUTHERLY AND CONDITIONS WILL REMAIN
VFR THROUGH REMAINDER OF PERIOD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MS AUG 14
SHORT TERM...FAB
LONG TERM...MS AUG 14
AVIATION...AWB





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