000
FXUS63 KDVN 091117
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
617 AM CDT WED JUL 9 2014

.SYNOPSIS...
ISSUED AT 315 AM CDT WED JUL 9 2014

ALOFT...THE UPPER MIDWEST REMAINS DOMINATED BY STRONG NORTHWEST
FLOW...AS A LARGE RIDGE HOLDS OVER THE SOUTHWESTERN US AND LONG WAVE
TROUGH SPANS THE OHIO VALLEY AND EAST COAST.  AT THE SURFACE...
SOMEWHAT DIFFUSE SECONDARY COLD FRONT CROSSING THE CWFA THIS MORNING
FROM MKX TO OAX AT 07Z.  DEW POINTS BEHIND THE FRONT IN THE LOWER TO
MID 50S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT WED JUL 9 2014

ANOTHER QUIET DAY TODAY WITH LOW HUMIDITY...BELOW NORMAL TEMPS...AND
SUNNY SKIES.  LOW 50S DEW POINTS ADVECTING IN BEHIND THE SURFACE
FRONT WILL YIELD A VERY LOW HUMIDITY DAY FOR JULY. WITH 850MB TEMPS
AROUND 11C...THE THERMAL TROUGH CROSSING THE CWFA LATE THIS
AFTERNOON...AND AFOREMENTIONED RELATIVELY DRY LOW LEVELS...EXPECT
TEMPS TO TOP OUT IN THE MID TO UPPER 70S.  SURFACE RIDGE LINGERS
OVER THE AREA THROUGH LATE TONIGHT...FOR ANOTHER COOL AND DRY JULY
NIGHT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 AM CDT WED JUL 9 2014

THURSDAY THROUGH FRIDAY...LATEST 00Z RUN MODELS CONTINUE WITH THE
IDEA OF LARGE SEASONABLY STRONG RIDGE CENTER SHIFT EAST ACRS THE GRT
LKS THU...WITH INCREASING SOUTHEASTERLY LLVL RETURN FLOW AS THE DAY
PROGRESSES. BUT WITH LINGERING COOL POOL AND MARGINAL MIXING...TEMPS
ONLY LOOK TO RECOVER BACK TO THE UPPER 70S TO LOWER 80S ACRS MOST
OF THE FCST AREA. ONGOING DRY MIXING TO CONTINUE TO MAKE FOR
UNSEASONABLY LOW DPTS IN THE 50S AGAIN THU...AND DESPITE A FEW
MODELS BREAKING OUT AIRMASS/WAA TYPE PRECIP THU AFTERNOON IN
PORTIONS OF THE LOCAL FCST AREA...WILL KEEP THE FCST DRY FOR NOW
WITH LINGERING RIDGE INFLUENCE JUST OFF TO THE EAST. AS FOR THE
THU NIGHT MCS POTENTIAL...ASSESSING THE LATEST 00Z RUN MEDIUM
RANGE MODEL GUIDANCE...THE HAVE FOR THE MOST PART SHIFTED
CONVECTIVE INITIATION PARAMETERS FURTHER TO THE WEST/NORTHWEST
THAT ANY ELEVATED STORM CLUSTERS OR EVEN AN MCS TYPE FEATURE
PROBABLY WILL NOT MAKE IT INTO THE WESTERN CWA UNTIL CLOSE TO DAWN
FRI MORNING. ELEVATED PLUME OF THTA-E ADVECTION...MID LAYER LAPSE
RATES AND OTHER CONVECTIVE SUPPORT MECHANISMS NOT ALL THAT
IMPRESSIVE LOOKING WITH LATEST RUNS AND SUGGEST JUST A ROUND OF
NON-SEVERE AND MODERATE RAINFALL PRODUCING SHOWERS AND
THUNDERSTORMS MOVING ACRS THE CWA MAINLY FRI MORNING INTO THE
EARLY AFTERNOON PERIOD BEFORE MOVING OUT OR FALLING APART. FRI
HIGHS DEPENDENT ON CONVECTIVE DEBRIS AND MAY PLAY TEMPS BEING HELD
DOWN SOME BY LINGERING CLOUD COVER WITH MOST OF THE FCST AREA IN
THE MID 70S TO NEAR 80 WITH A MID TO LATE AFTERNOON RECOVERY JUST
TO GET THOSE VALUES. AS FOR FRI NIGHT...WHERE LINGERING OUTFLOW
BOUNDARIES FROM THE FRIDAY ACTIVITY LAY OUT OR WHERE THE MAIN
RETURN FLOW WARM FRONT ITSELF ADJUSTS ACRS TRYING TO RETREAT
NORTHWARD WILL BE THE FRI NIGHT CONVECTIVE FOCAL POINTS. AND
CURRENT INDICATIONS SUGGEST THE SOUTHERN CWA OR EVEN INTO NORTHERN
MO WILL BE MORE PRIME FOR THIS POTENTIAL AND WILL PLACE HIGHER CHC
POPS IN THOSE LOCATIONS. SOME MIXED SIGNALS BY THE GUIDANCE ON HOW
STRONG THIS FRI NIGHT CONVECTION MAY BE...BUT THE OVERALL THEME
STILL SUGGESTS A MARGINAL SVR THREAT AT BEST. BUT PROJECTED PWATS
AND MOISTURE FEED SUGGEST SOME HEAVIER RAINFALL POTENTIAL.

SATURDAY AND SUNDAY...AFTER WHATEVER CONVECTIVE DEBRIS FROM FRI
NIGHT CAN CLEAR OFF FOR AIR MASS RECOVERY...THE WARMING POTENTIAL
FOR SAT SUGGESTS HIGH TEMPS TO RECOVER WELL BACK UP INTO THE 80S
ALONG WITH INCREASING HUMIDITY. THUS CAPES/POTENTIAL ENERGY THERE
FOR WHAT SEVERAL MEDIUM RANGE SOLUTIONS SUGGEST A DIGGING NORTHERN
STREAM UPPER TROF WILL LOOK TO ACT UPON FOR CONVECTIVE INITIATION
ACRS THE CENTRAL TO NORTHERN PLAINS SAT EVENING. THIS COULD SET UP
THE SCENARIO FOR A SUBSTANTIAL MATURE MCS EVENTUALLY PROPAGATING
ACRS SOME OR MUCH OF THE DVN CWA LATER SAT NIGHT INTO SUNDAY
MORNING. CURRENTLY PROJECTED THERMODYNAMICS AND FORCING SUGGESTING
BOTH SVR STORMS AND HEAVY RAINFALL POSSIBLE SAT NIGHT. BUT STILL
FAR ENOUGH OUT THAT MODEL TIMING ISSUES STILL MAKE FOR SOME
UNCERTAINTY. AFTER THAT POTENTIAL SYSTEM BLOWS THROUGH THE
REGION...THEN THERE MAY BE A LULL UNTIL THE MAIN COLD FRONT
ASSOCIATED WITH THE DEVELOPMENT OF A LARGE COOL CORE VORTEX
ESTABLISHING ACRS THE NORTHERN GRT LKS AGAIN OCCURS. THIS MAY NOT
BE UNTIL LATER MON OR MON NIGHT DEPENDING ON THE MODEL SOLUTIONS.
WILL HAVE TO KEEP CHC POPS GOING THROUGH THE PERIOD UNTIL
TIMING/FORCING WINDOWS BETTER DEFINED IN LATER MODEL RUNS.

NEXT MONDAY AND TUESDAY...LONGER RANGE INDICATIONS SUGGEST ANOTHER
REMARKABLE PATTERN FOR THIS TIME OF YEAR WITH A MORE OF A COOL
SEASON LIKE SET UP WITH A LARGE COLD CORE UPPER LOW/VORTEX
ESTABLISHING ACRS THE NORTHERN GRT LKS AND SHARP NORTHWESTERLY
STEERING FLOW PLUNGES DOWN ACRS THE UPPER MIDWEST/WESTERN GRT LKS
OUT OF CANADA. THE MAIN COLD FRONT ASSOCIATED WITH THIS PROCESS
ASSESSING LATEST MODEL ENSEMBLE TIMING...WILL LOOK TO SWEEP THROUGH
THE CWA LATE MON OR MON NIGHT FOR ANOTHER CONVECTIVE ROUND
POSSIBLE. THEN A BIG COOL DOWN AND MAINLY DRY WX IN STORE FOR THE MID
WEEK PERIOD. LOOKS SIMILAR TO WHAT IS CURRENTLY TAKING PLACE ACRS
THE UPPER CONUS...BUT MAYBE EVEN STRONGER ON THE LOW STRENGTH AND
POSSIBLE COOL INFLUX INTO THE AREA FROM THE NORTH.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 612 AM CDT WED JUL 9 2014

OPTIMUM VFR CONDITIONS TODAY WITH LIGHT NORTHWESTERLY SURFACE
WINDS. COULD SEE SOME AFTERNOON CUMULUS AOA 5000FT...BUT
OTHERWISE CLEAR SKIES WILL PREVAIL THROUGH THE TAF PERIOD. SOME
FORECAST MODELS ARE SUGGESTING LIGHT AVIATION FOG AFTER 0906Z
TONIGHT. HOWEVER...CURRENT THINKING IS THAT LOW SURFACE DEW POINTS
WILL KEEP FOG AT BAY.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...DMD
SHORT TERM...DMD
LONG TERM...12
AVIATION...DMD