000
FXUS63 KDVN 191104
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
604 AM CDT WED JUN 19 2013

.SYNOPSIS...
ISSUED AT 325 AM CDT WED JUN 19 2013

HIGH PRESSURE OVER THE GREAT LAKES AND AN UPPER LEVEL RIDGE SETTING
UP OVER THE PLAINS WILL COMBINE TO PROVIDE ANOTHER DAY OF LOW
HUMIDITY AND NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES. THE
SURFACE RIDGE OF HIGH PRESSURE...SITUATED FROM EASTERN WI THROUGH
NORTHERN LOWER MI INTO SW QUEBEC...WAS PRODUCING LIGHT EASTERLY
WINDS FEEDING DEWPOINTS IN THE 40S AND 50S INTO THE FORECAST AREA
EARLY THIS MORNING. RADAR MOSAIC AND SATELLITE IMAGERY SHOWED
THUNDERSTORM COMPLEXES ASSOCIATED WITH A SHORTWAVE MOVING INTO THE
UPPER RIDGE MOVING OFF THE HIGH PLAINS INTO NEB...KS AND OK.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT WED JUN 19 2013

PRIMARY CHALLENGE IS TEMPERATURES AS SURFACE HIGH PRESSURE SLOWLY
RETREATS EASTWARD. TODAY...THE RESULTING VEERING OF LIGHT SURFACE
WINDS TO A MORE EASTERLY...THEN SOUTHEAST DIRECTION BY AFTERNOON
WILL END THE COOL TRAJECTORY OFF LAKE MI THAT HAS BEEN IN PLACE
SINCE YESTERDAY MORNING. ALOFT...TEMPERATURES AT 850 MB ARE PROGGED
TO RISE A COUPLE DEGREES CELSIUS HIGHER THAN YESTERDAY AND SUNSHINE
WILL BE ONLY PARTIALLY FILTERED AS HIGH CLOUDS OFF THE PLAINS
CONVECTION SPILLS OVERHEAD THIS AFTERNOON. GIVEN THIS...THE DRY LOW
LEVEL AIRMASS AND NOW DRY TRENDING SURFACE CONDITIONS OVER
ESPECIALLY THE CENTRAL AND NORTHEAST PORTIONS OF THE FORECAST AREA...
TEMPERATURES SHOULD QUICKLY RECOVER FROM THE UNSEASONABLY COOL
READINGS THIS MORNING TO EXCEED YESTERDAY/S HIGHS. WILL GO WITH
HIGHS FROM AROUND 80 NORTHEAST TO THE LOWER 80S CENTRAL AND
SOUTHWEST...WHICH IS ON THE WARM SIDE OF LATEST GUIDANCE.

TONIGHT...THE POTENTIAL FOR AN MCS TO DEVELOP OR MOVE INTO THE AREA
LOOKS LIMITED BASED ON VARIOUS MCS FORECAST PARAMETERS FROM
LATEST MODELS AND CONSIDERING THE PRIMARY LOW LEVEL JET AXIS
POINTING INTO THE PLAINS WELL TO THE WEST. THERE WILL BE A SHORTWAVE
RIDING THROUGH THE RIDGE AXIS OVERHEAD TO KEEP AN EYE ON...BUT AT
THIS TIME...WILL ANTICIPATE LITTLE MORE THAN INCREASING HIGH CLOUDS
FROM UPSTREAM CONVECTION. THESE CLOUDS AND LIGHT SOUTHERLY WINDS
WILL KEEP MINS A BIT WARMER THAN THIS MORNING...BUT STILL WELL BELOW
NORMAL AS THE AIRMASS TRAJECTORY OUT OF THE RETREATING HIGH WILL
KEEP DEWPOINTS IN THE 50S TO LOWER 60S.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 325 AM CDT WED JUN 19 2013

THE OVERALL PATTERN INDICATES AN ACTIVE MCS ZONE WILL BE PRESENT
ACROSS THE MIDWEST LATE THIS WEEK AND INTO EARLY NEXT WEEK.
HOWEVER...THE INDIVIDUAL MODELS ARE VERY DIVERGENT ON WHERE THIS
ZONE WILL BE. WHERE CONVECTION DEVELOPS AT NIGHT WILL AFFECT WHERE
IT DEVELOPS THE FOLLOWING DAY. CONCEPTUALLY...THE ACTIVE MCS ZONE
WILL BE NEAR OR OVER THE CWFA. WHILE THE FCST LOOKS EXCEEDINGLY WET
THERE WILL BE PERIODS OF DRY WX BUT THEY MAY NOT BE KNOWN MORE THAN
6 TO 12 HRS IN ADVANCE.

THE MODELS AGREE ON BUILDING 500MB HEIGHTS ACROSS THE AREA FROM
THURSDAY INTO FRIDAY BEFORE SUGGESTING A MINOR DROP IN 500MB
HEIGHTS FRIDAY NIGHT.

THE MCS AND LIFT TOOLS ARE MIXED. SOME SHOW AN MCS THAT DEVELOPS WED
NIGHT DECAYING AS IT MOVES ACROSS THE AREA ON THURSDAY...
UKMET/ECMWF/GEM...WHILE OTHERS DO NOT...GFS/WRF. THE GEM ACTUALLY
HAS A RELATIVELY STRONGER MCS THAN THE UKMET/ECMWF.

SO...HAVE GONE WITH SCHC POPS FOR A POSSIBLE DECAYING MCS IN THE WAA
ACROSS THE FAR WEST/SOUTHWEST THURS MORNING. DIURNAL HEATING SHOULD
RESULT IN ISOLATED/SCATTERED CONVECTION DEVELOPING IN THE AFTERNOON
THAT LINGERS INTO EVENING. THERE IS A VERY REAL POSSIBILITY THAT
THURSDAY MORNING WILL BE DRY.

THURS NIGHT SCHC/CHC POPS ACROSS MOST OF THE AREA. DIURNAL
CONVECTION SHOULD BE IN A DECAYING MODE DURING THE EVENING. THE MCS
AND LIFT TOOLS SUGGEST A POSSIBLE MCS CATCHING THE CWFA AFTER
MIDNIGHT WITH THE MOST LIKELY AREA IN THE NORTHWEST AND NORTH PARTS
OF THE CWFA.

IF AN MCS AFFECTS THE CWFA LATE THURS NIGHT...IT WOULD BE IN A
DECAYING MODE FRIDAY MORNING AND BOUNDARIES FROM IT WOULD DEVELOP
DIURNAL CONVECTION FRI AFTERNOON/EVENING. THUS SCHC/CHC POPS LOOK
REASONABLE FOR NOW.

FRI NIGHT DIURNAL CONVECTION SHOULD BE SEEN ACROSS THE AREA DURING
THE EVENING WITH POSSIBLY ANOTHER MCS MOVING ACROSS THE NORTH THIRD
LATE FRIDAY NIGHT. THUS THE SCHC/CHC POPS LOOK REASONABLE.

SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY CHC POPS FROM SATURDAY THROUGH MONDAY
WITH DRY OR SCHC POPS FOR TUESDAY. CONDITIONS WILL BE VERY WARM AND
HUMID WITH TEMPERATURES LIKELY AVERAGING ABOVE NORMAL.     ..08..

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 604 AM CDT WED JUN 19 2013

HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP VFR CONDITIONS IN
PLACE ACROSS EASTERN IOWA AND NORTHWEST ILLINOIS TODAY AND
TONIGHT. LIGHT EAST TO NORTHEAST WINDS WILL GRADUALLY BECOME
EAST...THEN SOUTHEAST BY EVENING. DRY AIR WILL LIMIT THE BASES OF
ANY CLOUDS THAT DEVELOP TO ABOVE 4000 FT.

&&

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

$$

SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...08
AVIATION...SHEETS