Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 070848
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
348 AM CDT TUE JUL 7 2015

.SYNOPSIS...
ISSUED AT 330 AM CDT TUE JUL 7 2015

THE COLD FRONT THAT TRIGGERED HEAVY RAIN AND THUNDERSTORMS OVER THE
AREA LAST EVENING WAS LOCATED ROUGHLY FROM CENTRAL LOWER MI SW
THROUGH N CENTRAL IL NEAR PRINCETON...AND SW THROUGH QUINCY TO THE
KC AREA AT 3 AM. AREA RADARS SHOWED WIDESPREAD SHOWER AND A FEW
THUNDERSTORMS ALONG AND AHEAD OF THE FRONT...WITH SCATTERED LIGHT
SHOWERS TRAILING THE FRONT AS FAR W AS NW IL INTO FAR SE IA. THE
INCOMING AREA OF HIGH PRESSURE WAS CENTERED OVER ND. OVER THE PAST
SEVERAL HOURS ALONG AN AXIS ROUGHLY 100 TO 200 MILES BEHIND THE
FRONT...SURFACE OBSERVATIONS HAVE SHOWN AN AREA OF VISIBILITIES
REDUCED TO AS LOW AS 2 TO 3 MILES. THIS IS APPARENTLY DUE TO SMOKE
FROM CANADIAN WILDFIRES BEING SUPPRESSED TO THE SURFACE IN THE
SUBSIDENCE. THIS PHENOMENA WAS OVER MUCH OF EASTERN IA AT 3 AM.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUL 7 2015

A MUCH NEEDED BREAK FROM YESTERDAY/S WET WEATHER DOMINATES THE SHORT
TERM AS HIGH PRESSURE OVER THE NORTHERN PLAINS PASSES TO THE NORTH
TODAY AND TONIGHT. NORTH WINDS WILL CONTINUE TO BRING IN A DRIER
AIRMASS TODAY WITH FAIR WEATHER CU FOLLOWING EARLY MORNING CLEARING
FROM WEST TO EAST. SCATTERED LIGHT RAIN SHOWERS OVER THE SOUTHEAST
SHOULD EXIT THE REGION BY 8 AM. FOLLOWING THE OBSERVED TREND OF
ROUGHLY 5 TO 7 HOURS OF VISIBILITY RESTRICTIONS FROM THE SMOKE AT
OBSERVATIONS SITES...THERE MAY BE SOME SITES WITH HAZE AND POSSIBLE
SMOKE SCENT IN THE AIR EARLY IN THE MORNING ESPECIALLY EAST OF THE
MS RIVER BEFORE BETTER MIXING COMMENCES. HIGH TEMPERATURES WERE KEPT
IN A RANGE OF AROUND 70 NORTH TO THE MID 70S SOUTH...COMPATIBLE WITH
THE UPSTREAM OBSERVED HIGHS AND MODEL GUIDANCE.

TONIGHT...THE PASSING HIGH WILL RESULT IN LIGHT NORTHEAST WINDS
WHILE MODELS HINT AT SOME MID LEVEL MOISTURE TO KEEP SKIES AT LEAST
PARTLY CLOUDY. SHOWERS ARE NO LONGER EXPECTED IN THE FAR SOUTH
OVERNIGHT BASED ON A FURTHER SOUTH POSITION OF THE ELEVATED WARM
FRONT AND DELAYED RETURN FLOW ALOFT. LOWS WERE KEPT IN A RANGE FROM
AROUND 50 NORTH TO THE UPPER 50S SOUTH.


.LONG TERM...(WEDNESDAY THROUGH NEXT MONDAY)
ISSUED AT 330 AM CDT TUE JUL 7 2015

WEDNESDAY THROUGH FRIDAY...THE 00Z RUN MODELS GENERALLY HAVE TRENDED
FURTHER SOUTH WITH CONVECTIVELY REVVED UP VORT MAX THAT WILL LOOK TO
EJECT OUT OF THE SOUTHERN PLAINS...AND RIPPLE ALONG THE NORTHWESTERN
FLANK OF SOUTHEASTERN CONUS RIDGE WED INTO THU MORNING. THE 00Z GFS
MISSES THE CWA ENTIRELY JUST TO THE SOUTH WITH IT/S ASSOCIATED PRECIP
SHIELD...WHILE THE 00Z ECMWF...GEM AND NAM CLIP AT LEAST THE
SOUTHEASTERN THIRD OF THE FCST AREA MAINLY WED AFTERNOON THROUGH
MIDNIGHT. EXTENT OF LIFT AND MOISTURE DRAW/THTA-E FEED SUGGEST
THIS FEATURE COULD RING OUT SUBSTANTIAL RAINFALL UNDER A DEF ZONE-
LIKE PRECIP SHIELD...AND IF IT MANAGES TO MOVE ACRS THE SOUTHEASTERN
CWA THERE COULD BE SOME HYDRO RELATED IMPACTS IN THOSE AREAS SUCH
AS FLASH FLOODING AS WELL AS STREAM/RIVER FLOODING. FOR NOW WILL
SIDE WITH THE NAM/EURO BLEND IN TIMING AND TRAJECTORY AND KEEP
RATHER HIGH CHC OR LIKELY POPS ACRS THE SOUTHEASTERN CWA WED
AFTERNOON AND EVENING. IF THIS PRECIP SHIELD CAN MAKE IT ACRS
THESE AREAS...COULD SEE OVER AN INCH OF RAIN EASY IN A 5-8 HR PERIOD.
WELL BELOW NORMAL HIGH TEMPS CONTINUE ON WED.

AFTER A MAINLY DRY THU UNDER PASSING BUBBLE OF HIGH PRESSURE...THE
LATEST RUN MEDIUM RANGE GUIDANCE SUGGESTS MEAN LAYER FLOW
SOUTHWESTERLIES WILL ORGANIZE ACRS THE PLAINS WEST OF AMPLIFYING OH
RVR VALLEY UPPER RIDGE COMPLEX. THIS COULD SET THE STAGE FOR RETURN
FLOW/WARM FRONTAL SHOWERS AND STORMS IN OR NEAR THE LOCAL FCST AREA
LATER THU NIGHT INTO FRI. WHERE THE MAIN BOUNDARY AND CONVECTIVE
DEBRIS OUTFLOW FROM THE FRI MORNING ACTIVITY LAYS OUT WILL BE THE
FOCUS FOR FRI NIGHT INTO SAT MORNING RENEWED NOCTURNAL POTENTIAL MCS
GENERATION ZONE. COULD BE JUST TO THE NORTH...OR IN PORTIONS OF THE
DVN CWA...POPS WILL HAVE TO RIDE INTO THE START OF THE WEEKEND.
DEPENDING ON EXTENT OF CONVECTIVE DEBRIS AN RECOVERY...TEMPS MAY
WARM INTO THE 80S BACK CLOSE TO NORMAL BY MID FRI AFTERNOON.

SATURDAY THROUGH NEXT MONDAY...THE GENERAL IDEA ADVERTISED BY BULK OF
THE MEDIUM RANGE MODEL RUNS AND MREF OUTPUT...SUGGEST MORE OF A DEEP
SUMMER-LIKE PATTERN MAY BE EVOLVING WITH BROADENING UPPER RIDGE AND
BUILDING THERMAL DOME ACRS THE CENTRAL CONUS. THE MCS TRACK WOULD
THEN IGNITE AROUND IT IN A PERIPHERY TYPE RING OF FIRE PATTERN. THE
00Z GFS IS MORE BULLISH AND CLOSER TO THE LOCAL AREA WITH IT/S RIDGE
AXIS AND STRENGTH...EFFECTIVELY SHUNTING THE STORM TRACK TO THE
NORTH ACRS THE NORTHERN PLAINS AND INTO THE GRT LKS WITH BUILDING
HEAT LOCALLY...POSSIBLY INTO THE 90S BY SUNDAY. THE 00Z ECMWF IS
LESS AMPLIFIED AND FURTHER WEST WITH IT/S RIDGE AXIS... EFFECTIVELY
KEEPING THE LOCAL AREA UNDER THE MCS GUN OVER THE WEEKEND AND INTO
EARLY NEXT WEEK. WITH THE UNCERTAINTIES AND ECMWF TRACK RECORD
HANDLING SUCH A PATTERN FLUX...WILL HAVE TO KEEP CHC POPS ALMOST
DAILY FOR THE REST OF THE EXTENDED PERIOD. TEMPS OVER THE WEEKEND
HAVE A WARM POTENTIAL OF GOING ABOVE NORMAL...BUT AGAIN MUCH WILL
DEPEND ON THE EVENTUAL STORM TRACK AND ASSOCIATED CONVECTIVE DEBRIS.
   ..12..

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1134 PM CDT MON JUL 6 2015

THE COLD FRONT WHICH BROUGHT HEAVY RAINS AND STRONG WINDS IN
THUNDERSTORMS TO MLI AND BRL THIS EVENING WILL CONTINUE TO SHIFT
INTO ILLINOIS OVERNIGHT. WINDS BY 06Z WILL BE NORTHWEST AT ALL
SITES...AS COLDER AIR ARRIVES AND RAINS END. A PERIOD OF LIGHT
RAIN/FOG/AND CANADIAN WILDFIRE SMOKE IS LIKELY THROUGH AROUND 9 OR
10Z UNTIL A DEEPER LAYER OF DRY AIR ARRIVES FROM THE NORTH. CIGS
WILL ALSO BE POSSIBLE THROUGH THE EARLY MORNING HOURS...AROUND 600
TO 2500 FT...BUT WILL ALL LIFT TO VFR BY SUNRISE AS DRY AIR
ARRIVES AND LASTS THROUGH THE DAY TUESDAY.    ERVIN

&&

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

$$

SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...12
AVIATION...ERVIN



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