Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 271139
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
639 AM CDT MON JUL 27 2015

.SYNOPSIS...
ISSUED AT 238 AM CDT MON JUL 27 2015

AT 2 AM CDT...FORECAST AREA UNDER WEAK EASTERLY FLOW FROM YESTERDAYS/S
COOL FRONTAL PASSAGE. VERIFICATION INDICATES SLIGHTLY COOLER TREND
WITH FLOW OFF LAKE MICHIGAN AIDING IN SLIGHTLY MORE COMFORTABLE CONDITIONS.
UPSTREAM LOTS OF CLOUDS FROM PLAINS CONVECTION WHICH IS POORLY HANDLED
BY MOST SOLUTIONS. TRAJECTORIES UPSTREAM SUGGESTS WARM TO HOT AND HUMID
CONDITIONS THE NEXT COUPLE OF DAYS AND ISOLATED TO SCATTERED STORMS
POSSIBLE UNTIL NEXT FRONTAL PASSAGE ON WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 238 AM CDT MON JUL 27 2015

SHORT TERM FORECAST CONFIDENCE ASSESSMENT...FAIR TO GOOD OR AVERAGE
TO ABOVE AVERAGE. HIGHEST CONFIDENCE SW SECTIONS WITH NE SECTIONS
POSSIBLY A FEW DEGREES STILL TOO HIGH ON TEMPS AND DEWPOINTS WITH
EASTERLY FLOW OFF LAKE MICHIGAN.

TODAY...PARTLY TO MOSTLY SUNNY AND WARM TO VERY WARM AND HUMID IN
AT LEAST SW 1/2 OF AREA. LOWERED HIGHS SW BY A DEGREE AND NE SECTIONS
BY A COUPLE OF DEGREES DUE TO SLIGHTLY STRONGER AND COOLER FLOW OFF
LAKE MICHIGAN. HEAT INDICES IN FAR SW COUNTIES WILL APPROACH OR POSSIBLY
REACH HEAT ADVISORY CRITERIA OF 100F FOR A FEW HOURS BUT COVERAGE
NOT EXTENSIVE OR TEMPORALLY TO ISSUE ADVISORY ATTM. THIS ISSUE WILL
NEED TO BE MONITORED BY THE DAY SHIFT. TRENDS SUGGEST ANY ISOLATED
SHOWER OR STORM ACTIVITY IN THE SOUTH MAY BE ABLE TO BE PULLED DUE
TO LITTLE OR NO FORCING. HIGHS PROGGED TO BE MOSTLY 85 TO 90 DEGREES
NE TO SW.

TONIGHT...ONCE AGAIN PARTLY TO MOSTLY CLEAR AND HAVE TRIMMED MINS MOST
LOCATIONS 1 TO 2 DEGREES WITH STRONGER ESE FLOW AND DEWPOINTS A DEGREE
OR TWO LOWER. LIMITED FORCING AGAIN SUPPORTS KEEPING NO POPS ATTM. MINS
66 FAR NE TO AROUND 74 DEGREES FAR SW SECTIONS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 238 AM CDT MON JUL 27 2015

FORECAST FOCUS ON HOT AND HUMID CONDITIONS TUESDAY THEN THE
POTENTIAL FOR SEVERE WEATHER AHEAD OF A COLD FRONT.

TUESDAY...UPPER LEVEL RIDGE AND STRONG CAP WILL BE OVER THE CWA
WHICH WILL SUPPRESS CONVECTION MOST OF THE DAY. THIS WILL ALLOW A
THERMAL AXIS TO SHIFT OVER THE CWA WITH 850 MB TEMPERATURES RISING
TO 20 TO 22C WHICH SHOULD SUPPORT MAXIMUM TEMPERATURES IN THE UPPER
80S TO MID 90S. DEWPOINTS ARE EXPECTED TO PUSH INTO THE OPPRESSIVE
MID TO UPPER 70S...POSSIBLY HIGHER. THIS WILL ALLOW FOR HEAT INDEX
VALUES ABOVE 100 DEGREES OVER MOST OF THE CWA. DEPENDING ON THE
EXACT TEMPERATURE AND DEWPOINT SOME LOCATIONS MAY SEE HEAT INDEX
VALUES APPROACH 110. LATER SHIFTS MAY NEED TO CONSIDER HEADLINES.

LATER IN THE AFTERNOON ON TUESDAY AND INTO TUESDAY NIGHT...LARGE
SCALE ASCENT/COOLER AIR ALOFT BEGINS TO ARRIVE...AS AN UNSEASONABLY
STRONG UPPER LEVEL TROUGH/CLOSED UPPER LOW ADVANCES ACROSS THE UPPER
MIDWEST. THIS SHOULD EFFECTIVELY BREAK THE CAP AND WITH SBCAPES OF
4000-5000 J/KG AND INCREASINGLY DEEP LAYER SHEAR THIS SHOULD SPARK
ORGANIZED CONVECTION...POSSIBLY SEVERE WITH DAMAGING WINDS AND LARGE
HAIL. SPC HAS MOST OF THE CWA IN A SLIGHT RISK FOR LATE TUESDAY
AFTERNOON AND TUESDAY NIGHT. WITH PWAT`S OVER 2 INCHES THESE STORMS
WILL ALSO HAVE TORRENTIAL RAIN AND LOCALIZED FLASH FLOODING MAY
OCCUR. THE COLD FRONT SHOULD PUSH THROUGH THE CWA BY EARLY WEDNESDAY
ENDING THE CONVECTION.

WEDNESDAY THROUGH FRIDAY...WNW FLOW ALOFT SHOULD BRING DRY WEATHER
ALONG WITH TOLERABLE LATE JULY CONDITIONS. HIGHS WILL BE IN THE
LOWER TO MID 80S WITH LOWS IN THE LOWER TO MID 60S.

THIS WEEKEND...ANOTHER COLD FRONT ARRIVES BRINGING MORE CHANCES OF
THUNDERSTORMS...ESPECIALLY ON SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 634 AM CDT MON JUL 27 2015

VFR TO GENERALLY VFR CONDITIONS FOR THE NEXT 24 HOURS. LIGHT EAST TO
SOUTHEAST WINDS FROM A NEARBY WEAK SURFACE HIGH OVER LAKE MICHIGAN
WILL KEEP SKIES PARTLY SUNNY WITH ANY CIGS AOA 4K AGL AND VISIBILITIES
AOA 6 MILES. AFTER 28/07Z...PATCHY FOG MAY DEVELOP WITH LOCALIZED REDUCED
MVFR VISIBILITIES OF 3 TO 5 MILES POSSIBLE. ISOLATED LIGHT SHOWERS AND
BRIEF THUNDERSTORMS TOO LOW IN COVERAGE TO INCLUDE IN TAFS WITH ANY
RISK PROBABLY THE CID AND BRL TERMINALS.

&&

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

&&

$$

SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...NICHOLS


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