000
FXUS63 KDVN 012009
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
309 PM CDT FRI AUG 1 2014

.SYNOPSIS...
ISSUED AT 240 PM CDT FRI AUG 1 2014

12Z UA ANALYSIS HAS SEVERAL WEAK TROFS FROM THE OHIO VALLEY BACK
INTO THE UPPER MIDWEST. A SLIGHTLY HIGHER POOL OF MOISTURE WAS NOTED
AT 850MB ACROSS IOWA AND SOUTHERN MINNESOTA. SATELLITE/RADAR TRENDS
THROUGH MID AFTERNOON SHOW CONVECTION ACROSS THE AREA WITH THE MORE
WIDESPREAD CONVECTION FROM CENTRAL INTO EASTERN ILLINOIS.

18Z SFC ANALYSIS HAS HIGH PRESSURE OVER THE AREA WITH VERY SUBTLE
TROFS FROM NORTHEAST ILLINOIS BACK INTO MINNESOTA. DEW POINTS WERE
IN THE 60S FROM THE LOWER MISSISSIPPI VALLEY TO JUST SOUTH OF THE
GREAT LAKES WITH 50S ACROSS THE WESTERN PLAINS AND UPPER MIDWEST.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 240 PM CDT FRI AUG 1 2014

SATELLITE TRENDS WOULD SUPPORT ISOLATED TO LOW END SCATTERED SHOWERS
AND THUNDERSTORMS THROUGH THE PEAK HEATING OF LATE AFTERNOON.

BY EARLY EVENING AND THROUGH SUNSET THE OVERALL FORCING WEAKENS
AGAIN SO CONVECTION WILL BECOME MORE ISOLATED IN NATURE WITH ANY
LINGERING SHOWERS AND STORMS ENDING SHORTLY AFTER SUNSET.

FROM LATE EVENING THROUGH SUNRISE SATURDAY DRY CONDITIONS ARE
EXPECTED. THE LIGHT WINDS OVERNIGHT MAY ALLOW SOME PATCHY FOG TO
DEVELOP WITH RIVER VALLEYS AND LOW LYING AREAS BEING THE MOST
FAVORED.

SATURDAY WILL START OUT DRY ACROSS THE AREA WITH DIURNAL CLOUDS
DEVELOPING BY LATE MORNING AND CONTINUING THROUGH THE AFTERNOON.
ANOTHER WEAK DISTURBANCE ALOFT WILL MOVE THROUGH THE AREA WHICH
SHOULD INITIATE DIURNAL CONVECTION STARTING AROUND MID DAY AND
CONTINUING THROUGH SUNSET. DUE TO THE WEAK FORCING...ANY SHOWERS OR
STORMS WOULD BE ISOLATED TO LOW END SCATTERED IN NATURE AND WOULD BE
MOST NUMEROUS FROM MID AFTERNOON THROUGH SUNSET.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 240 PM CDT FRI AUG 1 2014

CONTINUED GENERALLY BELOW NORMAL TEMPERATURES AND LIKELY HOOD OF
SIGNIFICANT RAINS MIDDLE OF NEXT WEEK.

OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH NORMAL MINOR UPPER
LEVEL KINEMATIC VARIANCES AND MOST SOLUTIONS SLIGHTLY TOO MOIST IN
BL RESULTING IS SLIGHTLY TOO HIGH GUIDANCE POPS INTO MIDDLE OF NEXT
WEEK. PERSISTENCE SUPPORT HIGHS AND LOWS A FEW DEGREES NEAR GUIDANCE
BLEND THROUGH MONDAY. RUN TO RUN VARIANCES SUPPORTS A 70/30 MIX OF
HI-RES ECMWF/GEM-NH TO GFS AS GFS TOO FAR SOUTH WITH SYSTEM NEXT WEEK.
NORTHWEST FLOW TO ALMOST GUARANTEE HIGHS TO STAY BELOW 90 DEGREES
NEXT 7 DAYS AS OUR COOL SUMMER CONTINUES WITH UNSEASONABLY COOL HIGHS
POSSIBLE WED/THU.

SATURDAY NIGHT THROUGH MONDAY...CONTINUED NORTHWEST FLOW WITH WEAK UPPER
DISTURBANCES AHEAD OF NEXT WAVE NEXT WEEK. TEMPERATURES SLIGHTLY BELOW
NORMAL THROUGH SUNDAY WITH THEN NEAR NORMAL TEMPERATURES SUNDAY AND
MONDAY. LOW POPS...MOSTLY LATE PM...TO GRADUALLY INCREASE SUNDAY AND
MONDAY WITH SLIGHTLY INCREASED FORCING AND DEWPOINTS INTO LOWER 60S.
LIMITED INSTABILITY AOB 1500 J/KG AND FREEZING LEVELS AOA 11K AGL SUGGEST
LITTLE OR NO RISK OF SEVERE STORMS WITH LOCALLY LIGHT TO MODERATE RAINFALL
TOTALS. PATCHY LATE SUMMER MORNING FOG MAY BE POSSIBLE WITH LIGHT WINDS
AND HAZY SKIES OVER SEVERAL DAY PERIOD SUGGESTS ISOLATED AIR QUALITY
ISSUES CONDITIONS MAY BE POSSIBLE.

TUESDAY THROUGH THURSDAY...NORTHWEST FLOW WAVE TO RESULT IN BACKDOOR
COOL FRONT AND FLOW OFF LAKE MICHIGAN AND SURFACE WAVE TO BRING WIDESPREAD
RAINS WITH 1 TO OVER 2 INCHES POSSIBLE WITH RAIN AND EMBEDDED THUNDER
SUGGESTED DUE TO STRONG EVAPORATIVE COOLING. NEAR RECORD TO RECORD COOL
LAKE MICHIGAN WATER TEMPERATURES SUPPORTS RISK OF HIGHS WED/THU TOO
HIGH BY 5 TO 8+ DEGREES WITH NEAR RECORD COOL HIGHS ONCE AGAIN POSSIBLE
IF TRENDS CONTINUE FOR LATER SHIFTS...THIS MEANS HIGHS IN THE UPPER
60S TO LOWER 70S NOT OUT OF THE QUESTION AND THIS RISK WILL BE BETTER
CLARIFIED IN THE NEXT 24 TO 36 HOURS. LOW RISK OF SEVERE STORMS CONTINUE
AS AREA SHOULD BE ON THE COOL SIDE OF FRONTAL BOUNDARY. LOWS IN THE
UPPER 50S TO LOWER 60S ARE SUGGESTED.

FRIDAY...NEARBY FRONTAL BOUNDARY SUPPORTS CONTINUED CHANCE POPS WITH
LOW CONFIDENCE ON POPS AND TEMPERATURES. TRENDS SUGGEST COOL EASTERLY
WINDS WITH SOME RISK OF MORE SHOWERS AND POSSIBLE STORMS FROM OVERRUNNING.
HIGH TEMPERATURES ONCE AGAIN MAY BE A BIT TOO HIGH IF EAST WINDS DO
OCCUR OFF LAKE MICHIGAN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 240 PM CDT FRI AUG 1 2014

VFR CONDITIONS ARE EXPECTED THROUGH 06Z/02 AS HIGH PRESSURE
REMAINS ACROSS THE AREA. DIURNAL CONVECTION OF SHRA/TSRA ARE
EXPECTED THROUGH SUNSET. DUE TO NEW CONVECTION DEVELOPING ACROSS
EASTERN IOWA...ALL 18Z TAFS WERE AMENDED TO INCLUDED VCTS. THE
PROBABILITY OF A SHRA/TSRA HITTING A TAF SITE IS AROUND 10
PERCENT. AFT 06Z/02 MVFR CONDITIONS ARE EXPECTED TO DEVELOP DUE TO
LIGHT WINDS. THE POTENTIAL DOES EXIST FOR SPOTTY IFR/LIFR
CONDITIONS IN GROUND FOG.

&&

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

&&

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS
AVIATION...08