Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 300439
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1139 PM CDT TUE JUL 29 2014

.UPDATE...
ISSUED AT 1022 PM CDT TUE JUL 29 2014

SCATTERED SHOWERS ASSOCIATED WITH A 700 MB SHORTWAVE EMBEDDED IN
THE CYCLONIC FLOW AROUND THE UPPER LOW OVER QUEBEC CONTINUE TO
STREAM SOUTH SOUTHEAST OUT OF EASTERN MN AND WI INTO NORTHERN IL
LATE THIS EVENING. WHILE RADARS SHOW THESE SHOWERS AND AN
ISOLATED THUNDERSTORM OR TWO LINED UP WELL TO THE NW INTO W
CENTRAL WI AND SOUTHEAST MN...THE DIURNAL DECREASING INSTABILITY
AND PASSAGE OF THE SHORTWAVE SHOULD LEAD TO A CONTINUED
DISSIPATION TREND OVER THE NEXT COUPLE HOURS. HAVE UPDATED THE
FORECAST TO INCLUDE THESE SCATTERED SHOWERS ALONG THE MS RIVER
INTO NW IL UNTIL AROUND MIDNIGHT OR 1 AM. OTHERWISE...REMAINDER OF
TONIGHT SHOULD HAVE CLEAR SKIES WITH TEMPERATURES ON TRACK TO
REACH LOWS IN THE LOWER TO MID 50S. LIKE LAST NIGHT...THERE WILL
LIKELY BE SOME PATCHY SHALLOW GROUND FOG TOWARD SUNRISE...BUT DO
NOT ANTICIPATE THIS BEING EXTENSIVE OR PERSISTENT ENOUGH TO
MENTION IN THE FORECAST AT THIS TIME.

&&

.SYNOPSIS...
ISSUED AT 302 PM CDT TUE JUL 29 2014

12Z UA ANALYSIS HAS A RIDGE OVER THE PLAINS WITH A STRONG DEEP TROF
OVER THE EASTERN CONUS. SEVERAL WEAK DISTURBANCES WERE DROPPING DOWN
THE BACK SIDE OF THE TROF FROM THE OHIO VALLEY INTO THE UPPER
MIDWEST. SATELLITE TRENDS THROUGH MID AFTERNOON SHOW PLENTY OF
DIURNAL CLOUDS WITH NEW CONVECTION OVER WISCONSIN AND PART OF
NORTHERN ILLINOIS.

18Z SFC ANALYSIS HAS SEVERAL WEAK TROFS FROM THE OHIO VALLEY BACK
INTO THE GREAT LAKES AND UPPER MIDWEST. DEW POINTS WERE IN THE 50S
ACROSS MUCH OF THE MIDWEST WITH 60S FROM THE SOUTHERN PLAINS INTO
THE DEEP SOUTH.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 302 PM CDT TUE JUL 29 2014

DIURNAL CLOUDS WILL CONTINUE THROUGH SUNSET WITH ISOLATED CONVECTION
AS FORCING ACTS ON WHAT LIMITED MOISTURE IS AVAILABLE IN THE
ATMOSPHERE. BASED ON SATELLITE/RADAR TRENDS AND INPUT FROM THE
RAP...CONVECTION SHOULD MAXIMIZE IN COVERAGE THROUGH SUNSET WITH
MOST OF THE ACTIVITY OVER SOUTHEAST WISCONSIN AND NORTHEAST ILLINOIS.

ISOLATED TO VERY LOW END SCATTERED CONVECTION WILL PERSIST OVER THE
NORTHEAST THIRD OF THE AREA THROUGH SUNSET AND THEN RAPIDLY DECREASE
THROUGH MIDNIGHT.

AFTER MIDNIGHT QUIET CONDITIONS WILL AGAIN BE SEEN WITH POSSIBLY A
FEW MORE CLOUDS AS A WEAK DISTURBANCE ROTATES THROUGH THE AREA.
SHELTERED VALLEYS MAY SEE SOME PATCHY FOG DEVELOP DUE TO THE LIGHT
WINDS.

QUIET CONDITIONS WILL BE SEEN ACROSS THE AREA WEDNESDAY MORNING WITH
NEW DIURNAL CLOUDS DEVELOPING BY LATE MORNING. ANOTHER DISTURBANCE
ALOFT WILL DROP INTO THE WESTERN GREAT LAKES DURING THE AFTERNOON
AND INITIATE A NEW ROUND OF DIURNAL SHOWERS OVER THE NORTHEAST THIRD
TO HALF OF THE AREA. COVERAGE AGAIN WILL BE ISOLATED TO VERY LOW END
SCATTERED.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 302 PM CDT TUE JUL 29 2014

OVERALL NOT MUCH CHANGE TO THE EXTENDED FORECAST WHICH REMAINS BELOW
NORMAL ON TEMPS AND RELATIVELY DRY.  DAILY HIGHS WILL BE IN THE
UPPER 70S/LOW 80S THU THROUGH SAT...WITH LOWS IN THE UPPER 50S TO
LOW 60S.  SOME MODERATION IN TEMPS BACK TOWARD NORMAL EARLY AUGUST
VALUES IS EXPECTED FOR SUN THROUGH TUE...WITH LOW TO MID 80S FOR
HIGHS AND LOW TO MID 60S FOR MINS.

WE REMAIN IN BLOCKED CYCLONIC FLOW THROUGH THE WEEKEND...WHICH
LIMITS CHANCES FOR RAIN.  REMOVED SLIGHT POPS FOR THU. NEXT CHANCE
AT SHOWERS IS FRI...WITH A 20 TO 40 POP GRADIENT...HIGHER VALUES TO
THE NE PARTS OF THE CWFA. THE CONSENSUS FORECAST HAS SLIGHT-LOW
CHANCE POPS FOR SAT...WITH DRY CONDITIONS SAT NIGHT THROUGH EARLY
MONDAY.  LOW CHANCE POPS NORTH OF I 80 RETURN FOR MON.  MORE ACTIVE
WEATHER IS INDICATED FOR TUE AND AGAIN MID-LATE WEEK NEXT WEEK AS A
MORE ZONAL FLOW PATTERN DEVELOPS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1138 PM CDT TUE JUL 29 2014

A LARGE RIDGE OF HIGH PRESSURE FROM THE NORTHERN PLAINS INTO THE
MID MS VALLEY WILL KEEP CONDITIONS PREDOMINATELY VFR TONIGHT
THROUGH WEDNESDAY. LATER TONIGHT...THERE IS A POTENTIAL FOR GROUND
FOG...WHICH MAY RESULT IN VISIBILITIES AROUND 4SM TO 5SM IN THE
HOURS BEFORE SUNRISE AT CID..DBQ AND BRL. WEDNESDAY
AFTERNOON...AN UPPER LEVEL DISTURBANCE MAY LEAD TO AFTERNOON
SHOWERS AND PROB30 GROUPS HAVE BEEN ADDED FOR SHOWERS IN THE LATE
AFTERNOON INTO EARLY EVENING HOURS AT CID...DBQ...AND MLI. AN
ISOLATED THUNDERSTORM CANNOT BE RULED OUT...BUT FORECAST
CONFIDENCE IS NOT HIGH ENOUGH TO JUSTIFY MENTIONING THUNDER IN THE
TAF IN THIS TIMEFRAME.

&&

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

$$

UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...14
AVIATION...SHEETS






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