Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 262039
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
339 PM CDT TUE AUG 26 2014

.SYNOPSIS...
ISSUED AT 309 PM CDT TUE AUG 26 2014

AS OF 3 PM...A SURFACE FRONT WAS DRAPED FROM JUST SOUTH OF KANSAS
CITY...TO PEORIA...TO CHICAGO. HIGH PRESSURE WAS NUDGING INTO THE
AREA FROM THE NW.  HIGH DEWPOINTS IN THE LOW TO MID 70S WERE FOUND
ACROSS WEST CENTRAL AND CENTRAL ILLINOIS...WHILE MID TO UPPER 50 DEW
POINTS WERE SEEN IN PARTS OF SW WI AND ACROSS NORTHERN IA.  AS OF 3
PM...TEMPERATURES RANGED FROM THE MID 70S NEAR FREEPORT AND
DUBUQUE...UP TO THE MID TO UPPER 80S IN PARTS OF SOUTHEAST IA INTO
CENTRAL IL.

&&

.SHORT TERM...(TONIGHT)
ISSUED AT 309 PM CDT TUE AUG 26 2014

THE MAIN CONCERN FOR TONIGHT IS CONVECTIVE DEVELOPMENT LATE THIS
EVENING AND OVERNIGHT.  LIKE THIS PAST NIGHT/MORNING...AN MCS IS
EXPECTED TO DEVELOP AND TRACK INTO THE CWFA AFTER MIDNIGHT...AND
ESPECIALLY TOWARDS DAYBREAK.  REMOVED POPS THROUGH MID EVENING...
GRADUALLY RAMPING UP POPS AFTER 10 PM AND THROUGH THE NIGHT. MAYBE
BRINGING IN PCPN CHANCES TOO SOON.  FUTURE SHIFTS WILL MONITOR AND
UPDATE ACCORDINGLY.  LOWERED MINS A DEG OR SO SOUTH...WITH
ANTICIPATED SHOWER AND STORM ACTIVITY. THE MAIN CONCERN WITH THE
STORMS WILL BE HEAVY RAINFALL.  WIND GUSTS OVER 40 MPH WILL ALSO BE
POSSIBLE.

.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE AUG 26 2014

HEAVY RAIN POTENTIAL MID TO LATE WEEK MAIN FORECAST CONCERN.

WED... LINGERING CONVECTION WANING BY MID TO LATE AM...THEN LOW POPS
FOR AFTERNOON DEVELOPMENT MAINLY WEST OF THE MISSISSIPPI RIVER BUT
DEPENDENT ON AMOUNT OF HEATING AND IF MORE CLOUDS THEN CAN BE
REMOVED. HIGHS COOLEST NORTH 1/3-1/2 AND MAINLY IN THE 70S WITH 80S
FAR SOUTH. GIVEN SOME AREAS STRUGGLED TO MID 70S TODAY WITH FULL
PM SUNSHINE NORTH...WOULD BE A CONCERN THAT SOME AREAS COULD
STRUGGLE TO REACH 70 DEGS NORTH IF MORE CLOUDINESS PERSISTS THROUGH
THE DAY.

WED NGT-THU NGT... FAVORABLE PATTERN IN PLACE FOR HEAVY RAINS POSSIBLY
SIGNIFICANT WITH EASTERLY FLOW OFF LAKE MICHIGAN INTERACTING WITH
ENERGY EJECTING FROM SW TROUGH. PW/S APPROACHING 2 INCHES WITH DURATION
OF FORCING ALONG E-W FRONTAL ZONE AND SWLY MID LEVEL FLOW FOR POSSIBLE
BACKBUILDING SUGGESTIVE OF 2-3+ INCHES OF RAIN ARRIVING MAINLY LATER
WED NGT THROUGH THU... WHICH MAY RESULT IN WATER ISSUES BOTH RIVER AND
FLASH FLOODING. TEMPS QUITE CHALLENGING AND HIGHS THU MAY NEED
FURTHER LOWERING... WITH SOME AREAS STRUGGLING TO REACH 70 NOT OUT OF
THE QUESTION ACROSS THE NORTH WITH MUCH OF AREA STAYING IN THE 70S.

FRI-SAT... MAINTAINED POPS WITH CHALLENGE OF SPEED OF EJECTING
SW TROUGH AND TIMING OF ENDING POPS. DPROG/DT OF HI-RES ECMWF SHOWS
SLOWING TREND WHICH TYPICAL OF THESE SYSTEMS...THUS MOD/HIGH CHANCE
POPS REASONABLE AND IF TRENDS PERSIST MAY NEED TO BE RAISED ONCE TIMING
PINNED DOWN. LIKELY TO SEE TEMP CHALLENGE WITH DECENT GRADIENT POSSIBLE
NORTH TO SOUTH FRI...THEN POSSIBLY MORE WIDESPREAD PCPN COVERAGE SAT
WOULD NECESSITATE LOWERING HIGHS SAT.

SUN-TUE... ZONAL TO SEMI-ZONAL FLOW WITH LOWER CONFIDENCE ON TIMING
OF DISTURBANCES THUS UNFORTUNATELY CONTINUED WITH POPS ALL PERIODS
UNTIL AWAIT MORE CLARITY OF TIMING OF IMPULSES. TEMPS NEAR TO A LITTLE
BELOW SEASONAL NORMS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1233 PM CDT TUE AUG 26 2014

VFR CONDITIONS WILL PREVAIL THROUGH ABOUT 27/06Z AT ALL SITES. KBRL
AND KMLI MAY SEE SOME MVFR CONDITIONS IN A SHRA/TSRA 26/21Z TO 27/02Z...
BUT CONFIDENCE OF OCCURRENCE AT TERMINALS IS LOW AT THIS TIME. THUS...
WILL HANDLE WITH AMENDMENTS FOR NOW. AFTER 27/06Z...MVFR/IFR CONDITIONS
ARE POSSIBLE IN SHRA/TSRA...ESPECIALLY AFTER 10-12Z AT ALL TAF SITES.


&&

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

$$

SYNOPSIS...14
SHORT TERM...14
LONG TERM...05
AVIATION...14





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