Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 280430
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1130 PM CDT SAT SEP 27 2014

.SYNOPSIS...
ISSUED AT 236 PM CDT SAT SEP 27 2014

CONTINUED COMFORTABLY WARM AND DRY WITH EASTERLY LOW LEVEL FLOW
OFF GREAT LAKES HIGH DOMINATING AT MID AFTERNOON. TEMPS AT 2 PM
WERE MAINLY IN THE RANGE OF 80-84F... SOME 10+ DEGS ABOVE
NORMAL (70-74F). THE UPPER LEVEL LOW... WHICH HAS BEEN AROUND
THE REGION OVER THE PAST SEVERAL DAYS WAS LOCATED OVER NORTHWEST
IA.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM CDT SAT SEP 27 2014

UPPER LEVEL LOW OVER NORTHWEST IA TO WEAKEN/OPEN UP AND DRIFT
BACK TOWARD EASTERN IA DURING THE PERIOD BEING INFLUENCED
BY MAIN BELT OF WESTERLIES SINKING INTO FAR NORTHERN MN AND
NORTHERN GREAT LAKES. AT THE SURFACE... HIGH PRESSURE RIDGE WILL
BECOME RE-ESTABLISHED OVER THE AREA PROVIDING CONTINUATION OF
DRY CONDITIONS... ABOVE NORMAL TEMPS AND MAINLY CLEAR SKIES.
AS FOR TEMPS... PERSISTENCE REMAINS THE RULE WITH NEAR NEUTRAL
TEMP ADVECTION. LOWS TONIGHT TO BE MAINLY IN THE 50S AND SIDED AT
OR BELOW THE COOL SIDE OF GUIDANCE WITH DRY AIR AND LIGHT WINDS.
SOME LOW LYING AREAS COULD SEE LOWS POSSIBLY 48-51F WITH ANY
PROLONGED PERIOD OF CALM WINDS. AS FOR HIGHS SUNDAY... NAM/GFS
BUFR SOUNDINGS SUGGEST MIXING TO JUST BELOW 850 MB WHICH YIELDS
HIGHS IN THE UPPER 70S TO LOWER 80S... BUT WITH DRY GROUND AND
ABUNDANT SOLAR INSOLATION I ADJUSTED UPWARD SOME FOR MORE GENERAL
RANGE OF 80-85F WHICH IS RIGHT IN LINE WITH PERSISTENCE PAST FEW
DAYS.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM CDT SAT SEP 27 2014

QUIET AND DRY CONDITIONS WILL CONTINUE ACROSS THE AREA SUNDAY NIGHT
THROUGH TUESDAY AS HIGH PRESSURE REMAINS OVER THE AREA.

THE DRY GROUND AND AIR WILL RESULT IN LARGER THAN NORMAL DIURNAL
SWINGS IN TEMPERATURES. LOWS WILL BE CLOSE TO NORMAL AND HIGHS WILL
BE WARMER THAN NORMAL.

THE WEATHER PATTERN THEN UNDERGOES A CHANGE BEGINNING TUESDAY NIGHT.

TUESDAY NIGHT ON...
A STORM SYSTEM IN THE PLAINS WILL BEGIN MOVING TOWARD THE AREA
TUESDAY NIGHT. DPROG/DT TRENDS WITH THE MODELS CONTINUE TO SHOW A
SLOWER EASTWARD MOVEMENT OF THE SYSTEM. AS SUCH...TUESDAY EVENING
WILL BE DRY FOR THE AREA.

LATE TUESDAY NIGHT THE MODEL CONSENSUS HAS SLIGHT CHANCE/CHANCE POPS
OVER ROUGHLY THE WESTERN HALF OF THE AREA. IF THE SLOWING TREND IN
THE MODELS CONTINUE...THE POSSIBILITY EXISTS THAT TUESDAY NIGHT MAY
BE DRY FOR MUCH OF THE AREA.

THE MODEL CONSENSUS HAS SLIGHT CHANCE/CHANCE POPS FOR ALL BUT THE
FAR EASTERN AREAS ON WEDNESDAY. RAIN WILL BEGIN MOVING INTO THE AREA
FROM THE WEST WITH THE ONLY QUESTION BEING HOW QUICKLY IT MOVES
EAST. SOME MODEL SOLUTIONS ARE SUGGESTING THE POSSIBILITY OF
WEDNESDAY MORNING BEING DRY FOR AREAS ALONG/EAST OF THE MISSISSIPPI.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT THE MODEL CONSENSUS HAS
CHANCE TO LIKELY POPS FOR THE ENTIRE AREA. THE BIG PICTURE CLEARLY
INDICATES THAT IT WILL RAIN WITH AN INITIAL MOISTURE CONTRIBUTION
COMING FROM RACHAEL BEFORE THE GULF OPENS UP. THUS POPS FOR ONE OR
POSSIBLY TWO OF THE 12 HOUR PERIODS WILL INCREASE TO CATEGORICAL
WITH TIME.

ON FRIDAY THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS. THE
FRONT IS THROUGH THE AREA WITH COLDER AIR BEING PULLED DOWN FROM THE
PLAINS. TEMPERATURES ARE EXPECTED TO AVERAGE BELOW NORMAL.

FRIDAY NIGHT THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS OVER THE
AREA. THE MODELS SHOW SEVERAL WEAK DISTURBANCES MOVING THROUGH IN
THE FLOW ALOFT WHICH MAY RESULT IN SHOWERS PERSISTING INTO THE
EVENING.

ON SATURDAY THE MODEL CONSENSUS HAS DRY BUT COOL CONDITIONS AS HIGH
PRESSURE BUILDS INTO THE PLAINS. TEMPERATURES ARE EXPECTED TO
AVERAGE BELOW NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1126 PM CDT SAT SEP 27 2014

SURFACE HIGH PRESSURE WILL CONTINUE TO STRONGLY INFLUENCE THE
WEATHER IN EASTERN IOWA AND ILLINOIS THROUGH SUNDAY. UPPER LEVEL
LOW PRESSURE WILL MOVE NORTH AWAY FROM THE REGION DURING THIS TIME
AS WELL. THUS...THE VAST MAJORITY OF THE NEXT 24 HOURS WILL SEE
LIGHT WINDS AND CLEAR SKIES...EXCEPT FOR SOME POSSIBLE GROUND FOG
TOWARD SUNRISE SUNDAY MORNING. THIS IS NOT A HIGH CONFIDENCE FOG
EVENT...AND I HAVE ONLY ADDED IN MVFR FOG FOR NOW...BASED MAINLY
ON LOW TEMPERATURES FALLING ABOUT 3 DEGREES BELOW THE LATE
SATURDAY AFTERNOON DEWPOINTS. THIS MAY ALLOW FOR PATCHY
VISIBILITIES OF 2 TO 5 MILES...SOMETHING WE WILL NEED TO KEEP AN
EYE ON OVERNIGHT.
ERVIN

&&

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

$$

SYNOPSIS...05
SHORT TERM...05
LONG TERM...08
AVIATION...ERVIN





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