Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
301 PM CDT SAT OCT 25 2014

.SYNOPSIS...
ISSUED AT 301 PM CDT SAT OCT 25 2014

THE OVERNIGHT PASSAGE OF A WEAK COLD FRONT HAS BROUGHT A MUCH DRIER 
AIRMASS INTO THE REGION TODAY. THE DRY AIR AND FULL SUNSHINE WERE 
PROVIDING RATHER WARM AND MILD CONDITIONS FOR LATE OCTOBER WITH 
EARLY AFTERNOON READINGS ALREADY IN THE UPPER 60S TO LOWER 70S. AT 
THE SAME TIME...LIGHT NW WINDS AHEAD OF HIGH PRESSURE OVER THE 
DAKOTAS HAVE BROUGHT IN DEWPOINTS IN THE 30S NW TO LOWER 40S 
SOUTHEAST. 12Z UPPER AIR ANALYSIS SHOWED A LARGE UPPER LEVEL RIDGE 
OVER THE WESTERN U.S...WITH A NW FLOW OVERHEAD. ALONG AND EAST OF 
THE RIDGE...WARM AIR WAS BUILDING AT 850 MB...WHERE TEMPERATURES 
WERE IN THE LOWER 20S CELSIUS. THIS WAS LEADING TO TEMPERATURES IN 
THE 80S ALONG AND SOUTH OF THE NOW STALLED FRONT STRETCHED WEST TO 
EAST ACROSS KS AND MO.  FURTHER WEST...A STRONG VORTEX WAS EVIDENT 
ON WATER VAPOR LOOPS MOVING INTO THE PACIFIC NW. THIS SYSTEM IS 
EXPECTED TO FLATTEN THE RIDGE...AMPLIFY INTO A LONGER WAVE 
TROUGH...AND SEND A SURFACE FRONTAL SYSTEM THROUGH THE LOCAL AREA 
EARLY NEXT WEEK...PROVIDING OUR NEXT CHANCE OF RAIN. 

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CDT SAT OCT 25 2014

TEMPERATURES ARE THE PRIMARY SHORT TERM ISSUE AS THE PLAINS HIGH 
MIGRATES EASTWARD OVER THE REGION TONIGHT...FOLLOWED BY A DEVELOPING 
LOW LEVEL RETURN FLOW AHEAD OF THE SYSTEM TAKING SHAPE LEE OF THE 
ROCKIES SUNDAY. 

TONIGHT...THE LACK OF UPSTREAM CLOUD COVER...BENIGN NW FLOW ALOFT... 
AND DRY PLAINS AIRMASS IN PLACE POINT TOWARD A CLEAR AND COOL NIGHT. 
WINDS SHOULD BECOME LIGHT AND VARIABLE BY SUNRISE AS THE CENTER OF 
THE SURFACE RIDGE AXIS PASSES OVER THE AREA. BEING LATE 
OCTOBER...THIS WOULD NORMALLY BE AN IDEAL SETUP FOR WIDESPREAD FROST 
AND FREEZING TEMPERATURES...HOWEVER...WITH LOW LEVEL COLD AIR 
LACKING...THIS SHOULD NOT BE THE CASE TONIGHT. TECHNIQUES USING THE 
SEASONABLY MILD 850 MB TEMPERATURES AND TRAJECTORIES FROM UPSTREAM 
LOWS FROM THIS MORNING IN THE PLAINS...SUPPORT LOWS RANGING FROM AS 
LOW AS THE UPPER 30S NORTH TO MID 40S SOUTH. 

SUNDAY...THE DEVELOPING PLAINS SYSTEM PULLS THE SURFACE FRONT BACK 
NORTHWARD AS A WARM FRONT. SHORT TERM MODELS KEEP THIS TO THE SOUTH 
DURING THE DAY...RESULTING IN SE SURFACE WINDS. THE BIG QUESTION 
WILL BE TRENDS WITH LOW CLOUDS THAT ARE ANTICIPATED BY SOME MODELS 
TO DEVELOP IN THE PLAINS TONIGHT AND PUSH NORTHWARD POSSIBLY INTO 
THE SOUTHWEST DURING THE DAY IN A DISSIPATING FASHION. BASED ON 
MODEL MOISTURE FIELDS TODAY AND POOR VERIFICATION IN ESPECIALLY THE 
WRF CLOUD FIELDS TODAY...WILL DOWNPLAY THE POTENTIAL FOR STRATUS 
SPREADING INTO THE FAR SOUTH FROM LATE MORNING INTO AFTERNOON. AM 
MORE CONFIDENT THAT THE AREA WILL SEE THICKENING HIGH CLOUDS BY 
AFTERNOON AS HIGH LEVEL MOISTURE FOLLOWS THE PASSING UPPER LEVEL 
RIDGE AXIS. THE SOUTHEASTERLY WINDS AND AT LEAST PARTIALLY FILTERED 
SUNSHINE SHOULD HOLD TEMPERATURES A BIT LOWER THAN TODAY...BUT STILL 
ON THE HIGH SIDE OF GUIDANCE FROM THE MID 60S NORTHEAST TO THE MID 
70S IN THE FAR SOUTHWEST. IF THE MORE PESSIMISTIC MODEL CLOUD
TRENDS OF THE ECMWF...AND ESPECIALLY THE WRF...WERE TO
MATERIALIZE...READINGS WOULD BE HELD IN THE 60S.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CDT SAT OCT 25 2014

RETURN FLOW ALOFT DEVELOPING SUNDAY NIGHT COMBINED WITH AN 
APPROACHING UPPER LEVEL DISTURBANCE SHOULD GENERATE SOME SHOWERS. 
THE BETTER FORCING IS ACROSS WISCONSIN BUT THE NORTHEAST QUARTER OF 
THE AREA MAY SEE SOME ISOLATED TO SCATTERED SHOWERS AND ONE CANNOT 
RULE OUT AN ERRANT THUNDERSTORM OVER THE FAR NORTHEAST.

MONDAY MORNING SHOULD BE MAINLY DRY AS THE FIRST DISTURBANCE MOVES 
ACROSS THE GREAT LAKES WHILE A STORM SYSTEM MOVES NORTHEAST FROM THE 
PLAINS. MOISTURE FLOWING INTO THE AREA MONDAY AFTERNOON SHOULD 
GENERATE ISOLATED TO SCATTERED SHOWERS. FAVORABLE TEMPERATURE 
PROFILES WOULD ALSO SUPPORT SOME ISOLATED THUNDERSTORMS.

MAX TEMPERATURES ON MONDAY WILL BE DEPENDENT UPON CLOUD COVER AND 
WHEN CONVECTION DEVELOPS. IF ENOUGH SUN OCCURS ACROSS THE AREA FOR 
MOST OF THE DAY...TEMPERATURES WILL AVERAGE WELL ABOVE NORMAL.

MONDAY NIGHT/TUESDAY MORNING THE STORM SYSTEM MOVES THROUGH THE 
AREA. THE BETTER RAIN CHANCES WILL BE MONDAY EVENING WITH RAIN 
GRADUALLY ENDING FROM WEST TO EAST STARTING LATE MONDAY NIGHT AFTER 
THE COLD FRONT SWEEPS THROUGH THE AREA.

DRY BUT BREEZY CONDITIONS WILL BE SEEN ACROSS THE AREA TUESDAY 
AFTERNOON AS THE STORM SYSTEM MOVES INTO THE GREAT LAKES. 
TEMPERATURES SHOULD BE CLOSE TO NORMAL ON TUESDAY.

TUESDAY NIGHT ON...
THE MODEL CONSENSUS HAS DRY CONDITIONS TUESDAY NIGHT/WEDNESDAY AS 
HIGH PRESSURE MOVES THROUGH THE MIDWEST. A WEAK DISTURBANCE ALOFT IS 
FORECAST TO MOVE THROUGH THE AREA WEDNESDAY NIGHT/THURSDAY. MOISTURE 
IS QUITE LIMITED BUT THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS FOR 
MUCH OF THE AREA. TEMPERATURES TUESDAY NIGHT THROUGH THURSDAY SHOULD 
BE CLOSE TO NORMAL.

THURSDAY NIGHT THROUGH SATURDAY THE MODEL CONSENSUS HAS DRY 
CONDITIONS AS COLD CANADIAN HIGH PRESSURE BUILDS INTO THE MIDWEST. 
TEMPERATURES ARE EXPECTED TO AVERAGE WELL BELOW NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1209 PM CDT SAT OCT 25 2014

HIGH PRESSURE CENTERED OVER THE PLAINS WILL SLIDE EAST ACROSS IOWA
AND ILLINOIS TONIGHT THROUGH SUNDAY PROVIDING MOSTLY CLEAR SKIES
AND VFR CONDITIONS. NORTHERLY WINDS TODAY WILL BECOME LIGHT AND
VARIABLE TONIGHT...THEN SOUTHEAST AROUND 10 KTS BY MIDDAY SUNDAY. 


&&

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

$$

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




National Weather Service Glossary of Abbreviations