Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KDVN 190457
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1157 PM CDT FRI JUL 18 2014

.SYNOPSIS...
ISSUED AT 254 PM CDT FRI JUL 18 2014

LATEST SFC ANALYSIS WAS INDICATING HIGH CENTER ACRS THE GRT LKS...
BUT LONG FETCH RIDGE LOBE EXTENDED BACK INTO THE SOUTHEASTERN
PLAINS. BUT A FRONTAL SYSTEM PUSHING EASTWARD ACRS THE NORTHERN
PLAINS AND ENCOUNTERING THE WESTERN RIDGE FLANK INDUCING NICE LLVL
RETURN FLOW ACRS THE EASTERN PLAINS/MO RVR VALLEY...WITH EVEN SOME
INFLUENCE EXTENDING ACRS IA. ASSESSING 12Z UPPER AIR ANALYSIS AND
SYNOPTIC SCALE LAY OUT INDICATED BY FLOW PATTERNS ON CURRENT WATER
VAPOR IMAGERY...THE DVN CWA STILL IN BETWEEN TWO MAIN SYSTEMS IN
THEIR RESPECTIVE FLOWS. ONE VIGOROUS WAVE NEAR THE LK WINNIPEG
REGION...AND ANOTHER TROF ROLLING UP THE WESTERN OH RVR AND TN
VALLEY REGIONS. ONE OTHER UPSTREAM VORT SEEN ACRS WESTERN SD/NEB
MAY LOOK TO DROP IN BEHIND THE SOUTHERN STREAM WAVE AND MAINLY
MISS US TO THE SOUTHWEST/SOUTH BY LATE TONIGHT INTO SAT MORNING.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM CDT FRI JUL 18 2014

TONIGHT...ANOTHER NIGHT OF DECAYING CELLULAR CU BUT LINGERING
PATCHES OF AC ESPECIALLY IF THE WESTERN CENTRAL PLAINS VORT SKIRTS
ACRS A BIT FURTHER NORTH THAN CURRENTLY ANTICIPATED. LIGHT
SOUTHEASTERLY SFC WINDS OF 3-6 KTS MAINTAINING IN RETURN FLOW
GRADIENT ALONG WITH SOME CLOUD PATCHES...SHOULD MAKE FOR LOWS IN THE
55 TO 60 DEGREE RANGE. MID TO UPPER 50 SFC DPTS ALSO TO HELP WITH
LOWS. PATCHY LOW LYING AREA/RVR VALLEY FOG POSSIBLE AGAIN LATE
TONIGHT.

SATURDAY...THE NORTHERN STREAM SFC FRONT WILL PUSH EASTWARD ACRS MN
INTO THE NORTHWESTERN GRT LKS BATTLING DEPARTING RIDGE COMPLEX. LLVL
SOUTHERLY RETURN FLOW IN TIGHTENING GRADIENT/SQUEEZE PLAY SHOULD
INDUCE WINDS OF 8-13 MPH ACRS THE NORTHWESTERN THIRD OF THE DVN CWA
SAT AFTERNOON...BUT LESS FURTHER EAST AND SOUTH. BUT STILL WITH
SOMEWHAT BETTER MIXING AND ONGOING DAY BY DAY AIR MASS MODIFICATION
SHOULD MEAN A WIDESPREAD RETURN TO THE 80S ON SAT. WILL ADVERTISE
HIGHS FROM 80-85 DEGREES ACRS THE ENTIRE CWA WITH MOST SITES IN THE
LOWER 80S. AMBIENT CU AND AC...AND CIRRUS SPILLING OFF FRONTAL SYSTEM
TO THE NORTHWEST SHOULD STILL NOT BE ENOUGH TO RUIN A MOSTLY SUNNY
FCST.   ..12..

.LONG TERM...(SATURDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 254 PM CDT FRI JUL 18 2014

AN ACTIVE FRONTAL ZONE WILL EVENTUALLY SHIFT EAST TO AFFECT THE CWA
THE WEEK AHEAD. THE QUESTION IS WHEN THAT WILL BEGIN. LAST NIGHTS
MODELS HAD PUSHED THE FRONT CLOSE ENOUGH FOR STORMS SUNDAY NIGHT AND
MONDAY BEFORE A TUESDAY FROPA. TODAYS RUNS GENERALLY DO NOT BRING
THE FRONT CLOSE ENOUGH FOR SOLID CHANCE POPS UNTIL ABOUT TUESDAY.
CONSIDERING ONLY MODEST MOISTURE IN PLACE NOW...AND ONLY SEASONAL
MOISTURE FORECAST TO CONVERGE ALONG THE FRONT NEXT WEEK...IT IS
DIFFICULT TO IMAGINE THE SYNOPTIC BOUNDARY PUSHING SOUTHEAST QUICKLY
EARLY ON. THEREFORE...I HAVE LOWERED POPS SUNDAY THROUGH MONDAY TO
SLIGHTS AT MOST. FUTURE SHIFTS MAY CONTINUE TO LOWER POPS TO CENTER
THEM ONLY ON THE FROPA PERIOD...AS WE APPEAR TO LACK A WARM FRONTAL
BOUNDARY FOR PERSISTENT CONVECTION THIS WEEK.

TEMPERATURES WILL BE WARM...WITH MID 80S AND NOTICEABLE HUMIDITY
SUNDAY...THEN HOT AND HUMID MONDAY THROUGH TUESDAY. WEDNESDAY SHOULD
SEE LESS HEAT WITH THE FRONT EAST OF THE CWA BY MORNING. ANOTHER
SHORT WAVE IS FORECAST FOR FRIDAY...RESULTING IN ANOTHER ROUND OF
CHANCE POPS FOR SHOWERS AND THUNDER...AS WELL AS SLIGHTLY WARMER
TEMPERATURES AGAIN.

THIS LATE WEEK FRONT HAS BEEN SHOWN STRONGER IN EACH OF THE RECENT
RUNS OF BOTH THE GFS AND ECMWF...POSSIBLY ANOTHER SIGNIFICANT COOL
DOWN FOR NEXT WEEKEND.
ERVIN

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM CDT FRI JUL 18 2014

MAINLY VFR CONDITIONS WILL CONTINUE THROUGH PERIOD WITH S/SE WINDS
AOB 10 KTS. THERE IS A LOW PROBABILITY OF BRIEF PERIODS OF MVFR
FOG LATE.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...ERVIN
AVIATION...RP KINNEY






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.