Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 171439
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
939 AM CDT THU APR 17 2014

.UPDATE...
ISSUED AT 939 AM CDT THU APR 17 2014

HAVE UPDATED THE GRIDS TO GO MORE PESSIMISTIC ON CLOUD COVER AND ALSO
TO LOWER MAXIMUM TEMPERATURES A COUPLE OF DEGREES. COLD AIR ADVECTION
AND CYCLONIC FLOW AROUND LOW PRESSURE CENTERED IN CENTRAL WISCONSIN
WAS PRODUCING AN EXTENSIVE AREA OF LOW STRATUS IN THE MIDWEST.
WITH THE STRONGER MID APRIL SUN THE STRATUS CLOUDS SHOULD BEGIN
TO ERODE BY AFTERNOON. WILL CONTINUE TO MONITOR TRENDS.

IN THE MEANTIME...IR SATELLITE LOOPS SHOW MID/HIGH LEVEL CLOUDS
STREAMING NORTHEAST INTO THE CWA AS AN UPPER LEVEL TROUGH SWINGS
OUT OF THE CENTRAL/SOUTHERN PLAINS. THIS WILL BE ADDING MORE CLOUD
COVER TO THE CWA.

&&

.SYNOPSIS...
ISSUED AT 351 AM CDT THU APR 17 2014

1012 MB SFC LOW WAS LOCATED NORTHEAST OF ROCHESTER MN AT 07Z. TRAILING
COLD FRONT WAS MOVING THROUGH WESTERN CWA ACCOMPANIED BY STRATUS AND
GUSTY WIND SHIFT FROM SOUTHERLY TO WESTERLY. IN WAKE OF THE SFC
CYCLONE... RIDGING WAS BUILDING THROUGH THE NORTHERN AND CENTRAL PLNS.
PATTERN ALOFT FEATURES SEMI-ZONAL TO NORTHWEST FLOW OVER CENTRAL CONUS
WITH WELL DEFINED SHORTWAVE PASSING THROUGH THE UPPER MIDWEST AND
ANOTHER SHORTWAVE EMERGING INTO THE SOUTHERN PLAINS FROM THE ROCKIES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT THU APR 17 2014

COLD FRONT LOOKS TO EXIT EASTERN CWA BY MIDDAY. PERIOD OF BKN-OVC STRATUS
WILL ACCOMPANY FRONT MANY AREAS ALONG/WEST OF MISSISSIPPI... WITH
STRATUS LIKELY HALTED OR FRAGMENTED HEADING EAST OF QUAD CITIES AS
STRENGTHENING SOLAR INSOLATION GOES TO WORK. STRATUS THEN LIKELY TO
UNDERGO EROSION WITH INCREASING SUBSIDENCE AND DECREASING CYCLONIC
FLOW/COLD ADVECTION WITH LOW CONTINUING TO FILL/WEAKEN WHILE LIFTING INTO
THE GREAT LAKES. ATTENTION THOUGH SHIFTS TO OUR SOUTH WHERE ANTICIPATE
INCREASING MID/HIGH CLOUDINESS TO SPREAD BACK ACROSS CWA... MORE OPAQUE
ESPECIALLY SOUTHEAST 1/3-1/2 OF CWA THIS AFTN INTO EARLY EVE DUE TO
STRENGTHENING MID LEVEL FRONTOGENESIS AHEAD OF SOUTHERN PLAINS TROUGH
AND ATTENDANT JET STREAK AT ITS BASE. THESE FEATURES PROGGED TO LIFT OUT
ACROSS THE MID MISSISSIPPI VLY AND INTO OHIO VLY BY 12Z FRI. MID LEVEL
FRONTOGENESIS SHOWN TO PEAK THIS EVENING MAINLY TO OUR SOUTHEAST WITH
LEFT EXIT REGION OF JET. SOUNDINGS SHOW A FAIRLY LARGE AMOUNT OF DRY AIR
WITH TSECTS SHOWING MEAGER DEEP LAYER RH WITH NORTHERLY DRY ADVECTION IN
WAKE OF FRONTAL PASSAGE. THUS...CONCERNS IF ANY PCPN WILL BE ABLE TO
SURVIVE AND REACH THE GROUND DESPITE FORCING AND BAROCLINICITY... BUT IF
IT SHOULD MOST LIKELY WOULD BE JUST SPRINKLES FAR SOUTHEAST FOR A TIME
THIS EVENING.

HIGHS TDY SOMEWHAT CHALLENGING ESPECIALLY ON THE EDGES OF THE CWA WITH
CLOUDINESS. OVERALL...EXPECT HIGHS MAINLY IN THE 50S. BUT...IF
MORE SOLAR INSOLATION OCCURS LENDING TO DEEPER MIXING THEN COULD SEE
SEVERAL LOCATIONS HIT 60F OR L60S FROM NEAR QUAD CITIES TO THE SOUTHEAST.
ON THE FLIP SIDE...FAR NORTHWEST CWA COULD STRUGGLE TO TOUCH 50F IF THE
STRATUS HOLDS ON LONGER THAN ANTICIPATED.

TONIGHT...GENERALLY DECREASING CLOUDINESS WITH TROUGH PASSAGE AND INCOMING
SURFACE RIDGING. THIS COUPLED WITH LIGHT WINDS SHOULD PROMOTE GOOD
RADIATIONAL COOLING TO SIDE NEAR COLD SIDE OF GUIDANCE...WITH LOWS
MAINLY IN THE 30S. CANT RULE FEW DRAINAGE SITES INTO THE U20S NORTH.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 351 AM CDT THU APR 17 2014

FORECAST FOCUS IS ON WARMING TREND THIS WEEKEND AND INTO NEXT
WEEK...ALONG WITH PCPN CHANCES SUNDAY-MONDAY.

FRIDAY...DRY CONDITIONS WILL BE SEEN AS SURFACE HIGH TRACKS OVER THE
GREAT LAKES PROVIDING LIGHT WINDS AND MOSTLY SUNNY SKIES. INCREASED
SOLAR INSOLATION AND MIXING UP TO 850MB WILL ALLOW FOR TEMPS TO
REACH THE UPPER 50S NORTH TO LOW 60S SOUTH.

SATURDAY...STRONG SOUTHERLY RETURN FLOW DEVELOPS AHEAD OF SYSTEM
MOVING ACROSS THE NORTHERN PLAINS. LATEST MODEL RUNS HAVE SLOWED THE
MOVEMENT OF SYSTEM EAST AND THEREFORE ALLOWING TEMPERATURES TO WARM
EVEN MORE DURING THE DAY. DEEP MIXING IS FORECAST AND YIELDS HIGHS
IN THE UPPER 60S/LOW 70S. IF STORM SYSTEM SLOWS EVEN MORE THAN THESE
READINGS MAY BE TOO LOW FOR LATER SHIFTS TO CONSIDER.

SATURDAY NIGHT-MONDAY...FRONTAL BOUNDARY TO BE OVER NW IA AND WILL
SLOWLY MOVE CLOSER TO THE CWA DURING THE DAY ON SUNDAY. WITH DRY AIR
IN PLACE AND SYSTEM SLOWING DOWN SOMEWHAT...DO NOT EXPECT ANY PCPN
TO FALL MUCH BEFORE 12Z SUNDAY ACROSS THE NORTHWEST CWA. IF THE
LATEST ECMWF/GEM ARE CORRECT THEN WE MAY SEE LITTLE PRECIP IN OUR
CWA DURING THE DAY SUNDAY BEFORE ARRIVING SUNDAY NIGHT-MONDAY. AT
THIS TIME...IT DOES APPEAR THAT THE BEST WINDOW FOR SEEING ANY
PRECIP WILL BE SUNDAY NIGHT-EARLY MONDAY AS FORCING AND LOW LEVEL
MOISTURE INCREASE CONSIDERABLY IN THIS TIME FRAME. MODEL CONSENSUS
HAS CHANCE POPS SUNDAY THROUGH MONDAY FOR THIS STORM AND LATER
FORECASTS WILL BE ABLE TO FINE TUNE PERIODS IN WHICH PCPN IS MORE
LIKELY. HIGH TEMPERATURES TO BE GENERALLY IN THE UPPER 60S/LOW 70S.

TUESDAY...DRY CONDITIONS WILL BE SEEN AS HIGH PRESSURE BUILDS IN
BEHIND DEPARTING SYSTEM. TEMPERATURES TO REMAIN ABOVE NORMAL.

WEDNESDAY-THURSDAY...UPPER LEVEL RIDING TO BE OVER THE AREA WITH A
LARGE LONGWAVE TROUGH OVER THE WESTERN CONUS. BOTH THE GFS/ECMWF
DEPICT A STRONG STORM SYSTEM DEVELOPING OVER THE NORTHERN ROCKIES
THAT WILL LIKELY IMPACT THE REGION LATE IN THE WEEK. RAIN CHANCES
INCREASE WEDNESDAY WHERE MODELS SHOW WAA TYPE PRECIP AHEAD OF SYSTEM
IN THE ROCKIES MOVING INTO THE CWA FROM THE UPPER PLAINS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 939 AM CDT THU APR 17 2014

MVFR/LOCAL IFR CIGS THIS MORNING GIVING WAY TO VFR/LOCAL MVFR CIGS
THIS AFTERNOON. VFR CONDS TONIGHT AS HIGH PRESSURE BUILDS INTO THE
AREA. WEST TO NORTHWEST WINDS 10 TO 15 KNOTS TODAY THEN BECOMING
NORTH TO NORTHEAST AROUND 5 KNOTS OR LESS TONIGHT.

&&

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

$$

UPDATE...HAASE
SYNOPSIS...05
SHORT TERM...05
LONG TERM...GROSS
AVIATION...HAASE








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