Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 010819
AFDDVN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
319 AM CDT FRI AUG 1 2014

.SYNOPSIS...
ISSUED AT 317 AM CDT FRI AUG 1 2014

LATEST SFC ANALYSIS WAS INDICATING A LARGE MULTI CENTERED RIDGE
COMPLEX EXTENDING FROM THE NORTHERN PLAINS...DOWN ACRS IA AND TOWARD
THE OH RVR AND TN VALLEY REGIONS. A WEAK WAVE NOTED OVER THE NEB/KS
BORDER...WITH A BIT OF TROFFINESS OFF OF IT INTO SW IA. THIS A PART
OF A SFC REFLECTION OF A VORT MAX SEEN ON WATER VAPOR IMAGERY ACRS
NORTHWESTERN INTO CENTRAL IA...WITH ANOTHER UPSTREAM VORT MAX SEEN
ON THE ND/CANADIAN BORDER EMBEDDED IN ONGOING STEEP CYCLONIC
NORTH-WESTERLIES. THE NORTHWESTERN IA VORT INDUCING SOME NOCTURNAL
MID DECK OF CLOUDS ACRS THE SOUTH HALF OF IA...AS WELL AS SHOWER
CLUSTERS ACRS THE NEB/IA/MO/KS QUAD STATE REGION AND A FEW LOCALLY
SOUTH OF I80.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT FRI AUG 1 2014

TODAY...WITH THE VORT ROLLING ACRS THE AREA...WILL KEEP LOW CHC POPS
GOING MAINLY ACRS THE SOUTHERN CWA THROUGH MID MORNING...AND THEN
EXPAND NORTHWARD WITH DIURNAL HEATING THROUGH MIDDAY. THIS MAY BE
OVERDOING IT NORTH OF I80 FROM 10 AM TO 1 PM CDT...BUT JUST A
SLIGHT/ISOLATED CHC. WILL KEEP SHOWER WORDING THROUGH NOON...
ALTHOUGH AN ISOLATED RUMBLE OF THUNDER CAN NOT BE RULED OUT. AS THE
VORT PROPAGATES OUT OF THE CWA ACRS CENTRAL IL BY MIDDAY...AND THE
OTHER UPPER TROF DIGS MORE ACRS NORTHEASTERN MN INTO WI...COULD SEE
A LULL IN ANY ISOLATED TO WDLY SCTRD SHOWER ACTIVITY ACRS MUCH OF
THE WESTERN HALF OF THE CWA FROM MIDDAY TO MID AFTERNOON. A FEW OF
THE HIRES NEAR TERM MODELS KEEP SHOWERS AND A FEW THUNDERSTORMS
FESTERING ACRS WEST CENTRAL INTO NORTHWESTERN IL ESPECIALLY ALONG
THE I80 CORRIDOR EAST OF THE QUAD CITIES AREA. WITH HEATING OF THE
AFTERNOON...COULD EVEN BE AN UP TICK IN ACTIVITY IN THESE AREAS AS
THE AFTERNOON PROGRESSES. IF TEMPS CAN GET INTO THE LOWER 80S WITH
DPTS AROUND 60...CAPES OF 1500 J/KG WILL FUEL A FEW THUNDERSTORMS
THIS AFTERNOON. FCST SOUNDINGS DO SHOW WBZ/S AND FZ LEVELS THAT
WOULD BE IDEAL FOR HAIL FORMATION IF UPDRAFTS HAVE ENOUGH STRENGTH...
BUT ADEQUATE BUOYANCY MAY STILL BE AT QUESTION. WILL FCST HIGHS
SIMILAR TO YESTERDAY/S VALUES...OR A DEGREE OR TWO BELOW THOSE
HIGHS WITH VEIL OF SMOKE STREAMING DOWN ACRS THE REGION IN UPPER
NORTHWEST FLOW...AS WELL AS ONGOING CLOUDS PRODUCED BY THE INCOMING
VORT AND DIURNAL HEATING CU. THEN LATE THIS AFTERNOON INTO EARLY
EVENING THE NORTHERN CWA COULD HAVE SOME ISOLATED TO SCTRD SHOWERS
AND THUNDERSTORMS DRIFT DOWN OUT OF FAR SOUTHEASTERN MN INTO
SOUTHWESTERN WI AND INTO AREAS ALONG AND NORTH OF HWY 30. BUT ALL IN
ALL...ANOTHER DAY WHERE MORE AREAS STAY DRY THAN THOSE THAT MANAGE
TO GET UNDER A PASSING SHOWER/STORM. LIGHT AND VARIABLE WIND REGIME
ALL DAY.

TONIGHT...WILL KEEP LOW CHC POPS GOING THROUGH MID EVENING ESPECIALLY
ALONG AND NORTH OF I80...BEFORE THEY DIURNALLY WANE THROUGH MIDNIGHT.
LOWS IN THE UPPER 50S TO LOWER 60S...AND ALTHOUGH WILL NOT ADVERTISE
IT IN THE GRIDS...SOME LOCALIZED FOG POSSIBLE IN AREAS THAT GET RAIN
OR HAVE A POOL OF HIGHER SFC DPTS.    ..12..


.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 317 AM CDT FRI AUG 1 2014

MAIN ISSUE IN THE LONG TERM IS THE TRANSITION FROM COOL AND MOSTLY
DRY WEATHER TO A WARMER AND SOMEWHAT WETTER REGIME.

THIS WEEKEND...HIGH PRESSURE AT THE SURFACE AND 850 MB WILL REIGN
OVER THE REGION UNDER NORTHWEST FLOW ALOFT.  THIS MEANS GENERALLY
LITTLE CHANGE IN THE CURRENT PATTERN WITH MILD TEMPERATURES AND
PERHAPS A SPOTTY SHOWER OR THUNDERSTORM AT TIMES...MAINLY DIURNALLY
DRIVEN WITH NO CLEARLY APPARENT SHORT WAVE TROUGH TO LOCK ONTO.

AN UPPER LEVEL TROUGH OFF THE PACIFIC COAST WILL BEGIN TO MOVE
ONSHORE EARLY NEXT WEEK AND START THE PROCESS OF BEATING DOWN THE
WESTERN U.S. RIDGE.  THUS WARM AIR ADVECTION BEGINS MONDAY AS WEAK
850 MB WINDS SWING AROUND TO THE SOUTHWEST.  MONDAY AND TUESDAY
SHOULD BE A BIT WARMER AND MORE HUMID AS A MORE SUMMER-LIKE AIR
BEGINS TO INFILTRATE THE AREA.  FORCING IS NOT TOO IMPRESSIVE IN THE
DIRTY NORTHWEST FLOW THAT IS FORECAST TO DEVELOP...SO WHILE PRECIP
CHANCES ARE IN THE FORECAST...AREAL COVERAGE SHOULD NOT BE TOO
IMPRESSIVE WITH THE MAIN AXIS OF FLOW JUST TO OUR NORTH IN MN AND WI.

WEDNESDAY AND THURSDAY...THINGS BECOME EVEN WARMER AND MORE HUMID AS
GULF FLOW CONNECTS TO THE AREA.  WHILE TIMING BETWEEN THE GFS AND
ECMWF IS A LITTLE DIFFERENT...BOTH FORECAST A SURFACE AND 850 MB LOW
INTO THE AREA LATE WEDNESDAY INTO THURSDAY.  THIS ALONG WITH SOME
UPPER LEVEL SUPPORT WILL PROVIDE A BETTER FOCUS FOR THUNDERSTORM
ACTIVITY.  SO AT THIS POINT...OUR BEST CHANCE OF PRECIP LOOKS TO BE
LATE WEEK WITH THIS FEATURE.   WOLF

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1137 PM CDT THU JUL 31 2014

WEAK SHOWERS...MOSTLY SPRINKLES...MAY BE IN THE BRL VICINITY AROUND
MIDNIGHT. OTHERWISE...THE REST OF TONIGHT AND FRIDAY WILL HAVE
MAINLY VFR CONDITIONS AND VERY LIGHT WINDS UNDER A BROAD AREA OF
HIGH PRESSURE AT THE SURFACE. LOW LEVEL MOISTURE MAY AGAIN LEAD TO
MORNING GROUND FOG...WHICH HAS BEEN INCLUDED WITH POTENTIAL MVFR
VISIBILITIES AT BOTH CID AND BRL. AT BRL...REPORTED VISIBILITY MAY
BE AFFECTED AT TIMES BY GRAVEL ROAD DUST IN THE MORNING...MUCH AS
IT WAS THURSDAY EVENING. SKIES WILL AGAIN BE HAZY ALOFT AT ALL
TERMINALS THROUGH FRIDAY DUE TO AN EXTENSIVE PLUME OF THICK HIGH
ALTITUDE SMOKE STREAMING SOUTH OUT OF WILDFIRES IN NORTHERN
CANADA. THERE WILL BE A CHANCE FOR AFTERNOON SHOWERS AND
THUNDERSTORMS...BUT THESE LOOK TO FEW TO MENTION IN THE TAFS IN
THIS TIMEFRAME.

&&

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

$$

SYNOPSIS...12
SHORT TERM...12
LONG TERM...WOLF
AVIATION...SHEETS






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