Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 KMKX 281607 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1107 AM CDT THU AUG 28 2014

.UPDATE...

AREA OF RAIN WITH A FEW THUNDERSTORMS CURRENTLY MOVING NORTHEAST
TOWARD THE AREA FROM IOWA. THIS IS BEING DRIVEN BY REMNANT 500 MB
MESOSCALE CONVECTIVE VORTEX AND 850 MB LOW LEVEL JET. MESOSCALE
MODELS ARE SHOWING SOUTHERN PORTION OF THIS PRECIPITATION TO
AFFECT AREAS ACROSS SOUTH CENTRAL WISCONSIN THIS AFTERNOON.
12Z NAM LIMITING QPF TO THE FAR WEST...WITH THE GFS IN THE
NORTHWEST HALF OF THE AREA. FEEL REALITY SHOULD BE BETWEEN THESE
TWO SOLUTIONS...MAINLY OVER SOUTH CENTRAL WISCONSIN.

MAIN 850 MB LOW LEVEL JET WILL FOCUS MORE TO THE NORTHWEST OF THE
AREA...SO PRECIPITATION MAY BECOME MORE SCATTERED AS IT MOVES INTO
THE AREA. AREA FORECAST SOUNDINGS NOT SHOWING MUCH IN THE WAY OF
ELEVATED CAPE.

WILL KEEP GENERAL TREND WITH HIGH POPS IN THE FAR WEST AND
NORTHWEST COUNTIES THIS AFTERNOON...WITH LOWER POPS TO THE SOUTH
AND EAST. CONTINUED SHOWER MENTION WITH CHANCES FOR THUNDER GIVEN
LOW ELEVATED CAPES. PRECIPITABLE WATER VALUES ARE AROUND 1.80
INCHES...SO LOCALLY HEAVY RAINFALL IS STILL POSSIBLE DESPITE WEAK
INSTABILITY. INCREASING CLOUDS AND PRECIPITATION SHOULD HELP KEEP
HIGHS IN THE LOWER TO MID 70S INLAND...AND AROUND 70 LAKESIDE WITH
ONSHORE WINDS.

&&

.AVIATION/18Z TAFS/...

EXPECT MIDDLE LEVEL CLOUDS TO MOVE INTO THE AREA EARLY THIS
AFTERNOON...WITH MAINLY LIGHT SOUTHEAST TO EAST WINDS. AREA OF
RAIN SHOWERS WITH A FEW THUNDERSTORMS SHOULD CLIP MADISON AFTER
20Z THURSDAY INTO THE EARLY EVENING HOURS. MVFR/IFR VISIBILITIES
ARE POSSIBLE AT TIMES...ALONG WITH MVFR CEILINGS.

SHOWERS AND STORMS MAY LINGER THROUGH THE NIGHT INTO FRIDAY...AS
WARM FRONT MOVES NORTH THROUGH THE AREA. WILL USE VICINITY THUNDER
WORDING IN TAFS BEYOND 02Z FRIDAY.

MAY BE A PERIOD OF QUIET WEATHER LATER FRIDAY MORNING INTO THE
AFTERNOON...AS BEST PRECIPITATION AREA WILL REMAIN TO THE NORTH OF
THE AREA. SOME UNCERTAINTY HERE WITH THE PRECIPITATION
TRENDS...THUS THE VICINITY THUNDER WORDING. SOUTHEAST WINDS
TONIGHT WILL SHIFT TO THE SOUTH FRIDAY AND INCREASE IN MAGNITUDE.

&&

.MARINE...

INCREASED EAST TO SOUTHEAST WINDS INTO THE MIDDLE AFTERNOON HOURS
ACROSS THE NEARSHORE WATERS...GIVEN CURRENT TRENDS. SHOULD SEE A
GENERAL 1O TO 15 KNOT RANGE DURING THIS TIME. THIS SHOULD ALLOW
FOR WAVES OF 1 TO 2 FEET ACROSS MOST OF THE WATERS.

&&

.PREV DISCUSSION... /ISSUED 339 AM CDT THU AUG 28 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH

00Z MODEL CONSENSUS CONTINUES TO SLOW SHOWERS AND STORMS MOVING INTO
THE REGION...WITH THE NAM THE SLOWEST BARELY BRUSHING THE FAR
WESTERN CWA WITH QPF UNTIL AFTER 21Z...AND EASTERN SECTIONS AFTER
06Z.

UPPER LEVEL DIVERGENCE IN THE RIGHT ENTRANCE REGION OF UPPER
JET...DOES NOT MOVE IN UNTIL 18Z...A LEAD SHORT WAVE/POSSIBLE MCV?/
MOVES ACROSS BETWEEN 16Z AND 00Z FRIDAY WITH OMEGA AND DEEP MOISTURE
NOT ARRIVING UNTIL AFTER 18Z. WILL TIME PCPN IN WITH LAYER Q-VECTOR
CONVERGENCE MAX AND FRONTOGENESIS WHICH BRINGS SHOWERS AND STORMS
INTO THE WESTERN CWA BETWEEN 18Z AND 21Z...AND INTO THE EAST BETWEEN
21Z AND 00Z. HAVE GONE MORE WITH SHOWERS AND ONLY A CHANCE OF
THUNDER AS POOR MID-LEVEL LAPSE RATES PROVIDE LITTLE IN THE WAY OF
CAPE.

WHILE CAPE IS MINIMAL...PRECIPITABLE WATER VALUES ARE STILL AROUND 2
INCHES SO LOOKING AT SOME HEAVY RAINFALL. CORFIDI VECTOR MAGNITUDES
START OUT FAIRLY SMALL AROUND 5 KTS LATE THIS AFTERNOON...THEN
INCREASE THIS EVENING AND OVERNIGHT.  STRONGEST FORCING AND BETTER
MOISTURE TRANSPORT WITH THIS INITIAL ROUND OF PRECIPITATION REMAINS
ACROSS THE WESTERN AND NORTHERN CWA SO HAVE HIGHEST QPF AMOUNTS
THERE...CLOSING IN ON 1 INCH OVER THE FAR NW PORTION OF CWA BY 12Z
FRIDAY. WILL RE-ISSUE THE ESF FOR NOW AS PROGRESSIVE CELL MOVEMENT
PRECLUDES HIGHER POTENTIAL FOR FLOODING/FLASH FLOODING THOUGH LOCAL
URBAN STREET FLOODING POSSIBLE.

FRIDAY AND SATURDAY - CONFIDENCE...MEDIUM
ACTIVE PERIOD WITH POTENTIAL FOR HEAVY RAINS WITH VERY MOIST FLOW
AHEAD OF APPROACHING MID LEVEL TROUGH AXIS. ONE COMPLEX WILL BE
EXITING TO THE NNE FRIDAY MORNING ASSOCIATED WITH THE INITIAL
MOISTURE/WAA SURGE. CLOUD COVER WILL HAVE A SAY ON TEMPS AND ALSO
SUBSEQUENT DEVELOPMENT. THE NAM IS TRENDING DRIER TOWARDS MIDDAY
WHILE OTHER MODELS DO SHOW QPF BUT IN A MORE DISORGANIZED FASHION.
SO TRENDED POPS A BIT LOWER AFTER THE MORNING ROUND SHIFTS AWAY.
BETTER DYNAMICS ALOFT AND LOW LEVEL FRONTAL FORCING ARRIVE FRIDAY
NIGHT INTO SATURDAY AS MID LEVEL TROUGH AND ASSOCIATED CVA AND
SURFACE/850 FRONTS DRAW CLOSER. STILL SEEING SIGNALS FOR AREAS OF
HEAVY RAINFALL WITH TALLER SKINNY CAPE...PRECIPITABLE WATER VALUES
1.9-2.0 AND PERIODS OF MBE VELOCITIES AOB 10 KTS. OUR QPF SHOWS
VALUES THROUGH SATURDAY AROUND AN INCH IN THE FAR SE CWA TO OVER 2
INCHES IN THE NW CWA.

SATURDAY NIGHT AND SUNDAY - CONFIDENCE...MEDIUM
SUBSIDENCE/DRYING WORKS IN THIS PERIOD WITH SURFACE HIGH TAKING
HOLD. THE HIGH DOES SHIFT EAST DURING THE AFTERNOON WITH RETURN
SOUTHERLY FLOW GETTING BACK UNDERWAY. WILL LEAN TOWARDS THE DRY
SOLUTION OF THE ECMWF. GFS BARELY HINTS AT LIGHT PRECIP IN THE FAR
SOUTH BUT WILL PLAN ON THIS BEING A DRY PERIOD WITH BETTER FORCING
HOLDING OFF TO THE WEST.

SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM
GFS AND ECMWF IN DECENT AGREEMENT ON BRINGING HIGHLY DYNAMICAL
NEGATIVELY TILT SYSTEM THROUGH THIS PERIOD. GFS IS A SMIDGE
QUICKER ON BRINGING PRECIP IN ON SUNDAY EVENING. STRONGEST FORCING
SIGNAL COMES LATER IN THE NIGHT THROUGH MONDAY MORNING. NOT BEST
TIME FOR TAPPING INTO AVAILABLE MLCAPE...BUT AGAIN THIS SYSTEM HAS
SOME DYNAMIC PUNCH TO IT. STORMS SHOULD BE MOVING ALONG AT A
BETTER CLIP WITH THIS SYSTEM.

TUESDAY AND WEDNESDAY - CONFIDENCE...MEDIUM
500 MILLIBAR FLOW NEARLY ZONAL ACROSS THE NRN STATES WITH
SPRAWLING RIDGE IN THE SRN STATES. WILL GO WITH A MAINLY QUIET
PERIOD WITH SURFACE/850 HIGH IN CONTROL AND LOW LEVEL MOISTURE
FEED/H8 LLJ STAYING TO THE WEST OF OUR AREA.

AVIATION/12Z TAFS/...WATCHING FOR SOME GROUND FOG DEVELOPMENT AT
OTHER TAF SITES PRIOR TO 12Z...WITH VFR CONDITIONS EXPECTED AT ALL
SITES THROUGH 18Z TODAY. MODELS HAVE BACKED OFF EVEN MORE WITH ONSET
OF SHOWERS AND STORMS. WILL HOLD OFF ON PCPN AND MVFR CONDITIONS
UNTIL AFTER 18Z AT KMSN AND 21Z AT EASTERN TAF SITES. WILL BE MORE
SHOWERS WITH A CHANCE OF THUNDERSTORMS DUE TO LIMITED INSTABILITY.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...COLLAR
FRIDAY THROUGH WEDNESDAY...REM


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