Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 112041
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
341 PM CDT FRI JUL 11 2014

TONIGHT...FORECAST CONFIDENCE MEDIUM.

AREA OF LIGHT RAIN SHOWERS ASSOCIATED WITH WEAK VORTICITY ADVECTION
AND STEADY 850-700MB WARM AIR ADVECTION OVER SOUTH CENTRAL WI ARE
RUNNING INTO VERY DRY AIR BELOW 10 KFT IN SOUTHEAST WI. ONLY A SMALL
PORTION OF THE RAIN WE SEE ON RADAR IS MAKING IT TO THE GROUND.

THE LOW LEVEL JET WILL BE FOCUSED OVER IOWA AND NORTHERN ILLINOIS
OVERNIGHT... ALONG AN 850MB THERMAL BOUNDARY/BAROCLINIC ZONE. THESE
AREAS WILL BE THE TARGET FOR SHOWERS AND STORMS AS A WEAK SHORTWAVE
ROLLS ALONG THIS BOUNDARY. SOUTHERN WI MAY END UP GETTING SOME RAIN
AND A FEW RUMBLES OF THUNDER ON THE NORTH SIDE OF THIS SYSTEM LATER
TONIGHT INTO SATURDAY MORNING.

SATURDAY...FORECAST CONFIDENCE MEDIUM.

THE 850MB BAROCLINIC ZONE IS EXPECTED TO LIFT INTO FAR SOUTHERN WI
SATURDAY AFTERNOON. THERE IS UNCERTAINTY BETWEEN THE MODELS ABOUT
EXACTLY WHERE IT WILL END UP. ALL OF THE MODELS PAINT A BULLSEYE OF
QPF SATURDAY AFTERNOON...BUT IT IS IN ALL DIFFERENT AREAS OF WI FROM
NORTH TO CENTRAL TO SOUTH. PRECIPITABLE WATER VALUES WILL BE
APPROACHING 2 INCHES OVER SOUTHERN WI SATURDAY AFTERNOON...LEADING
TO A HEAVY RAIN POTENTIAL.

SPC CONTINUED THE DAY 2 SLIGHT RISK OF SEVERE STORMS OVER SOUTHERN
WI FOR SATURDAY AFTERNOON AND EVENING. THIS WILL BE THE TIME PERIOD
THAT THE LOW LEVEL JET STRENGTHENS OVER NORTHERN IL...THE SURFACE
AND 850MB BAROCLINIC ZONES LIFT NORTHWARD...A SHORTWAVE TROUGH MOVES
OVER SOUTHERN WI AND THE RIGHT ENTRANCE REGION OF THE UPPER JET
SLIDES OVERHEAD AS WELL.

CAPE WILL BE MODERATE BUT TALL AND SKINNY GIVEN THE MOIST PROFILE ON
FORECAST SOUNDINGS. BULK SHEAR WILL BE HIGH IN THE 35 TO 55 KNOT
RANGE AND THERE IS POTENTIAL FOR STRONG LOW LEVEL SHEAR DEPENDING ON
WHERE THE SURFACE FRONT LINES UP. BOWING LINE SEGMENTS PRODUCING
STRONG WINDS WILL BE POSSIBLE AS WELL. ALL FORMS OF SEVERE WEATHER
WILL BE POSSIBLE...BUT THERE IS STILL UNCERTAINTY ABOUT WHERE IT
WILL END UP...WHETHER IN SOUTHERN WI OR NORTHERN IL.

.SHORT TERM...SATURDAY NIGHT THROUGH MONDAY NIGHT

SATURDAY NIGHT...FORECAST CONFIDENCE HIGH

THUNDERSTORMS WILL BE ONGOING AT START OF PERIOD IN WARM ADVECTION
AHEAD OF MID-LEVEL TROUGH. STRONG FRONTOGENETIC RESPONSE TO SURFACE
CONVERGENCE ALONG WARM FRONT AHEAD OF WEAK SURFACE WAVE AND 30-40 KT
SWLY LOW-LEVEL WINDS IMPINGING ON TIGHT BAROCLINIC ZONE ON NOSE OF
850 THERMAL RIDGE OVER CWA AT 00Z SUNDAY THAT FALLS OFF TO THE SOUTH
AS WINDS BECOME WESTERLY BY 06Z...WITH SURFACE TROUGH SAGGING SOUTH
INTO NRN ILLINOIS.

NAM SHOWING MUCH MORE CAPE THAN GFS...WITH 0-6KM BULK SHEAR BETWEEN
35KTS AND 40 KTS ON BOTH SUFFICIENT FOR ORGANIZED AND SUSTAINED
UPDRAFTS TO CONTINUE THE CHANCE OF SEVERE IN THE FORECAST THROUGH
THE EVENING HOURS. PRECIPITABLE WATER VALUES RISE TO 2 INCHES SO
HEAVY RAIN A GOOD BET...THOUGH MESO-BETA ELEMENT SPEEDS ARE 15 TO 20
KTS SO DO NOT EXPECT WIDESPREAD FLOODING/FLASH FLOODING...BUT SOME
URBAN AND SMALL STREAM ISSUES ESPECIALLY IN THOSE LOW-LYING
LOCATIONS/UNDERPASSES THAT NORMALLY FILL WITH WATER IN HEAVY RAINS.

SUNDAY AND SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM

A BREAK IN THE PCPN AS INITIAL TROUGH/COOL FRONT CONTINUES TO PUSH
SOUTH INTO CENTRAL IL BY 12Z SUNDAY...WITH SECOND COLD FRONT
 MOVING INTO NRN WI AND REACHING THE NRN CWA BY AFTERNOON.

GFS AND NAM SOUNDINGS SHOWING 200-300 J/KG OF CAPE...WITH WEAK LOW-
MID FRONTOGENETIC FORCING. THOUGH THUNDERSTORMS CAN NOT BE RULED OUT
NOT CONFIDENT ENOUGH TO INCLUDE IN FORECAST WITH MINIMAL MOISTURE.
PRECIPITATION ALONG FRONT TO MOVE SOUTH OF STATE WITH FORCING SUNDAY
EVENING. SHOULD SEE TEMPS RISE INTO THE UPPER 70S...LOW 80S FAR
SOUTH BEFORE PCPN AND FRONT MOVE IN. LOWS COOL INTO THE MID-UPPER
50S BY MONDAY MORNING.

MONDAY AND MONDAY NIGHT...FORECAST CONFIDENCE HIGH

MAIN COLD FRONT ASSOCIATED WITH CLOSED 500 MB SYSTEM DROPS THROUGH
STATE MONDAY. NOT MUCH MOISTURE BUT STRONG Q-VECTOR CONVERGENCE WITH
DYNAMICS LEADS TO CHANCE OF  SHOWERS IN THE AFTERNOON. WITH CLOUDS
AND PCPN LEANED TOWARD A CONSENSUS OF RAW MODEL TEMPERATURES FOR
HIGHS. COLD POOL FIRMLY OVER STATE MONDAY NIGHT...BUT CLOUDS AND 5
TO 10 MPH NW WINDS WILL KEEP TEMPS FROM DROPPING MORE THAN LOW-MID
50S.

.LONG TERM...TUESDAY THROUGH FRIDAY. FORECAST CONFIDENCE MEDIUM

COOLEST DAY OF THE WEEK TUESDAY IN NW FLOW AS 500 MB LOW PUSHES EAST
INTO LOWER MICHIGAN. HIGHS IN THE MID 60S...OR ABOUT 15 DEGREES
BELOW NORMAL. WILL SEE A CHANCE OF SHOWERS UNDER RETREATING CYCLONIC
FLOW...WITH THE BEST CHANCE IN THE NE CWA. DRY WEATHER AND A SLOW
WARM UP THE REST OF THE WEEK AS 500 LOW LIFTS AWAY TO THE NORTHEAST
AND SURFACE HIGH AND MID-LEVEL RIDGING MOVE IN. LOW 70S GIVE WAY TO
MID 70S THURSDAY...AND NEAR-NORMAL READINGS IN THE UPPER 70S
EXPECTED FRIDAY.

&&

.AVIATION/00Z TAFS/...

VFR CONDITIONS ARE EXPECTED THROUGH THE EVENING. WE MAY SEE AREAS OF
FOG DEVELOP WITH MVFR VISIBILITIES AND CIGS EARLY SATURDAY MORNING
AS WINDS WEAKEN SOMEWHAT AND LOW LEVEL MOISTURE INCREASES.

VICINITY SHOWER/THUNDERSTORM IN TAFS FOR LATER TONIGHT...AS MORE
WARM AND MOIST AIR TRIES TO PUSH INTO THE AREA. BEST CHANCES WILL
REMAIN JUST SOUTH OF WI. MAY SEE LIGHT FOG DEVELOP WITH MVFR
VISIBILITIES LATER TONIGHT ACROSS TAF SITES...AS WINDS WEAKEN
SOMEWHAT.

THUNDERSTORMS ARE LIKELY SATURDAY AFTERNOON AND EVENING...SOME COULD
BE SEVERE.

&&

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

$$

TONIGHT/SATURDAY AND AVIATION/MARINE...MRC
SATURDAY NIGHT THROUGH FRIDAY...REM



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