Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Text Only | 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 111542
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1042 AM CDT THU SEP 11 2014

.AVIATION/18Z TAFS/...WIDESPREAD MVFR CIGS WILL PERSIST THROUGH
THIS AFTERNOON AND LIKELY INTO THIS EVENING AS WELL. SEEING SOME
BREAKS TRENDING SOUTH FROM WC WI BUT GIVEN DEGREE OF COLD AIR
ALOFT EXPECTING CU TO FILL IN ACROSS THESE AREAS AS WELL SO MVFR
BKN-OVC SEEMS REASONABLE INTO AT LEAST THE EVENING HOURS.
DEVELOPING ONSHORE FLOW...LINGERING COLD AIR ALOFT AND APPROACHING
SHORTWAVE FOR FRIDAY WILL MEAN THAT CLOUD COVER WILL PERSIST. ANY
LAKE ENHANCED CLOUD COVER WILL LIKELY REINFORCE THE MVFR CIGS.
INVERSION HEIGHTS RISE UP TO 4-6K FEET LATER TONIGHT INTO FRIDAY
MORNING SO LIKE THE IDEA OF SEEING SOME LAKE EFFECT SHRA IN THE
SOUTHEAST. THE NAM AMOUNTS LOOK A BIT OVERDONE BUT LIKE THE IDEA
OF SHOWING PRECIP. SYNOPTIC INDUCED PRECIP KICKS IN DURING THE
AFTERNOON MERGING WITH ANY LINGERING LAKE EFFECT SHRA.

PC

&&

.PREV DISCUSSION... /ISSUED 326 AM CDT THU SEP 11 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.

A 115 KNOT WEST/NORTHWEST 250 MB JET EXTENDS ACROSS NORTHERN
WISCONSIN...AHEAD OF A SHORTWAVE OVER THE NORTHERN ROCKIES THAT
PUSHES EAST INTO THE NORTHERN PLAINS TONIGHT. WEAK UPPER
DIVERGENCE WITH WEAK DOWNWARD 700 MB VERTICAL VELOCITY THAT
BECOMES WEAK UPWARD TONIGHT.

MAIN FEATURE IS THE STRONG INVERSION ON TOP OF THE SHALLOW
BOUNDARY LAYER COOL AIR. THIS SHOULD KEEP THE STRATOCUMULUS
TRAPPED TODAY WITH NOT ENOUGH MIXING TO CAUSE MUCH
CLEARING...ALTHOUGH SOME BREAKS SHOULD OCCUR.

SOME LIMITED SCATTERING OUT TONIGHT...BUT THEN WITH NORTHEAST LOW
LEVEL FLOW EXPECT CLOUDS TO CONTINUE. FORECAST SOUNDINGS SHOW
STEEP ENOUGH LAPSE RATES TO PRODUCE LIGHT LAKE EFFECT SHOWERS.
HOWEVER INVERSION AROUND 5 THSD FT WILL LIMIT THE INTENSITY OF THE
SHOWERS.

UNSEASONABLE COOL AIR AND CLOUDS WILL CAUSE TEMPERATURES TO
STRUGGLE TO REACH 60...WITH UPPER 50S MOST AREAS. NORTHEAST FLOW
WILL KEEP TEMPERATURES WARMER NEAR LAKE MICHIGAN...ESPECIALLY
TONIGHT.

SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS HIGH.

MODELS CONTINUE TO SHOW POTENTIAL FOR LAKE EFFECT SHOWERS ON
FRIDAY...WITH NORTHEAST FETCH...DELTA T VALUES AROUND 15 DEGREES
CELSIUS AND MOIST LOW LEVELS. NAM FOCUSES MORE OVER LAKESHORE
AREAS FROM SHEBOYGAN TO RACINE...WITH GFS FOCUSING FURTHER TO THE
SOUTH. CONTINUED CHANCE POPS NEAR LAKESHORE FRIDAY.

MODELS CONTINUE TO AGREE WITH BRINGING STRONG 500 MB SHORTWAVE
TROUGH EAST TOWARD THE AREA FRIDAY...THEN ACROSS THE AREA FRIDAY
NIGHT. UPWARD VERTICAL MOTION IS DECENT WITH THIS FEATURE...WITH
AREA FORECAST SOUNDINGS BECOMING SATURATED IN THE LOW TO MID
LEVELS. NAM IS MORE SATURATED THAN GFS...THOUGH BOTH BRING SWATH
OF QPF THROUGH THE AREA. BROUGHT LIKELY POPS FOR SHOWERS ACROSS
THE ENTIRE AREA BY FRIDAY AFTERNOON...WITH POPS LINGERING FRIDAY
NIGHT. COOL TEMPERATURES WILL CONTINUE FRIDAY PER 925 MB
TEMPERATURE FIELDS.

DOWNWARD MOTION WITH BACKSIDE OF SHORTWAVE TROUGH LATER FRIDAY
NIGHT SHOULD ALLOW FOR AT LEAST SOME CLEARING IN THE WESTERN
COUNTIES. HIGH PRESSURE MOVING EAST FROM THE CENTRAL PLAINS WILL
HELP WEAKEN WINDS. THUS...LOWS SHOULD DROP INTO THE UPPER 30S
ACROSS MOST OF SOUTH CENTRAL WISCONSIN. ADDED PATCHY FROST TO
COLDEST AREAS IN PORTIONS OF SAUK COUNTY LATE FRIDAY NIGHT. MAY
SEE PATCHY FROST ELSEWHERE IN SOUTH CENTRAL WISCONSIN IF CLOUDS
MOVE OUT OR DISSIPATE SOONER.

HIGH PRESSURE WILL THEN BRING QUIET WEATHER SATURDAY INTO SATURDAY
NIGHT. TEMPERATURES WILL CONTINUE TO BE COOL...WITH HIGHS IN THE
60S AND LOWS IN THE 40S.

LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
HIGH.

GFS/ECMWF MODELS ARE IN DECENT AGREEMENT WITH FEATURES DURING THIS
TIME. HIGH PRESSURE INFLUENCE WILL KEEP DRY FORECAST GOING ON
SUNDAY...WITH TEMPERATURES REMAINING COOL. INVERTED SURFACE TROUGH
SUNDAY NIGHT...FOLLOWED BY PASSING 500 MB SHORTWAVE TROUGH MONDAY
INTO MONDAY EVENING...SHOULD BRING CHANCES FOR SHOWERS TO THE
AREA.

HIGH PRESSURE THEN BRINGS QUIET WEATHER TUESDAY INTO
WEDNESDAY...WITH TEMPERATURES REMAINING BELOW SEASONAL NORMALS.

AVIATION/12Z TAFS/...

EXPECT MVFR CIGS TO CONTINUE INTO TONIGHT. MAIN FEATURE IS THE
STRONG INVERSION ON TOP OF THE SHALLOW BOUNDARY LAYER COOL AIR.
THIS SHOULD KEEP THE STRATOCUMULUS TRAPPED TODAY WITH NOT ENOUGH
MIXING TO CAUSE MUCH CLEARING...ALTHOUGH SOME BREAKS SHOULD OCCUR.

SOME LIMITED SCATTERING OUT TONIGHT...BUT THEN WITH NORTHEAST LOW
LEVEL FLOW EXPECT CLOUDS TO CONTINUE. FORECAST SOUNDINGS SHOW
STEEP ENOUGH LAPSE RATES TO PRODUCE LIGHT LAKE EFFECT SHOWERS.
HOWEVER...INVERSION AROUND 5 THSD FT WILL LIMIT THE INTENSITY OF
THE SHOWERS.

MARINE...

SMALL CRAFT ADVISORY WILL NEED TO BE EXTENDED INTO THE AFTERNOON.
WINDS SHOULD DECREASE A LITTLE...BUT THEN BECOME MORE NORTH THEN
NORTHEAST TONIGHT. WAVES ARE HIGH DUE TO THE BRISK WINDS...WARM
WATERS AND COOL AIR FLOWING ACROSS THE LAKE.

BEACHES...

HIGH SWIM RISK WITH RIP CURRENTS TODAY INTO THIS EVENING. BRISK
NORTH WINDS ARE EXPECTED ALONG SHORE AREAS...WITH HIGH WAVES.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...BEACH HAZARDS STATEMENT UNTIL 7 PM CDT THIS EVENING FOR WIZ052-
     060-066-071-072.

LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.

&&

$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
FRIDAY THROUGH WEDNESDAY...WOOD


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