Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 161624 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1124 AM CDT THU OCT 16 2014

.UPDATE...

THE LARGE CLOSED UPPER LOW OVER THE LOWER GREAT LAKES IS CONTINUING
TO CAUSE PERSISTENT LOW CLOUDS ALL THE WAY BACK ACROSS SOUTHERN
WISCONSIN THIS MORNING. THE AIR ABOVE THIS LOW CLOUD DECK IS VERY
DRY. THAT UPPER LOW WILL FINALLY SHIFT NORTHEAST THIS AFTERNOON AND
EVENING WHICH WILL ALLOW THE LOW CLOUDS TO FINALLY BREAK UP AND
CLEAR FROM WEST TO EAST.

AN AREA OF DRIZZLE IS MOVING EAST ACROSS SOUTHEAST WISCONSIN...
AND WILL GRADUALLY DIMINISH BY 1 PM.

TIMING OF THE CLEARING SKIES IS STILL UNCERTAIN... ALTHOUGH MOST
MODELS HAVE LATCHED ONTO THE IDEA OF CLEAR AT MADISON BETWEEN 3 AND
4 PM. AS I AM WRITING THIS...THE LATEST VISIBLE SATELLITE IMAGERY IS
SHOWING THE CLOUDS BREAKING UP FROM MARQUETTE COUNTY DOWN THROUGH
WESTERN DANE COUNTY ALREADY AT 11 AM. THE LOW STRATUS IS STILL
HANGING ON OVER THE FAR WESTERN FORECAST AREA NEAR THE DELLS AND
MINERAL POINT. EXPECTING THE STRATUS TO EVOLVE INTO STRATOCUMULUS
EARLY THIS AFTERNOON BEFORE COMPLETELY CLEARING.

THE TIME OF CLEARING SKIES IN MILWAUKEE AND ALONG THE LAKESHORE IS
EVEN MORE UNCERTAIN. AN 850-700MB THERMAL TROUGH AND A 500MB
SHORTWAVE WILL MOVE THROUGH FAR SOUTHEAST WISCONSIN THIS EVENING
WHICH COULD REINFORCE THE LOWER CLOUD COVER OVER THAT AREA UNTIL
AFTER MIDNIGHT.

&&

.AVIATION/18Z TAFS/...

THE DRIZZLE IN SOUTHEAST WI HAS A BACK EDGE ON IT PER THE RADAR
IMAGERY. IFR TO MVFR VSBY AND IFR CIGS WITHIN THE DRIZZLE AREA.

CEILINGS WILL GRADUALLY RISE ABOVE 1000 FEET EARLY THIS AFTERNOON
BEFORE CLEARING. SKIES ARE ALREADY BREAKING UP ACROSS WESTERN DANE
COUNTY UP THROUGH MARQUETTE COUNTY AT 11 AM. THE STRATUS IS STILL
HANGING ON NEAR THE DELLS AND MINERAL POINT BUT SHOWING SIGNS OF
DISSIPATING. EXPECTING THIS WHOLE AREA TO FILL BACK IN WITH AT LEAST
SCATTERED STRATOCUMULUS CLOUDS THROUGH MID AFTERNOON. IT WILL TAKE A
LOT LONGER TO CLEAR OUT SOUTHEAST WISCONSIN. SEE THE MAIN DISCUSSION
SECTION FOR FURTHER EXPLANATION.

&&

.PREV DISCUSSION... /ISSUED 336 AM CDT THU OCT 16 2014/

TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH

THE LARGE UPPER LEVEL TROUGH WAS MOVING EAST AS IT BECOMES A LITTLE
MOVE NEGATIVELY TILTED AS IT CROSSES THE EASTERN GREAT LAKES AHEAD
OF THE NEXT SHORTWAVE TROUGH...PUSHING ACROSS NORTH DAKOTA AND THE
NORTHERN MINNESOTA AREA TODAY. THIS BRIEFLY BUILDS A RIDGE ACROSS
WISCONSIN THIS AFTERNOON BEFORE THE SHORTWAVE REACHES LAKE SUPERIOR
TONIGHT AND A 250 MB SPEED MAX REACHES 80 KNOTS ACROSS SOUTHERN
WISCONSIN BY SUNRISE FRIDAY.  UPPER DIVERGENCE IS RATHER WEAK WITH
WEAK 700 MB UPWARD MOTION THIS AFTERNOON AND TONIGHT.

THE MID LEVELS ARE DRY WITH A BAND OF HIGHER RH AT 700 MB MOVING
QUICKLY ACROSS SOUTHERN WISCONSIN TONIGHT AHEAD OF THE APPROACHING
SHORTWAVE.

MAIN FORECAST CONCERN IS THE HIGH LOW LEVEL MOISTURE IN PLACE OVER
MOST OF THE FORECAST AREA...WITH SOME DRYING IN THE FAR WEST THIS
MORNING. THE NAM FORECAST SOUNDINGS INCREASE TEMPERATURES AROUND 5
THSD FT THAT PRODUCES AN ISOTHERMAL LAYER AND EVENTUAL LOW LEVEL
INVERSION AROUND 4 THSD FT.  THIS WILL TRAP THE MOISTURE OVER THE
EAST LIKELY RESULTING IN LINGERING LOW CLOUDS IN THE FAR EAST
POSSIBLY INTO THE EVENING.  THESE SHOULD EVENTUALLY CLEAR JUST AS
MID/UPPER LEVEL CLOUDS MOVE IN.  AS A RESULT THE EAST WILL STAY COOL
WHILE AREAS ESPECIALLY WEST OF MADISON WARM WITH AT LEAST SOME
SUNSHINE.  ALSO SOME DENSE FOG IN THE FEW CLEAR AREAS OF THE FAR
EAST EARLY THIS MORNING.

FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM

NORTHWEST FLOW WILL GENERALLY PERSIST FRIDAY THROUGH MONDAY.
TEMPERATURES WILL THUS BE NEAR TO A FEW DEGREES BELOW NORMAL
THROUGH THIS PERIOD. THE COLDEST NIGHT WILL BE SATURDAY
NIGHT...WHEN ANOTHER ROUND OF FROST IS EXPECTED. FROST HEADLINES
MAY BE NEEDED FOR THE FAR SOUTHEAST COUNTIES WHERE WIDESPREAD
FROST HAS NOT BEEN OBSERVED YET THIS SEASON.

THERE WILL BE A CHANCE FOR SHOWERS FRIDAY INTO FRIDAY NIGHT AND
SUNDAY NIGHT INTO MONDAY AS A SERIES OF SHORTWAVES MOVE THROUGH.

TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM

HIGH PRESSURE IS EXPECTED TO BRING MOSTLY SUNNY SKIES TUESDAY AND
WEDNESDAY. TEMPERATURES SHOULD BE NEAR TO A COUPLE DEGREES BELOW
NORMAL.

AVIATION/12Z TAFS/...

BACK EDGE OF LOW IFR/LIFR CLOUDS IS WEST OF MADISON BUT LATEST NAM
LOW-LAYER RH FORECASTS SUPPORT IFR CLOUD DECK HOLDING IN OVER ALL
BUT THE FAR WEST EARLY THIS MORNING...WITH SLOW IMPROVEMENT FROM
WEST TO EAST DURING THE DAY.  SOME LOCATIONS WILL SEE DRIZZLE MAINLY
EAST WITH SOME IFR/LIFR FOG MAINLY FAR WEST AS SKIES TRY TO CLEAR
WEST OF MADISON.  A DEVELOPING LOW LEVEL INVERSION SHOULD TRAP THE
LOW CLOUDS OVER THE FAR EAST INTO THE EVENING BEFORE THE CLOUDS
DISSIPATE.  AS THIS HAPPENS MID/HIGH CLOUDS WILL INCREASE FROM THE
WEST AHEAD OF A SHORTWAVE MOVING TOWARD LAKE SUPERIOR.

MARINE...

WINDS/WAVES WILL SUBSIDE EARLY THIS MORNING AHEAD OF A RIDGE OF
HIGH PRESSURE.  WEST WINDS ARE EXPECTED TO REACH SMALL CRAFT
ADVISORY CRITERIA THURSDAY AS LOW PRESSURE CONTINUES ACROSS THE
UPPER GREAT LAKES.

&&

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

$$

UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
FRIDAY THROUGH WEDNESDAY...DDV



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